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Not a chance, the downpipe is now a permanent fixture in the engine bay. I would need to, at a minimum, remove the turbo and the turbo header to get it out. With 1/2" of clearance in every direction, and it made out of a bunch of pie cuts and bends, it's there permanently.
Flexalite eh? Is that an amazon thing? I only have 1 ground output for my fan control. I'm out of I/O. I had to wire my intercooler relay (pump + fans) to the same output as my fuel pump relay. I would have preferred enabling the intercooler fan based on coolant temp or something.
I'm hoping to get the car to the point where I can move it in and out of the shop by next week. I need to move it over to the 4 post lift so I can do an alignment, and I need to drag the 4th gen Formula into the bay with the 2 post lift so I can deal with the blown head gasket. Good thing we have another two months of winter.
Oh man that sucks lol.
Flexalite has been around a long time- good stuff too. You can control with a single negative or single positive for override. It its just power, ground and igintion and then uses the temp sensor so you don't need a trigger unless its for override or AC. Here is a link to the thread in probe that I get, but it also has a push in probe for the radiator if you don't want to find a 1/4" port. If you tie it into the flexalite controller it will follow coolant temp with soft start etc. since its a soft start you don't need a crazy fuse, I run 40amp Maxi fuse on my dual spals which are big pullers. On my C3 I run the same but spal dual knockoffs and just use a 40amp resettable breaker. The inrush current is much less so your only worried about continuous amperage which is usually less than 20amps a fan if they are high end. https://www.summitracing.com/parts/flx-107012
You got alot to do. I still need to finish the coil relocation on the C3 and redo the exhaust as I want to add flowmaster high flow cats, and shorter flex couplers with Vbands. With 3 young kids, just finishing a massive reno and it being so cold I haven't had chance to get out on the car in months. 2 months will be gone in a flash!
Last edited by customblackbird; 02-20-2024 at 10:14 AM.
#1, my 97-98 LS1 coolant temp sensor appears to be not working properly. At 70 degrees water temp I'm getting just under 2,000ohm and it reads 100 degrees. At 140 degrees it reads 197.
#2, I didn't realize Megasquirt 2 'reset' every time you apply settings / a table /etc. I never noticed this before because I was either running HEI or EDIS. Both use a 'module' with a fixed advance table unless commanded to advance or retard timing. This little 'blip' that happens isn't even noticed. However, not that I have the 58x crank trigger directly wired to my Megasquirt, whenever I apply a table the little 'blip' causes a stall. I played with it key on, engine off, and I found that when it burns the table or whatever it resets all input/output channels, spark channels, IAC stepper, etc. Guys on the forums say if you snap the throttle when clicking "burn" it won't stall. Apparently Megasquirt 3 doesn't have this issue. I'm rather annoyed. If I knew this was how it would behave I would have either updated to an MS3 or went terminator X.
#3 My wideband is being weird. At idle, which seemed rich by all account, it's showing like 22.5 AFR. I'm not sure if the controller is having an issue or the 10 year old sensor finally is dead.
I still have 1 or 2 exhaust leaks.
I did wire a second circuit/relay/fuse so now each fan is controlled by it's own 30 amp relay and fuse. Of course, since my coolant temp sensor is reading high the fans come on at like 130..
Fixed the driveshaft rubbing on the loop. I had some misalignment going on with the engine + transmission.
Wideband working properly.
I need to really work on the tune. I moved the car in and out of the shop and onto the 4 post lift. It moves. Clutch grabs right off the floor. Probably would be better with a 3.73, the second you let the clutch out and give it a tap of throttle the tires break loose.
Alignment next.
Ride height is a little mad max with the new moog springs. 28.5" in the front.
I've been doing an engine swap on the 4th gen so I have been neglecting the thirdgen, but I did take it for a ride the other day when it was 60 out (now snowing). I've got a nasty nasty stumble from 1800-2400, but after 2500 it just lights the tires on fire even when you are not trying to. I think the 3.42 rear ratio is too low (numerically). Maybe 3.73 be better.
Interesting, it will cruise just fine 1200rpm in gear going down the road. I gotta figure out if it's fuel or whatnot between 1800-2400, it's like a nasty stumble/breakup almost like a miss.
Turbo makes cool spin down noises every time I let off the throttle though.
Once I get the tune dialed in, I think I'll be happy with it.
I've been doing an engine swap on the 4th gen so I have been neglecting the thirdgen, but I did take it for a ride the other day when it was 60 out (now snowing). I've got a nasty nasty stumble from 1800-2400, but after 2500 it just lights the tires on fire even when you are not trying to. I think the 3.42 rear ratio is too low (numerically). Maybe 3.73 be better.
Interesting, it will cruise just fine 1200rpm in gear going down the road. I gotta figure out if it's fuel or whatnot between 1800-2400, it's like a nasty stumble/breakup almost like a miss.
Turbo makes cool spin down noises every time I let off the throttle though.
Once I get the tune dialed in, I think I'll be happy with it.
Can't help you with the megasquirt but hopefully you figure it out. Breakup down that low I doubt is spark related but what plugs are you running? Did you log anything?
I would keep the 3.42 and I would not step up to a lower gear like a 3.73. If your having traction problems now you won't want any more mechanical leverage assisting that. I have 3.55s and I would rather a 3.08 or something but I have a ford 8.8. Since you have a manual trans the power hit is even harder.
Glad to hear you got a test drive in. The 70/70 is a very responsive lil $hit lol. I love the decel noise its my favorite almost as much as the boost noise. Did you do any logs? What boost have you hit? Did you do a atmospheric or recirculated WG dump (can't remember) but it looks like its recirculated in the video?
Traction will be hard and its the reason I had to move to MT drag radials in the back.
Can't help you with the megasquirt but hopefully you figure it out. Breakup down that low I doubt is spark related but what plugs are you running? Did you log anything?
I would keep the 3.42 and I would not step up to a lower gear like a 3.73. If your having traction problems now you won't want any more mechanical leverage assisting that. I have 3.55s and I would rather a 3.08 or something but I have a ford 8.8. Since you have a manual trans the power hit is even harder.
Glad to hear you got a test drive in. The 70/70 is a very responsive lil $hit lol. I love the decel noise its my favorite almost as much as the boost noise. Did you do any logs? What boost have you hit? Did you do a atmospheric or recirculated WG dump (can't remember) but it looks like its recirculated in the video?
Traction will be hard and its the reason I had to move to MT drag radials in the back.
NGK BR7EF plugs. So, I noticed my TPS kept going out of whack. I'd start the car and it would be -5. So I'd go into my TPS calibration and the number of AD counts had changed for both closed and WOT TPS. After a few minutes of running it would change again. I also noticed while idling, my TPS value would bounce around a little. I know for 100% certain the throttle is slammed shut against the set screw.
So I ordered a Delphi TPS which came in today. Also says made in china. Hopefully that will solve that problem, which I don't think is related to my weird breakup/shake.
Unfortunately I didn't log taking the car for a drive, but I've been trying to tune out the issue in the shop. It shakes/stumbles soo much it's dangerous in traffic because you need to basically rev past the issue and let the clutch out, which lights the tires on fire and kicks the rear end out.
My WG dumps to atmosphere in the fender.
I've always thought that while a larger (numerically) gear aids in mechanical leverage, it has a less tendency to spin the tire when letting the clutch out?
Anyhow, so back to the tuning issue. I don't know what is going on. I've rebuilt the fuel map several times. the wideband has been zero help, it doesn't matter if I have those cells dialed in at 13.5:1 or 16.5:1, it breaks up and shakes almost like it's missing on 3 cylinders. But once you rev past that it's clean and pulls like a rocket!
NGK BR7EF plugs. So, I noticed my TPS kept going out of whack. I'd start the car and it would be -5. So I'd go into my TPS calibration and the number of AD counts had changed for both closed and WOT TPS. After a few minutes of running it would change again. I also noticed while idling, my TPS value would bounce around a little. I know for 100% certain the throttle is slammed shut against the set screw.
So I ordered a Delphi TPS which came in today. Also says made in china. Hopefully that will solve that problem, which I don't think is related to my weird breakup/shake.
Unfortunately I didn't log taking the car for a drive, but I've been trying to tune out the issue in the shop. It shakes/stumbles soo much it's dangerous in traffic because you need to basically rev past the issue and let the clutch out, which lights the tires on fire and kicks the rear end out.
My WG dumps to atmosphere in the fender.
I've always thought that while a larger (numerically) gear aids in mechanical leverage, it has a less tendency to spin the tire when letting the clutch out?
Anyhow, so back to the tuning issue. I don't know what is going on. I've rebuilt the fuel map several times. the wideband has been zero help, it doesn't matter if I have those cells dialed in at 13.5:1 or 16.5:1, it breaks up and shakes almost like it's missing on 3 cylinders. But once you rev past that it's clean and pulls like a rocket!
I haven't made the jump to the BR7 plugs yet, I'm still running the NGK TR6s which have been up to 16lbs. Not saying thats your issue but I've heard some things about the BR7s and idling/drivability which is why I never took the jump up. https://ls1tech.com/forums/generatio...ough-idle.html with the colder plug you have to add timing they say.
I don't want to also tell you to jump to a holley Term X but I've also read a few threads over time about issues with those style EFI systems (micro/mega squirt and all those gold box brands). They are jam packed with features/options at an attractive price but alot of ppl chased there tails to find it was a hardware issue. If you don't need tranny control your like $1200 ish for a holley term X at the moment I believe. Heat does affect failing sensors so it might be worth throwing the TR6 plugs and new TPS and see what that does. Have you adjust the dwell or anything on the coils?
How do like the dumped WG? I couldn't stand the sound of an exhaust leak.
If you add mechanical leverage your making it easier to spin the tire and kick out the rear end. The higher number (lower gear) will limit how fast the tire spins at a given rpm but your adding the leverage to break the tire loose except instead of spinning at 35mph its spinning at 30mph or something... its still spinning so the rear end is already kicked out is how my brain works. Reducing the mechanical leverage should make it harder to spin the tire as the engine would have to work harder to break it free, once its free it will spin faster. I think the idea here is to limit how easy it breaks free vs how fast its spinning once it's broken free lol. The taller gear (lower number) should also load the engine more to help with spool. Typically in boosted applications you want a taller (lower number) gear as boosted motors have lots of low end tq which causes the tires to break free easily.
I haven't made the jump to the BR7 plugs yet, I'm still running the NGK TR6s which have been up to 16lbs. Not saying thats your issue but I've heard some things about the BR7s and idling/drivability which is why I never took the jump up. https://ls1tech.com/forums/generatio...ough-idle.html with the colder plug you have to add timing they say.
I don't want to also tell you to jump to a holley Term X but I've also read a few threads over time about issues with those style EFI systems (micro/mega squirt and all those gold box brands). They are jam packed with features/options at an attractive price but alot of ppl chased there tails to find it was a hardware issue. If you don't need tranny control your like $1200 ish for a holley term X at the moment I believe. Heat does affect failing sensors so it might be worth throwing the TR6 plugs and new TPS and see what that does. Have you adjust the dwell or anything on the coils?
How do like the dumped WG? I couldn't stand the sound of an exhaust leak.
If you add mechanical leverage your making it easier to spin the tire and kick out the rear end. The higher number (lower gear) will limit how fast the tire spins at a given rpm but your adding the leverage to break the tire loose except instead of spinning at 35mph its spinning at 30mph or something... its still spinning so the rear end is already kicked out is how my brain works. Reducing the mechanical leverage should make it harder to spin the tire as the engine would have to work harder to break it free, once its free it will spin faster. I think the idea here is to limit how easy it breaks free vs how fast its spinning once it's broken free lol. The taller gear (lower number) should also load the engine more to help with spool. Typically in boosted applications you want a taller (lower number) gear as boosted motors have lots of low end tq which causes the tires to break free easily.
OMG I'm an idiot, sorry, my BOV is vented to atmosphere not my WG. The WG goes into the downpipe. My brain has been fried lately. No, the whole "screamer pipe" thing isn't appealing to me at all. When I built this car, I wanted to make it as quiet as possible, and I wanted to run a cam that was near stock for drivability. The only thing right now slightly obnoxious is the whine from the intercooler pump, which is quite pronounced. (using a Bosch / Ford pump).
Soo.. The plug thing is interesting. I'm running 18-19 degrees for most of the MAP, it will dive out to 24 degrees in higher RPM under 100kpa, but then.. Eh, I'll just show you:
So the 'Sloppy mechanics' guys are running something like this on a MS2 LY6 Turbo:
So now I'm wondering, after reading your comments and link, if perhaps the problem is really timing after all. Maybe the plugs are getting loaded up, because after 2400 when it is smooth I'm interpolating between 24-30 degrees.
Good point on the gearing vs spool for loading the engine.. Something to really consider. I'm still running the 10 bolt I built over a decade ago, but I've been collecting pats for a 9". That's next winters plan, along with probably a TKX. Currently running the T5.
OMG I'm an idiot, sorry, my BOV is vented to atmosphere not my WG. The WG goes into the downpipe. My brain has been fried lately. No, the whole "screamer pipe" thing isn't appealing to me at all. When I built this car, I wanted to make it as quiet as possible, and I wanted to run a cam that was near stock for drivability. The only thing right now slightly obnoxious is the whine from the intercooler pump, which is quite pronounced. (using a Bosch / Ford pump).
Soo.. The plug thing is interesting. I'm running 18-19 degrees for most of the MAP, it will dive out to 24 degrees in higher RPM under 100kpa, but then.. Eh, I'll just show you:
So the 'Sloppy mechanics' guys are running something like this on a MS2 LY6 Turbo:
So now I'm wondering, after reading your comments and link, if perhaps the problem is really timing after all. Maybe the plugs are getting loaded up, because after 2400 when it is smooth I'm interpolating between 24-30 degrees.
Good point on the gearing vs spool for loading the engine.. Something to really consider. I'm still running the 10 bolt I built over a decade ago, but I've been collecting pats for a 9". That's next winters plan, along with probably a TKX. Currently running the T5.
-- Joe
lol no problem! I also appreciate the quieter car now as well. Have you looked into the Davis Craig brushless intercooler pump? I can one a while back for a min and if I remember it wasn’t very loud.
your timing is a bit soft not gona lie. I’ll try to snap a pick of the tune later when I have access to the laptop. I know I’m beteeen 18-21 at idle and it ramps up to 28* around WOT before boost.
lol no problem! I also appreciate the quieter car now as well. Have you looked into the Davis Craig brushless intercooler pump? I can one a while back for a min and if I remember it wasn’t very loud.
your timing is a bit soft not gona lie. I’ll try to snap a pick of the tune later when I have access to the laptop. I know I’m beteeen 18-21 at idle and it ramps up to 28* around WOT before boost.
Spent a few hours last night tinkering. I have a couple theories ..
I'm using Bosch 4 injectors, and I have the dead time (at 13.2v) set to .518. This might be too low. I noticed when I changed the injection strategy from 2 squirts per cycle to 4, the idle and everything was unstable. This leads me to believe that perhaps the dead time is wrong.
the injectors are decapped, which likely wasn't much of an issue on the SBC/miniram, but I wonder if with the slightly different firing order of the LS, the bank by bank firing at 2 squirts per cycle is causing raw fuel to run down the walls of some cylinders. This is why I tried changing to 4 squirts to see if it would provide slightly better fuel distribution.
I know, I know, I should upgrade the ECU and run sequential but I was hoping to avoid that and continue using the MS2.
I did play with timing, adding, removing, isolating idle vs part throttle cells. No change. Wideband shows stable during the stumble/shake, but I've never really trusted wideband sensors.
I've considered buying an MS3 gold box and splicing it into my harness, or a used Terminator X and doing the same. I assume the TermX can wire up to just about anything and the 5v or 12v for the crank sensor is in the harness?
One of my biggest gripes with the MS2 is that it "resets" when you save the flash, so you lose ignition control for long enough for the car to stall. Super annoying. If I updated to a MS3 gold box it wouldn't do that, plus I would be able to run full sequential if I wanted to.
Spent a few hours last night tinkering. I have a couple theories ..
I'm using Bosch 4 injectors, and I have the dead time (at 13.2v) set to .518. This might be too low. I noticed when I changed the injection strategy from 2 squirts per cycle to 4, the idle and everything was unstable. This leads me to believe that perhaps the dead time is wrong.
the injectors are decapped, which likely wasn't much of an issue on the SBC/miniram, but I wonder if with the slightly different firing order of the LS, the bank by bank firing at 2 squirts per cycle is causing raw fuel to run down the walls of some cylinders. This is why I tried changing to 4 squirts to see if it would provide slightly better fuel distribution.
I know, I know, I should upgrade the ECU and run sequential but I was hoping to avoid that and continue using the MS2.
I did play with timing, adding, removing, isolating idle vs part throttle cells. No change. Wideband shows stable during the stumble/shake, but I've never really trusted wideband sensors.
I've considered buying an MS3 gold box and splicing it into my harness, or a used Terminator X and doing the same. I assume the TermX can wire up to just about anything and the 5v or 12v for the crank sensor is in the harness?
One of my biggest gripes with the MS2 is that it "resets" when you save the flash, so you lose ignition control for long enough for the car to stall. Super annoying. If I updated to a MS3 gold box it wouldn't do that, plus I would be able to run full sequential if I wanted to.
-- Joe
Injector data is not my strong suit lol but I would guess that would have to be spot on. I know with HP tuners it was required and with the holley they have a ton of injector data already stored in the system so you just pick the injector out of the list. I did that when I switched from Deka 60lb to Bosch 42lb corvette injector. Just swapped and found the GM part number in the drop down.
So your batch firing?! yikes...
With how much messing around your doing at what point to you just remove and start enjoying the car? I also don't trust widebands 100% at least for small intermittent issues. Decapped doesn't change injector performance it just affects the fuel stream pattern. Deka injectors are all decapped. Have you tried making huge fuel changes below the 3k RPM? What do the plugs look like? What plug gaps? Are you running water/meth? Could that be getting sucked out or accidentally triggered?
If you were doing A Term X or any ECM swap I would use the provided harness and run it like its intended. I can't say for sure about the Term X but since the harness is included why not just unplug and remove your current and swap the new stuff in. Could be a wiring issue as well with your current setup.
man anesthes - i feel your pain. you're kind of in the same boat as me... except you got much farther with turning your engine than i ever did with the FITech system.
i'm just finishing up swapping a FITech Ultimate LS system to a Holley Terminator X setup. redoing all the nice harness routing behind the dash and through the firewall was awful. the only advice i can give is if you're planning to make a switch, just do it sooner than later to get it over with. i'm glad i installed a heater in my garage last fall or i would've wasted this whole summer doing the switch-over.
Injector data is not my strong suit lol but I would guess that would have to be spot on. I know with HP tuners it was required and with the holley they have a ton of injector data already stored in the system so you just pick the injector out of the list. I did that when I switched from Deka 60lb to Bosch 42lb corvette injector. Just swapped and found the GM part number in the drop down.
So your batch firing?! yikes...
With how much messing around your doing at what point to you just remove and start enjoying the car? I also don't trust widebands 100% at least for small intermittent issues. Decapped doesn't change injector performance it just affects the fuel stream pattern. Deka injectors are all decapped. Have you tried making huge fuel changes below the 3k RPM? What do the plugs look like? What plug gaps? Are you running water/meth? Could that be getting sucked out or accidentally triggered?
If you were doing A Term X or any ECM swap I would use the provided harness and run it like its intended. I can't say for sure about the Term X but since the harness is included why not just unplug and remove your current and swap the new stuff in. Could be a wiring issue as well with your current setup.
Batch and wasted spark!
I spent a tone of time getting the Megasquirt into a factory ECU case, using the factory harness so it all looks OEM. Kinda annoying to be thinking of swapping ECU's. The MS3 gold would be easiest as I could just splice it under the dash since my harness is all run and cut to length.
Holley has it's pros for sure, the plug n play with their harness is nice (although I don't think they make one for my exact combination of 58x, 4x cam, ev1 injectors). My biggest concern is outputs and functionality.
Will it drive my factory tach without mods? I didn't see any "tach out" in the software.
Will it operate my mac valve (boost control) or do I need a special "holley" unit? (I can adjust the frequency, polarity, and duty cycle with the MS) From the software it looks like I only have a few options for solenoids.
They come with a wideband controller for a 4.9 sensor but don't include the sensor right?
I went for more drive time today.. Basically, in gear, 1500rpm it just bucks and bucks. AFR all over the place. I logged it. Did VE analyze and it recommends some cell changes so I might give that a try and see if it gets better. Then re-evaluate my life haha.
man anesthes - i feel your pain. you're kind of in the same boat as me... except you got much farther with turning your engine than i ever did with the FITech system.
i'm just finishing up swapping a FITech Ultimate LS system to a Holley Terminator X setup. redoing all the nice harness routing behind the dash and through the firewall was awful. the only advice i can give is if you're planning to make a switch, just do it sooner than later to get it over with. i'm glad i installed a heater in my garage last fall or i would've wasted this whole summer doing the switch-over.
I'm more concerned about that then the money honestly. I have a ton of hours into re-doing the harness and making everything cut to length, splicing, weatherproofing, etc. That's why I'm learning towards MS3. But I am a little disgruntled with MS right now.
I spent like $150k last year building the new shop, and it's about $400 a month to heat. But I'm glad I did it. I have a lot more room, and when we have 3 feet of snow outside I can play with the cars.
I spent a tone of time getting the Megasquirt into a factory ECU case, using the factory harness so it all looks OEM. Kinda annoying to be thinking of swapping ECU's. The MS3 gold would be easiest as I could just splice it under the dash since my harness is all run and cut to length.
Holley has it's pros for sure, the plug n play with their harness is nice (although I don't think they make one for my exact combination of 58x, 4x cam, ev1 injectors). My biggest concern is outputs and functionality.
Will it drive my factory tach without mods? I didn't see any "tach out" in the software.
Will it operate my mac valve (boost control) or do I need a special "holley" unit? (I can adjust the frequency, polarity, and duty cycle with the MS) From the software it looks like I only have a few options for solenoids.
They come with a wideband controller for a 4.9 sensor but don't include the sensor right?
I went for more drive time today.. Basically, in gear, 1500rpm it just bucks and bucks. AFR all over the place. I logged it. Did VE analyze and it recommends some cell changes so I might give that a try and see if it gets better. Then re-evaluate my life haha.
Jesus! It's 2024 man and sequential has been out for like 25 years!
I would see if Holley can put that specific kit together for you. I think they can and you can buy the EV1 harness separately. I run EV1 with USCAR adapters as I changed injectors on the vette. So get the adapters for cheap.
Tach output is standard 8cyl but I don't know if you can adjust it. It can run your boost valve and doesnt need anything fancy.
you also do n't need a dome switch and ppl use the MAP wire as a reference. The holley 3/4 valve is the same as the MAC off amazon.
It comes with a single 02 sensor, and it is NOT setup for dual 02s. Only bad thing with the holley is that it only works with bosch and alot of serious boosted guys want the NGK 02s which the holley doesn't support unless you went with a dominator. Only thing you really need on the engine to run the term X is the alternator control harness which is less than $20 from holley on all the sites. Its a single wire with resistor on plug which sets 14.7 charge and it works with my Fbody and Truck style alternators. Since its separate you can run whatever you want as the holley doesn't care but you need it to charge your battery lol.
What cells is it requesting to be changed? Anything to do with airflow/fuel? Could it be an airflow issue? What about IAC settings and counts? What about MAP sensor? With the summit stage 1 in my 5.3 I can lug that thing around at 1500rpms and not have any issues.
It's not letting me attach tune pics from my 70/70 turbo 5.3 but it has a 218/228 cam so you can see timing and commanded fuel AFRs. THis is not from the 5.3 vette which has the summit stage 1 cam but thats also NA.
Jesus! It's 2024 man and sequential has been out for like 25 years!
I would see if Holley can put that specific kit together for you. I think they can and you can buy the EV1 harness separately. I run EV1 with USCAR adapters as I changed injectors on the vette. So get the adapters for cheap.
Tach output is standard 8cyl but I don't know if you can adjust it. It can run your boost valve and doesnt need anything fancy. https://youtu.be/9hDwGuYhJCo?si=NTX4Bbp7_Ca_Uf6t you also do n't need a dome switch and ppl use the MAP wire as a reference. The holley 3/4 valve is the same as the MAC off amazon.
It comes with a single 02 sensor, and it is NOT setup for dual 02s. Only bad thing with the holley is that it only works with bosch and alot of serious boosted guys want the NGK 02s which the holley doesn't support unless you went with a dominator. Only thing you really need on the engine to run the term X is the alternator control harness which is less than $20 from holley on all the sites. Its a single wire with resistor on plug which sets 14.7 charge and it works with my Fbody and Truck style alternators. Since its separate you can run whatever you want as the holley doesn't care but you need it to charge your battery lol.
What cells is it requesting to be changed? Anything to do with airflow/fuel? Could it be an airflow issue? What about IAC settings and counts? What about MAP sensor? With the summit stage 1 in my 5.3 I can lug that thing around at 1500rpms and not have any issues.
It's not letting me attach tune pics from my 70/70 turbo 5.3 but it has a 218/228 cam so you can see timing and commanded fuel AFRs. THis is not from the 5.3 vette which has the summit stage 1 cam but thats also NA.
I built the ECU in 2012 originally when I was running HEI and an SBC, so I didn't opt for the MS3 at the time.
I did however figure out my issue, after hours and hours and hours of troubleshooting. I had the trigger input capture set to Rising Edge instead of Falling Edge. This was causing misfires on RPM changes, and was late by about 6 degrees.
Once I changed the input capture, everything is great! This turbo is pretty awesome by the way. It spools at 2/3 throttle. I did a hard throttle pull, not wide open, and it made 5psi at 3200 rpm. Once I have the fuel map dialed in I'll do some hard pulls.
I'm also going to see if I can get it on my buddies dyno.
I'm actually running the Holley alternator harness, that's how I got my LS alternator to turn on with the MS2. MS3 supports the PWM alternators (DR36, DR44) but not MS2 so I went with an early LS alternator and the holley resistor harness/wire.
I'm idling around 38-40kpa at 800 RPM with that cam. Is that consistent with what you are seeing on the C3? It seems like a great street cam, especially with the 5 speed.
Speaking of IAC, I was having some issues with the throttle follower that I couldn't safely tune out. When you do a little throttle in blip it will sometimes add like 100 steps to the IAC which results in the engine racing to 1700-2000RPM, which I felt was kind of dangers. I decided to disable closed loop idle control, and instead have a programmed table for warm up enrichment, cranking steps, and then once the coolant is hot I completely close the IAC. The 92mm throttle body with the screw backed all the way out idles around 800rpm. I may enable the "idle timing" table to keep the idle stable if needed but so far it seems to idle just fine on the minimum air that exists in the throttle body.
IAT on the street is about 93 degrees under boost when ambient was 65. My problem now is my aluminum elbow is heating up because it's right behind the radiator. I need to figure out some sort of heat shield or something to keep it from getting heat soaked. The actual intercooler itself is like 30 degrees cooler.
glad to hear you got your main issue figured out - that's awesome!
when using the Holley alternator harness, are you guys adding a wire to the S terminal? i read about that on LS1tech and running a wire from this terminal to the battery or main power distribution block. looks like you need a metri-pack 150 series female terminal (20-18ga) to add the wire in the Holley connector.
glad to hear you got your main issue figured out - that's awesome!
when using the Holley alternator harness, are you guys adding a wire to the S terminal? i read about that on LS1tech and running a wire from this terminal to the battery or main power distribution block. looks like you need a metri-pack 150 series female terminal (20-18ga) to add the wire in the Holley connector.
Nope, the holley alt harness just gets wired to a 12v ignition source. I run mine to a distribution block/fused terminal block from Blue Sea brand.
I built the ECU in 2012 originally when I was running HEI and an SBC, so I didn't opt for the MS3 at the time.
I did however figure out my issue, after hours and hours and hours of troubleshooting. I had the trigger input capture set to Rising Edge instead of Falling Edge. This was causing misfires on RPM changes, and was late by about 6 degrees.
Once I changed the input capture, everything is great! This turbo is pretty awesome by the way. It spools at 2/3 throttle. I did a hard throttle pull, not wide open, and it made 5psi at 3200 rpm. Once I have the fuel map dialed in I'll do some hard pulls.
I'm also going to see if I can get it on my buddies dyno.
I'm actually running the Holley alternator harness, that's how I got my LS alternator to turn on with the MS2. MS3 supports the PWM alternators (DR36, DR44) but not MS2 so I went with an early LS alternator and the holley resistor harness/wire.
I'm idling around 38-40kpa at 800 RPM with that cam. Is that consistent with what you are seeing on the C3? It seems like a great street cam, especially with the 5 speed.
Speaking of IAC, I was having some issues with the throttle follower that I couldn't safely tune out. When you do a little throttle in blip it will sometimes add like 100 steps to the IAC which results in the engine racing to 1700-2000RPM, which I felt was kind of dangers. I decided to disable closed loop idle control, and instead have a programmed table for warm up enrichment, cranking steps, and then once the coolant is hot I completely close the IAC. The 92mm throttle body with the screw backed all the way out idles around 800rpm. I may enable the "idle timing" table to keep the idle stable if needed but so far it seems to idle just fine on the minimum air that exists in the throttle body.
IAT on the street is about 93 degrees under boost when ambient was 65. My problem now is my aluminum elbow is heating up because it's right behind the radiator. I need to figure out some sort of heat shield or something to keep it from getting heat soaked. The actual intercooler itself is like 30 degrees cooler.
I need to build a PCV system next.
Great! Glad you got that figured out!
I told you the turbo is a beast. Light switch response and pulls hard. Mine starts coming online like right before 1/2 throttle.
At like 700-750rpm i'm around 47-19kpa in an image I found but it wasn't up to operating temp. I want to say I'm in the mid 40s.
IAC is weird, some of the cheaper TBs have some issues with IAC bc of how they are drilled. I would pay attention to hot restarts when your out and about. I had an issue which almost left me stranded with a hot restart with the fitech system due to the IAC being off somehow.
Can you move the intake plumbing out and away from behind the radiator? I've had good luck with these helping keep heat in pipes or heat away from pipes https://www.summitracing.com/parts/d...xoCbnoQAvD_BwE Mine runs in the trays or into the fender openings to keep it way from that radiator. You could also setup a small shot of water meth to knock that heat out.
glad to hear you got your main issue figured out - that's awesome!
when using the Holley alternator harness, are you guys adding a wire to the S terminal? i read about that on LS1tech and running a wire from this terminal to the battery or main power distribution block. looks like you need a metri-pack 150 series female terminal (20-18ga) to add the wire in the Holley connector.
thank you!
I connected it to the "charge indicator" wire from the c100 connector. Seems to work fine.
I told you the turbo is a beast. Light switch response and pulls hard. Mine starts coming online like right before 1/2 throttle.
At like 700-750rpm i'm around 47-19kpa in an image I found but it wasn't up to operating temp. I want to say I'm in the mid 40s.
IAC is weird, some of the cheaper TBs have some issues with IAC bc of how they are drilled. I would pay attention to hot restarts when your out and about. I had an issue which almost left me stranded with a hot restart with the fitech system due to the IAC being off somehow.
Can you move the intake plumbing out and away from behind the radiator? I've had good luck with these helping keep heat in pipes or heat away from pipes https://www.summitracing.com/parts/d...xoCbnoQAvD_BwE Mine runs in the trays or into the fender openings to keep it way from that radiator. You could also setup a small shot of water meth to knock that heat out.
Thank you. The IAC isn't so much an issue with the IAC itself or the TB, but rather the ECU commands absurd high number of steps which, I guess to your point, if it was a smaller TB it might have less impact on airflow, but from 0-100 steps almost have way open. it's a LOT of air.
There really is no moving the piping, I have an elbow right off the TB and into the intercooler. No room. I think I'm going to have to do some type of shielding. That shield is probably good for preventing burn through from exhaust, but I think in this case I literally need to insulate the pipe. I wonder if I can wrap it in 1/2" fiberglass or something.
This guy came up with this solution to the same problem:
Here is my routing:
The aluminum actually gets quite hot from the radiator heated air. I think I have enough room that I can wrap that pipe though.
Another thing I can do, I suppose I could bend up some metal over the top of the radiator and angled under the pipe as a shield.
Most of my fuel map is dialed in, except for boost. All the part throttle and cruise stuff is good.
Boost is pig rich, need to back the ve way off. Boost comes on pretty good though. So by 3600 rpm it makes 7psi. @customblackbird what are you seeing for boost at 3600 ?
Most of my fuel map is dialed in, except for boost. All the part throttle and cruise stuff is good.
Boost is pig rich, need to back the ve way off. Boost comes on pretty good though. So by 3600 rpm it makes 7psi. @customblackbird what are you seeing for boost at 3600 ?
Its not 7psi I'm pretty sure lol. My converter stalls around 3k so that's when I start to roll into boost usually but I would need to check a log and see. If I had to guess it was prob 3psi.
Its not 7psi I'm pretty sure lol. My converter stalls around 3k so that's when I start to roll into boost usually but I would need to check a log and see. If I had to guess it was prob 3psi.
Ahh. So I spent some time yesterday tuning the car. Still rich. It makes 7.5psi at 4200 when the tires break loose. Boost comes in around 2800. I'm curious at what RPM peak boost will be. I actually kinda thought it would make way more boost earlier.
After properly scaling my exhaust pressure sensor I was seeing 13 psi of back pressure when at 7psi of boost. Then it died. Now it's reporting 100 psi all the time. Guess that's what $15 gets.
I need to pull some more fuel out because it's hitting like 9.8 are in boost. But I guess I'm wondering if the wastegate is even going to be used. I have my booster target set to 14psi.
Ahh. So I spent some time yesterday tuning the car. Still rich. It makes 7.5psi at 4200 when the tires break loose. Boost comes in around 2800. I'm curious at what RPM peak boost will be. I actually kinda thought it would make way more boost earlier.
After properly scaling my exhaust pressure sensor I was seeing 13 psi of back pressure when at 7psi of boost. Then it died. Now it's reporting 100 psi all the time. Guess that's what $15 gets.
I need to pull some more fuel out because it's hitting like 9.8 are in boost. But I guess I'm wondering if the wastegate is even going to be used. I have my booster target set to 14psi.
Leaning it out and adding timing would help boost come in sooner/harder. 13psi of back pressure is lower than mine which was like 16psi at 7psi which is the benefit of 3.5" piping vs my 3".
What PSI does the gate start to open on the bench? Once you have that you will know that in the exhaust it will open sooner and with my truboost controller I had to know my cracking and open pressures for it to work correctly.
FWIW a billet 78/75 was just rolling into boost 0psi at 3700rpms. I know once mine starts to build boost it ramps up fast so you could be all in 1000rpms and when that's at WOT its like .25s. You also have to consider your probably slightly undercammed and could have used a stage 2 in the 220-230 range to light that guy off faster. I have had zero failures with the lowdollarmotorsport sensors so that's what I run. I did/do run the amazon for the backpressure bc of the heat and I don't care if it dies. I would get the tune sorted and see what it does. With the TermX you would have just floored it and let the 02 auto tune and then one click transferred the learned fuel tables to the tune and adjusted that like 4 times to get the correction less than 2-5%. 100% worth the money just in that.
Leaning it out and adding timing would help boost come in sooner/harder. 13psi of back pressure is lower than mine which was like 16psi at 7psi which is the benefit of 3.5" piping vs my 3".
What PSI does the gate start to open on the bench? Once you have that you will know that in the exhaust it will open sooner and with my truboost controller I had to know my cracking and open pressures for it to work correctly.
FWIW a billet 78/75 was just rolling into boost 0psi at 3700rpms. I know once mine starts to build boost it ramps up fast so you could be all in 1000rpms and when that's at WOT its like .25s. You also have to consider your probably slightly undercammed and could have used a stage 2 in the 220-230 range to light that guy off faster. I have had zero failures with the lowdollarmotorsport sensors so that's what I run. I did/do run the amazon for the backpressure bc of the heat and I don't care if it dies. I would get the tune sorted and see what it does. With the TermX you would have just floored it and let the 02 auto tune and then one click transferred the learned fuel tables to the tune and adjusted that like 4 times to get the correction less than 2-5%. 100% worth the money just in that.
I need to think about this more.
So, the valve opens when 8psi is supplied to the bottom port. I have the MAC valve hooked up so it should be supplying boost to both ports until boost target is met, so in theory, it should require 16lbs to overcome the spring.
However, the exhaust back pressure is going to also push on the valve and try to open it. So I would think it would be boost = (16 - backpressure) but that would only be 3psi.
Kinda makes me want to just buy one of those fancy electronic boost valves.
I really like this cam. I can just walk the clutch out from a light. I can cruise at 1200-1400 RPM in 4th gear and no surging or anything. I just need to be careful that I don't "get on it" unless I'm a bit above 2,000 rpm because I've been warned even gen4 rods like to bend at low rpm loads.
When I was young I used to be into radical hot cams with nasty idles. I'm getting older and less tolerant. I recently rebuilt the LT1 in my convertible and I used a small summit cam, 204/214 Dur., 112 LSA. Drives really nice, good idle. The CC-305 (220/230) in my LT1 C4 is difficult to leave a light with the 6 speed unless you spin the tires.
How does the auto tune work on the term X? I've always been nervous about using auto tune in boost. The way it works on Megasquirt is you have an AFR table you pre-define with what you want your target AFR to be:
Then you drive around with auto-tune enabled and it re-works your VE table:
You can create custom filters too to skip certain things, these are in the form of expressions. So for example you can write an expression like ((fuelload > 100) && (fuelload < 150) && (coolant > 120) && (rpm > 5200)) So then for example, if you had the max map (fuel load) set to 300kpa, but then you created this exception filter it would only auto tune between 100-150 kpa when coolant was above 120 and engine speed above 5200.
So, the valve opens when 8psi is supplied to the bottom port. I have the MAC valve hooked up so it should be supplying boost to both ports until boost target is met, so in theory, it should require 16lbs to overcome the spring.
However, the exhaust back pressure is going to also push on the valve and try to open it. So I would think it would be boost = (16 - backpressure) but that would only be 3psi.
Kinda makes me want to just buy one of those fancy electronic boost valves.
I really like this cam. I can just walk the clutch out from a light. I can cruise at 1200-1400 RPM in 4th gear and no surging or anything. I just need to be careful that I don't "get on it" unless I'm a bit above 2,000 rpm because I've been warned even gen4 rods like to bend at low rpm loads.
When I was young I used to be into radical hot cams with nasty idles. I'm getting older and less tolerant. I recently rebuilt the LT1 in my convertible and I used a small summit cam, 204/214 Dur., 112 LSA. Drives really nice, good idle. The CC-305 (220/230) in my LT1 C4 is difficult to leave a light with the 6 speed unless you spin the tires.
How does the auto tune work on the term X? I've always been nervous about using auto tune in boost. The way it works on Megasquirt is you have an AFR table you pre-define with what you want your target AFR to be:
Then you drive around with auto-tune enabled and it re-works your VE table:
You can create custom filters too to skip certain things, these are in the form of expressions. So for example you can write an expression like ((fuelload > 100) && (fuelload < 150) && (coolant > 120) && (rpm > 5200)) So then for example, if you had the max map (fuel load) set to 300kpa, but then you created this exception filter it would only auto tune between 100-150 kpa when coolant was above 120 and engine speed above 5200.
-- Joe
So that 8psi should be less than 8psi of boost because your adding exhaust back pressure which is trying to push that valve open as well. the top port is getting boost which could double the boost rating of the spring. Take the top port off and let it run normally with just the bottom hooked up. that will give you your base gate spring boost pressure. That pressure is what your adding to with the EBC and could be double of whatever that is. it might open at 6psi but pre turbo pressure and WG placement and WG valve size all affect the pressure and thus the open pressure. The backpressure isn't a 1;1 against the valve... there is a formula but on mine I was 12psi on the bench (with fire ring) and I was getting 6-8psi on the car. But its a big 60mm valve.
The summit stage 1 cam I agree is a nice little cam. Drives nice and smooth, I can cruise on the highway at 1300rpms with it. I would have liked to try the torkinator cam (maybe on my next build).
The termX is similar, you just plug in your timing and all that jazz and set your AFR for MAP and RPM. Then you drive the pi$$ out of it and it shows you learned table data which is fuel adjustments. Click the copy learned table data to VE or whatever and save changes. Do that a few times and and you will see less than 2-5% difference. Then you adjust the 02 sensor correction from 50/50 to 10/10 or 20/20 (percentage for fuel adjustment) and your all set. You don't want 50/50 on fuel in case the 02 takes dump and it can destroy your AFR and make the car undrivable. No formulas... just toggles to say fuel learn enable 140*F. I've done this with the TermX and Fitech and go into boost on my first drive no issues. Your system seems customizable which is nice but I just want mine to work and never touch it again unless I change something. I want to plug it in, set it up, drive the heck out of it and do a few touchups and enjoy the car. Basically the whole issue you had in the beginning wouldn't have happened bc the system doesn't support it lol. It does one thing essentially but does it well
You really shouldn't have hit 9.5:1 (maybe for a sec) as the WB02 should be calling to lean it out. Once it noticed you were rich it should leaned it out and kept leaning it out till was closer to commanded AFR. A few days, conditions and cool/heat cycles with lots of different driving styles/scenarios and you should be all set
Last edited by customblackbird; 04-22-2024 at 03:25 PM.
So that 8psi should be less than 8psi of boost because your adding exhaust back pressure which is trying to push that valve open as well. the top port is getting boost which could double the boost rating of the spring. Take the top port off and let it run normally with just the bottom hooked up. that will give you your base gate spring boost pressure. That pressure is what your adding to with the EBC and could be double of whatever that is. it might open at 6psi but pre turbo pressure and WG placement and WG valve size all affect the pressure and thus the open pressure. The backpressure isn't a 1;1 against the valve... there is a formula but on mine I was 12psi on the bench (with fire ring) and I was getting 6-8psi on the car. But its a big 60mm valve.
So as I was tuning I did a lot of testing yesterday. It was running just about 8 psi (7.8) from about 3600 all the way up to 5400 RPM once I had the fuel dialed in a little better. So I went back to the shop and started testing the mac valve and I found it wasn't opening. So I was running the whole time just off the spring. Took the ECU apart, ohmed out the boost control circuit (made up of a transistor, a couple resistors connected to a CPU pin) and all checked out. Did a continuity test on the harness and the signal wire was dead. Followed it through, bad crimp..
So now the MAC valve works properly. I'll need to do some more road testing now.
Originally Posted by customblackbird
The summit stage 1 cam I agree is a nice little cam. Drives nice and smooth, I can cruise on the highway at 1300rpms with it. I would have liked to try the torkinator cam (maybe on my next build).
The termX is similar, you just plug in your timing and all that jazz and set your AFR for MAP and RPM. Then you drive the pi$$ out of it and it shows you learned table data which is fuel adjustments. Click the copy learned table data to VE or whatever and save changes. Do that a few times and and you will see less than 2-5% difference. Then you adjust the 02 sensor correction from 50/50 to 10/10 or 20/20 (percentage for fuel adjustment) and your all set. You don't want 50/50 on fuel in case the 02 takes dump and it can destroy your AFR and make the car undrivable. No formulas... just toggles to say fuel learn enable 140*F. I've done this with the TermX and Fitech and go into boost on my first drive no issues. Your system seems customizable which is nice but I just want mine to work and never touch it again unless I change something. I want to plug it in, set it up, drive the heck out of it and do a few touchups and enjoy the car. Basically the whole issue you had in the beginning wouldn't have happened bc the system doesn't support it lol. It does one thing essentially but does it well
You really shouldn't have hit 9.5:1 (maybe for a sec) as the WB02 should be calling to lean it out. Once it noticed you were rich it should leaned it out and kept leaning it out till was closer to commanded AFR. A few days, conditions and cool/heat cycles with lots of different driving styles/scenarios and you should be all set
So, a couple things. I have/had EGO / wb02 control disabled while I was tuning, but even then, I have the limit set to 100kpa because I don't want it correcting under boost. There may be nothing wrong with it, but I've always had people tell me when a WB craps out it usually reads way rich not lean, so if it fails under boost and the ECU pulls fuel boom. Especially since I don't run knock sensors.
Now that I have the base map under 100kpa dialed in pretty good, I have EGO control enabled. The only real area I see correction now is my overrun (aka DFCO on stock ecu, not sure what holley calls it).
I do have an issue with fuel pressure, probably caused by a combination of the way I modified the fuel rails and the fact that I'm firing all four injectors on each rail at the same time. My fuel pressure jumps 3-5psi between injection firing events. Both my mechanical gauge and my log show it, so after doing some reading I ordered a Holley 12-1006 fuel pulse dampener. I'm going to give that a try when it comes in next week to see if it will stabilize the fuel pressure in the rails.
Still a little rich, but I've got the MAC valve working properly now. 13.1 psi by 3200 I think is pretty good .
That's what my boost control is set to currently. I'll probably eventually adjust it to max out at 195kpa. I think the max a GM 2bar map can read is 200kpa so.
Still a little rich, but I've got the MAC valve working properly now. 13.1 psi by 3200 I think is pretty good .
That's what my boost control is set to currently. I'll probably eventually adjust it to max out at 195kpa. I think the max a GM 2bar map can read is 200kpa so.
-- Joe
13lbs by 3200 is darn good lol. That’s a lot of rod bending tq so be careful. I’m def not even close to that at 3200.
why not do the ls9 MAP which is 2.5bar… gives you an extra 7psi over a 2 bar setup. 2 bar isn’t really enough as you will be cranking that up as you get some more street time.
13lbs by 3200 is darn good lol. That’s a lot of rod bending tq so be careful. I’m def not even close to that at 3200.
why not do the ls9 MAP which is 2.5bar… gives you an extra 7psi over a 2 bar setup. 2 bar isn’t really enough as you will be cranking that up as you get some more street time.
I tried the Holley version and it won't fit. The hole on the ls2 intake is smaller. You can't drill it out because the plastic is super thin.
My buddy warned me about the rods. Even though my gen 4 rods are supposedly stronger, he said stay out of boost under 2k.
Still surprised it's rich at 106ve but I even replaced the wide and to be sure. Guess I'll keep pulling fuel.
I tried the Holley version and it won't fit. The hole on the ls2 intake is smaller. You can't drill it out because the plastic is super thin.
My buddy warned me about the rods. Even though my gen 4 rods are supposedly stronger, he said stay out of boost under 2k.
Still surprised it's rich at 106ve but I even replaced the wide and to be sure. Guess I'll keep pulling fuel.
prob the same as the ls1. I drilled out the map hole for the LS9 on the NNbS intake and it works fine. Otherwise leave it as a plug and run a block and a hose to a 3 bar. Or tap the stock hole for a hose and run a 3 bar.
having seen gen 3 and gen 4 rods (in two diff motors I have) there is a big difference in size of the gen 4 rods. I heard the gen 4s will give you more rpm but if im
not going fast enough by 6500rpms then I don’t need to rev any higher.
what injectors are your running again?
sounds like it’s running good tho and u got most of the issues ironed out.
prob the same as the ls1. I drilled out the map hole for the LS9 on the NNbS intake and it works fine. Otherwise leave it as a plug and run a block and a hose to a 3 bar. Or tap the stock hole for a hose and run a 3 bar.
having seen gen 3 and gen 4 rods (in two diff motors I have) there is a big difference in size of the gen 4 rods. I heard the gen 4s will give you more rpm but if im
not going fast enough by 6500rpms then I don’t need to rev any higher.
what injectors are your running again?
sounds like it’s running good tho and u got most of the issues ironed out.
I had read of people drilling the TBSS intakes so I figured I could drill the LS2, but when I looked at it the MAP port is an inverted nipple, and the thickness is that of a piece of paper. I think if I sent a drill be down it would disappear completely.
I could run a 2.5 or 3 bar off my vac block on the firewall, which I have considered down the road. At the same time, I'm not sure how much boost is reasonable on a 5.3 with pump gas. I keep seeing the 14:14 rule for 5.3's with stock rotating assemblies, plus, my LC9 is 10:1 compression. Most iron 5.3's are 9.6:1 I think. The LC9 has flat top pistons.
I'm running Bosch 4 #0280158205, which have been decapped. They flow about 72.5lb at 43.5psi.
I installed the Holley pulse damper on the feed rail. It may have been a waste of $140 or maybe not. I still have the needle bounce on the fuel gauge with injection events, but under boost my fuel pressure seems stable on an upward trend.
I had read of people drilling the TBSS intakes so I figured I could drill the LS2, but when I looked at it the MAP port is an inverted nipple, and the thickness is that of a piece of paper. I think if I sent a drill be down it would disappear completely.
I could run a 2.5 or 3 bar off my vac block on the firewall, which I have considered down the road. At the same time, I'm not sure how much boost is reasonable on a 5.3 with pump gas. I keep seeing the 14:14 rule for 5.3's with stock rotating assemblies, plus, my LC9 is 10:1 compression. Most iron 5.3's are 9.6:1 I think. The LC9 has flat top pistons.
I'm running Bosch 4 #0280158205, which have been decapped. They flow about 72.5lb at 43.5psi.
I installed the Holley pulse damper on the feed rail. It may have been a waste of $140 or maybe not. I still have the needle bounce on the fuel gauge with injection events, but under boost my fuel pressure seems stable on an upward trend.
-- Joe
Then I would just leave it, plug it with a stock sensor and run a remote MAP. Its up to you on the boost but I would tell you its always better to have more sensor so you can tune it if its an overboost situation. I've been up to 16-17psi on my stock 5.3 with gen 3 rods but I'm running slightly decked heads and stock GM LS1 MLS gaskets and don't go above 6500. Makes me think I'm prob closer to 10:1 but when I had the centri supercharger I was making 2psi at like 1300rpms in Overdrive and the rods survived. That 10.1 is on pump 93 but also spraying a bit of wiper fluid. Depending on your IATs you could probably do a little more boost like 15psi and be ok. I'm sure Batch fire doesn't help either on the fuel side. Isn't the LC9 an aluminum block too? 73lb at 43.5 psi is pretty good that's basically a 80lb injector at 58psi so on pump you should be good for way more 800hp or so. 800hp on your combo would prob be closer to 20psi boost.
On my truboost setting A I'm at 13psi for the street and setting B puts me at 15-16psi which I don't use much. 13psi on the street is more than enough to have fun and as you have learned traction will be your biggest issue. I would put in a 2.5 bar MAP, leave the boost at 13psi and then invest in better rear tires likely drag radials (MT streets) and see if you can get traction, then up the boost if you need it.
Then I would just leave it, plug it with a stock sensor and run a remote MAP. Its up to you on the boost but I would tell you its always better to have more sensor so you can tune it if its an overboost situation. I've been up to 16-17psi on my stock 5.3 with gen 3 rods but I'm running slightly decked heads and stock GM LS1 MLS gaskets and don't go above 6500. Makes me think I'm prob closer to 10:1 but when I had the centri supercharger I was making 2psi at like 1300rpms in Overdrive and the rods survived. That 10.1 is on pump 93 but also spraying a bit of wiper fluid. Depending on your IATs you could probably do a little more boost like 15psi and be ok. I'm sure Batch fire doesn't help either on the fuel side. Isn't the LC9 an aluminum block too? 73lb at 43.5 psi is pretty good that's basically a 80lb injector at 58psi so on pump you should be good for way more 800hp or so. 800hp on your combo would prob be closer to 20psi boost.
On my truboost setting A I'm at 13psi for the street and setting B puts me at 15-16psi which I don't use much. 13psi on the street is more than enough to have fun and as you have learned traction will be your biggest issue. I would put in a 2.5 bar MAP, leave the boost at 13psi and then invest in better rear tires likely drag radials (MT streets) and see if you can get traction, then up the boost if you need it.
The LC9 is an aluminum block.
I meant to mention, I'm still a little fuzzy on the exhaust backpressure. My transducer came back to life, but then it started reading weird (like 15psi at idle). I think maybe it is pooched. I'll probably buy another one and do another short pull to see what the pressure ratio is.
Once I got the MAC valve working properly, I do think it's kinda cool how it works. On the 8lb spring I see just under 8psi boost. With the ECU commanding the valve open it holds my target boost of 13psi steady.
Another thing I can do, my ECU has 2 map inputs. I could run the engine off the 2 bar and run boost control off a remote 2.5. That would keep the part throttle resolution decent.
Some people actually do table switching (not sure if holley does that?) Where you run 0-100kpa off a 1 bar map on a 16x16 table, and then have another 16x16 table on a 3 bar map sensor for boost. I can't imagine needing that much resolution when in boost but for some cars having more off boost resolution is helpful.
I meant to mention, I'm still a little fuzzy on the exhaust backpressure. My transducer came back to life, but then it started reading weird (like 15psi at idle). I think maybe it is pooched. I'll probably buy another one and do another short pull to see what the pressure ratio is.
Once I got the MAC valve working properly, I do think it's kinda cool how it works. On the 8lb spring I see just under 8psi boost. With the ECU commanding the valve open it holds my target boost of 13psi steady.
Another thing I can do, my ECU has 2 map inputs. I could run the engine off the 2 bar and run boost control off a remote 2.5. That would keep the part throttle resolution decent.
Some people actually do table switching (not sure if holley does that?) Where you run 0-100kpa off a 1 bar map on a 16x16 table, and then have another 16x16 table on a 3 bar map sensor for boost. I can't imagine needing that much resolution when in boost but for some cars having more off boost resolution is helpful.
Nice, thats 100lbs of savings in the block alone! I always wanted to find a LC9 shortblock and build a motor out of out it.
Yes, I'd say your transducer is F'd. Get a new one and see what it reads. I believe the lowdollarmotorsports ones are like $35 or so. It's pretty great to just push a button and adjust the boost and if it fails it should revert back to spring boost which is safer then having a high lb spring in there.
I wouldn't worry about the resolution lol. If you saw how much resolution Fitech had you would be like how did that even run. You can't do multiple tables in the Term X but you can scale the table however you want to customize the resolution. So I could take a 16x16 and dedicate 10 to NA and the 6 for boost. I didn't do that but honestly the car drives fine on the street/cruising and does what I need it to under boost.
02-20-2024, 10:11 AM
