Precision Turbos New Turbo Listing for Buicks !!!!!!!

2QUICK2B6

Black Car Fever
Sep 15, 2004
2,481
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My 6768dbb billet wheel on a stock longblock feels alot better than a 70GTQ on a built TTA with worked stock heads !
 

RUQWKNF

KEEPER OF SECRETS
Staff member
May 26, 2001
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Actually, we still carry the 6157 turbo. The new school list only included the newer billet compressor wheel and HP series model turbos. Not the ones that have been sold under the GT series nomenclature the past few years.

AXA,
Thanks for the kind words. Honestly, the only difference between those three models, are turbine wheels.

HPQ turbine wheel measures 3.111" inducer, 2.693" exducer with 75 trim.
HPS turbine wheel measures 3.228" inducer, 2.956" exducer with 84 trim.
The turbine wheel used in the Billet HP4271, (or what is now known as the HP7175) is an 82mm turbine wheel with an 84 trim. (aka GT42)

Spool up would increase going from the HPQ on up. Exactly how much, is going to be combination specific. In the Buick world, it can be as much as 300-400 rpms. The dual ball bearing cartridge, would dramatically help alleviate the difference.


The Billet 76 compressor wheel, is available with the HPQ or HPS turbine wheel. The cast 72mm HPQ, cast 74mm HPQ and both cast and billet 76mm HPQ were left off the list because, this New School list best represents what 90% of the Buick market currently runs in a 3-bolt turbine housing configuration.

For the record, we still carry Garrett parts and turbos.
Hope this helps.

Patrick
 

AXA

New Member
Dec 5, 2009
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Actually, we still carry the 6157 turbo. The new school list only included the newer billet compressor wheel and HP series model turbos. Not the ones that have been sold under the GT series nomenclature the past few years.

AXA,
Thanks for the kind words. Honestly, the only difference between those three models, are turbine wheels.

HPQ turbine wheel measures 3.111" inducer, 2.693" exducer with 75 trim.
HPS turbine wheel measures 3.228" inducer, 2.956" exducer with 84 trim.
The turbine wheel used in the Billet HP4271, (or what is now known as the HP7175) is an 82mm turbine wheel with an 84 trim. (aka GT42)

Spool up would increase going from the HPQ on up. Exactly how much, is going to be combination specific. In the Buick world, it can be as much as 300-400 rpms. The dual ball bearing cartridge, would dramatically help alleviate the difference.


The Billet 76 compressor wheel, is available with the HPQ or HPS turbine wheel. The cast 72mm HPQ, cast 74mm HPQ and both cast and billet 76mm HPQ were left off the list because, this New School list best represents what 90% of the Buick market currently runs in a 3-bolt turbine housing configuration.

For the record, we still carry Garrett parts and turbos.
Hope this helps.

Patrick
Thanks for the rapid response....

I am between a 6768 DBB and a Billet HP4271RL.
The PT Billet 6765 in the Supra world is making from 800 to 850 WHP on a manual 6 speed equip car on E85 and gas application between 30 and 35 PSI of boost.

My transmission is a big 4L80E and I need 750 WHP in my application to reach my goals at the track.
I love the spool characteristic of the billet 6768 dbb on the 2JZGTE but I am afraid that the 6768 dbb will come out a little short for my WHP goals to to my drivetraing lost do to my transmission that has a 15% more lost than a Supra 6 speed transmission.

Thanks again...
 

John Wilde

I'm getting too old for this $#!%
Staff member
May 27, 2001
8,463
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If there is a big concern about my post it can be deleted.
There certainly was no ill will intended.
I thought Harry was developing and manufacturing his own designs and moving away from using other OEM.
My wording was a little strong and definitive about the Garrett parts.
They still have and use Garrett parts on some turbos.

BTW I have only run Precision Turbos on my three turbo regals and
I have known Harry for years, there is no hidden agenda.
Patrick and I spoke and everything is cool.
 
Nov 14, 2005
680
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Amherst,NY
No harm done.I was just wondering why it wasnt on the list.I didnt know where it fell in the list seeing i just bought it about a year and a half ago.I have no problems with it and it works great for me.
 

GNBRETT

Pelennor Fields
Feb 8, 2004
10,601
238
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Middle Earth (Connecticut)
This is the type of misinformation that starts rumors and causes big problems
for vendors. Even worse when is comes from someoone like you John that people look up and believe.
I doubt it caused any vendors a BIG problem. In fact I doubt it caused ANY vendors ANY problems. Lets not blow what John said out of the water here:rolleyes:.
 

Dean

Senior Member
Jul 26, 2002
470
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San Francisco Bay Area
Patrick, thanks for the updated comparison charts, it was certainly way overdue.

Now for a question on the ported shrouds - Under what circumstances should one consider a ported shroud compressor housing? I understand the point of the ported shroud, but until turbo "X" is on the car, you wouldn't know if surge was going to be an issue.

Thanks again for your efforts and providing this community with information.
 

V6UnderPressure

The Artist FKA Scott4DMny
May 27, 2001
2,512
30
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New Lenox, IL
Since the housings will need to be remachined (if possible) and the backplate is different in most cases a Conversion/upgrade will have about the same cost as a New unit, may be most cost effictive to sell the old and buy new.
Mike
What about a rebuild on the older units, will precision still be doing those? Or once our old turbo is shot, they are trash???
 

TurboTR

sprayhead
May 25, 2001
1,167
1
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Austin, TX
www.amd.com
Here's a representative compressor map comparison, to help get an idea of the increased steam available from the new GTX wheel:

TurboByGarrett.com - Race Updates






This map is for the 94 mm 56 trim at least (should be a 70 mm inlet); it goes to near 100 lbs min with the billet wheel. Pretty impressive!

Patrick, in your experience does the smallest available a/r in the T4 flange GT series being 1.01 sort of take them out of consideration for most Buick street cars? Or can the new GT turbos somehow spool like say, an old T4 .81 tangential would on a Buick? That's what most of us have to compare with at least.

Thanks,
TurboTR
 
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edv2

SPOOLIN' NO FOOLIN'
May 31, 2005
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Visit site
Thanks pat!!!

I JUST WANTED TO SAY THANKS PAT FOR TAKING THE TIME TO FIGURE WHICH TURBO WAS RIGHT FOR MY APPLICATION!GREATLY APPRECIATED,CAN'T WAIT TO GET IT AND THE NEW INTERCOOLER ON THE CAR!JUST HOPE THE STOCK BOTTON END HOLDS TOGETHER FOR A 10 SEC, PASS :biggrin:
 

Steve V

Steve V's Automotive 757 560 2782
Jan 5, 2004
4,108
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Elberon,Va
Just installed 5857 on petes gn last week and happy to report no surge like the 44/49's 21-25psi with alky.
 

king kong

Better,Stronger,n Faster
Jun 28, 2010
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i just installed a 6765 about a month ago and i LOVE IT! serious if you have the goodies to go along with it! And by the way a 6765 is a 900HP rated turbo.....:tongue:
 
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