LT1/4

Hey guys. Have a 94 TA here and had her for awhile now and was looking at the idea of pro touring & road racing her rather then the traditional drag racing. Want to get your thoughts on a high rpm big inch build. Either a 370, a 383, or a 396. Wanting to keep the RPM range around 7000-8500rpms. My budget is roughly 20-22k for the whole car motor, tranny, rear, suspension.

My thoughts were:
AFR heads
Shaft mount rockers
Solid Roller Cam
Isky Valve-Train
All forged bottom end
Callies crank
Eagle H-beams
Mahle or JE Pistons
Hell Fire Rings
Dry-sump oiling system
Be cool rad
12:1-12.5 compression
Fuel system recommended
TR6060 tranny
12 bolt;3.73
Boze forged Wheels

Goal 700rwhp on E85

Or


A simple Pro-charged 370 or 396
Water to Air CX Intercooler
9:1 compression
AFR227 heads
Solid Roller
7000-7500rpms

My goal is around 800RWHP 93 octane still being drivable with A/C


Please post your thoughts on big inch & high rpm builds and your thoughts on pro-charged set-ups.

97Z28SS

iTrader: (5)

Big inch and high rpm don't usually go hand in hand unless you have really good heads not to mention the stock pcm has a hard rev limit of 7000 rpm? Is there a reason you want to turn 7500 - 8000 rpm?

BOOSTED AFR

The ProCharger build you lined out would be more realistic. Along with the blower, a 24x swap would net you COP, the ability to run a 2 or 3 Bar MAP sensor, no 7000 RPM limit, and get rid of the Optispark.

LT1/4

@ 97Z28SS: Well im wanting a broader HP range up top and a little more power with a hefty cam to get the most out of a big inch LT which will require a top notch oiling system. Plus ill be needing those rpms on the track when constantly above 5000+rpm.

@ BOOSTED AFR: Yeah I am obviously going to have to ditch the stock computer for something more advance. Stock computer can only handle a little over 7000. Could be going LS computer swap or F.A.S.T system or Stand Alone. As far as the blower was looking into a D1 pro-charger or V-4 Vortech.

BOOSTED AFR

800+ rwhp would be incredibly impressive on an LTX car with only a D1. I'd think the F series would do you much better at that level but plan on piecing the kit together and doing a lot of fabrication also a meth kit would be almost a must with pump gas.

Edit: looking around I'd say darn near impossible to get near 800 wheel horsepower without at least an F1A on these cars.

Nophix

The idea of Pro-Touring is to be able to truely drive the car. 800hp sound fun, but in such a light car, it's going to be a bear. Aside from that, revving this engine that high after doing a stroker is going to be an issue. Piston angle on big stroker LT's is already an issue.

Even most of the big body pro-touring guys that are really deep in it are pushing under 700hp.

I'm in the process of doing the Pro-Touring build on my Formula. The best recommendations I can make are go more reasonable on the power, consider going with a turbo instead, and focus mostly on the chassis, suspension, and brakes.

600hp would be much more attainable, and far better on the road courses anyhow.

BOOSTED AFR

Nophix is the voice of true reason. I couldn't have said it better. At any rate 600whp is plenty to scare the **** out of just about anybody in the passenger seat and probably the driver occasionally.

SoxXpupPeT

iTrader: (34)

Agreed a pro touring car is mostly focused on handling, braking, control. 800 HP is Alot for anything. To much and it will be negate the overall effect of the car.

LT1/4

Thanks guys. Yeah 800 was just a number I threw out there that might be imminent. My goal is somewhere in the range of 600-800 depending on the set-up & boost. Just having a hard time juggling on a high rpm build or a simple boosted set-up.

High end torque is what im aiming for, low weight, Eibach Coil-overs, Baer brakes.

BOOSTED AFR

RPMs are really hard on parts. A low speed, forged, ProCharger motor would probably be much easier on parts than a motor with triple valve springs, titanium retainers, shaft rockers, a solid roller, and huge compression. Those are all pieces that are tough to keep on a street car.

FormulaJoe

iTrader: (5)

Join the Frrax.com forums and tell them what you want. They will be able to shoot you straight on the road course/ PT thing and give you a better idea of what you will be needing. There is tons of RR experience there from guys who have been there and done that and can help you not make the mistakes that they have already learned from years ago.

kgkern01

iTrader: (10)

^This!

Best advice on this entire thread. Frrax.com is a strictly autox/rr board with a lot of hardcore experienced autox/RR/ORR racers and builders.

That said, I would go NA solid roller 383 if staying LTx. You are adding a LOT of heat soak with a boosted car on a road course. With good 6" rods, light rotating assembly, and good heads, and high RPMs are not an issue. Focus on a power to weight goal for your intended class instead of a hp goal.

Turnin20s

iTrader: (12)

OP-You are planning a build similar to what I want to end up with.

My plan is to do an aluminum 5.3 (L33) so it's nice and light with heads, cam, & intake with supporting mods with a goal of around 500 rwhp on E85. Then later on I can add a turbo, switch the heads and cam and have a really good base to get around 700 whp.

I have a MWC 9" with a watts link and chromoly everything, UMI k-member, UMI chromoly a arms, UMI 3 point SFCs, Hellwig hollow sway bars with the adjustable rear sway, Edelbrock IAS shocks with 625# front springs and 175# rear springs, 17x11 ZR1s at all 4 corners with 315/35 Nitto NT555 tires for the moment. My LT1 is just a basic 355 with higher compression and good flowing heads. This year I will be switching to an extremely light clutch (11.7#s with flywheel) to see how that makes the package feel. But my car should weigh in at about 289X right now with a goal of getting it at least 300#s lighter.


Good luck with the build OP

94nismoformula

OP, have you considered swapping to an irs setup instead of the 12 bolt?

speed_demon24

iTrader: (6)

You're going to go way over budget or come up short on the goals.

Turnin20s

iTrader: (12)

I agree, it is HARD to do both motor and suspension at the sametime. I would start with suspension and grow into a more powerful motor. If you do it that way at least you have something that will safely handle the power.

LT1/4

Appreciate it guys. I guess ill have to start with suspension and work my way into the drive-train.

Ill def take a check out that forum.

To answer your question 94formula I have though about going IRS but heard some guys lose a few extra RWHP going that route over a 12 or 10 bolt?! YOu never know though with the misinformation.

As far as the motor ill be running it through a 6-speed and start out small with a goal of 500+rwhp then gradually work my way up. Guess Ill have to give AI or AFR a call. Which preferences have you had better luck with heads; AI or AFR?

As for the suspension im looking into a UMI set-up, moser rear end with a T56 what I have now.

How strong are the stock T56’s?

LT1

iTrader: (1)

93 stock Borg Warner T56 holds around 350 tq.

94 - 97 stock Borg Warner T56 holds around 450 tq.

98 -02 stock Tremec T56 holds around 450 tq.

BOOSTED AFR

The power/torque capabilities of the transmission are irrelevant if the tires can't provide enough traction to cause the driveline parts to become the weakest link in the chain.

v7guy

iTrader: (1)

I'll echo that the suggestion that reading on frrax is of massive importance.

My car is setup like you're talking about.

18x11s on all four corners, brembo brakes from a twin turbo porsche, spherical bearings from global west in the stock a arms (the after market arms failed on me), Bilstien racing coilovers on all 4 corners from Unbalanced engineering, subframe connectors, big honkin sway bars, DIY adj rod ended LCAs and PHR, lowered PHR and LCAs, solid motor mounts, rebuilt the t56 to handle 700 or so hp. Started lightening the car... no rear seats, started removing all the unnecessary brackets etc
It only has about 400 hp but is a hoot to drive. It was my daily driver in TX but it's not so practical up here in the NYC area.

After you get used to the way the car behaves it's very predictable, it's just a matter of not blowing off the tires. I'd like more power these days, but it's probably still a little ways off. You should really build the car to support the motor and do the motor last. But that's not how most guys go after it. lol