91_B4C_RS

1991 Camaro388 stroker 10.5:1 comp. Dart ironeagle heads 215cc. Victor jr intake. 850 profotm carbon box jetting. .606 /. 6 06 lift 108 las 300 deg
rees duration.

Th400 with transbrake 3600 stall. True stall on the transbrake is 4000rpm

Ford 9 inch Moser 4.11 gears locker diff

26x11.5x16 et streets bias ply ran 13-15 psi

Lakewood 90/10 up front with morosso sbc trick springs
Lakewood 50/50 in rear with v6 springs


Umi. Crossmember mounted torque arm highest mounting location on crossmember. pinion angle -3

Car is full weight

Best pass was leaving at 4000 rpm ran 11.86 @ 116 mph in with a 1.750 60 foot no tire spin shifting at 6600 rpm

pancherj

Do you have all the incrementals from that pass? What was the DA? You are shifting at 6600, but what are you crossing the stripe at? What is your timing setup? Any videos of the pass (I'd like to see how the suspension reacts)?

91_B4C_RS

1.750 60'

7.669 1/8 Th @ 92 mph

10.992 1000' or 9.996 can't remember

11.862 1/4 @ 116. 04

That's all I have off the top of ny head

Crossing the line at roughly 6000 rpm.

Ran best locked down timing at 38deg


Here's a vid from a 11.97 run

http://video.l3.fbcdn.net/cfs-l3-snc...9afb541b366752

91_B4C_RS

1.750 60'

7.669 1/8 Th @ 92 mph

10.992 1000' or 9.992 can't remember

11.862 1/4 @ 116. 04

That's all I have off the top of ny head

Crossing the line at roughly 6000 rpm.

Ran best locked down timing at 38deg


Here's a vid from a 11.97 run

http://video.l3.fbcdn.net/cfs-l3-snc...9afb541b366752

xpndbl3

iTrader: (5)

duration at .050 for that cam?


How do you know there was no tire spin? Paint a white stripe on the slick and make a run, your 60' is really soggy, motor bogging? Or not enough stall?

jbenge

iTrader: (2)

I've seen your car run a few times, I'm from Danville. Its nice to see another thirdgen out there! Your car doesn't seem to hit the tires hard at all. Are you flooring it or easing into it? Just wondering if its a lean condition on the initial hit or if its a suspension or converter issue.

Do you use the transbrake all the time or do you normally footbrake? Either way you may want to experiment with different launch RPM. Every combo likes something different.

Do you still have the front sway bar on? If so you may want to take it off.

I also think you could benefit from a higher stall converter, although I think you should be at a lower 60' with what you have already. What size and brand is the converter?

Do you have LCA relocation brackets? If not you might want to get those too.

GSRacing

ok so after watching the video enlarging it on my mac and slowing it down the car dose spin you need to get rid of the et streets and switch to the new style drag radial i run the 275 60's on my car i am 60'ft 1.63 and running 12 flat @113 i am also gonna suggest if you switch to these tires you need to run about 18-20 psi in them you may wanna try that with your current tires i also have 373 gears not sure what kinda diff thats gonna make down low .... i am gonna watch the vid a couple more times and see what i can pick up

skinny z

.

DIGGLER

iTrader: (1)

i do not agree with the drag radial suggestion. the et streets would tend to be more forgiving on the typical car.

91_B4C_RS

xpndbl3 cam duration is 287 / 295 advertised 110 lsa cant find cam card. think it is at parents house. rpm does dip down after i launch then comes back up. i think i need more converter

jbenge i do have a off idle hestitation if i stab it off throttle. messed with it for a whille and never could get it to go away. never have the problem leaving the line. ive left off the brake everytime foot to the floor this year so far. my best result was leaving at full stall which is 4000 rpm with the two step off. tried different rpm from 2700 to 4000 rpm. might try foot brake a couple times next time out.

no front sway bar

converter is a 10 inch big end performance with anti ballon plate

no lca reloc brackets just though of that today. forgot that the moser i put in didnt have them.

Gsracing now that i slow it down i do see them spin thanks for the observation


what kinda pressures should i be running in these et streets?

jbenge

iTrader: (2)

When I ran ET streets, they liked about 15-16lbs. I would start around 17lbs and work your way down.

It sounds like you may have a carb issue, I had a very similar combo to yours about 3-4 years ago with a proform 750 carb. I had to put a lot of time into tuning the carb before I got it right...lots of trial and error. I had to change accelerator pump cams, drill holes in the throttle blades, and put larger squirters in before it ran well. I ended up selling that carb and getting a pro-systems carb built and picked up another tenth from it. Once you get your carb tuned well you should be able to floor it from idle with no stumble or hesitation. I would start with some carb tuning and see where you are after that. Then look at the converter depending on how it reacts after the carb tuning.

It will be interesting to see how your car reacts to footbraking too.

91_B4C_RS

Thanks for the info guys. Gonna weld on some Lca brackets and mess with the carb. a lil before I go back to the track. I got the carb set at factory settings from preform with the power valve.

My question is should I just plug the power valve or continue to use it?

xpndbl3

iTrader: (5)

leave it, you might need bigger squirters up front and play with pump cams here or there

pancherj

I have the same tires, 4.10 gears, same stall speed (but in a 700R4) and I ran almost identical to you. However, I am shifting at 6800 and crossing the line at 6600. This is in a 350, not a 383. It just seems odd that our ET, MPH, tires and gears would be the same and our finish line RPM would be so different. Is the car laying over on the top end?

ihatemustangs

iTrader: (3)

I pretty much have the same motor and am pulling about 1.41's on pretty much the same setup, but no trans brake. I have a 3600 stall, its stalls nice but isn't flashy. I had a problem like yours in a another car and the converter was wrong. I was too loose and I couldn't get the car of the line right. I have been using trans specialties. Fast 383 on here works for them. That car should be def in the low 1.4's, and I never used control arm relocation brackets or a drag bar. I was taught that some converters need big power to tighten up fast enough, or that hit of nitrous. Just thought I would pass it on, good luck!

ihatemustangs

iTrader: (3)

Try flashing the converter of the launch, no brake and see if comes out any harder.

DIGGLER

iTrader: (1)

more info on ur combo?

ihatemustangs

iTrader: (3)

91 Z28, 383 h-beam with all 4340 intrenals, Dart Pro'1 215's, 11.5 to 1, cam was a comp solid roller, (don't have the card in font of me, I had it custom made and I at work), .612i .618E with around 318 duration, vicotr jr, Holley hp 830, Trans Specialties th400 with brake, 3600 stall, stock rear with 4.10 and axles, aeromotive fuel system, lakewood arms and panhard bar, umi torque arm, rear 50/50's, front 90/10's with stock springs, 6pt cage , 3200#'s empty, electric fans, water pump and manual steering. I ran 28/11.50/15 et street and was in the high 1.4's with 22lbs of air in them. I have owned a ton of 3rd gens, built alot of cars for people, and we never had too much of a problem with hooking these cars. Hope any info I got can help ya's out. Building a big single turbo car now and gonna running all spohn stuff, drag bar etc. I do drive these on the street and they will fully function on and off the track. Good Luck!

DIGGLER

iTrader: (1)

1.41 60's with that combo is super good. nice job! what does the rest of the timeslip look like?

mw66nova

iTrader: (13)

while i could see converter being a posible issue, i think these two are more related than you might think.

ihatemustangs

iTrader: (3)

Thanks, let me see if I can dig one of the slips up. I start simple and go from there.

91_B4C_RS

I have #33 squirter on front and back

jbenge

iTrader: (2)

I think I had to go to a #37 or #40 squirter when I tuned my carb. Its been awhile now, can't remember for sure.

mw66nova

iTrader: (13)

yeah, you'll have to play with squirter size to get that right

brandoz28

iTrader: (1)

excuse my ignorance.......


but if the engine is already at WOT on the brake, is the pump shot from the squirters going to make a big difference? i know it makes a big difference in the footbrake stuff

mw66nova

iTrader: (13)

not necessarily, but jet size can dictate how well it works at the hit too. i'd try adjusting that too.

brandoz28

iTrader: (1)

i would think that would have a bigger affect if you're already WFO on a trans brake

RWB____s

would engine vacuum and power valve opening at wide open throttle on the Tbrake be different than WOT rolling because of the difference in engine load ? Just curious

mw66nova

iTrader: (13)

that's what i was trying to convey, that at WOT, jetting seems to have a lot of effect on how the car reacts when you let go of the tbrake. i know i keep adding jet size and the car keeps going faster to the 60' lol. tuning is never over i feel, lol!

brandoz28

iTrader: (1)

you know that's half the fun of a car like that lol.

greezemonkey

iTrader: (14)

Just my 2 cent, the 850 may be too much for the 388 with a tighter converter, smallish cam, even with that gear and small tire, I`d try upping the squirter too and tune the jets by MPH but a 750 would run harder at the launch, make more torque thus increase the stall slightly. the LCARB`s will help. I never had good luck with the comp 3 ways, I always had separation, 10 way qa1`s were a huge leap forward for me. I`m guessing about 7%, slip at the 6600 rpm which isnt too terrible with the gearing you have, with 116 mph though, your down about 2 tenths IMO and your slip numbers tell me you can pick up in the low and mid track area. 1 tenth in the 60 will get you 2 down at the stripe. may have been asked or mentioned but is the cam solid/hyd/ or roller?

91_B4C_RS

Solid roller cam.I am jetted 76/84.

mw66nova

iTrader: (13)

hmm...seems kinda smallish, but then again, every combo likes something different. how do the plugs look? what i suggest is making a test hit just like you are, then jet up two sizes and see how things improve. then keep jetting up two, till you stop seeing increases in mph and decreases in et/60' times.

greezemonkey

iTrader: (14)

what do have for a fuel system too?

brandoz28

iTrader: (1)

76/84 sounds smallish to me too, that's around what we run in my friend's car that's just a vortec headed 350.

91_B4C_RS

Procomp 140gph.similar to the holley black I believe. Holley regulator regulated to 7psi.

What you guys think about jetting?

mw66nova

iTrader: (13)

greezemonkey

iTrader: (14)

I think I would raise the stall speed, the launch is killing the ET- it`s sitting at a flat RPM too long where it`s not making peak power

91_B4C_RS

Update.. got the hesitation taken out of it. Had to drill out my squirter to. 039" and mess with the pump cam on the secondaries. Actually took the cam off and flipped it over backwards to get a more aggressive ramp.

xpndbl3

iTrader: (5)

you can't go larger than .035 on a 30cc pump shot really, larger than that and the shot is already flowing at maximum. That tight converter might be making the hesistation more apparent.

Fast 383

iTrader: (2)

Sorry if I mis a few things here I kind of skimmed the thread.


First off, Its a 350 stroker motor with 10.5 CR and a fairly mild cam. It's probably got a 475hp-500hp at best. The heads are big (215cc) and the carb seems big IMO. It probably doesnt have a good range of torque at all. Not to mention the T-400 and 9 inch rear.
I would suspect this car with the magic 60ft is capable of a 11.60, maybe a .50 figuring 3300-3500lbs. So I don't think the car is really that far off.

However, something needs to give with your 60ft. It really should be a 1.55-1.59 for the best results. Especially with a brake.

I think swapping out your converter will give you some much better results. Your car probably has good horsepower and okay TQ. It's going to need some stall speed to 60ft well. The fact that your crossing traps at 6000 is a major problem. It tells me that your 10 inch converter is doing what most of them do. It's transbraking high at the line do to the 10" slippage but becoming a tight 3200-3500 afterwards. Thats why your ******* around and crossing the traps at 6000 with a 4.10 gear. Street/strip 10 inch converters are kind of funny. I know this because I hear the results of them daily. In fact, my company actually makes the Big End converter thats in your car so I have a good understanding of them. They can be your worst enemy or your best friend depending on the application.

My 383 had 195cc heads(AFR) and a 750 carb. With a 3200-3400 stall it would do 1.52 60ft on footbrake no problem.It was a bone stock chassis. If I put 215 heads and an 850 carb, it would kill the torque down low and the 3200 stall wouldn't be worth crap. There would be no good torque to use. I would have needed a 4800-5000 stall.
Hope this is relative. lol

I would say pull your converter out and have it loosened to a 4500 which is the highest it can be made. That would be the cheapest fix. Or you can spring for a good 9 or 8 inch 4500-5000 stall and let it leave with all your cards showing.

Hope this helps.

greezemonkey

iTrader: (14)

Well said ! OR he could strap a 250 shot of sneeze to it, instant torque :-)

brandoz28

iTrader: (1)

a man after my own heart!

91_B4C_RS

Update. Went to the track 60' went from 1.750 to 1.730 ran 11.808 at 116.47 mph.

Added Lca location brackets set pinion angle to -2* remove a lil weight reduction rear seats and stuff. Et streets at 15psi. Crossed line at 6200rpm.

Def. Need a converter

Fast 383

iTrader: (2)

Pull that converter and send it to me. Let me crack it open. Or spring for the 8 inch. Your defientely bound by the limits of the one you have though.

91_B4C_RS

Update having an 8"Coan converter built as we speak. 4500/4800 rpm should have it friday since I live in town.

I was informed that it uses the small pattern mounting tabs. The 10" converter I currently have is a dual mounting pattern.with this fit on my stock L98 flywheel?

Fast 383

iTrader: (2)

Most flexplates will accept the small pattern but sometimes won't fit the big pattern. Ex. BOP stuff uses 153 T plate and small bolt only. Some early T-400 equipped cars had a Large bolt pattern only. Thats why S/S converter have both patterns. Because there universal converters that can end up behind anything.

mod313

Couple quick thoughts is more stall and more rear gear. You may need to have the stall adjusted but you have to try it first. Not sure on your converter place but I know ATI gives you one free adjustment with a new converter purchase. Also maximize the gearing by using the biggest slick possible. You can fit a larger slick under the stock wheel well. Since you have a 9" gear choice shouldn't be a problem. Start by getting the combo to use the full power band of the motor before you start tuning the chassis.

1gary

Data log with a weather station everything and the changes made.Doing that builds a info ref.

91_B4C_RS

Installed new Coan 8"Converter 4500-4800 stall. S.O.P dyno shows huge improvement. Best money I've spent in a while. Going to the track the 14th to see what happens. Second and third gear pulls feel amazing. Not as much rpm drop between gears.