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-   -   Picking the right Turbo (http://www.focusfanatics.com/forum/showthread.php?t=284811)

Schroeder02 04-12-2012 09:46 AM

Picking the right Turbo
 
Iím building a new motor and turbo for my SVT track car (road course), my motor is going to be a low compression (8.5 to 1) forged rods, pistons and billet main caps, along with a ported head over sized valves, and a ford racing intake manifold. The turbo manifold is a Milteck manifold converted to run a external weaistgate, I also have a 3Ē down pipe and a exhaust.
Iím looking to make about 300whp, I know the motor and that is over kill for that amount of power but I want the car to last. Typically on track Iím never lower then 3500 to 4000 rpm, so Iím looking to have the turbo start building power in the range. My wuestion is what turbo sould I go with a GT2876R with a turbine housing a/r of .86 or go to a bigger like a GT3071r with an a/r of .63.

bmylez 04-14-2012 07:42 AM

A gt2876r is a weird turbo and I would not recommend it. The compressor wheel is too big for the turbine wheel. A gt2871 would get you to 300whp very easily and would offer tons of transient response. 300whp for a gt3071 is child's play and would spool a little slower, but if you're never below 3500, it wouldn't be a problem. It's a tough call because both turbos would work for what you want. Really, if you flipped a coin and chose one, you wouldn't be worse off. I would say if you were doing AutoX, gt2871, but you said you're doing road course.

Also, it's "wastegate" [:)]

pasta 05-08-2012 04:12 PM

talk to turbotom

Roushturboedzx3 05-08-2012 05:41 PM

Gt2871r you won't be disappointed.

Schroeder02 05-09-2012 07:04 AM

The key for me is slowing the spooling of the turbo down, I have a 07 st with the GT2860 on my street car, it work nice as a dally driver the power comes in early around 2700rpm, however I have taken it on the track to see how it is, and the power comes to quickly coming out of the corner tending the make the car understeer or Push for the NASCAR fans. My street car doesn’t have near the grip as the track car and has a lot more understeer built into it, but the coroner speed in the race car is much higher and I’m in the gas much sooner. So I want the power to come in a bit slower and not hit like a sledge hammer.

Right now I’m leaning to the GTX2863 with a larger .82 a/r. Still need to get my motor back so I have a bit more time.

1turbofocus 05-09-2012 09:41 AM

I am glad some one else realises how worthless a uber quick spooling turbo is when you use the car and make it work

I am not a garrett fan so wouldnt be able to help you choose a garrett

Tom

Roushturboedzx3 05-09-2012 12:08 PM

Quote:

Originally Posted by Schroeder02 (Post 4155188)
The key for me is slowing the spooling of the turbo down, I have a 07 st with the GT2860 on my street car, it work nice as a dally driver the power comes in early around 2700rpm, however I have taken it on the track to see how it is, and the power comes to quickly coming out of the corner tending the make the car understeer or Push for the NASCAR fans. My street car doesnít have near the grip as the track car and has a lot more understeer built into it, but the coroner speed in the race car is much higher and Iím in the gas much sooner. So I want the power to come in a bit slower and not hit like a sledge hammer.

Right now Iím leaning to the GTX2863 with a larger .82 a/r. Still need to get my motor back so I have a bit more time.

The GTX series will spool a little faster from what ppl say. and the 2863 is smaller then the 2871, so spool will be faster also. The GTX is overkill for what you need. the Gt2871r with a .82 housing will give you all the power you want with a nice spool up. Also your gonna have to use more throttle control to hold the spinning out of the corners.

Schroeder02 05-09-2012 12:14 PM

Thanks for the info, I’ll give the 2871 a go then.


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