85T/A350

Im currently in the rebuilding process of my 1987 Trans Am and all though it may never see a track, Im just curious of what you all think it could do in the 1/8 and 1/4.

1987 Trans Am

1996 350 Vortec (fresh rebuild on block) stock bore, pistons, manifolds
XE264HR
Edelbrock Performer Intake
Stock CC Quadrajet
Single in dual out Flowmaster Exhaust
2.73 gears
Automatic

I know it isnt much but it is a long term project between my dad, fiancee, and myself. So all the bad such as gears and exhaust will all be changed one day. Just got some curiosity built up. Thanks to everyone who gives me their opinion!

mw66nova

iTrader: (13)

14.ohs

84firebird383

I agree with mw66nova. Somewhere in the mid to lower 14s' depending on the usual factors like traction and how bad your exhaust is holding you back.

AlkyIROC

Exhaust holding it back? What about those 2.73 highway gears. I doubt it will be in high gear when it crosses the finish line.

I remember having 3.27 gears. I was shifting at 7000 rpm and got into high gear about half way between the 1/8 and 1/4. By the time I hit the finish line, the engine was finally getting into it's powerband.

xpndbl3

iTrader: (5)

3600-3800 stall and 3.73 gears with some 26x10 stiff side wall ET drags or similar and it would be rocking a lot quicker.

85T/A350

It wont ever have a stall that big lol. It will primarily be a weekend street cruiser with very very limited track time. LIke I said, Im just curios lol. I am going to be switching to 3.42s and shorty headers hopefully soon. What about then?

mw66nova

iTrader: (13)

that big? i DD'd a 4000 rpm stall speed 10" ati unit when i still had a regular sbc in the car with a 700r4...got 22mpg on the highway on average, and would run bottom 12's consistently. i'm looking at a 5500 8" now to replace what i have, lol! 3600 is mild street car stuff!

85T/A350

Ill still probably wont run one that size lol. I might go with a 2500-2800 or so.
What if I go with this combo:

3.42 gears
XR270HR (http://www.compcams.com/Company/CC/c...?csid=187&sb=2)
Shorty Headers
3in single exhaust

The tires are quite a bit wider than stock but im at college and dont know the exact specs. The most racing this car will see is roll racing but Ive always wanted to go to the track.

xpndbl3

iTrader: (5)

Converter technology has come a LONG way since the 70s. I had a 10" tci super street fighter that stalled 3800 out of the gate but would take 1800 rpm to pull away slowly from a stoplight, nothing crazy about it at all. You're planning an even bigger cam but have too little stall right now, you need a matched combo.

built91Z28

Yep. When I had a TH-350 in the car, I had a 10" stall in it. I was told it was a 3500 stall, but I found it to be closer to 4000. It would take about 1500 or so rpm to get it to move. It wasnt that bad.

85T/A350

What size stall would be good for this then? Something around 3500-3800?

mw66nova

iTrader: (13)

probably something in the 3200-3500 range

85T/A350

What kind of horsepower will this combo give? At flywheel

350 Vortec Fresh Rebuilt Stock bore and pistons
Edelbrock Performer Intake
Holly 750 4160 Carb
XR270HR
Shorty Headers 1.5in primaries, 2.5in collectors

xpndbl3

iTrader: (5)

performer rpm will be a 10 hp at least improvement, the 4160 will be holding you back also compared to a 4150 carb, those headers are far too small also.

85T/A350

They are what Ill have to use for the time being. Its a very long term project that Im sure will see many different combos. But as of now thats probably what it will start with. So what do you think it would be anyway?

mw66nova

iTrader: (13)

given the limitations, if it makes over 260fwhp, i'd be very pleased.

Shadow Z

iTrader: (2)

It'll run upper 30's if you take your time.

But probably a mid 14.

And instead of recommending a higher stall torque converter, different cam, etc, I'll do a one up to end all one ups.

Sonny Leonard 903 C.I. 2,700+ HP pro mod engine. It'll run you over $90,000 complete. I believe just the heads are worth over $15,000. It'd be a challenge to run a 14 then! Tap that gas pedal a little bit too much and there's an instant 10.

mw66nova

iTrader: (13)

sounds practical

85T/A350

Would that combo not be better for 5 ore horsepower than the stock vortec has? The headers may be small but surely they're better than manifolds? Would that intake and carb be less than the factory tbi? I know its not optimal stuff but that doesnt sound right. I could be wrong though.

mw66nova

iTrader: (13)

the performer intake runners are nearly identical to the factory intakes of the 1970's, and is commonly referred to as a stock replacement. for the vortec heads, they just moved the mounting holes around, the runners are the same old design. it's not ideal. a performer rpm air gap would be a much better option.

the carb is also not ideal, a 4150 style carb (even vacuum secondary) would be better with the rear metering block, and all the adjustability to be had there. mechanical secondary is always ideal in my opinion, though will show your lack of converter in a big way...

the headers suck...about the same as stock manifolds...if you're stuck with stock exhaust routing, atleast try to pick up some hedman shorties. they're 1 5/8"x3". if you have the fab skills, or the money to pay someone with fab skills, or are willing to learn some fab skills, then put some cheapy hedman longtubes on it, build a nice y-pipe and a quality catback, or run duals.

Shadow Z

iTrader: (2)

Truth. I have a mechnical secondary Edelbrock, stock converter, and it wasn't exactly a perfect daily driver. I unbolted it, and set it on the floor of my garage, as a testament to wanting a turbo 383 with a CSU blow through carb.

xpndbl3

iTrader: (5)

edelbrock carbs are not mechanical secondary, they work off an air flow flap something errrr other. Either way they're not a "performance" carb and work great on 4x4s and motorhomes or car show cruisers.

Shadow Z

iTrader: (2)

That is news to me then. I was told that's what my carb was, and never looked into it, since I didn't really care. Considered it a junk carb to begin with.

I'd rather have a Holley due to the good things I've heard about their street manners.

Street Lethal

iTrader: (16)

.... that would be their weighted air-door for the secondary, and the only adjustment for them was to replace them with a lighter or heavier door, but I don't think anyone even makes replacement doors anymore, Carter did once upon a time though.

85T/A350

Looks like im going with Hedman 68460 Long Tubes with duals. Would 3in duals be to big for my application? Should I step it down to 2.5in?

mw66nova

iTrader: (13)

3" would be a bit big. i'd go 2.5"

Shadow Z

iTrader: (2)

Honestly, a single 3.0" would offer you more than enough flow. 2.5" duals would be adequate, and offer you room to improve.

85T/A350

Thanks, I figured 3 would be a bit big with my mild combo. Appreciate guys.

85T/A350

The car is about finished and with a few changes from what I had planned. I figured I would ask again what you all think it might do in the 1/4 as well as the 1/8.

96 Vortec 350
Comp XE270HR
Stock Stall(will be 2800-3000 in a month or so)
3.42 rear end
Hedman Long Tubes
Dual 2.5in exhaust
Jet Stage 2 Quadrajet
Performer Intake

mw66nova

iTrader: (13)

i say not much better still till you get a better converter and better intake. maybe some 13.3's or so.

85T/A350

The intake change may happen somewhat soon. The converter Im still struggling with. I've had several people here tell me 2800 or so would be perfect and any higher will be to much. But a few of you in this thread tell me I need to be higher into the 3000s?

mw66nova

iTrader: (13)

3200+ or don't waste your time. it's a lockup style converter so it'll drive like stock once locked up in OD anyway (assuming you've taken the proper steps to ensure it locks up). it'll be a little soft in the first three gears around town, but highway driving will be unchanged. give Fast_383 a shout at Transmission Specialties, he gives a hookup price to tgo members.

that coupled with a performer rpm air gap and jump into the 12's with both feet. get ready to start picking up 10 bolt pieces off the racetrack!

85T/A350

So you think that combo would be good for 12s? It never crossed my mind that I could get into the 12s. I was pretty happy when you said 13.3s lol. I'll look into a stall from 3200-3400 or so. As far as the converter locking up, as of now I have not fixed it to lock up. Would I be better off doing so?

mw66nova

iTrader: (13)

absolutelty. you won't be taking advantage of what makes the 700r4 such a great street/strip transmission if you don't. if you don't lockup the converter, it'll just free spin below stall speed, which will do nothing but put heat in the transmission, and quickly decrease the life of the trans/converter.

tci makes a very nice universal lockup kit. it's about 100 dollars, and works like a charm.

with traction and proper tuning, i see no reason why that thing won't go 106+ mph, which will be good for 12.7x's or better.

xpndbl3

iTrader: (5)

3600 converter, performer rpm air gap, 750dp and 3.73 rear gear.....good for 12s like I wrote months ago

85T/A350

I seen that lol, but I have 3.42s and a different carb then what you defined. I was referring to mw66nova thinking that I can hit 12s with the combo I have. Assuming I use a 3200+ stall and change intakes.

mw66nova

iTrader: (13)

i believe that the combo will run 12's with 3200-3400 rpm stall speed, your jet 2 q-jet, performer rpm, your 3.42's, and some traction, steve's will just go further into the 12's.

DIGGLER

iTrader: (1)

run the stock converter and spray it into the 11's.

Fast 383

iTrader: (2)

I think you guys are trying to make lemonade out of lemons. Bringing up your street motor in this forum is like driving your daily driver Hundai into a Nascar Pitstop to have your tires rotated. These guys have you running 12's with a Tahoe motor.

Am I missing something? It's a stock replacement truck motor with a "Less than Hot" cam. It's actually worse, it has a Quadrajet carb and Performer intake. It would probably be faster with the Vortec throttle body on it.

Please don't take what i'm saying as any kind of insult. You didn't set out to build a race motor or a race car and you made that clear. I think you'd be ahead of the game with a 13.99 slip. As far as torque converters are concerned you're probably right on track with a 12 inch 2800 stall. I have sold about 20 of them to members on this board with more agressive combinations than yours. All of them have felt they worked great. A 10 inch converter with 3000-3200 stall would be nice to if you want to spend the extra money and have more of a punch to the car. IT will also show you more slippage driving around through the higher gears. Your motor is very mild. A mild torque converter will work nicely with it.

aheld13

14.50 at best especially with street tires and stock rear suspension