Well i just blew up my LS1 @15psi and i am ready to build a new block and get a bigger turbo. I am looking to run high to mid 8s. I need help picking the right combo. I am thinking LS2 or Lq9 with a 88 or 91mm and some and some thick deck heads. I run a th400 and 9"rear with a 3400 stall. Please give me your input and what i should build.

 

402 with good heads and a 88mm will get it done

 

I am going with a ERL LS2 (364ci) along with a PT88. This is pretty much what MightyMouse uses and he is in the 8's. Granted there is more to the combo but this will get you headed in the right direction. I decided against the 402 due to the fact that I am running the PT88(t4 flange). If you go with a bigger t6 then as shawn said a 402 will work out great. I just dont think the bigger cubes are needed as most are deep into the 8's and 9's with 370's and PT88's.

 

402 and GT91 T4 or T6 version. I would highly suggest the T6 version though since 402 is a big motor for a T4 flange.

 

I have an lq9 based 408 with an s91 goin into it right now. I'm hoping to see high 8's and low 9's on this setup. I was thinking of running a pt91.5 also as an option.

 

Thanks guys. I would really like to keep the CU around 370...i think

 

With a 370 that GT91 will still rock the house.

 

I agree

 

not sure why everybody always wants to go with a small motor,big turbo combo when just the opposite works better at the track.

The bigger motor with the smaller turbo will make alot more low end tq,which means you can run a tighter converter,less rpm and less boost which equals to less wear and tear on the engine.

 

Hook me up Shawn!

 

Is this the Garett street turbo? Is it better to run a t4 or t6 on a 370?

 

It's all here.

https://ls1tech.com/forums/forced-in...olds-pt88.html

 

I see what you are saying, but alot of guys running the 370 and PT88 are saying a 402 will max out that head unit and some are seeing that the 370 is close to doing so already. I can see on the other side of the arguement like you have pointed out, a 402 with a smaller turbo makes more torque and stays lower in the rpm range. I would think that would lend to a vicious street car. But I have never done it so you would know better.

 

I got plenty of torque everywhere.

 

My 364ci/pt88 makes 4.02psi by 2552rpms(according to my vcm scanner)..i think a 370/pt88 would be a perfect combo.

 

You think 91 is an overkill with a 370 or will I be ok?

98z28cobrakiller: how much hp do you have, what psi?

 

I think that the T4 PT88 exhaust housing is slightly undersized for the track on the 370 but more than enough for the street. So far I have pushed 19 psi thru mine and run an 8.98 @ 153. Car weighs 3700 with me in it. Never been on the rollers as I dont really care much about a HP number. There are a couple of changes that I want to make before I push the boost any harder. First one being larger injectors, then an aftermarket PCM, switch to E85, and finally, come up with some sort of cold air intake as my turbo is currently sucking hot air from behind the radiator.

 

Yes it is over kill if you are just shooting for high 8's. But I imagine most people think all out turbo lsx cars are over kill. If you arn't limited by a class I would go with larger cubes as long as your budget allows for the proper heads to go along with it.

 

I'm no engine builder but I did stay at a Holiday Inn once

Stick to the stock crank and spend the grand somehwere else. I've sung my song about the strokers.

 

Thanks guys! I am for sure keeping the stock crank! Does let lq9 use the same crank as the ls1 or am I way off? I am leaning towards the 91mm but I will have to do some more research. I am also thinking I will upgrade to FAST xfi or BS3, why not lol! It's only money