what is a best cubic inch and Turbo ???
Thread Starter
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Joined: Apr 2003
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From: KUWAIT
what is a best cubic inch and Turbo ??? I was wondering what would be better on my setup,my motor is going to be a built 346 or 371 ci ??
my friend say T70mm its a good for street, pls i want opinion my friends .
what is the best T??? and ???ci ?
thank you
navy
my friend say T70mm its a good for street, pls i want opinion my friends .
what is the best T??? and ???ci ?
thank you
navy
Well thats a hard one to say, but from what ive read for the past years is that for a mild setup a 346 is more than enough. For a more race setup 6.0 iron block at 370 cid is best. The t 70 will be good for the street and spool pretty quick with 346 cid. Thats just my opinion.
The relatively slow burn rate common to a "turbo tune" is better matched to a slower piston speed such as what you would get with a short stroke /big bore engine.
Aside from that you want to look at your desired RPM range. A given set of heads will be more efficient at higher RPM on a smaller cube engine. The same set of heads would be efficient at a lower RPM on a larger cube engine.
A longer stroke crankshaft tends to move efficiency and power down in the RPM range a bit.
With these being general truths, an example of a mismatch would be a small turbocharger on a large cube stroker engine cammed for making power at very high RPM, and using a close-geared manual trans.
Turbo sizing depends a lot on your transmission type and what you want the car to do. Low RPM automatic trans applications may run better with a turbo on the smaller side, where a higher RPM manual trans would do better with a larger turbo. I think it's best to talk to a turbo sizing expert about picking the right one, and be honest about what you want the car to do.
HTH
Aside from that you want to look at your desired RPM range. A given set of heads will be more efficient at higher RPM on a smaller cube engine. The same set of heads would be efficient at a lower RPM on a larger cube engine.
A longer stroke crankshaft tends to move efficiency and power down in the RPM range a bit.
With these being general truths, an example of a mismatch would be a small turbocharger on a large cube stroker engine cammed for making power at very high RPM, and using a close-geared manual trans.
Turbo sizing depends a lot on your transmission type and what you want the car to do. Low RPM automatic trans applications may run better with a turbo on the smaller side, where a higher RPM manual trans would do better with a larger turbo. I think it's best to talk to a turbo sizing expert about picking the right one, and be honest about what you want the car to do.
HTH
there are too many variables in this question how much power are you wanting to make? daily driver or race only, I would say for a street car the turbo reguardless would be a t76gts, but engine wise its up in the air, are you worried about the extra engine weight etc
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From: Frisco TX (Dallas Area)
Well, guys, this isn't a definitive answer, just a point of data. I've got a 383 stroked LS1 that I went to Moore for cam specs. they recommended 224/228 @114 with .580 lift. So I go to the various web sites for info on turbos and performance and wound up doing a plot of my 383 on a T76 compressor map. I plotted various boost levels vs. rpm for the engine. A 371 would show a little better efficiency on the graph. Here's the map as I plotted it. Draw whatever conclusions you think appropriate. I'm going with the T76 based on what I just said and the graph. HTH 
OBTW, 75 pph (bottom of the graph) should make about 815 crank hp or about 650 rwhp.
OBTW, 75 pph (bottom of the graph) should make about 815 crank hp or about 650 rwhp.
Last edited by TeeKay; Mar 16, 2006 at 02:44 PM.
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Originally Posted by TeeKay
A 371 would show a little better efficiency on the graph. Here's the map as I plotted it. Draw whatever conclusions you think appropriate. I'm going with the T76 based on what I just said and the graph.
Thread Starter
TECH Regular
Joined: Apr 2003
Posts: 406
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From: KUWAIT
thank you ool for your opinions and im going 371ci i think its a good machines. 
* this is my parts :
i know im not forgetting my turbo kit
PTS LS1 Camaro Single Turbo System -
* Turbosmart Manual Boost Controller -
* 1600* Silver Hot Side Coating
* (8) 55 lbs High Impedence Injectors -
* LS1 Air to Air Intercooler Upgrade -
* Snow Stage 2 Meth System (over 500hp) -
* Precision 70-GTS-H Turbo
* T-Bolt Clamp Upgrade (Std. On DR & Race Kits) -
* TiAL 50mm Billet Blow Off Valve -
* Poished Compressor Cover T04 -
* Turbine Housing Silver Polished Ceramic Coated
thank you
navy
* this is my parts :
i know im not forgetting my turbo kit
PTS LS1 Camaro Single Turbo System -
* Turbosmart Manual Boost Controller -
* 1600* Silver Hot Side Coating
* (8) 55 lbs High Impedence Injectors -
* LS1 Air to Air Intercooler Upgrade -
* Snow Stage 2 Meth System (over 500hp) -
* Precision 70-GTS-H Turbo
* T-Bolt Clamp Upgrade (Std. On DR & Race Kits) -
* TiAL 50mm Billet Blow Off Valve -
* Poished Compressor Cover T04 -
* Turbine Housing Silver Polished Ceramic Coated
thank you
navy
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TECH Apprentice
Joined: Jan 2004
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From: Frisco TX (Dallas Area)
Originally Posted by engineermike
My 383 made 30 more rwhp than my current 363, both at 13 psi. It may be more efficient on a smaller motor, but it efficiently flows less air.
Just one small point though, the graph shows 6,000 rpm. If you wind the smaller motor tighter, you'll get more flow - and hp. However, you can see the way I chose - 383!BTW, NAVY, GL on the 371. I think you'll be pleased.
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From: Colorado
A 6.0 iron block would be a good choice.. lot of guys are running that with good results.. a 76 would be a good choice too, so that you have room to grow when you get tired of 600rwhp and want more
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Joined: Jan 2004
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From: Frisco TX (Dallas Area)
Originally Posted by NAVY
you mean 383ci its a best than 371ci. 
Navy. A lot will depend on what your goals are. BUT
Since you are going to bore and stroke anyway. Buy a 6.0L iron block shortblock. Keep your stocker or sell it. Iron blocks can be had for reasonably cheap. Use the stock 6.0 crank and bore .030 over. You'll have the 370. Make sure you have the block and crank checked out my a damn good machine shop. Buy your pistons and rods carefully. Don't skimp on the small stuff (balancer, oil pump,etc). If you're short on cash you can always use your stock heads for now. Upgrade your springs. This should give you a start. For cam, use one of our sponsors that specialize in turbos -- W2W is my choice. There is a lot good info on this site. Read some of the other builds going on.
Most importantly. Decide on your goals. Get your budget together and go for it.
David (oh by the way, I am a retired Navy YNC(SW)
)
Since you are going to bore and stroke anyway. Buy a 6.0L iron block shortblock. Keep your stocker or sell it. Iron blocks can be had for reasonably cheap. Use the stock 6.0 crank and bore .030 over. You'll have the 370. Make sure you have the block and crank checked out my a damn good machine shop. Buy your pistons and rods carefully. Don't skimp on the small stuff (balancer, oil pump,etc). If you're short on cash you can always use your stock heads for now. Upgrade your springs. This should give you a start. For cam, use one of our sponsors that specialize in turbos -- W2W is my choice. There is a lot good info on this site. Read some of the other builds going on.
Most importantly. Decide on your goals. Get your budget together and go for it.
David (oh by the way, I am a retired Navy YNC(SW)
) 
