Turbo questions???

[DIESEL5]

Recently my stock 93 6.5 chewed up three main bearings and the journals pretty bad so i decided to buy a new remanufactured long block from Jasper. My question is will any of GM turbos work for a 6.5 work and/or if not what is the option when looking at the after market stuff. This doesn t have any vacuum lines or electrics to it so I am assuming its all mechanical.

[daustin]

Hello,
The '93 models came with the GM-3, i put a GM-8 on mine but any of the GM turbo's 3,4,5,8 will bolt on. The differences are the later models utilize the vacumn waste-gate controller and the earlier ones used a spring. I fabb'd a spring controller for my GM-8, works just fine.
Don

[DaveBr]

Daustin
Did you notice any power increase, performance differences or general running differences between the GM3 and the GM8? I was wondering if the upgrade is worth it.

[daustin]

The -8 builds boost quicker than the -3 and seems to build a little more boost given the same conditions. The -3 through -5 have a very restrictive outlet, and the -8 is much smoother. I took a -8 off a 98 i think, took the vacumn actuator apart and replaced the rod & bellows with a spring off the rear of an older GM drum brake retainer. Took me about 15 minutes to fab it up, i set it with my boost guage to max out at 11psi. I used a poly-lock nut (actually 2 of them) and a large washer to retain the spring. Got the 1/4 rod at home depot, threaded one end and bent a 90 on the other, then drilled a small hole for a cotter pin. I swapped mine 'cause i got a sweet deal on the -8, then sold my -3 on flea-bay and actually made money. lol Aside from the actuator fab, it was a bolt-on swap.
Don

[DIESEL5]

You said it builds more boost quicker, i assume it feels as if you have more bottom end grunt then, and is there any way to set the rod without a boost gauge if i do decide to go to an 8 from the 3. And i assume all other aspects of the overall performance is good?(no harm done to the engine) and thanks for all the great info!!

[DmaxMaverick]

You said it builds more boost quicker, i assume it feels as if you have more bottom end grunt then, and is there any way to set the rod without a boost gauge if i do decide to go to an 8 from the 3. And i assume all other aspects of the overall performance is good?(no harm done to the engine) and thanks for all the great info!!

Just some friendly advice.....

When you modify ANYTHING on the fuel and/or air systems that varies from OEM, you must have, at the very least, an EGT gage. This is to prevent a meltdown. And, without a boost gage, you have no way to see gains or losses from your mod. WAG's, for the most part, are counter productive, and can be very expensive. Your PCM does not monitor EGT's. Just about anything you modify to change performance will have some effect on the EGT's. Most often, hotter.