I have a stock 4.8 with ls6 springs, and im using an on3 70mm BB turbo from my buddies mustang when he had it, it has a .70 a/r on compressor side and .80 a/r on the turbine side.

My question is that too small of a turbine side for my truck, it spools up instantly which is great but i think its not pushing the air out the exhaust fast enough and its causing my engine to get hot. if that makes sense
Thanks

 

My 66mm is .91 ar exhaust and it starts spooling at about 2300 and no problems... Does it hold boost for as long as you want it to?

 

How big is your downpipe?

 

So is the engine over heating? If not then no its fine...

 

It holds boost till it starts gettin up top and it starts pulling timing and i can feel it slowing down, see im thinking my exhaust AR is too small

 

Its 3" for about 12", then 3.5" all the way to the rear axle

 

Yea my water temp is fine, but the engine itself is gettin hot under boost, driving is normal but when i start boosting no matter if its cold outside my engine gets hot

 

that's normal.

 

Sounds like your intake temps...get a better intercooler or spray meth is the only solution really.

 

I have the biggest intercooler i can fit in there lol, i had to cut away s good bit of my bumper to get in there, i have a snow performance stage 2 kit just havent had a chance to put it with a 28/14 schedule and just had the second son, but ima try to get it on there when i get home and see what it does, thanks for the input