ziggy89

allright guys heres the deal. im to fast for one class but not as fast as i want to be for another class and 12.5's would put me right where i want o be.

right now im runing 13.0 very consistantly.

motor is a 383 stroker
eagle rotating assembly, cast crank, i beam rods, speed pro hyper pistons
286 h cam .490/.490 lift 236/236 duration at 050
edlebrock performer rpm intake
holly 770 street avenger
dart iron eagle heads 2.02/160 valves with 180cc intake runners
headman shorty headers and y pipe into flowmaster 3inch


now here is what i have planned
ive got a set of hooker super comps and a mufflex y pipe that im goin to modify with cutouts for the track.

i might throw in a set of 1.6 rockers to help it breath a little better

i went from stock tires to 28inch drag radials wich lowered my rpm so im goin to go from 4.11's to 4.30's

so what do you guys think will letting it breath a little better and giving it some more gear get me to or close to my goals. im open to sugestions too so let me know.

thnx
zig

sofakingdom

iTrader: (1)

What's the rest of the car? (gears, converter, etc.)

ziggy89

built 700r4 with a 2800 stall, 9 inch with 4.11's and a detroit locker. spohn adjustable torque arm, lower controll arms and panhard bar.
all other suspension componets are stock. it still sees street time so its got full interior and weighs in at 3700 with me in. might put a fiberglass hood on it to cut some nose weight.

Brando5641

iTrader: (-1)

Bigger Stall Bigger Cam

SDTransAM

iTrader: (5)

Only running 13's with that setup? That don't seem right. Bigger cam and do some tuning.

Irockz

iTrader: (1)

Make your changes one or two at a time.If it doesn't respond like you want after making many changes at once,you'll have no idea what helped and what didn't.

ziggy89

yeah i seam to hear that a lot for some reason but i think its from running everything through that tiny 2.5inch y pipe. just my thoughts.

i could change the stall that wouldnt bother me for street driving since it has a lock up converter. the cam id like to keep because i only turn it justt over 6k and its making and its good on the street too.

what do you guys think about my heads. does a 180cc intake have enough flow to feed a 383 in the upper end? been looking at AFR elimators.

Orr89RocZ

iTrader: (20)

Those heads are kinda small for a 383 trying to go to 6K rpm and higher. 195 cc minimum. A better head with abit more flow and better port shape will pick up alot more power over iron eagles.

You have more than enough intake manifold to go mid 12's. You have more than enough tire to hook and run mid 12's. Combo does seem to have alot of gear for the setup with such a low converter. Peak torque should be in the mid high 3000 range on your setup, maybe 4000 rpm and should hold pretty flat. I'd bump stall up alittle more, 3500-3600 ish would be nice. Get those 60 foots down. Thats where most ET is made

Like said above, that setup should be much faster than 13.0's even with 3700lbs

gp90gta

iTrader: (1)

I agree you need better heads and I would go with a custom cam, I run 12.90's with my stock bottom end 350 and my car with me in it is 3808lbs, I'd step up to a set of 195's and at least a 3200 stall.

ziggy89

well i think you guys just justified new heads for me and it looks like this freshin up just got a little expensive lol.

1gary

I like the RHS heads with 195CC's.The thing to consider while shopping heads is it isn't the runner CC's as much as it is the cross section that make a good head or not.

The cheapest way to go fast is a wt reduction.Glass truck lid/hood,remove the rear seat,etc all matters.It used to be said 100lbs is = to 10hp.

Orr89RocZ

iTrader: (20)

Figure you want to run 12.5's consistantly...that means you need to run 12.5's in the worse case scenario air conditions and then detune when cold air hits to keep it a 12.5 car. Thats fairly easy to do, but when you run 12.5's in the cold and hot air keeps you back in the 12.7's....then you are stuck there with no way to increase power.

Profiler 195's, some RHS castings are decent especialy if cleaned up by a head porter like Dr J's or Chad Speier or similar. I know they both have developed some heads using RHS castings. I own a set for my new combo. AFR 195's will support a 383 to 6K but a decent cammed 195cc head 383 should be running mid high 11's, not mid 12's. SO its overkill.

Its quite possible your heads will support a 12.5, heck my stock L98 heads supported 12.90s with stock cam! I would definately think they should. You could try better cam and stall, work on tune and launch to see what it gives you before running new heads. I'd maximize what you have now and see what that gives you.

1gary

Good post Orr.The thing is the amount of flow bench R & D is key to duplication port to port,side to side so you can build a program for a 5 probe CNC porting.To have a guy just go in there with a die grinder is a pretty bad solution.It might be the single reason why people need to go to a head manufacture like RHS that is large enough to afford the costs of the R & D.It doesn't take much to have mismatched heads/ports.So the msg is the term porting can and does mean many different things.And of course the top haft of SBC's is critical and normally not cheap.

So here is a link with a number of articles from industry leaders.I suggest you bookmark it and read a article as you have time.They are all good reads.

http://www.enginebuildermag.com/Sear...chTerm=porting

five7kid

iTrader: (14)

I'd say lose the vacuum secondary carb (get a double pumper, in case you're wondering - 650 should be enough), get more stall, and get a dyno tune. Long tube Hedmans would probably help as well. You should be at your goal with the engine you've got (although an XE cam would probably work better as well).

Something to think about: Read about my Berlinetta #1 in my vBGarage. Its best pass at a lower elevation (like you have in Iowa) was at about 55 degrees (although the humidity was very high). Now add that .2 sec mentioned above for hot temps. And, it weighs 3450 going down the track, so add another .25 sec for your weight.

I've been using Hoosier Quicktime Pro DOT rears for several years (on the track only - I drive to the track on highway radials). These are 26-9.5x14's. This is the launch from that best pass (I call the car "Ugly Betty" - paint don't make it go faster or more consistently):




(FWIW, I drove the car to work today, like I did last week, and I'll do tomorrow.)

1gary

I know this is the engine section,but all the foot brake racing isn't consistent.Sooooooo,a convertor,glide,brake,is going to fix that.And instead of flashing a stall,you'er going to leave on a consistent rpm all the time at a torque curve that is repeatable.

Orr89RocZ

iTrader: (20)

I've always ran faster when footbraking as high as the converter would let me before the car either spins the tires or pushes thru the brakes.... Doesnt matter what car I'm in or what combo, it always ran quicker 60's doing it that way. My 99 LS1 car did it, my bolt on L98 did it with 2800 stall, my 383 motor with 3600 stall, and my 401 with 4000+ stall, but the turbo car starts to get near boost the higher you brake stall so the torque curve jumps even higher than n/a.

five7kid

iTrader: (14)

I run a 2-step foot braking.

ziggy89

i dont mind the foot breaking part i usually cut pretty good lights and make other play the top end. i just dont want to be the super slow guy in the class. class is 11.5 to 13.49. my problem is most of the class runs 11.50 to 12.0 i just want to narrow the gap for the top end game.

1gary

Me on a button cuts like a knife.And of course I had come from a foot brake background.

ziggy89

well if they made a reliable brake for a 700 id probably do it but i cant justify giving up my overdrive for a brake when i still drive it on the street and not just in town

Orr89RocZ

iTrader: (20)

If you do it right, theres no reason why a foot brake car cant be consistent.

My 99 TA with the 3200 stall, would CONSISTENTLY run 8.22's in the summer...1/8 mile that is. With stock converter it was soo simple and super consistent 8.5's

Cold air at the 1/4 mile, it was running pretty consistent 12.3's. Keeping it simple eliminates alot of variables. Stock converter is stupid easy to drive. Mash off the line and doesnt spin even on street tires. Consistent 60 foots. 3200 stall seems to have abit more variance since the foot brake RPM sometimes fluctuates. As long as I cut a decent R/T, I know the car will repeat ET

1gary

The mechanical release of foot brakes can't match the release of a trans brake.I did say a glide because of fewer shifts and less wt too.Being able to launch at the same RPM and bring it to the stall will and does lower 60' times.I guess I should have asked how many guys have driven a trans brake and for how long??.

1gary

But in all fairness,can you run 12.5's on a foot brake??. You surely can.But then you run across a mid 60's yr old racer like me and your getting tree'ed week after week.You kind of get tired of that quick.

The suggestion here is any advantage in drag racing that most don't have is one you should take and the brake,glide,convertor,is a proven system widely used.Oh-I almost forgot the glides don't eat up as much torque because of less rotating internal wt.

five7kid

iTrader: (14)

A tranny brake is an advantage. In fact, I run in several classes that don't allow them for that reason.

On the other hand, I also run in classes that do allow them. Not running one probably meant I finished 3rd in that one tranny-brake-allowed class in 2009 (out of about 120 racers) instead of 1st (the two who finished ahead of me and the three behind me all run tranny brakes). But, in '10, I finished 1st in a class that allows tranny brakes and delay boxes (only about 80 racers in that class, though).

I would consider 12.5 ET's a "street car" class, driven to the track. In the street-type classes I run, they allow ET's down to 10.50 (10.00 in a couple of them). With DOT tires and mufflers, but no tranny brakes.

If you're going to run a 'Glide with tranny brake, I would also expect weight reduction, 6-point, mini-tubs, and at least 10's. But, I suppose I'm a bit of a street/strip snob, so do what you like.

Orr89RocZ

iTrader: (20)

Not debating the mechanical advantage t-brakes have Just saying you can cut good lights with a foot brake if you can drive and have good reaction timing. Just gotta practice.

ziggy89

i agree 12.5 should be a street class and it is and most of the surrounding tracks. (sportsman) however the closest track by over an hour has the street class stop at 13.5 and for and extra 10 bucks i might as well race for cash and try to get some return for playing there.

ziggy89

one more thing i was doin the math with the performance calculators on here with a 3500 stall my 1-2 shift will drop me below stall i know it shouldnt be hard on the converter but what will it do for my consistancy?

five7kid

iTrader: (14)

How can a shift drop you below your stall RPMs?

Orr89RocZ

iTrader: (20)

Theoretical rpm of engine can drop below stall speed if you calculate the mph of the shift, tire size and get an RPM for that point, but the stall will just slip to bring engine rpm to stall level and the rear tires will just play catch up til it matches the stall rpm and then starts pulling again.

My car did this with a 5500 stall converter and 2.73 gears. Turbo setup, I'd go WOT and the engine rpm would just sit at 5500 rpm the entire pass until I was going fast enough mph-wise to allow motor to go above stall rpm.

Same thing on the dyno.. converter would flash, motor would sit at 5500 rpm while dyno roller spun faster and faster and faster til I hit something over 140mph and then required the motor to spin higher. Converter just slips more at a lower tire speed til it all catches up.

ziggy89

i ment theoriticaly. i was jus wondering if if slipping the converter for a bit would make it inconsistant

89irocconvt

I run 12.7 @ 108 mph with mild 383 cheap votec heads old flat tappet 327 350hp cam old 750 vac secondary carb 3.73 10 bolt through single cat exhaust and a 700r4 i picked up on craigslist and cheap 2800 stall from ebay. you could maybe pick up a few tenths by leaning it out a bit or stepping up the timing. just be careful with detonation.

articwhiteZ

iTrader: (56)

and remember.. most of the Guys are sandbagging.
most of the cars that run mid 11 are mid 10 sec cars at my track.
some faster. i always ran in the mid 11 (11.70) just stomp the Gas!
but with the bottel in 2nd and 3rd only was mid 10.54.

you will always want to go faster! Trust Me

and we all drive them to the track.