Who does your tuning?

 

Yes, you for sure need a retune with a larger turbo.

 

try granite state for yor tune. ive been very unsatisfied with dons work tuning wise as also is the same with my friends from up here. heard granite state is amazing to work with and they will tune a 671 blow big block to a supra to any ls powered anything fwiw

 

I went to slowhawk, which is who RST is talking about. For what hes done for me its been fine so I dont know what to tell you.

 

So I think I found my issue with my wastegate, its got a little toasty



Those yellow plastic pieces have never melted before

I took it apart some more and there was no lubrication left and all the white residue in it, so I cleaned it all out and put some new grease in there





Aside from that the new turbo went on good, put some an fittings on my oil drain too so it'll come apart easy now















Got my new boost controller in too



So my plan is run 12 psi now

Trucks down at the tuner now and he'll hopefully get it done by the end of the week

 

So I got the truck back and WOW what a difference. It just barely stays hooked up in 1st gear now I love it

Don put it to 10, he said it seems happiest there and Id agree since at 12 I only gained 10 hp and 5 ft/lbs torque, I dont know why, maybe the turbo is out of its efficiency there. He was also confused about why the power falls of in the upper rpms, on lower boost it doesnt do that. He said the cam may have been degreed? Which I didnt know you could do with our motors

The the three numbers are
Torque
HP
Boost



This was also only done in 2nd gear



He also said going down the road the longer you hold it open the higher the IATs get so maybe I will get that 4" IC

All in all im still wicked happy with the new turbo

 

Awesome! Congrats

New turbo is 78/76 what was the old one?

 

Old was an On3 76/64

 

Power still seems low for 10 psi and if it's a true 78/76 turbo, it shouldn't be falling off at 12 psi unless there's massive backpressure issues.

 

Well its 4wd 2500hd with 33s so im not surprised that its low on power compared to others. And as for backpressure i dont see how it would, its a 3 inch downpipe to a 4 inch duramax catback system