understanding turbos

Dustin27987

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Dec 1, 2005
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What is the difference in the different compressor covers? I've heard people talk of E's, S's and all different types of covers and i wanted to know the difference in them. On the same note i would like to know about the different types of trims. thanks for any feedback
 

RUQWKNF

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May 26, 2001
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Ok, I know I've posted tons of pictures in the past but I'll do it again for all the new turbo owners.

TO4E compressor cover

PTE casting with 3" inlet and 2" discharge.



It has a .60 A/R ratio and comes on the following turbos.
TE-32, TE-34, TE-44, TE-60, PT51, 52, 53, 54, PT61, T63E, T64E, PT6776E, PT6776RE, GT6776E, GT6776RE. Those last 4 are the same thing, just journal bearing and dual ball bearing. Does require one of the backing plate brackets to be welded to either a standard spring or heavy duty spring wastegate actuator.





TO4S compressor cover

Garrett casting with 4" inlet and 2.5" discharge. Requires a very specific cnc machined bracket to get the wastegate to bolt up close.




It has a .70 A/R and is available on these turbos.
PT61, TE-60, 60-1, PT6776S, PT6776RS, GT6776S, GT6776RS.



Old PTE H cover.



PTE casting with 4" inlet, 3" discharge. Actual A/R was never published, but was close to .75.





New PTE H compressor cover.

PTE casting with 4" inlet and 3" discharge, it has a .75 A/R ratio and the Precision logo casted into the discharge.



Does require one of the backing plate clamps be welded to the actuator for proper wastegate orientation. Turbos this cover is available on, PT6776H, PT6776RH, GT6776H, GT6776RH (again same turbo just different name from different vendor) PT7076H, PT7080H, PT7080RH, PT7180H, PT7280H, PT7280RH, PT7480H, PT7480RH, PT7680H, PT7680RH.
And on non 3-bolt Buick setups, PT70GTSH, PT71GTSH, PT72GTSH, PT74GTSH, PT76GTSH, PT88. Those 70 series turbos should also be available with the dual ball bearing cartridge as well.




Now here is the old school comp cover from way back in the day.

Garrett casted 3" inlet, 2.5" discharge compressor cover.



This cover was used on the old school TE63-1, TE64-1, TE68-1, TE70-1 and TE72-1. It has a .55 A/R and is very hard to come by today. It also required one of the backing plate clamps to be welded to the wastegate actuator for it to bolt up.

These are the covers that are/were sold by PTE.

Hope this helps.

Patrick
 

RobV6

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May 31, 2001
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RE: State

That very cool. Ma to know that much about. A subject I'm
trying to figure on buying very soon Thanks again...even though I didn't start
this one.....ROB
 

ThebigbadWolF

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Jun 26, 2013
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Ok so, what would be the reason to ADD a bov if the car dosent need one?

not to thread jack, just I recently purchased my first g body, and it has a BOV mounted to the up pipe.


long story short is I need to replace the up pipe, and idk if I should include the BOV or not.

from my understanding the BOV releases boost to keep your throttle body blades in stock location and not inside the motor :)
 

we4Mateo

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Apr 7, 2010
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Ok so, what would be the reason to ADD a bov if the car dosent need one?

not to thread jack, just I recently purchased my first g body, and it has a BOV mounted to the up pipe.


long story short is I need to replace the up pipe, and idk if I should include the BOV or not.

from my understanding the BOV releases boost to keep your throttle body blades in stock location and not inside the motor :)
Do a search but this is a VERY contested and MUCH debated topic. Bottom line, do what you like...

Posted from the TurboBuick.Com mobile app
 

ThebigbadWolF

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Do a search but this is a VERY contested and MUCH debated topic. Bottom line, do what you like...

Posted from the TurboBuick.Com mobile app
maybe its because I am new to this forum, but the search button and I don't get along well. ill try lookin more

thanks
 

jlat

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Jun 3, 2009
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hello people; I'm new to ID ing turbos. So what does a stock turbo have?
IBBY
 

bison

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Dec 19, 2005
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hello people; I'm new to ID ing turbos. So what does a stock turbo have?
IBBY
Its basically the same as a T04B internally. Very small and suited for small compressor wheels. Probably the most important thing about compressor covers is the diffuser and it has yet to be mentioned. Its the part of the compressor cover with the radius on it where the air is flung through the nozzle. Larger diffusers raise the potential for larger compressor wheels to let the air undergo the energy change more efficiently it does as it moves through the compressor. The size of the inlet and outlet DO NOT determine the size or potential of the diffuser. The Garrett cover pictured above with the 3" in 2.5" out has the largest diffuser of any of them pictured and a lot of potential.
 
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Two T's

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Thanks Patric and Bison like the tec info it is clear and helps people understand more about our cars I like it when brought down to basics. I get lost in the termonoligy you guys are great.
 

RIFF RAFF

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Nov 30, 2010
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Ok so, what would be the reason to ADD a bov if the car dosent need one?

not to thread jack, just I recently purchased my first g body, and it has a BOV mounted to the up pipe.


long story short is I need to replace the up pipe, and idk if I should include the BOV or not.

from my understanding the BOV releases boost to keep your throttle body blades in stock location and not inside the motor :)
WHAT !!! WORD IS IT MAKES YOUR TURBO LAST LONGER .. NO BACK FLOW THRU THE TURBO WHEN YOU LET OFF THE GAS . BUT I LIKE TO SCARE PEOPLE SO IM GOOD WITHOUT ONE .
 

sscamino

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Aug 3, 2010
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Yes, I use 50mm Tial BOV to get rid of pressurized air so it doesnt go back threw the turbo, this can ruin the shaft bushing .Im also running PTE 6766 CEA with ported S cover (refer to the pic below) that helps get rid of pressure by recirculating air caught by fast closing of the TB. With both of these Im double covered.The other pic shows about the only room to put a BOV.
 

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robzombie

Well-Known Member
hello, When you buy turbo covers you must keep certain things in your mind. The lowest priced way to rebuild the turbocharger is to be able to rebuild a turbo by you. However, if you were to grab a turbo, without having any information about how to rebuild the turbo, and simply begin taking it apart. When choosing a new turbo, you may not know that you have different options for the actual compressor cover. This is often only true for non-stock location turbos. Stock location replacement turbos normally only have one compressor cover option in order that they fit in the stock.


Are you FN kidding me!!!

Take your batmowheel ass back to the future from whence you came.

Nice setup ya got there chuckles. :rolleyes:
 

NY Twin Turbo

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Dec 10, 2014
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where is the blow off valve on a 87 BGN
We as "a group" generally don't use them. Buick never put one on the car. There are some few members here who have installed one and justify its existence with real techno info. And that's OK. Putting one on to hear that stupid fart sound is not OK.

-I think If you want to impress all the inner city ghetto type ricers in the make believe cartoon racing world, then this should be just the right upgrade for your TR.
-Or you have some sick high revving road racing combination that makes a gazillion horsepower.
-Or if you get it for free.

Other than that..........It has no business on a TR.
 

Phoneguy

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Aug 27, 2002
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My 6766 BB turbo just ate a bearing ...

Less than 2000 miles on it , I ran it a handful of 1/8th mile runs ....

I would say it can't hurt to have one but I hate the sound of them !!!

I may just put one on....:(

Bryan
 

robzombie

Well-Known Member
My 6766 BB turbo just ate a bearing ...

Less than 2000 miles on it , I ran it a handful of 1/8th mile runs ....

I would say it can't hurt to have one but I hate the sound of them !!!

I may just put one on....:(

Bryan
I have to agree with you on that one. Slamming the throttle shut at full boost has got to be like hell on a turbos bearings BB or journal.

I get a mental picture of what the stress must be like when something goes from 100,000 plus RPMs to almost 10,000 or less in a split second. OUCH!!!

I have EFI live on my diesel and whether real or estimated it shows that the turbo idles at 14/15,000 rpm and I've seen it as high as 180,000 at full throttle.

I will see what the speed decrease is with that setup tomorrow when I lift the pedal at full boost. It is an electronic VGT so it may have different results then we do with our TB setups but now I'm curious as to how much and how fast they decelerate.

I will take a vid and see what the results are. LOL