TURBO info required

[tank140]

Hi all

Does anyone know what is the differance between the GM turbos?

i.e. GM3 GM5 GM6 GM7 GM8

what is the main differance of the turbo?

as i have a GM8 on my 6.5 V8


anyone know?


cheers
tank

http://i21.photobucket.com/albums/b264/tank110/140aug20063.jpg

[Robyn]

Mostly its in the bracketry and such and how the wastegate actuator is mounted.

The basics of the turbo are about the same I am led to believe.

The compressors specs are the same inside.

Also I can't say from actually taking them apart and comparing but this is what I have been told.

The only real differences as I mentioned are slight running changes to suit other changes in the build such as air filter type and location.

The early turbo trucks did not have the top brace bar that ran from the engine to the turbo oulet casting.
This was added later to either stop cracked manifolds or as an after thought to prevent it.

The early turbos (92-93) had a spring device on the wastegate that worked just like a turbo master other than it was set at a fixed boost level.

The GM 4 was used in 94-95 and these were basically the same except they had the vacuum controlled wastegate actuator that ran off the computer control.

96 saw some changes in the air filter design on some models and the wastegate actuator was relocated to work with these changes.

Again the overall design is very very similar all across the lineup.

Some of the guys here that have worked with the turbos a lot may know of any real internal differences but I dont think there was much change.

One of the biggest issues with the GM-X series is the exhaust outlet housing. The flow through these is not the best and under high boost levels the backpressure starts to climb and they tend to hold a lot of excess heat in the heads.

If you have the room to work with, there are far better turbos out there that will really flow some air through these engines.

A better flowing turbo will really help lower Exhaust gas temps.

As far as what GM-X to use, its a mix and match game pretty much.

Use what you find and modify to suit the application.

Beat to fit, pound to suit and paint to match :D:D:D

Just a little humor

Missy

[tank140]

Hi Robyn

Many thanks for the info on extracting the GLOW plugs with expanded ends.
It was still a bitch of a job with the injector out as the end of the glow plug was to long for the chamber i had to use a 8 mm allan key to bend the sucker to fit in the chamber, but i got the suckers out took me about 2 hours to get the two out.

at one stage i thaught i needed to take the dam head off but abit of poking about sorted it

many thanks

tank

[Robyn]

Didn't say it was easy :D just that it was possible.

So glad you got it done OK

OH BTW, Lovely Pix of your rig.

Best

Robyn

[john8662]

FYI GM6 & 7 are center mount turbo's H1 & Savanna Van engines.

J