I just recently blew my motor and want a rebuild. I will be doing a low compression 396 or 400+ ci motor for a turbo. I was wondering besides the obvious (everything forged) what is needed? Is there a certain type of piston that works best for turbo? I will of course be getting the basics, heads, a new cam and already have a built valvetrain.

How long will the stock transmission handle this power too?

thanks

 

What are your goals? Track only or street car? If you want to drive it on the street, then you want quick spool...

This will be an issue for you with big cubic inch displacement. The 396-400ci pushes the T76 off the map, but will still work, just not efficiently. If I were you i would go with a 355ci LT1 with a T76 setup. Dependig on what T76 you get...(GTQ, GTS...) 800-900rwhp should be attainable with a decent turbo kit, high boost and race fuel.

 

well that was my first plan, but I figured for near the same price I can get a bigger ci motor. What internals are best for 800-900 hp? forged 4340 eagle crank not enough? What about h-beams? and for pistons? assume a 355

thanks for the help

 

This will be your best friend: http://www.forcedinductions.com/help.htm

If you go above a 383ci, I'd step up to a t88, but I suspect you want make peak boost on the street until ~4800-5000rpm. If you go with a 355-383ci, then a T76 can be used and peak boost will hit in the 3000-3600range depending on which c.i. you go with and the design of the system. We need to know more facts as far as your goals.

I am building a 383LTx with a T76 and plan on making 700rwhp on pump gas and a little more with racefuel. I have an Eagle forged crank, eagle forged h-beam rods, and je/srp forged pistons. Just dont run into detonation and your forged parts should do okay.

 

wow, thanks a lot for the help, RealQuick. I will definitly think about that. why does everyone suggest a 355 over a 383 or any other motor ci?

thanks again

 

I'm not going as far as saying the extra cid will hurt power, but anything over 350 cid will not help power with a T-76. So, why spend the extra money. Also, the 355 piston will have extra meat between the rings. I've broken 2 SRP piston ring lands on 2 separate occasions in my 383 with no signs of melting or detonation.

 

As far as the short block and what I have found more cubic inch is better. Yes you want a strong bottom end to take the stress. Steel crank and rods. The compression ratio should stay under 9:1 and the cam profile will be different from a NA motor. Forced induction motors don't like duration. They love lift.

As for what turbo to use I would suggest you get with Limited Eng (John Craig) John was a R&D person for Garette (sp) and still uses there parts along with some of his own. The other place would be to check with Precision Engine and Turbo. These places any more make turbos that have a lot more range than the off the shelf ones listed from the turbo Mfg companies. The price is about the same but they can mix and match intake wheels, housings and exhaust wheels to match the rpm range and power you want to obtain.

I agree with the statement you need to have an idea of what your goal will be first.

Good Luck

 

96LT1TX - here is the point...what are your goals. Is is to drifve it on the street and have fun and occasionally hit the track? Is it a just goint ot be a racecar? Answering this will help dramatically in pointing you in the right direction.

 

Not really. . . you really can't go wrong with a 355/T76 combo. That would be best for street and track. Unless of course you do a large frame turbo. . .

 

If he wants to set himself up to go faster than mid to high nines and makes this a track only car... then maybe a bigger cubed T88-T91mm will be best. we dont really know his goals yet. Weekend warior and street cruiser (like mine will be then I'd say definitely T76...

 

I want it to be a track monster and run 10s out here (though I dont have the money for the roll cage, new trans, or new driveshaft ) at 5800-6500DA. so 600 or more rwhp corrected. but want it to also handle nitrous eventually...

and yes i have a daily driver

 

In turbo-land, 10's is not a track monster. That's a mild-mannered street car. 10's will be not problem with a 355/T76. In fact, mid 9's would be no problem with a 355/T76.

Mike

 

well I like what I am hearing, because 10's out here is like mid-low 9's at ennis...
who makes the exhaust manifold for a turbo ? does garrett? I am looking at the gt3576 or gt3582 and like the horsepower potential... how could I go about making this turbo system?

thanks for the help

 

There really isn't much point in going with anything bigger than a 355/t76 on the street. Hell, a T70 will make more power than most people can actually use, much less drive. If you're looking for a quick street car that won't break the bank, that should be fine. If you're looking for a dyno queen, then consider the big inch/big turbo route.

As for the system, if you're looking for a kit, you're probably going to be calling PTK pretty soon.

 

Stock trans nope no way no how



really you should gett all the right stuff befor you make this mean power house