Just finished tuning a stock 6.2 with 72mm .96a/r and the truck would not take timing well at all. The turbo spooled full boost 8lbs at just less than 2000rpm's. I've been getting opinions on the problem, and have heard backpressure may be too high, or the turbo is to small. I did want something that would come on instantly, which it does, but I expected to be able to run more boost 10-12lbs and decent timing. My tuner doesnt want to push the boost any further because of IAT's and low timing. Anybody have experience with something similar, or can offer other suggestions to look at?

 

That turbo is way to small for 6.2. The back pressure is too high because of the small turbine wheel. Need a bigger turbo. A s475 83mm turbine should help a lot and still spool up really fast. Less back pressure will allow you to add in some timing too.

 

Yea your gonna need a decent size turbo.. It will feed it at 12# but its not gonna make the power as say a S475 will on 12#..

Lower the boost or get a bigger turbo.. not much else way around it.

 

Compressor size seems ok for that boost level, 76mm .96 a/r. What's the turbine size?

How much timing?

 

I want to see pics and video of this setup.

Denali08- op posted a 72mm turbo. not a 76

 

So the general concensus is too small of a turbo?

I'll get some videos up soon.

 

I was looking at his signature "Trick Performance Stage 3". Stage-3 comes with T76. I forgot that he mentioned 72mm.

Thanks

 

Isnt Three6GMC running a 72mm? his spools pretty quick

 

I requested something that would spool almost instantly, so we sized a 72mm turbo. It is a trick stage 3.

 

yea, turbine size will help out alot on this information adventure