identifying gm turbo

[just a number]

What I'm looking at is turbochaging the 6.2. I found a 6.5 at the wreckers still in good shape are was thinking about getting the turbo setup off it. I know it's atleast a 94(DS4 pump). can anybody pint me in the right direction as to identifying it and things to look for? it'll be switched or the a DB2 pump. I hate electronics. I'll have more info when I get out again tomorrow.

 

[chevyCowboy]

there is a tag cast into the compressor almost right above the inlet. the numbers and letters are ingraved into it. they can be hard to read sometimes but they are there. was the waste gate vertical or horizontal?

 

[tanman_2006]

A 94 typically has a GM4

 

[bk95td]

A 94 typically has a GM4

Not mine My 94 has a gm8:thumbsup:Maybe that's why it has a 2 piece crankshaft:mad2::sad: They did come with a GM4 from the factory. The GM5 and GM8 have the wastegate actuator like the one in the pic.

 

[just a number]

I knew you guys would have the answers. anything to look for as for as possible problems with it? what does the gm4 use for a wastegate setup? vacuum, spring or something else?

 

[ak diesel driver]

AFAIK all gmx turbos used a vacuum wastegate. the sping setup is a turbomaster.

 

[chevyCowboy]

93 does not use a vaccume acctuator they are spring. not a very stiff spring. im pretty sure that 94 is when the vaccume pumps started showing up

 

[GM Guy]

92 and 93 had a spring setup from OEM. just non-adjustable though.

EDIT: Chevy cowboy said it before I refreshed!

 

[just a number]

how hard is it to change it to a spring setup? I don't need more parts I can break.:mad2:

 

[chevyCowboy]

pretty easy you can make your own out of the vacume can. you cut the top off weld in a piece of 1/4 allthread or bolt and put a spring in. thats the long and short of it any way

 

[just a number]

1/4 allthread??

 

[ak diesel driver]

yes the shaft in there is too small. I threaded one with a #14 machine screw die had to squish the nuts to grip it hard enough. #14 is also very hard to find

 

[bk95td]

on the left gm4 on the right GM3

 

[tanman_2006]

Not mine My 94 has a gm8:thumbsup:Maybe that's why it has a 2 piece crankshaft:mad2::sad: They did come with a GM4 from the factory. The GM5 and GM8 have the wastegate actuator like the one in the pic.

Damn them better turbos! lol

When you get the turbo check for play in the shaft and look the blades over to make sure they havn't been rubbing on the inner-housing.

 

[tanman_2006]

on the left gm4 on the right GM3

Your GM4 w/o paint looks WAY prettier than mine! Mine has the awesome special edition rust coat! My CDR tube has oil leaked onto everything too.

 

[6chevy9]

my turbo has the numbers 123975 next to the inlet on the plate? i thought it was a gm8 but it has the horazontal arm. it does push around 18 psi though... just curious as to what it is. i know for fact its brand new

 

[tanman_2006]

my turbo has the numbers 123975 next to the inlet on the plate? i thought it was a gm8 but it has the horazontal arm. it does push around 18 psi though... just curious as to what it is. i know for fact its brand new

If it is new I think the plate should be painted black and GM? should be on it in silver letters. My 95's is missing the paint now so all it has is a serial # stamped in it.

My 94's is new and still has shiny black paint with GM4 on it.

 

[6chevy9]

there is no paint on it and i belive it came from the "wonderful" ( hahaha ) ss diesel. i was told its a gm8 but it has the horazontal vacuume rod set up? i could take a picture but i wouldnt know how to post it lol.

 

[tanman_2006]

Saving the pic on photobucket usually works, then transfer the link or HTML (i think) to the post you are making. I haven't posted a pic on this site yet.

 

[6chevy9]

well im at work and photo bucket is blocked here i guess it will have to wait. any idea on what kind of psi a 6.5 can safley and reliable handle with nothing more done than injectors and arp head bolts?