Chris White

To answer an earlier post - you measure the air temp AFTER the intercooler. You want to figure the density/volume of the air in the condition that it is mixed with the fuel.

J Chen

Sorry Edman,
Last question. Do you remember the OD size
of the oil drain hole on the engine mount &
how deep can we tap into it ?

Sorry & thank you again

Laust Pedersen

Just curious, but what is this large area outside the compressor impeller diameter? It appears not to be connected to the housing interior.
If it was connected to the interior, it would probably move a lot of air at the cost of the ability to generating pressure.
Laust

Edman951

J Chen.
No problem am happy to answer your question.
I will get you the exact size and thread for the adapter i used. But later today when i get home.
You can thread the adapter very deap into the mount because its a straight hole.

Edman951

Laust,
Those hole are there for 2 reason.
1- the design of the housing is made to reduse compressor surge when you get off the gas. these hole are their to catch the boost that rebounds from the closed trottle plate. This design first started in diesel truck since they don't have blow off valves.
And since the T04E is a truck based turbo. You get that into the GT if you used that particular housing.

2- Those hole also feed small vent grooved into the end of the housing. Kinda like a small slot. To feed the big part of the compreesor wheel. (major) This help increass spool up at low pressure.
For example my car can boost a solid 5psi by 2000rpm. And as soon as i press the gas. Then it raises to 10psi by 2800-3000rpm.

I don't know if you understand what i mean.

Laust Pedersen

So a small portion of those 4 peripheral slots are actually open into the larger portion of the compressor wheel?

In that case it is like blowing on a small straw with an opening into a larger straw, which increases the airflow, but limits the pressure (at the end of the larger straw).

By changing the size of those slots the flow characteristics can be changed without having to re-design the whole thing.

I see what you are saying on the BOV and the closed throttle pressure wave, which all makes sense. I can also see that it will create low pressure early.

johne

Edman951,
Holy cow this is great information. This is exactly what I plan on doing to my 951 within the next month or so. Thanks for the excellent writeup. If you don?t mind though I would like to pick your brain for a couple more details:

1) I am very interested in the crossover pipe connection. If you could provide more pics of the ?adapter? you made that would be great. If you could provide some measurements or perhaps a ruler beside the ?adapter? that would be really awesome.

2) The oil drain/turbo mount adapter. If you could provide some picks of the middle section and/or measurements that would be pretty sweet too.

3) Do you know the diameter of the outlet of the exhaust turbine and the space between 2 studs(diagonal or horizontal). You said your 3 inch downpipe fit perfectly, so I am wondering if my stock 2.5inch downpipe would fit great as well.

4) Where did you buy your turbo, and how much did you pay? I am wonder who all has good deals on T03/T04e turbos.

Thanks a million man, this post made my day.


Regards,
John

Luke

AWESOME!

Edman951

Thanks Luke,

Johne,
1)
For the cross overpipe it was fairly easy.
I did not really use an adapter. And even if i give you the mesurement of the angle i cut the pipe, it might not be exact when you come to do it.
So its really a custom piece.
This is what i did.
I bought a T3 steel flange an a 90deg 2-1/2’’ SS bend. I cut the 90deg to the angle required to line it up to the crossover pipe ( COP) and welded it to the t3 flange. Then i cut the COP to line up with the new flange bolted to the turbo. After some good welding by my friend. We got the new 2-1/2’’ pipe to fit good on the 2’’ COP. Some porting is required on the flange to ease the flow into the turbo.

2)
The adapter used consists of 2 parts.
The flange is a standard t3 oil return flange and it about 3/8'' thick.
The other is like this one, On the big end its about 3/4'' and the small end 5/8''. I don't know the thread but they are standard pipe threads. (NPT)


I will try and take picture of it on the car for you guys. And get the exact thread

3) My LOWER downpipe is 3''. But the upper is factory 2-1/2''.
I can give you the bolt spacing tomorow of the old turbo if you want.

4)
I bought the turbo from a local guys near my town.
http://www.euroracing.org/pages/3/index.htm

Her is the Garrett tag that is on my box the turbo came in



Hope this help

turbo951fan

It's only oil cooled I assume. I had a water/oil cooled KKK 27/6 before and you can really feel the difference when going to oil cooled only.

RajDatta

I have a garrett dual bb GT30 and it looks nothing like this turbo. The inlet is completely different. I did not have any issues fitting it with AC as I used a puacil 4-3 inch reducer. I will have some pics soon.
I guess there are a few turbo's out there being called GT30.

Sam Lin

What are you talking about?

Raj, with any of the GT__Rs, there are so many configurations available that within the broad model number, there can be quite a few different housings and appearances.

Sam

Edman951

My gt30r turbo is oil and water cooled.

And a GT30 turbo is like a ford F150.
With all the option available, they are not all the same.

Tomas L

According to the Garret catalogue (can be downloaded from the Garrett website, www.egarrett.com) there is only one GT30R. It has part # 700382-12 and it consists of a center section and a compressor with A/R 0.60 and trim 56, the inlet is 4". The turbine wheel is 84 trim. The turbine housing however must be ordered separately and there are two sizes available, one A/R 0.82 (part # 740902-1) and one A/R 1.06 (part # 740902-2).

The GT series (as it comes from Garrett) has it's own compressor and turbine housings.
Quote from the catalogue.
"The GT designation refers to Garrett's state-of-the-art turbocharger line. All GT turbos us modern compressor and turbine aerodynamics which represent huge efficiency improvements over the old T2, T3, T3/T4, TO4 products. The net result is increased durability, higher boost, and more engine power over the older product line."

I can understand why a T3 turbine has been fitted as the GT turbines may be to large, but are you sure that the compressor is a TO4?
This appears to be a genuine Garrett GT turbo apart from the turbine (which there is a very logical reason to replace) but there seems to be many companies assembling turbos from older Garrett part and selling them as GT turbos.

Tomas

Edman951

Tomas,
The new GT turbo that are in the catalog are off the shelf turbo.
You can custom order anything you want from garrett.
It clearlly says it in the catalog.

Now all turbo's from garrett are based arround the original design.
Like my turbo is the newest released from garrett but it's still build with the same "Garrett family" housings. Either T04E,T04S. but they are machined differentlly for every wheel that goes in it.

And i can confirm you that my GT30R uses a T04E .60a/r comp housing.
And can be considered a t3/t4.