I'm running 3.70 gears in my 1989 GTA with my modded TPI. Best time so far is 12.73 and 105.85. Running a ZZ9 cam with a Yank SS3600 converter and a bunch of other mods. Race weight is 3760 pounds.

Expect to be in the 12.5's by the end of the year and cooler weather. By the way I have my trans governor set up to shift at 6000 rpm in the 1-2 shift and 5600 rpm in the 2-3 shift. On the Dyno my max power is at 5000rpm with 304RWHP and torque is at 4600 with 334 RWTQ. Graph starts at 4200 because the car will downshift into 2nd any lower. Allen

 

If your max power is at 5, and your running to 6, what does your power look like after 5? On a stock tpi it's going to plummet. It's not worth it to spin it that high, you're better off just shifting to the next gear.

 

I have a modded TPI with good air flow and the power does not drop off like a rock after 5000 rpm . The reason I shift at 6000 is the low first gear of the 700R4 transmission. When it shifts I want the RPM to be around 3900 rpm after the shift. My 2-3 shift is at 5600 which also brings me back to around 3900 rpm. Allen

 

What do you consider modded tpi?

 

I'm going to guess either aftermarket runners and ported base, or ported runners and ported base, ooooor ported aftermarket runners and ported base.

If you really hog out that tpi itll make good power i dont know about until 6000 but very close till there

 

wow i forgot i posted this, thanks for all the info guys.
Heres what i have from just looking in magazines and such, i either want to go with a stealth ram, or the LT4 hot cam kit with cam, 1.6 rocker arms, springs, caps, keys and shims. Both about $550.

I dont want to go super ram because of cost, new in summit its $780 for the plenum and runners and another $518 for the base (and i know i could use a different base, im just making my point)

anyway i figure if i went cam when i pulled the intake off to put the cam in i could just port all of that and be happy for a while. anyone know of a better cam than the LT4 cam?

I dont want to go gears because i think 3.73 would be too low and my car already feels like it has nothing the last 150-200 feet on the track as it is. when i raced a car with 3.42s, a small cam and headers (at the time i didnt have my headers) he jumped me 2.5 cars off the line but by 60mph i had all but passed him and i didnt like that.

as for tires, i have some used ET streets, they just havent been mounted on anything yet to be run

im also really thinking about suspension parts that i could use on a 4th gen later on. i kinda figure use what you got.

 

Sorry about hijacking the thread but for the TPI answer. I have the Edelbrock TPI base extrude honed to 1.70 inches on the runners. I have SLP runners that are highly modified in that both pairs are fully siamesed from top to bottom so one big oval so to speak.

The stock plenum has 4 ports on each side. I modified the plenum so that its one big oval starting from the first port and ending with the last port. Also opened it up to accept a 58mm throttle body. Had to weld up the sides so I would not go through while porting for the 58mm.

Back to the thread. The LT4 hot cam will work with the Stealth Ram quite nicely. The Kit sounds like the way to go. I just searched and it looks like you still have the stock heads. They will have to be worked over to accept the LT4 hot cam and 1.6 rockers.

As you know heads is the key to power. I would save my pennies and try to get some good aftermarket heads or at least get yours ported while they are off.