The motor in my Trans Am is pretty tired, and has been bored .005" already. It has another .004" of taper. Does that mean the block is done?

Being tired of emission woes and not planning to do any more racing, I am thinking about using the stock LS6 intake (maybe have it ported), stock '01 injectors (28# IIRC), and stock '01 exhaust manifolds and cats.

Given those constraints, and full bolt ons otherwise (ported t/b, underdrive pulley, catback, lid, etc...) is 400 rwhp and 400+ rwtq possible with a 10-bolt and M6? I know this sounds stereotypical but I'd like as much area under the curve as possible, as it will just be a street car. I'd also like the motor to last 50k+ miles, and am willing to change plugs, fluids and valve springs but prefer not to go inside for a while. The car has <47k miles, motor was rebuilt once and refreshed once, so I'm tired of wrenching on it.

It will never have forced induction and nitrous is unlikely, and would be limited to 100 or 150 shot.

Would a 383 or 395 stroker be a waste with the stock parts?

 

Not even close. You'll need full bolt-ons (including long tubes) and medium cam to get those numbers.

Heck, an LS2 has trouble hitting that number even with long tubes and FAST intake. An LS1 with OEM exhaust and intake manifolds will struggle to hit 330rwhp much less 400.

 

I disagree. The car made more than that with the stock cam and same intake & exhaust manifolds + cats I want to put back on. Heck with headers and the same intake/other parts it made 419 rwhp.

I think this is doable, in fact I think PatG did it long long ago, on a 346 with AFR heads.

The '01-02 manifolds & cats flow significantly better than the '99-00 parts, which in turn flow better than the '98 parts.


EDIT:
Mods: K&N FIPK2
Shaner S2 ported throttle body
Hooker catback
ASP 25% underdrive crank pulley
Plastic ported MAF ends
MAF translator tuned with AutoTap

Results on stock tuning: http://i59.tinypic.com/ek1g6f.jpg

 

FWIW aftermarket heads and a cam are a given, I just want to know the limits of choking them down.

 

Its rarely done on thus forum, but heads only, or maybe heads and a larger OEM cam, or maybe a HUC/QXX/EPS lobed cam would get you there easily.

What's your total budget, excluding labor if you're not doing the work yourself.


I personally would do ported 243s, a baby EPS or Tick custom cam, non ported LS6 intake, and other bolt ons you mentioned. Shoot for roughly 11.3 SCR, cylinder pressure will be high from the small cam so you don't have to over do compression ratio. Should make your goal.

 

Thanks. I haven't contacted him yet, but my plan was to talk to PatG, spec out a motor, buy the cam from PatG, have ATK (local to me) build the engine. Probably send Pat the computer for a prelim tune, then I'll swap motors. Drive it down to his place to break it in, have him finish tune it, and drive it home. Enjoy.

FWIW the car has a lot of little things done and is pretty efficient from a loss perspective.

I'd like to keep it under $10k total, doing the non-motor-build wrenching myself.

 

420 rwhp on an LS1 with only bolt-ons and stock heads/cam? Lawl ok buddy you can believe what you want.

You can also believe that an LS1 with iron manifolds will break 400rwhp on the same stock cam/heads. The thing is, a true bolt-on car with headers making only 340rwhp on a real dyno will blow your doors off. But I digress.

 

Who said anything about stock heads and cam?

It has a largish cam now and ported heads, which is why I have inspection woes.

Do you think I would be planning to change valve springs on a stock cam before 50k miles? Read son.

 

In your first post I don't see anything regarding heads and or aftermarket cam. You even said you preferred not to go inside the motor at all.

Aaaaanyway, what type of heads and size cam you got right now the 400rwhp goal?

You would make more power, especially under the curve, with a smaller cam and headers than a huge cam and stock manifolds. An emissions friendly cam with a proper tune and you should have no problem in any state but California.

 

I don't want a huge cam, nor should one be necessary.

I don't want to use the Patriot heads and TSP 231/237 cam that is in it now.

This car has had headers for >10 years, and they are a pain.

I'm not looking for advice on what headers to run. I want to know what motor would make the most total power using the stock intake, throttle body, manifolds and cats.

What I am thinking is a 383 or 395 stroker, with AFR heads, the right cam, and good tuning should get me real close.

 

Obviously the bigger displacement the better chance you'd have. With AFR heads and a low 220s/low 230s cam will easily get you there if not more.

Stick with a 4" stroke at the most, a 383 is plenty for your goals.

 

I don't understand what you're asking. Do you want a 383 with like C6Z06 manifolds, a mild cam, a FAST, and ported heads? You should be able to hit pretty close to 400rwhp with that.