My quest for a good wheelie: suggestions on transbrake, converter, or something else
10-12-2022, 08:16 PM
#51
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Went over to Island Dragway this past Sunday knowing the track prep was going to be good. Knew I am not dialed in for a big bracket race, but since there was no available lanes for Test-n-Tune, I jumped into the N2 (10.00-11.99) Bracket for the Fall Nostalgia Event. Weather was stellar. There were a LOT of cars racing, plus they had 10 nostalgia alcohol funny cars and two nitromethane vintage funny cars, so lots of crowds that day. Got there way early before the gates opened and I was already at the end of a long line of traliers and cars. After I got in, I found an available spot wayyy up by the end of the 1/4 mile where the overhead E.T. and MPH signs are.
Each group only got 1 timeshot test pass in the morning, and then it would be on to round 1 eliminations where I fully expected to get knocked out. For my first pass, I had the car setup with The front skinnies at 48 psi. Rear tires at 17.6 psi. Rear air bags 7 psi drivers side and 10.2 psi passenger side. Rear shocks at 2.0 drivers side and 2.5 passenger side. The 150 jets were in it, and I am beginning to think that when i was doing the math to pick the jutting #'s for a 150 shot, I went too big on the fuel jet? Anyways, I had a progressive tuneup for that 150 shot, and it ramped in from a 75 shot to the 150 shot over 1.2 seconds, and timing ramps from 34.0 na to be 2.0 degrees while spraying the full 150 shot at 1.2 seconds in. Nitrous bottle pressure is kinda ballpark where it should be. My gauge at the bottom can say 1100, but hte one on my a-pillar nitrous gauge shows around 950, so I am going to have to figure that situation out, probably in wintertime, but I am guessing bottle pressure is closer to 1050psi.
Pass 1: Did a decent 6 second burnout. Was not concerned with reaction time, more about getting a good footbrake rpm at the line. Footbraked the car to 2506 rpms and let off sending the flash stall to 5130 rpms. I shifted 1st at 6622 rpms and the new converter put the 2nd gear rpms at 5562. I then short shifted the 2-3 shift at 6267 and it landed at 5724 in 3rd gear. I went through the finish line after hitting the top-end rev limiter on the nitrous file, so I got off the button and shifted 3-4 actually, just to see what it would do. I shifted from 3rd at 6243 and it brought rpms to 5482. Then i went through the traps finally, at 5518 rpms. The sixty foot felt great, but not earth shattering. I expected a good 1/8th mile but the back half of the track was going to be slower because of shifting into 4th and ******* the car down. I almost wish I had a better reaction time, because the race would have been a full side-by-side-to-the-finish race with the car next to me.
Timeslip:
datalog:
r
Go Pro Video:
Dash cam video:
Checked 3 plugs after the run and they were good. Looked at the datalog above and noticed what might be signs of knock in the rpm trace. Lowered rear tires to 17.0 psi, but all shock and suspension setting stayed the same. Decided to go add a little of the "race Fuel" additive that I used last year when doing full track nitrous passes. Decided to put a 10.55 e.t on the dial-in for round 1, and I moved the ramp nitrous come on with more % since I felt certain it would hook on the surface; after all, funny cars were! Did a 6 second burnout. Footbraked the rpms up to 3006 rpms which I quickly found out was just a little too muhc. the car began to push forward and I was staged so i couldn't back off. The car pushed through the beams and started the clock and thene I decided to hammer down anyways to get data and a full pass. Converter flashed to 5212. I hit the rev limiter in 1st gear and shifted away from that at 6558 which dropped roms to 5557 in 2nd gear. Shifted 2nd at 6360 and that landed a 5714 rpm in 3rd gear. Knowing that shifting into OD/4th was a bad idea, I figured it was time to lock up the converter so at 6108 rpms I hit the converter lockup button (too early?) and it pulled rpms down to 5729. I crossed the finish at 6389 rpms. On the datalog, the AFR was rich, the Closed Loop compensation was maxed out pulling 20% fuel almost the whole run (yellow line)....so either too big of a fuel jet or the issue with nitrous bottle pressure. ..also, i didn't really stand a chance of winning that round, the guy went 11.608 on an 11.60 dial-in.
Timeslip (my times all skewed because I rolled the beams and then launched, but the mph is useable):
Datalog:
GoPro video:
Dashcam video:
Hungout for a while with my Dad and some other racer buddies that were there; including jerry and his 57 in the N3 bracket. He was going rounds, winning like usual and picking up time/speed as the day went on but dead on his dial-ins and lights. Awesome! watched funny cars and gassers, and various groups of brackets run. After the funny cars made their last pass, most spectators cleared out. I asked the track staff if I could get one test-tune pass if there was a rbeak in the bracket action for a moment. They let me do so, and I was hopeful to redeem myself before heading home.
Pass 3: I loaded in a fixed 150-shot tuneup, one that I had used back in may 2022; no progressive nitrous ramp. All shock and airbag settings were the same but I lowerd rear tire pressure to 16.2 psi in both. Did a 6 second bunout. I footbraked, but never held a steady amount, so its aard to tell when I started to push the nose again, and unknown where I launched from. It does look like hte converter flashed around 4741 and I took first gear to 6515 rpms which dropped it into second at 5754. Took second gear to 6335 and this dropped into 3rd at 5733 rpms. Carried 3rd gear all the way to teh finish, and got off the nitrous which let me cross the line at 6503 rpms. AFR again was still very rich averaging 11.8-12.2 across most of the run. CL comp% was again maxed out removing fuel.
Timeslip:
datalog:
Dashcam video:
other video:
Was decently happy with that, as it did hookup and launch pretty good but I think I gotta shot for a 2800 rpm footbrake launch. I am still hoping for that 1.3xx sixty-foot on a timeslip, and would love to run a real solid 10.4x quarter. I think it has it in it, the car pulls great and wicks through 1st gear wildly fast, but I think now my shifting habits from the old converter need to be adjusted so I stop hitting the 1st gear limiter, and so I rev out 2nd gear more.
Anyways, I packed up my gear, but I knew that Jerry was still in it, so I went down to watch him keep on doing what he does best. He went to the N3 brackt's finals, and won it. Got a nice trophy and that was real cool to see a friend win something at the track!
Video:
Some photos and funny car videos:
the usual way I do the burnout:
The wheelies I am getting:
The wheelie photo I want!!!
Pretty surprised It is wrinkling the sidewall of this drag radial.
Slicks wrinkle for sure, but wasn't expecting this size drag radial to do so!
Each group only got 1 timeshot test pass in the morning, and then it would be on to round 1 eliminations where I fully expected to get knocked out. For my first pass, I had the car setup with The front skinnies at 48 psi. Rear tires at 17.6 psi. Rear air bags 7 psi drivers side and 10.2 psi passenger side. Rear shocks at 2.0 drivers side and 2.5 passenger side. The 150 jets were in it, and I am beginning to think that when i was doing the math to pick the jutting #'s for a 150 shot, I went too big on the fuel jet? Anyways, I had a progressive tuneup for that 150 shot, and it ramped in from a 75 shot to the 150 shot over 1.2 seconds, and timing ramps from 34.0 na to be 2.0 degrees while spraying the full 150 shot at 1.2 seconds in. Nitrous bottle pressure is kinda ballpark where it should be. My gauge at the bottom can say 1100, but hte one on my a-pillar nitrous gauge shows around 950, so I am going to have to figure that situation out, probably in wintertime, but I am guessing bottle pressure is closer to 1050psi.
Pass 1: Did a decent 6 second burnout. Was not concerned with reaction time, more about getting a good footbrake rpm at the line. Footbraked the car to 2506 rpms and let off sending the flash stall to 5130 rpms. I shifted 1st at 6622 rpms and the new converter put the 2nd gear rpms at 5562. I then short shifted the 2-3 shift at 6267 and it landed at 5724 in 3rd gear. I went through the finish line after hitting the top-end rev limiter on the nitrous file, so I got off the button and shifted 3-4 actually, just to see what it would do. I shifted from 3rd at 6243 and it brought rpms to 5482. Then i went through the traps finally, at 5518 rpms. The sixty foot felt great, but not earth shattering. I expected a good 1/8th mile but the back half of the track was going to be slower because of shifting into 4th and ******* the car down. I almost wish I had a better reaction time, because the race would have been a full side-by-side-to-the-finish race with the car next to me.
Timeslip:
datalog:
rGo Pro Video:
Dash cam video:
Checked 3 plugs after the run and they were good. Looked at the datalog above and noticed what might be signs of knock in the rpm trace. Lowered rear tires to 17.0 psi, but all shock and suspension setting stayed the same. Decided to go add a little of the "race Fuel" additive that I used last year when doing full track nitrous passes. Decided to put a 10.55 e.t on the dial-in for round 1, and I moved the ramp nitrous come on with more % since I felt certain it would hook on the surface; after all, funny cars were! Did a 6 second burnout. Footbraked the rpms up to 3006 rpms which I quickly found out was just a little too muhc. the car began to push forward and I was staged so i couldn't back off. The car pushed through the beams and started the clock and thene I decided to hammer down anyways to get data and a full pass. Converter flashed to 5212. I hit the rev limiter in 1st gear and shifted away from that at 6558 which dropped roms to 5557 in 2nd gear. Shifted 2nd at 6360 and that landed a 5714 rpm in 3rd gear. Knowing that shifting into OD/4th was a bad idea, I figured it was time to lock up the converter so at 6108 rpms I hit the converter lockup button (too early?) and it pulled rpms down to 5729. I crossed the finish at 6389 rpms. On the datalog, the AFR was rich, the Closed Loop compensation was maxed out pulling 20% fuel almost the whole run (yellow line)....so either too big of a fuel jet or the issue with nitrous bottle pressure. ..also, i didn't really stand a chance of winning that round, the guy went 11.608 on an 11.60 dial-in.
Timeslip (my times all skewed because I rolled the beams and then launched, but the mph is useable):
Datalog:
GoPro video:
Dashcam video:
Hungout for a while with my Dad and some other racer buddies that were there; including jerry and his 57 in the N3 bracket. He was going rounds, winning like usual and picking up time/speed as the day went on but dead on his dial-ins and lights. Awesome! watched funny cars and gassers, and various groups of brackets run. After the funny cars made their last pass, most spectators cleared out. I asked the track staff if I could get one test-tune pass if there was a rbeak in the bracket action for a moment. They let me do so, and I was hopeful to redeem myself before heading home.
Pass 3: I loaded in a fixed 150-shot tuneup, one that I had used back in may 2022; no progressive nitrous ramp. All shock and airbag settings were the same but I lowerd rear tire pressure to 16.2 psi in both. Did a 6 second bunout. I footbraked, but never held a steady amount, so its aard to tell when I started to push the nose again, and unknown where I launched from. It does look like hte converter flashed around 4741 and I took first gear to 6515 rpms which dropped it into second at 5754. Took second gear to 6335 and this dropped into 3rd at 5733 rpms. Carried 3rd gear all the way to teh finish, and got off the nitrous which let me cross the line at 6503 rpms. AFR again was still very rich averaging 11.8-12.2 across most of the run. CL comp% was again maxed out removing fuel.
Timeslip:
datalog:
Dashcam video:
other video:
Was decently happy with that, as it did hookup and launch pretty good but I think I gotta shot for a 2800 rpm footbrake launch. I am still hoping for that 1.3xx sixty-foot on a timeslip, and would love to run a real solid 10.4x quarter. I think it has it in it, the car pulls great and wicks through 1st gear wildly fast, but I think now my shifting habits from the old converter need to be adjusted so I stop hitting the 1st gear limiter, and so I rev out 2nd gear more.
Anyways, I packed up my gear, but I knew that Jerry was still in it, so I went down to watch him keep on doing what he does best. He went to the N3 brackt's finals, and won it. Got a nice trophy and that was real cool to see a friend win something at the track!
Video:
Some photos and funny car videos:
the usual way I do the burnout:
The wheelies I am getting:
The wheelie photo I want!!!
Pretty surprised It is wrinkling the sidewall of this drag radial.
Slicks wrinkle for sure, but wasn't expecting this size drag radial to do so!
10-12-2022, 08:17 PM
#52
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Went over to Island Dragway this past Sunday knowing the track prep was going to be good. Knew I am not dialed in for a big bracket race, but since there was no available lanes for Test-n-Tune, I jumped into the N2 (10.00-11.99) Bracket for the Fall Nostalgia Event. Weather was stellar. There were a LOT of cars racing, plus they had 10 nostalgia alcohol funny cars and two nitromethane vintage funny cars, so lots of crowds that day. Got there way early before the gates opened and I was already at the end of a long line of traliers and cars. After I got in, I found an available spot wayyy up by the end of the 1/4 mile where the overhead E.T. and MPH signs are.
Each group only got 1 timeshot test pass in the morning, and then it would be on to round 1 eliminations where I fully expected to get knocked out. For my first pass, I had the car setup with The front skinnies at 48 psi. Rear tires at 17.6 psi. Rear air bags 7 psi drivers side and 10.2 psi passenger side. Rear shocks at 2.0 drivers side and 2.5 passenger side. The 150 jets were in it, and I am beginning to think that when i was doing the math to pick the jutting #'s for a 150 shot, I went too big on the fuel jet? Anyways, I had a progressive tuneup for that 150 shot, and it ramped in from a 75 shot to the 150 shot over 1.2 seconds, and timing ramps from 34.0 na to be 2.0 degrees while spraying the full 150 shot at 1.2 seconds in. Nitrous bottle pressure is kinda ballpark where it should be. My gauge at the bottom can say 1100, but hte one on my a-pillar nitrous gauge shows around 950, so I am going to have to figure that situation out, probably in wintertime, but I am guessing bottle pressure is closer to 1050psi.
Pass 1: Did a decent 6 second burnout. Was not concerned with reaction time, more about getting a good footbrake rpm at the line. Footbraked the car to 2506 rpms and let off sending the flash stall to 5130 rpms. I shifted 1st at 6622 rpms and the new converter put the 2nd gear rpms at 5562. I then short shifted the 2-3 shift at 6267 and it landed at 5724 in 3rd gear. I went through the finish line after hitting the top-end rev limiter on the nitrous file, so I got off the button and shifted 3-4 actually, just to see what it would do. I shifted from 3rd at 6243 and it brought rpms to 5482. Then i went through the traps finally, at 5518 rpms. The sixty foot felt great, but not earth shattering. I expected a good 1/8th mile but the back half of the track was going to be slower because of shifting into 4th and ******* the car down. I almost wish I had a better reaction time, because the race would have been a full side-by-side-to-the-finish race with the car next to me.
Timeslip:
datalog:
r
Go Pro Video:
Dash cam video:
Checked 3 plugs after the run and they were good. Looked at the datalog above and noticed what might be signs of knock in the rpm trace. Lowered rear tires to 17.0 psi, but all shock and suspension setting stayed the same. Decided to go add a little of the "race Fuel" additive that I used last year when doing full track nitrous passes. Decided to put a 10.55 e.t on the dial-in for round 1, and I moved the ramp nitrous come on with more % since I felt certain it would hook on the surface; after all, funny cars were! Did a 6 second burnout. Footbraked the rpms up to 3006 rpms which I quickly found out was just a little too muhc. the car began to push forward and I was staged so i couldn't back off. The car pushed through the beams and started the clock and thene I decided to hammer down anyways to get data and a full pass. Converter flashed to 5212. I hit the rev limiter in 1st gear and shifted away from that at 6558 which dropped roms to 5557 in 2nd gear. Shifted 2nd at 6360 and that landed a 5714 rpm in 3rd gear. Knowing that shifting into OD/4th was a bad idea, I figured it was time to lock up the converter so at 6108 rpms I hit the converter lockup button (too early?) and it pulled rpms down to 5729. I crossed the finish at 6389 rpms. On the datalog, the AFR was rich, the Closed Loop compensation was maxed out pulling 20% fuel almost the whole run (yellow line)....so either too big of a fuel jet or the issue with nitrous bottle pressure. ..also, i didn't really stand a chance of winning that round, the guy went 11.608 on an 11.60 dial-in.
Timeslip (my times all skewed because I rolled the beams and then launched, but the mph is useable):
Datalog:
GoPro video:
Dashcam video:
Hungout for a while with my Dad and some other racer buddies that were there; including jerry and his 57 in the N3 bracket. He was going rounds, winning like usual and picking up time/speed as the day went on but dead on his dial-ins and lights. Awesome! watched funny cars and gassers, and various groups of brackets run. After the funny cars made their last pass, most spectators cleared out. I asked the track staff if I could get one test-tune pass if there was a rbeak in the bracket action for a moment. They let me do so, and I was hopeful to redeem myself before heading home.
Pass 3: I loaded in a fixed 150-shot tuneup, one that I had used back in may 2022; no progressive nitrous ramp. All shock and airbag settings were the same but I lowerd rear tire pressure to 16.2 psi in both. Did a 6 second bunout. I footbraked, but never held a steady amount, so its aard to tell when I started to push the nose again, and unknown where I launched from. It does look like hte converter flashed around 4741 and I took first gear to 6515 rpms which dropped it into second at 5754. Took second gear to 6335 and this dropped into 3rd at 5733 rpms. Carried 3rd gear all the way to teh finish, and got off the nitrous which let me cross the line at 6503 rpms. AFR again was still very rich averaging 11.8-12.2 across most of the run. CL comp% was again maxed out removing fuel.
Timeslip:
datalog:
Dashcam video:
other video:
Was decently happy with that, as it did hookup and launch pretty good but I think I gotta shot for a 2800 rpm footbrake launch. I am still hoping for that 1.3xx sixty-foot on a timeslip, and would love to run a real solid 10.4x quarter. I think it has it in it, the car pulls great and wicks through 1st gear wildly fast, but I think now my shifting habits from the old converter need to be adjusted so I stop hittingthe 1st gear limiter, and so I rev out 2nd gear more.
Anyways, I packe dup my gear, but I knew that Jerry was still in it, so I went down to watch him keep on doing what he does best. He went to the N3 brackt's finals, and won it. Got a nice trophy and that was real cool to see a friend win something at the track!
Video:
Some photos and funny car videos:
the usual way I do the burnout:
The wheelies I am getting:
The wheelie photo I want!!!
Pretty surprised It is wrinkling the sidewall of this drag radial. Slicks wrinkle for sure, but wasn't expecting this size drag radial to do so!
Each group only got 1 timeshot test pass in the morning, and then it would be on to round 1 eliminations where I fully expected to get knocked out. For my first pass, I had the car setup with The front skinnies at 48 psi. Rear tires at 17.6 psi. Rear air bags 7 psi drivers side and 10.2 psi passenger side. Rear shocks at 2.0 drivers side and 2.5 passenger side. The 150 jets were in it, and I am beginning to think that when i was doing the math to pick the jutting #'s for a 150 shot, I went too big on the fuel jet? Anyways, I had a progressive tuneup for that 150 shot, and it ramped in from a 75 shot to the 150 shot over 1.2 seconds, and timing ramps from 34.0 na to be 2.0 degrees while spraying the full 150 shot at 1.2 seconds in. Nitrous bottle pressure is kinda ballpark where it should be. My gauge at the bottom can say 1100, but hte one on my a-pillar nitrous gauge shows around 950, so I am going to have to figure that situation out, probably in wintertime, but I am guessing bottle pressure is closer to 1050psi.
Pass 1: Did a decent 6 second burnout. Was not concerned with reaction time, more about getting a good footbrake rpm at the line. Footbraked the car to 2506 rpms and let off sending the flash stall to 5130 rpms. I shifted 1st at 6622 rpms and the new converter put the 2nd gear rpms at 5562. I then short shifted the 2-3 shift at 6267 and it landed at 5724 in 3rd gear. I went through the finish line after hitting the top-end rev limiter on the nitrous file, so I got off the button and shifted 3-4 actually, just to see what it would do. I shifted from 3rd at 6243 and it brought rpms to 5482. Then i went through the traps finally, at 5518 rpms. The sixty foot felt great, but not earth shattering. I expected a good 1/8th mile but the back half of the track was going to be slower because of shifting into 4th and ******* the car down. I almost wish I had a better reaction time, because the race would have been a full side-by-side-to-the-finish race with the car next to me.
Timeslip:
datalog:
rGo Pro Video:
Dash cam video:
Checked 3 plugs after the run and they were good. Looked at the datalog above and noticed what might be signs of knock in the rpm trace. Lowered rear tires to 17.0 psi, but all shock and suspension setting stayed the same. Decided to go add a little of the "race Fuel" additive that I used last year when doing full track nitrous passes. Decided to put a 10.55 e.t on the dial-in for round 1, and I moved the ramp nitrous come on with more % since I felt certain it would hook on the surface; after all, funny cars were! Did a 6 second burnout. Footbraked the rpms up to 3006 rpms which I quickly found out was just a little too muhc. the car began to push forward and I was staged so i couldn't back off. The car pushed through the beams and started the clock and thene I decided to hammer down anyways to get data and a full pass. Converter flashed to 5212. I hit the rev limiter in 1st gear and shifted away from that at 6558 which dropped roms to 5557 in 2nd gear. Shifted 2nd at 6360 and that landed a 5714 rpm in 3rd gear. Knowing that shifting into OD/4th was a bad idea, I figured it was time to lock up the converter so at 6108 rpms I hit the converter lockup button (too early?) and it pulled rpms down to 5729. I crossed the finish at 6389 rpms. On the datalog, the AFR was rich, the Closed Loop compensation was maxed out pulling 20% fuel almost the whole run (yellow line)....so either too big of a fuel jet or the issue with nitrous bottle pressure. ..also, i didn't really stand a chance of winning that round, the guy went 11.608 on an 11.60 dial-in.
Timeslip (my times all skewed because I rolled the beams and then launched, but the mph is useable):
Datalog:
GoPro video:
Dashcam video:
Hungout for a while with my Dad and some other racer buddies that were there; including jerry and his 57 in the N3 bracket. He was going rounds, winning like usual and picking up time/speed as the day went on but dead on his dial-ins and lights. Awesome! watched funny cars and gassers, and various groups of brackets run. After the funny cars made their last pass, most spectators cleared out. I asked the track staff if I could get one test-tune pass if there was a rbeak in the bracket action for a moment. They let me do so, and I was hopeful to redeem myself before heading home.
Pass 3: I loaded in a fixed 150-shot tuneup, one that I had used back in may 2022; no progressive nitrous ramp. All shock and airbag settings were the same but I lowerd rear tire pressure to 16.2 psi in both. Did a 6 second bunout. I footbraked, but never held a steady amount, so its aard to tell when I started to push the nose again, and unknown where I launched from. It does look like hte converter flashed around 4741 and I took first gear to 6515 rpms which dropped it into second at 5754. Took second gear to 6335 and this dropped into 3rd at 5733 rpms. Carried 3rd gear all the way to teh finish, and got off the nitrous which let me cross the line at 6503 rpms. AFR again was still very rich averaging 11.8-12.2 across most of the run. CL comp% was again maxed out removing fuel.
Timeslip:
datalog:
Dashcam video:
other video:
Was decently happy with that, as it did hookup and launch pretty good but I think I gotta shot for a 2800 rpm footbrake launch. I am still hoping for that 1.3xx sixty-foot on a timeslip, and would love to run a real solid 10.4x quarter. I think it has it in it, the car pulls great and wicks through 1st gear wildly fast, but I think now my shifting habits from the old converter need to be adjusted so I stop hittingthe 1st gear limiter, and so I rev out 2nd gear more.
Anyways, I packe dup my gear, but I knew that Jerry was still in it, so I went down to watch him keep on doing what he does best. He went to the N3 brackt's finals, and won it. Got a nice trophy and that was real cool to see a friend win something at the track!
Video:
Some photos and funny car videos:
the usual way I do the burnout:
The wheelies I am getting:
The wheelie photo I want!!!
Pretty surprised It is wrinkling the sidewall of this drag radial. Slicks wrinkle for sure, but wasn't expecting this size drag radial to do so!
The following users liked this post:
DynoDave43 (10-12-2022)
10-12-2022, 08:24 PM
#53
Supreme Member
Join Date: Jul 2006
Location: 212 is up in this Bit@#
Posts: 2,763
Received 739 Likes
on
565 Posts
Car: Resto-Mod 1987 IROC-Z Clone
Engine: Alky fed L92 Vortec Twin-Turbo 6.8L
Transmission: My own built/ design 4L80M
Axle/Gears: Custom 12 bolt (4.10:1)
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Looking Great!!!
Keep at it!
The Drag Radials can wrinkle from the Air Pressure being too low..
Not typically desired with a Drag Radial compared to a True-Slick.
Keep at it!
The Drag Radials can wrinkle from the Air Pressure being too low..
Not typically desired with a Drag Radial compared to a True-Slick.
10-12-2022, 09:00 PM
#54
Supreme Member
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Excellent outing all things considered. Getting out there in the crowd and hoping to get another round adds another element to the track experience for sure.
I'm really digging your converter data. The footbrake and flash RPMs are very interesting. I'm hope to use that against what I also hope will be my finally getting back to the track next season (Next year will mark eight years since I've made a bonafide pass). New engine, new transmission, new converter and new tires should prove to be an eye opener.
Thanks for posting up IROCZman. Awesome thread.
I'm really digging your converter data. The footbrake and flash RPMs are very interesting. I'm hope to use that against what I also hope will be my finally getting back to the track next season (Next year will mark eight years since I've made a bonafide pass). New engine, new transmission, new converter and new tires should prove to be an eye opener.
Thanks for posting up IROCZman. Awesome thread.
The following 2 users liked this post by skinny z:
NoEmissions84TA (10-13-2022), vorteciroc (10-12-2022)
10-13-2022, 07:05 AM
#55
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Yup too low air pressure will wrinkle a radial hard. You might be on the low end side of being ok. As long as the tire isnt walking over itself. You’d see it in the marks on the track. May want a lb more air pressure
good runs tho. Just needs a loose shock up front and more power on the leave lol it will come up
also def take some fuel jet out. Want the port injection to do the fueling work, and not be pulling fuel there as wet kit distribution could be the concern. My 150 kit i needed the 75 fuel jet and 150 nitrous jet to be ideal
good runs tho. Just needs a loose shock up front and more power on the leave lol it will come up
also def take some fuel jet out. Want the port injection to do the fueling work, and not be pulling fuel there as wet kit distribution could be the concern. My 150 kit i needed the 75 fuel jet and 150 nitrous jet to be ideal
Last edited by Orr89RocZ; 10-13-2022 at 07:09 AM.
10-13-2022, 08:18 PM
#56
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Thanks guys! All good stuff here indeed. Skinny, you deserve some well overdue seat-time!
And yes, now I can see what you guys mean about low tire psi being the cause of the wrinkle. Like was stated above, I am probably on the low-end borderline of being ok, so now that I know the tire works best in the 17.5-16.0 psi range, I will try to keep them at the higher side of that range. cool.
yea, as for the nitrous jetting, I had done some jetting math way back in the late summer of last year and had to come up with my own numbers for jetting. I think we discussed this in my "nitrous install" thread, link: https://www.thirdgen.org/forums/powe...ous-406-a.html
But for the jetting I had to figure out numbers ( http://robietherobot.com/nitrousjetcalculator.htm was a big help I think) because of the 60 psi that the fuel system is running due to the snipers 59 psi regulator. Most nitrous jetting charts were for carb setups and the injected engines used a 54 psi system.. I have used this combination :
75 shot: . .042 N and .021 F
100 shot: .050 N and .025 F
125 shot: .055 N and .029 F
150 shot: .057 N and .030 F
175: shot: .062 N and .032 F
200 shot: .067 N and .035 F
225 shot: .071 N and .038 F
I do think I will downsize the jet for the 150 shot, and your thought process got me thinking about how much CL comp I have had removing fuel for my other decent nitrous passes in the last year. On my best pass to date, May 1 2022, pass #4 I did a progressive 175 nitrous shot, and the car went 10.060 with a 1.446 sixty and 6.744 in the 8th mile. 127.76 mph and 106.38 mph at halftrack. The datalog from that run shows the CL Comp removing between -11% and 15% fuel during most of the run, so even on that pass, I was still too big on the fuel jetting. Great food-for-thought, thanks!
So, with the year winding down towards winter in NJ soon-ish, I have to get some more track time in. I was thinking of going in on a rental next friday that a friend said needed participants, but I have an Iron Maiden concert with my dad that same night so thats out. The rest of that weekend I am also packed busy. Therefore, I am going to try to squeeze in a track day on this upcoming sunday, where there is a Mopar event and open Test-n-tune.
Some things I want to try if I can get 5-6 passes in include.
- finally making an all motor pass withOUT touching the shifter. I have always force shifted the car, and I am wondering how good/bad it will do if I put the shifter in D(3rd) and let it do its thing!?!
- jetting down the 150 shot fuel jet to probably a .027 jet which i will buy at Bruces Speed shop when I get the nitrous filled on saturday.
- trying to figure out the big psi discrepancy in my ntrous bottle pressure gauges and determine which one is accurate.
- launching from a dead 920 rpm idle both N/A and on nitrous
- launching from a 2800 rpm footbrake both N/A and on nitrous
- maybe trying to short shift 1st (or at least not ouch the rev limiter on the 1-2 shift). while revving out the 2-3 shift longer
I think the car is capable of a 1.39 sixty foot on the nitrous, I just have to re-figure out what it likes best at the launch with the new converter. I do remember when talking to Yank converters, they said that the way they are setting up this converter is for quickness, so my mph being lower than the 126 and 127 mph is not suprising to me. A 10.4x on the 175 shot would be awesome. Then, maybe next spring I can go onto the 200 shot.
edit: my dad was there and took some videos. Here is a freeze-frame from the first pass (because I had no dial-in numbers written on the back glass) so this is when it went 1.424 in the sixty. I'm going to take some air out of the drivers bag and put some air into the passenger bag tomorrow.
And yes, now I can see what you guys mean about low tire psi being the cause of the wrinkle. Like was stated above, I am probably on the low-end borderline of being ok, so now that I know the tire works best in the 17.5-16.0 psi range, I will try to keep them at the higher side of that range. cool.
yea, as for the nitrous jetting, I had done some jetting math way back in the late summer of last year and had to come up with my own numbers for jetting. I think we discussed this in my "nitrous install" thread, link: https://www.thirdgen.org/forums/powe...ous-406-a.html
But for the jetting I had to figure out numbers ( http://robietherobot.com/nitrousjetcalculator.htm was a big help I think) because of the 60 psi that the fuel system is running due to the snipers 59 psi regulator. Most nitrous jetting charts were for carb setups and the injected engines used a 54 psi system.. I have used this combination :
75 shot: . .042 N and .021 F
100 shot: .050 N and .025 F
125 shot: .055 N and .029 F
150 shot: .057 N and .030 F
175: shot: .062 N and .032 F
200 shot: .067 N and .035 F
225 shot: .071 N and .038 F
I do think I will downsize the jet for the 150 shot, and your thought process got me thinking about how much CL comp I have had removing fuel for my other decent nitrous passes in the last year. On my best pass to date, May 1 2022, pass #4 I did a progressive 175 nitrous shot, and the car went 10.060 with a 1.446 sixty and 6.744 in the 8th mile. 127.76 mph and 106.38 mph at halftrack. The datalog from that run shows the CL Comp removing between -11% and 15% fuel during most of the run, so even on that pass, I was still too big on the fuel jetting. Great food-for-thought, thanks!
So, with the year winding down towards winter in NJ soon-ish, I have to get some more track time in. I was thinking of going in on a rental next friday that a friend said needed participants, but I have an Iron Maiden concert with my dad that same night so thats out. The rest of that weekend I am also packed busy. Therefore, I am going to try to squeeze in a track day on this upcoming sunday, where there is a Mopar event and open Test-n-tune.
Some things I want to try if I can get 5-6 passes in include.
- finally making an all motor pass withOUT touching the shifter. I have always force shifted the car, and I am wondering how good/bad it will do if I put the shifter in D(3rd) and let it do its thing!?!
- jetting down the 150 shot fuel jet to probably a .027 jet which i will buy at Bruces Speed shop when I get the nitrous filled on saturday.
- trying to figure out the big psi discrepancy in my ntrous bottle pressure gauges and determine which one is accurate.
- launching from a dead 920 rpm idle both N/A and on nitrous
- launching from a 2800 rpm footbrake both N/A and on nitrous
- maybe trying to short shift 1st (or at least not ouch the rev limiter on the 1-2 shift). while revving out the 2-3 shift longer
I think the car is capable of a 1.39 sixty foot on the nitrous, I just have to re-figure out what it likes best at the launch with the new converter. I do remember when talking to Yank converters, they said that the way they are setting up this converter is for quickness, so my mph being lower than the 126 and 127 mph is not suprising to me. A 10.4x on the 175 shot would be awesome. Then, maybe next spring I can go onto the 200 shot.
edit: my dad was there and took some videos. Here is a freeze-frame from the first pass (because I had no dial-in numbers written on the back glass) so this is when it went 1.424 in the sixty. I'm going to take some air out of the drivers bag and put some air into the passenger bag tomorrow.
Last edited by IROCZman15; 10-15-2022 at 07:58 AM.
10-15-2022, 10:21 AM
#57
Supreme Member
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
edit: my dad was there and took some videos. Here is a freeze-frame from the first pass (because I had no dial-in numbers written on the back glass) so this is when it went 1.424 in the sixty. I'm going to take some air out of the drivers bag and put some air into the passenger bag tomorrow.
As for the airbags, I've run as much as a 15 pound offset between the passenger side @ 25 and the captain's side @ 10. I like an overall preload back there as it seems to improve the LCA angle for a better bite (car is lowered by close to 2" overall). The bias in my case helped the car stay in the groove.
Full sway bars front and rear too which didn't help my drag racing cause much.
Do you have a full on side shot of your car in drag race trim?
10-23-2022, 11:53 AM
#58
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
SkinnyZ; I like that idea about the bigger psi difference in the rear airbags. I did that last weekend and it seemed to work good. I lowered my actual shock adjustment to make them softer, and that might have hurt me a bit, but now I know where to put them back to.
here is a full side-shot photo for ya. I have more I can get to you too if needed, just ask!
Whew, its been a busy week for sure, so I have not had a chance to get all the videos, datalogs, photos, and typing done until now...a week later. Damn!
I went to Island Dragway last Sunday, Oct 16 for the Test-N-Tune portion of the Mopar Event. Weather was pretty good and with no chance of rain, I knew that I would get at least 4 passes in. I ran into a snag beforehand though, because Bruce's Speed shop (and the other place in Belville) are both out of all Nitrous-Oxide for refills. Orders have been delayed and delayed again, next delivery date is supposed to be November 3rd. So I only had half a bottle of nitrous to work with. I decided I could experiment with the nitrous stuff at the end of the day, and I was going to experiment with different launch and shifting stuff on the all-moto passes early on. So that's what I did. FYI: I haven't really had a chance to dive deep into the datalogs just yet, but i did take a look at some of them the day at the track and a little bit while I was taking the below screenshot datalog photos; I do need to dig into them a little more before hitting the track again.
Pass 1:
Rear tires at 17.2 psi, rear shock a tad lower than previous events at 1.5 drivers and 2.0 passenger side. Rear air bags at 5psi Drivers and 18 psi passenger.
Since I put the engine in the car and began racing it back in the Spring of 2020, I have always force-shifted the gears on every pass. I never had just left the shifter in D (not D-overdrive, but just D which is 1-2-3), so this was a good opportunity to see exactly what the trans does and how the converter acts also. I did this for Pass 2 also, but with a different launch technique. So, on this pass, I did a 5 second burnout and rolled to the line. I decided top launch from a dead idle, which was at 956 rpm as per the datalog. The car left and converter flashed at 4797 rpms. It made the 1-2 shift EARLY which was at 5530 and brought eth rpms down to 5043. It then shifted the 2-3 shift real quick, almost instantly, and also low in the rpm band, at 5244 rpms and dropped it to 5019 rpms in 3rd gear. It was a long long pull all the way through 3rd gear, and I crossed the finish line at 5980 rpms. I fully expected something like a 12.60 time on the timeslip, so I was quite surprised when it showed an 11.81 at 113.3 mph ! The low rpm shifts and that very quick 2-3 shift right after the 1-2 shift was interesting.
Timeslip:
Datalog:
look at the rpm trace. wow. way different and more tame than the past few years!
Video:
GoPro Video:
Pass 2:
I kept the tune file and all the airbag, shock settings, and tire pressure 917.2 psi) the same. 5. second burnout. All I did on this pass differently, was launch the car from a higher footbrake rpm, but I still let the car shift itself. I wanted a good 60 foot comparison between launching off an idle (pass 1) and launching from a footbrake rpm. The car looks like it held up to 3211 rpms on the footbrake and after I launched it flashed to 4540 rpms. It did spin the rear tires just a bit, and you can hear it slip/grab on the video. It shifted itself at 5413 rpms and into 2nd gear at 4958 rpms. Sidenote- my TPS (green line) is not at 100% wide-open-throttle because during this point in the run, I noticed my windshield mounted rear view mirror must have vibrated itself loose recently and it began shaking all wildly so I was partially noticing that. Anyways, it shifted the 2-3 shift at 5195 and this dropped rpms to 5001 in 3rd gear. I crossed the finish line at 6050 rpms, mirror still shaking but not falling off.
Timeslip:
Datalog:
TPS trace is wiggly as I was half watching the mirror about to vibrate itself off. whoops!
Video:
GoPro:
Pass 3:
Shock and airbag settings are the same, but I brought the rear tires down to 16.4 psi. These next two passes I wanted to shift the car where I typically shift but launch as I did in pass 1 and 2 for some comparison data. I did a 7 second burnout, and launched the car from a dead idle, which was 947 rpms. It flashed the converter to 4851 and then I shifted 1-2 at 6449 and it dropped to 5147 9which is more of a drop than I've seen in recent weeks using this new converter?). I made the 2-3 shift at 6279 rpms, and it dropped to 5152. Crossed the finish line at 6006 rpms. The big drop-off in rpms between the shifts is all of a sudden similar to my results with the Edge Racing converter, so that confused me. The yank converters datalogs can be seen in previous posts I made during the recent month since installing it. Strange, but ok? IT launched good, pulled the wheels up, and I shifted real close to my target rpms, nothing outrageous happened, so it is good comparison data to pass #1 where I launched from an idle also. sixty foot times were close, but E.T. i went faster on pass 1 which had MUCH lower rpm shift points.
Timeslip:
Datalog:
Video:
GoPro video:
Pass 4:
Rear tires were both at 16.6 so I left them there. Decent 6 second burnout. Brought the rpms up to 2564 and left off the footbrake. Flashed at 4856 rpms, and shifted 1-2 at 6450 which dropped it to 5233 in second gear. Shifted 2-3 at 6285 and dropped to 5331. Crossed the finish line at 6013 rpms.
Timeslip:
Datalog:
Video:
GoPro Video:
here is a full side-shot photo for ya. I have more I can get to you too if needed, just ask!
Whew, its been a busy week for sure, so I have not had a chance to get all the videos, datalogs, photos, and typing done until now...a week later. Damn!
I went to Island Dragway last Sunday, Oct 16 for the Test-N-Tune portion of the Mopar Event. Weather was pretty good and with no chance of rain, I knew that I would get at least 4 passes in. I ran into a snag beforehand though, because Bruce's Speed shop (and the other place in Belville) are both out of all Nitrous-Oxide for refills. Orders have been delayed and delayed again, next delivery date is supposed to be November 3rd. So I only had half a bottle of nitrous to work with. I decided I could experiment with the nitrous stuff at the end of the day, and I was going to experiment with different launch and shifting stuff on the all-moto passes early on. So that's what I did. FYI: I haven't really had a chance to dive deep into the datalogs just yet, but i did take a look at some of them the day at the track and a little bit while I was taking the below screenshot datalog photos; I do need to dig into them a little more before hitting the track again.
Pass 1:
Rear tires at 17.2 psi, rear shock a tad lower than previous events at 1.5 drivers and 2.0 passenger side. Rear air bags at 5psi Drivers and 18 psi passenger.
Since I put the engine in the car and began racing it back in the Spring of 2020, I have always force-shifted the gears on every pass. I never had just left the shifter in D (not D-overdrive, but just D which is 1-2-3), so this was a good opportunity to see exactly what the trans does and how the converter acts also. I did this for Pass 2 also, but with a different launch technique. So, on this pass, I did a 5 second burnout and rolled to the line. I decided top launch from a dead idle, which was at 956 rpm as per the datalog. The car left and converter flashed at 4797 rpms. It made the 1-2 shift EARLY which was at 5530 and brought eth rpms down to 5043. It then shifted the 2-3 shift real quick, almost instantly, and also low in the rpm band, at 5244 rpms and dropped it to 5019 rpms in 3rd gear. It was a long long pull all the way through 3rd gear, and I crossed the finish line at 5980 rpms. I fully expected something like a 12.60 time on the timeslip, so I was quite surprised when it showed an 11.81 at 113.3 mph ! The low rpm shifts and that very quick 2-3 shift right after the 1-2 shift was interesting.
Timeslip:
Datalog:
look at the rpm trace. wow. way different and more tame than the past few years!
Video:
GoPro Video:
Pass 2:
I kept the tune file and all the airbag, shock settings, and tire pressure 917.2 psi) the same. 5. second burnout. All I did on this pass differently, was launch the car from a higher footbrake rpm, but I still let the car shift itself. I wanted a good 60 foot comparison between launching off an idle (pass 1) and launching from a footbrake rpm. The car looks like it held up to 3211 rpms on the footbrake and after I launched it flashed to 4540 rpms. It did spin the rear tires just a bit, and you can hear it slip/grab on the video. It shifted itself at 5413 rpms and into 2nd gear at 4958 rpms. Sidenote- my TPS (green line) is not at 100% wide-open-throttle because during this point in the run, I noticed my windshield mounted rear view mirror must have vibrated itself loose recently and it began shaking all wildly so I was partially noticing that. Anyways, it shifted the 2-3 shift at 5195 and this dropped rpms to 5001 in 3rd gear. I crossed the finish line at 6050 rpms, mirror still shaking but not falling off.
Timeslip:
Datalog:
TPS trace is wiggly as I was half watching the mirror about to vibrate itself off. whoops!
Video:
GoPro:
Pass 3:
Shock and airbag settings are the same, but I brought the rear tires down to 16.4 psi. These next two passes I wanted to shift the car where I typically shift but launch as I did in pass 1 and 2 for some comparison data. I did a 7 second burnout, and launched the car from a dead idle, which was 947 rpms. It flashed the converter to 4851 and then I shifted 1-2 at 6449 and it dropped to 5147 9which is more of a drop than I've seen in recent weeks using this new converter?). I made the 2-3 shift at 6279 rpms, and it dropped to 5152. Crossed the finish line at 6006 rpms. The big drop-off in rpms between the shifts is all of a sudden similar to my results with the Edge Racing converter, so that confused me. The yank converters datalogs can be seen in previous posts I made during the recent month since installing it. Strange, but ok? IT launched good, pulled the wheels up, and I shifted real close to my target rpms, nothing outrageous happened, so it is good comparison data to pass #1 where I launched from an idle also. sixty foot times were close, but E.T. i went faster on pass 1 which had MUCH lower rpm shift points.
Timeslip:
Datalog:
Video:
GoPro video:
Pass 4:
Rear tires were both at 16.6 so I left them there. Decent 6 second burnout. Brought the rpms up to 2564 and left off the footbrake. Flashed at 4856 rpms, and shifted 1-2 at 6450 which dropped it to 5233 in second gear. Shifted 2-3 at 6285 and dropped to 5331. Crossed the finish line at 6013 rpms.
Timeslip:
Datalog:
Video:
GoPro Video:
10-23-2022, 11:55 AM
#59
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
I figured I had gotten some good info for comparing footbrake vs idle launches and me shifting vs trans shifting itself, and I might enough time to turn on the nitrous bottle and make two passes. Remembering that I had been overfueling the nitrous the other weekend, I did two things to compensate for it; in hindsight, I should have just done one. First, I left the fuel jet set for the 150 shot and put the nitrous jet for a 175 shot in the plate. I left the ClosedLoop Compensation fueling range to =/- 20% thinking this should cover it. The other thing I did, and this was because for a few months I have had a substantial PSI difference in what my two nitrous system pressure gauges are reading. The one mounted to the bottle never zeroes out even when system is disconnected, it is always reading 175-200 psi. The one in the a-pillar drops down to zero. The gauge at the bottle I have had probably 8 years now, so its seen its life, but I wasn't sure which one to trust. In recent months I have still trusted the bottle gauge, so when I have been making nitrous passes, I let it get to 1,000 psi and in-turn, the one on my a-pillar is reading in the 850 range. However, for Sunday's race day, I decided to try to rely on the a-pillar one and I heated the bottle up so that the A pillar gauge read 1,000 psi. Therefore, the gauge at the bottle was 1,200 psi, probably closer to 1,225. Again, experimental situation here.
Pass 5:
Tires at 16.6 psi all other settings the same, did a 6 second burnout. Launched from a 957 rpm idle and the nitrous was set to start coming on at 3300 rpms. It did, and it flashed the converter to 5976 according to the datalog. It spun the tire a very slight amount, I did a quick pedal of the throttle, Shifted 1-2 at 6353 rpms and this dropped it to 5639 in second gear. Should have started looking more intently at my AFR gauges, because AFR was dangerous, but thankfully the safe-guards I put into the tune-file caught it and turned off the system. I have the high side limit set to anything over 13.5 afr for more than .5 seconds, it kills the nitrous and runs all motor. But here is where I am still confused, as the rest of the lame and confused pass, the AFR still stayed pretty lean.. see the pink line, thats actual AFR and it should be very tight to the light-blue line (target AFR) that is below it. Not good. Got nervous after that run, which was unsuccessful in having a good timeslip whatsoever. Event eh 60 foot was off, it should be at least low 1.4s, yikes.
Timeslip:
Datalog:
Video:
GoPro video:
Pass 6. I knew lanes were closing and I had almost no time. I pulled up to my spot in the pits, gabbed the computer and a spark plug socket and went right into the lanes before they closed. Pulled two plugs and thankfully they looks ok. wow, whew. I didn't have time to change the nitrous jets, so I did what I thought was my only option, I opened up the ClosedLoop Cfuel compensation limits to 60%. and re-uploaded the file. In hindsight, now that I think of it... I could have simply lowered bottle pressure, and kept the jets and CL comp the same, but it did not dawn on me until the ride home. This time instead of leaving from an idle, I footbraked to 2209 rpms and it flashed at 4691. AFR numbers were getting wild, so I abandoned the run.
Timeslip:
Datalog:
Video: no need for video here, just a bad run.
Packed up the tools and headed home, this time it was NOT raining so that was a bonus.
Typing this up hopefully will help me get my brain into the data I obtained regarding if all-motor the car launches faster and runs a better ET if I footbrake, and/or if I let it shift itself vs me power-shifting. Wish the nitrous passes went better, but I was experimenting. I called Bruce's speed shop again and hopefully I can get a bottle filled November 3rd and ALSO buy a new in-line nitrous PSI gauge to mount at the bottle, as I do think the 8 year old gauge is reading incorrectly.
Any launch photos are of the car all-motor as the photographers were not taking photos during the late afternoon nitrous attempts/fails.
Pass 5:
Tires at 16.6 psi all other settings the same, did a 6 second burnout. Launched from a 957 rpm idle and the nitrous was set to start coming on at 3300 rpms. It did, and it flashed the converter to 5976 according to the datalog. It spun the tire a very slight amount, I did a quick pedal of the throttle, Shifted 1-2 at 6353 rpms and this dropped it to 5639 in second gear. Should have started looking more intently at my AFR gauges, because AFR was dangerous, but thankfully the safe-guards I put into the tune-file caught it and turned off the system. I have the high side limit set to anything over 13.5 afr for more than .5 seconds, it kills the nitrous and runs all motor. But here is where I am still confused, as the rest of the lame and confused pass, the AFR still stayed pretty lean.. see the pink line, thats actual AFR and it should be very tight to the light-blue line (target AFR) that is below it. Not good. Got nervous after that run, which was unsuccessful in having a good timeslip whatsoever. Event eh 60 foot was off, it should be at least low 1.4s, yikes.
Timeslip:
Datalog:
Video:
GoPro video:
Pass 6. I knew lanes were closing and I had almost no time. I pulled up to my spot in the pits, gabbed the computer and a spark plug socket and went right into the lanes before they closed. Pulled two plugs and thankfully they looks ok. wow, whew. I didn't have time to change the nitrous jets, so I did what I thought was my only option, I opened up the ClosedLoop Cfuel compensation limits to 60%. and re-uploaded the file. In hindsight, now that I think of it... I could have simply lowered bottle pressure, and kept the jets and CL comp the same, but it did not dawn on me until the ride home. This time instead of leaving from an idle, I footbraked to 2209 rpms and it flashed at 4691. AFR numbers were getting wild, so I abandoned the run.
Timeslip:
Datalog:
Video: no need for video here, just a bad run.
Packed up the tools and headed home, this time it was NOT raining so that was a bonus.
Typing this up hopefully will help me get my brain into the data I obtained regarding if all-motor the car launches faster and runs a better ET if I footbrake, and/or if I let it shift itself vs me power-shifting. Wish the nitrous passes went better, but I was experimenting. I called Bruce's speed shop again and hopefully I can get a bottle filled November 3rd and ALSO buy a new in-line nitrous PSI gauge to mount at the bottle, as I do think the 8 year old gauge is reading incorrectly.
Any launch photos are of the car all-motor as the photographers were not taking photos during the late afternoon nitrous attempts/fails.
10-24-2022, 06:11 PM
#60
Supreme Member
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
SkinnyZ; I like that idea about the bigger psi difference in the rear airbags. I did that last weekend and it seemed to work good. I lowered my actual shock adjustment to make them softer, and that might have hurt me a bit, but now I know where to put them back to.
here is a full side-shot photo for ya. I have more I can get to you too if needed, just ask!
here is a full side-shot photo for ya. I have more I can get to you too if needed, just ask!
Judging from the tail up bias, I suspect the arms inclination is OK. Arms that are parallel to the ground or front end high is not a good thing. That's why the adjustment on the relocation brackets are designed like they are. My car is very lowered in comparison to yours and I've got the LCARB's on the bottom most hole. A little air bag action helps lift the back a little but I still suffer from poor geometry in this regard. And my 60' times show it. It doesn't help that my old ET Streets (bias DOT slick) are well past their prime and are now retired.
I see you like to do a hefty burnout everytime. Like several seconds. I don't recall what your rear tires are (MT?) but I do remember reading on MT's tire website that after a thorough 1st burnout, any that follow are more of the quick variety and you're ready to go.
10-25-2022, 07:23 PM
#61
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Thanks for the reply Skinny. As for the rear Lower control arms, and forgive me, but I am very lacking in sleep and brainpower in recent days, but I was almost certain that my LCA's were are a good angle for many recent years, but now you have my brain a bit frazzled. I could have sworn that a slight upward angle (upward towards the front of the car) or a parallel to the ground "angle" was preferred over an angle that puts the rear mount higher than the front mount?
-As my car sits now, in drag race mode, with air bags inflated a little bit for street use, the front mount of the rer LCA is higher than the rear mount at the axle. I used my digital angle finder and got a reading of 4 deg on both sides. So, my rear lower control arms point downward as they get to the rear axle location; this was preferred right? I have the Moser 12 bolt rear which I had the LCA mounts welded on and there are a few choices of mounting holes. I am on the lowest hole. The hole above it would probably get my LCA bars at a 0deg angle or so. I was under the impression that dragstrip launches would be best in the way I have it setup....but if you are saying I am wrong, I am definitely all ears. Sidenote. the angle might change a slight bit over the winter time as I am going to trim off a tiny bit of my rear coil spring to sit the rear of the car down lower over the wheels. On both these drag wheels, and my street/autocross wheels, there is too much gap between the rubber and fender, but it only became this increased gap after I added the air-lift drag-bags. I am leaving the bags in but probably going to trim off another 1/4 of the top of the coil. Looking for about 3/8" of a drop in fender height.
As for the burnout, I think I did try a shorter burnout during some test and tune events last summer. I got mixed results form the launch, but also because I was trying several other different things on each run at that time. I run the 275/65/15 Mickey Thompson ET Street SS tires. I do remember Mickey Thompson website, so maybe I will try a shorter burnout as the day goes on, provided I can go to the track again this year. Looking to get a fast nitrous pass in, because my best one to date is still back in May 1, 2022 and thats not enough improvement for me to end the year on, I hope.
-As my car sits now, in drag race mode, with air bags inflated a little bit for street use, the front mount of the rer LCA is higher than the rear mount at the axle. I used my digital angle finder and got a reading of 4 deg on both sides. So, my rear lower control arms point downward as they get to the rear axle location; this was preferred right? I have the Moser 12 bolt rear which I had the LCA mounts welded on and there are a few choices of mounting holes. I am on the lowest hole. The hole above it would probably get my LCA bars at a 0deg angle or so. I was under the impression that dragstrip launches would be best in the way I have it setup....but if you are saying I am wrong, I am definitely all ears. Sidenote. the angle might change a slight bit over the winter time as I am going to trim off a tiny bit of my rear coil spring to sit the rear of the car down lower over the wheels. On both these drag wheels, and my street/autocross wheels, there is too much gap between the rubber and fender, but it only became this increased gap after I added the air-lift drag-bags. I am leaving the bags in but probably going to trim off another 1/4 of the top of the coil. Looking for about 3/8" of a drop in fender height.
As for the burnout, I think I did try a shorter burnout during some test and tune events last summer. I got mixed results form the launch, but also because I was trying several other different things on each run at that time. I run the 275/65/15 Mickey Thompson ET Street SS tires. I do remember Mickey Thompson website, so maybe I will try a shorter burnout as the day goes on, provided I can go to the track again this year. Looking to get a fast nitrous pass in, because my best one to date is still back in May 1, 2022 and thats not enough improvement for me to end the year on, I hope.
10-25-2022, 08:37 PM
#62
Supreme Member
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
Sorry about that IROC. It would seem I'm as frazzled as you. You are correct. We're looking for the inclination of the LCA to be lower at the back. At least what followed describing mine as being on the lowest most hole in the LCARB's was accurate. Sorry for the confusion.
As for the burnouts, further to my recollection of the MT instructions, it's also mentioned that it's track temperature specific.
Just so I don't add to the confusion (which I seem to be good at sometimes), I lifted this from the MT website.
The length of your burnout will be dictated primarily by the ambient and track conditions. The hotter the temperatures, the shorter the burnout. When the temps get cool, a longer burnout will be necessary. Ideally you want the tire temp to be within 15 degrees of the track temperature on the launch. When the track temps exceed 120 degrees, it is always best to keep your tire temps on the lower side. Here are some additional tips for maximizing the performance of your M/T racing tires.
As for your results, I admire your getting out there. And I especially like your updates and results analysis. I'm hoping (really hoping) that I can be doing the same for this upcoming season.
As for the burnouts, further to my recollection of the MT instructions, it's also mentioned that it's track temperature specific.
Just so I don't add to the confusion (which I seem to be good at sometimes), I lifted this from the MT website.
The length of your burnout will be dictated primarily by the ambient and track conditions. The hotter the temperatures, the shorter the burnout. When the temps get cool, a longer burnout will be necessary. Ideally you want the tire temp to be within 15 degrees of the track temperature on the launch. When the track temps exceed 120 degrees, it is always best to keep your tire temps on the lower side. Here are some additional tips for maximizing the performance of your M/T racing tires.
As for your results, I admire your getting out there. And I especially like your updates and results analysis. I'm hoping (really hoping) that I can be doing the same for this upcoming season.
The following 2 users liked this post by skinny z:
DynoDave43 (10-27-2022), vorteciroc (10-26-2022)
10-26-2022, 06:27 AM
#63
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
If you want more lift and rear separation, a lower bar hole would be needed. Most only seem to give 2-3 deg down angle to rear. Longer lca bracket to allow 5-8 deg would help separate the rear with the long torque arm.
The following users liked this post:
NoEmissions84TA (10-27-2022)
02-07-2023, 07:07 PM
#64
Supreme Member
Thread Starter
iTrader: (25)
Join Date: Sep 2005
Location: NJ
Posts: 1,816
Received 280 Likes
on
218 Posts
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: My quest for a good wheelie: suggestions on transbrake, converter, or something e
This weekend I am going to tackle the rear-end ride-height issue that bothered me ever since I installed the Air-Ride air-lift bags in the fall of 2021. Even with the bags at the lowest (5psi) the rear end fender eight sits up about 1/2 higher than without them in. This was something I immediately noticed when I put them in, and back then when I was troubleshooting it, I think it still has something to do with the red 'puck" that goes between the bag and the spring perch. So, the only thing I can do, is take out my coil springs and take another little part of the coil off to drop the ride height. I don't run the rubber isolators anymore, I have been doing the heater hose method on my current springs which I cut back in 2008 and then again back in 2015 to get the ride height dialed in back then. Currently the drivers side rear fender sits at 28 3/8" and the passenger rear sits at 28 1/2". I'm looking to take these numbers down about 5/8" via the coil-cut process. Also will trim the bump-stops accordingly. These are the 5665 springs, constant rate, have never had a problem with them.
No big deal,
but,
I figured while I am in there, maybe I should get a more drag-race oriented rear shock for the car. For spring and fall drag racing, I run the 90/10 Lakewoods up front, but with my Koni yellow rear shocks, and they are usually adjusted to the 3/5 settings while at the dragstrip. (For autocross I take out the front Lakewoods and put in the front koni yellow struts.) The rear shocks on these cars are a 5 minute swap per-side, so I wouldn't mind buying a set of drag-based rear shocks ONLY if I stand a chance of seeing a significant improvement in the launch/60 foot at the track. I don't want to waste money if the koni's are well suited enough. I am not looking for anything high dollar (Afco, viking, etc), but more like the Lakewood 50/50 shocks.
link: https://www.summitracing.com/parts/l...maro/year/1984
And While on the topic of a faster launch, I am wondering if it's time I get away from relying on the oem 1987 iroc-z rear sway bar, and maybe get something of an upgrade. I Take the the front sway bar completely off the car for drag racing and leave the oem rear on on. For autocross, I put the oem iroc one back on, and of course the rear one is already in place. Was thinking of a rear drag sway bar, and then perhaps a separate upgraded front/rear swaybar for autocross action. I do wish the UMI drag-bar was cheaper, because $450 is a lot of money and I might not need to be doing this yet. Maybe see how the shocks do and then decide about sway-bar later on.
drag bar - https://www.umiperformance.com/home/...drag-sway-bar/
bigger street/autoX bar: https://www.umiperformance.com/home/...-22mm-tubular/
No big deal,
but,
I figured while I am in there, maybe I should get a more drag-race oriented rear shock for the car. For spring and fall drag racing, I run the 90/10 Lakewoods up front, but with my Koni yellow rear shocks, and they are usually adjusted to the 3/5 settings while at the dragstrip. (For autocross I take out the front Lakewoods and put in the front koni yellow struts.) The rear shocks on these cars are a 5 minute swap per-side, so I wouldn't mind buying a set of drag-based rear shocks ONLY if I stand a chance of seeing a significant improvement in the launch/60 foot at the track. I don't want to waste money if the koni's are well suited enough. I am not looking for anything high dollar (Afco, viking, etc), but more like the Lakewood 50/50 shocks.
link: https://www.summitracing.com/parts/l...maro/year/1984
And While on the topic of a faster launch, I am wondering if it's time I get away from relying on the oem 1987 iroc-z rear sway bar, and maybe get something of an upgrade. I Take the the front sway bar completely off the car for drag racing and leave the oem rear on on. For autocross, I put the oem iroc one back on, and of course the rear one is already in place. Was thinking of a rear drag sway bar, and then perhaps a separate upgraded front/rear swaybar for autocross action. I do wish the UMI drag-bar was cheaper, because $450 is a lot of money and I might not need to be doing this yet. Maybe see how the shocks do and then decide about sway-bar later on.
drag bar - https://www.umiperformance.com/home/...drag-sway-bar/
bigger street/autoX bar: https://www.umiperformance.com/home/...-22mm-tubular/
Thread
Thread Starter
Forum
Replies
Last Post