Author Topic: WTB. 6.5 chevy turbo diesel turbo (Read 7820 times)

SMOKEYDUB · « **on:** June 10, 2006, 01:24:12 pm »

this morning i boosted my engine and my turbo let go so i was wondering if anybody had one kickin around. its a gm-8 made by borgwarner on i believe 94 - 99 chevy pickups flatbeds and tow trucks.

andy2 · « **Reply #1 on:** June 10, 2006, 08:05:27 pm »

I should be able to help you out there.I may only access to GM3 and 4 turbos(92-95).The GM8 is the best out of them and was used from (96-00).

How much boost were you running at the time,Mabye that turbo isn't upto the task,I duno.Could it have been starved from oil as it takes more oil "volume" to libricate.Did you up size the oil supply and oil drain lines?They only run 15-20 psi max on the 6.5 before grenading.

It may be worth looking into an hy35 from a 00-02 dodge diesel (auto trans only).They spool ok and will take 35-40 psi.

Dr. Diesel · « **Reply #2 on:** June 11, 2006, 10:11:24 am »

i guess the question is, if it's a max of 20 psi on a big V8, what's it good for on a little 1.6L?

Quick and dirty comparison:
for ease of calculating, let's say max psi on a gm 6.5 with said turbo is 1.5 atmospheres.
1.5atm x 6.5L = Xatm x 1.6L
9.75=1.6X
9.75/1.6=X
6.09atm=X

Going by this admittedly very rough calculation, it could be said that this turbo should be good for 6 atmospheres on the 1.6L, or 90psi. I believe it's heat and speed that kill a turbo, (ignoring andy2's excellent point about oil supply) not so much boost output. It won't need to spin as fast to make 20 psi on a 1.6L as it would on a 6.5L.

andy2 · « **Reply #3 on:** June 11, 2006, 10:57:43 am »

So as long as oil supply is adequate then It shouldn't have blown,The only reason I've seen these turbos fail was due to various lubrication issues.I'm not sure exactly what size the ol supply line should be,but will find out tomarrow :wink:.

SMOKEYDUB · « **Reply #4 on:** June 11, 2006, 01:30:57 pm »

well i looked at my dads truck and the oil feed is the same size as the one feeding it on my veeedub

DVST8R · « **Reply #5 on:** June 11, 2006, 06:17:18 pm »

Well now that you spent the big bucks and got your new pump you will have to save up and do it one more time for a good turbo:

Garrett GT 30R/25 hybrid would be about the same size as your GM8 but ball bearing and a better turbo, or for less money a straight GT 25R ball bearing turbo, or for a lot more money but the best going a GT30V (dual axis varible vane GT30...

Holset HX-30 or a HY-35.

Just a cople options off the top of my head.

SMOKEYDUB · « **Reply #6 on:** June 11, 2006, 07:12:14 pm »

the specs i know on the gm 8

compressor

inducer 52mm
exducer72 mm
52 trim

turbine 55 mm

andy2 · « **Reply #7 on:** June 12, 2006, 09:32:42 am »

What about the oil supply "restrictor" Fitting on the turbo? It needs to have the correct sized orfice to control oil flow.if the hole is too small then the turbo may not be getting the required oil flow.I would think that the 1.6 oil fitting has a smaller hole than the 6.5 turbos.Which fitting did you use?

I went through this while installing The hx30 and hy35,Very important detail to look at.

andy2 · « **Reply #8 on:** June 12, 2006, 09:34:08 am »

BTW I don't have any GM8's kicking around,mabye some 3's and 4's though.

lord_verminaard · « **Reply #9 on:** June 12, 2006, 06:12:29 pm »

Quote from: DVST8R

Holset HX-30 or a HY-35.

Just a cople options off the top of my head.

Are either one of these "variable geometry"?

Brendan

SMOKEYDUB · « **Reply #10 on:** June 12, 2006, 08:33:05 pm »

gm3 s and 4s are they pretty close in specs to a gm8? i have never seen on my dad has a gm5 on his and it looks identical

DVST8R · « **Reply #11 on:** June 12, 2006, 09:34:39 pm »

Quote from: "lord_verminaard"

Quote from: "DVST8R"

Holset HX-30 or a HY-35.

Just a cople options off the top of my head.

Are either one of these "variable geometry"?

Brendan

No.

The holeset line from what I have seen doesnt get into varible geometry until the Hx-40 size or possibly bigger. [\hijack]

Powjetta · « **Reply #12 on:** June 14, 2006, 12:55:42 pm »

I have the GM-4 on my 1994 truck and the story is from other owners that the GM-8 has more power in the higher rpms, 2750 and up over the GM-3,4. I think you actually would be better off for VW application with the GM-3 or 4 because of the boost at lower flow volumes.