Engine/Transmission (1994 - 1998) 94 all stock,what should max boostbe?

[DickersonD]

I finally got gauges and my max boost is about 16psi. I am wondering if this is normal for an all stock 175 hp truck. It is a five speed. I assume I have the hc1 turbo and if I start doing mods,what psi of boost is this turbo most efficent at?I am considering the #5 plate from tst. Does anyone run this plate in a 94 five speed and are you happy with it?

 

[CToney]

The 175hp trucks are supposed to run 15-19psi in stock trim. I would not run anymore than 35psi of boost after that the turbo is out of the effiency map. Stock headgaskets don't like too much boost either. Some guys check torque on the headbolts before they add any more fuel. The #10 plate seems popular no matter what truck you have and can grow with you (ie slid forward for more fuel) and not affect the drivabilty too much. Injectors, boost elbow, and a 3k GSK might also prove to be good mods do some searches to learn more. You will need a boost elbow to control when your wastegate opens. Opens sooner on 175hp than 215hp trucks.

 

[DickersonD]

Thanks, when all I could get was 16psi I was wondering if I had a leak or my gauge wasn't right.

 

[MacMc]

I'm still learning all the ropes about my 96. Only mods are the timing adjusted to 15. 5 degrees and a #6 plate. These were done before I got my boost gauge. I'm getting 32PSI in hard, flat acceleration, and about 35PSI uphill when hard-accelerating from slow. Is this from the mods? I can't remember if there was a significant factory HP gain between 94 and 96, either.

 

[DickersonD]

I think different turbos and different stock power ratings.

 

[CToney]

Probably same turbo, early '94's had WH1 turbo instead of HX-35. '96 autos were 160 or 180hp not sure exactly but I think they were probably 180.

 

[RyanStewart]

Before I put my #10 plate in all I would see is about 16-17 lbs max, even on a hard pull. Your boost sounds about right.