We here have been getting alot of GM Diesel (Non-Duramax) cust. and want to help them out. BUT being the least popular of the diesel engines, we dont have a firm supplier of parts for upgrading these trucks. ALSO what are the popular upgrades that can be done? I have heard of boost controllers, Injector upgrades, PROM Chip, Exhaust (not sure if that includes the Hummer). What about an intake of some sorts? We want to try to help this guy out and make his truck run...also to help us out for the early Chevy crowd here in town! Thanks much!

Hello Darrell,


Exhausts kits are available from the affordable (summit's flowmaster kit)to the pricey(Banks kit) for the 6.5 with many in between, although the hummer should have a different intake/exhaust than the pickup and require a different downpipe (same as the van possibly). My personal opinion on this is that you should be able to find a exhaust shop (perhaps an 18 wheeler shop)in your area that can make a 3" or 3 1/2" or even 4" down pipe and all. It should be cheaper to make one than order one if you find the right shop to bend it, and then you install it.


Intercooling is an upgrade the 6.5 should have. kits are available from $2500 forced air to under $400 for water injection. and a creative guy could retro fit a ford or dodge chargecooler.


There are boost foolers that plug in from $90 and up but I prefer $1 10K fixed resistors sodered inline off the MAP sensor. good for 2-3 psi across the RPM range.


Proms and reflashes are available but require a "system approach" in that everything I mentioned before this should come first.

we understand the "System Approach" here! We wont sell anything over 80HP for any of the Big 3 without exhaust or intake upgrades. And we dont mean drop in filters! haha....i dont know....we just dont see much of these trucks at all...last one needed an injection pump, injectors and a lift pump....that is how i cut my teeth on this motor...and i will be happy if i never see one again! But when they run...they run great! haha....thanks much for the info.


Also...i wasnt too impressed with the injector "Upgrade" we did on the last truck....didnt seem to do much....Edited by: HPDOFNTX

which injectors did you use?

we used some from Diesel Injection Service up in Washington. They were apx 10% over stock....BUT I didnt drive the truck before we did the pump and stuff....well heck...it didnt run! it drove good after all the work.....and suggestion on injectors? I have been lookin at Kennedy Diesel...but cant get them to answer their phone.....look to have a good set...among other stuff....thanks!

Keep knocking on John's door he's pretty busy, also check out Bill Heath at Heath Diesel JK's IC was $1300 IIRC not sure it will direct fit a HUMMER it did not fit my K1500 nor was it advertised to fit it, maybe you can work up a deal with him you guys R&D a kit, SPEARCO is the IC mfr maybe you can go direct with them also.


I'm not sure what realestate there is for a Hummer check my install and see if you can do something like it http://myweb.cableone.net/tbogemirep/


As big as a HUMMER is WMI might be a better option, unless expecting a lot of time above 10 psi boost where you will need full time misting using a lot of water. Bill's reflash is the best I've tested so far JK has a new one in the works, due out soon.Edited by: Turbine Doc

jk's high pop injectors are supposed to be the best.

I keep hearing good things about John Kennedy......looks like he knows his stuff and has lots of good little tid-bits on the site to help you out....i like people like that....i got a message in to him...guess he should call back tommrow. Thanks for the suggestions......


That IC install was very informantive.....good square peg, round hole install! Looks cool too......