best size turbo

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02-20-2008, 05:08 PM

#21

powerhouse7256

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so what kind of power would a 50 trim with .48 a/r see at say only 6-7 psi? something similar to the stage 0 like 230whp?

02-20-2008, 05:10 PM

#22

20tCDude05

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Depends on altitude, temperature, everything.

02-20-2008, 06:33 PM

#23

Guru

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Quote:

Originally Posted by 20tCDude05

I just basically told you. The higher the A/R, the more lag. So, a 50 trim with .48 A/R will spool much quicker than a 50 trim with a .63 A/R. ALSO, a .48 A/R has more low end power whereas a .63 A/R has more top end power.

That is a VASTLY oversimplified statement. Remember it isn't just about lag. Too small an AR for the displacement and rev range and your turbo will run out of steam at the top end, start knocking easier at lower boost levels and make your EGT's go sky high. Personally I would never go smaller than a 0.63 AR unless the turbine was HUGE (bigger than a GT35R) which you will have trouble finding. I use 0.82 housings on all the turbo's I do unless the motor is built in which case I use 1.01 housing. Lag is no issue with the large 2.4 motor. If you want torque use a smaller turbo like a GT30R or even a GT28R and keep the AR ratio moderate like 0.63. You'll be happier but don't expect to use it if you build the motor. Two completely different animals. Keep in mind with a large GT35R and 0.84 AR ratio housing, you can still make 340+ Ft lbs of torque to the wheel at only 10 lbs with a standalone ECU and proper supporting mods. If going piggy back may want to use something smaller and be cautious with boost.

02-20-2008, 06:40 PM

#24

Joe_Dezod

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AR is more of a fine tuning system for the selected turbine size and trim.

To the thread starter, we spoke earlier on AIM, so you've heard my suggestions.

02-20-2008, 07:22 PM

#25

powerhouse7256

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yep thanks for the help joe!

02-20-2008, 10:52 PM

#26

t_urbo_C_harged

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Quote:

Originally Posted by Mightygnu

Well if you are going to do some internal work, why not build the head so you can rev out that motor and put full use to that turbo. get that baby up to 7500rpms and see how that snail feels.

well when I say built motor, I include a built head along with it... to me, a motor isn't completely built until the head is also done as well... thats a built motor, if it is just pistons and rods then to me thats just internals... no if I am taking the motor apart everything is going to be built up, well everything I can build anyway....

so you would agree and say go for the 60 trim??? I would like that redline!!!

thats around my goal redline anyway :D

02-21-2008, 07:32 AM

#27

Mr_Meaty

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powerhouse:
I thought you had a used zpi stage 0 kit?
Anyway, I have a 54 trim .63 ar and I'm making 252whp at 5psi...I had it up to 320 at 8psi, so it's got room to grow.
It's not as quick as a smaller turbo, but it comes on quick enough. I think anything quicker would give you traction issues. and it's GREAT on the freeway.