Question regarding Garrett .63 vs. Precision .63 exhaust housings.

V6UnderPressure

The Artist FKA Scott4DMny
May 27, 2001
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I’ve been idle for a while and trying to get familiar again. We know that a Garrett will spool quicker than a precision housing if using the stock converter. If using the same turbo with a precision exhaust housing yet using a proper (higher stall) converter in order to match the Garrett spool time, I’m assuming there’s no other downsides to using the precision housing besides extra transmission heat from the higher stall. This sound about right or is there something I’m missing?
 

deezdad

Active Member
Mar 25, 2005
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My understanding is stall speed should be matched with Cam rpm range so going to a higher stall would make the usable rpm range smaller.
 

SCOOBY DOO

Stock Junk Rules!
Feb 18, 2007
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If you're using Erics chip, the low gear fueling is usually pig rich. Dial in the low gear fueling and timing...and watch how much faster the Precision housing spools. Most can't tune...so they'll immediately go to a looser convertor.
 

V6UnderPressure

The Artist FKA Scott4DMny
May 27, 2001
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what info do you seek?list the combo and goals.most dont even know how the ex housing plays its part.
Straight 93 octane street car, stock spec roller cam, valve springs, te44, front mount, 62mm plenum/precision plenum/rjc pp, downpipe, exhaust, Would like the additional top end with the precision housing for the highway...seeing if possible to get that while getting the spool close to the garrett...
 

Mr.Spool

Well-Known Member
Nov 6, 2006
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Would like the additional top end with the precision housing for the highway.
it will not give you top end.you are limited by running very low boost with 93 and when the car gets into high gear and the goes 1.1 it will fall on its face with low boost.the 44 will really wake up at 25psi.a larger ex housing will make the power come in more gradually and since you are nowhere near backprerssure limitations with the loss of torque you will slow down.fyi we didnt see any gains over the stock turbo untill boost was over 23psi.i also went 125mph in the 1/4 on a 49 with a garret.63.the pte.63 did the same the compressor/turbine wheel was the limitation
 

SCOOBY DOO

Stock Junk Rules!
Feb 18, 2007
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Around town driving in regards to responsiveness would prolly be lessened if you've retained the stock D5 with the larger Precision housing.
 

V6UnderPressure

The Artist FKA Scott4DMny
May 27, 2001
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New Lenox, IL
it will not give you top end.you are limited by running very low boost with 93 and when the car gets into high gear and the goes 1.1 it will fall on its face with low boost.the 44 will really wake up at 25psi.a larger ex housing will make the power come in more gradually and since you are nowhere near backprerssure limitations with the loss of torque you will slow down.fyi we didnt see any gains over the stock turbo untill boost was over 23psi.i also went 125mph in the 1/4 on a 49 with a garret.63.the pte.63 did the same the compressor/turbine wheel was the limitation
I was aware that the stock turbo could probably be enough for me. Was looking for something a little more. Back in the day with similar combinations and boost levels the larger turbo seemed to pull harder a little bit. So maybe even a 44 is overkill.
 

V6UnderPressure

The Artist FKA Scott4DMny
May 27, 2001
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New Lenox, IL
Around town driving in regards to responsiveness would prolly be lessened if you've retained the stock D5 with the larger Precision housing.
That’s what I’m saying though. I’m trying to compare stock turbo/stock converter with te44/2800 stall. Spoolup wise how much difference...
 

SCOOBY DOO

Stock Junk Rules!
Feb 18, 2007
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That’s what I’m saying though. I’m trying to compare stock turbo/stock converter with te44/2800 stall. Spoolup wise how much difference...
It'll spool slower with the larger housing. Try both with PL...you'll know exactly time wise what the difference is to get to the same boost/RPM on the line.