Not sure what year it is but it has a E6 metric 350HP motor in it and it only has like 12-15lbs of boost so its a dog till you get it wound up. My question is how can i make more boost so it has some power.. oh the turbo is non wastegated.

I've never seen a mack engine so can't help you specifically. but bottom line is you have to add more fuel to make more boost.

I've run E-6 350 horse Macks but it has been quite a while back. As near as I can remember they ran around 30 lbs of boost so yours sounds quite low to me. They ran OK for what they were but sure wouldn't have been worth a hoot with only 15 lbs boost. Not sure why your boost would be down unless you have a leak somewhere. Not much help.[duhhh][duhhh]

Depends on which pump it has. There's a United Technologies (on the left) or Bosch (on the right).

I would have to look in my tune up book for the year model and that engine but most all of the older Mack engines had a boost spec of 17-22psi. You should pressure test your intake system from the turbo over and see if you dont have a leak. Also make sure your throtle linkage is breaking over. Have someone push it to the floor while you watch and ensure its getting full throtle. Then check the fuel shut off arm and make sure its all the way open when the cable is in the run position.

Depends on which pump it has. There's a United Technologies (on the left) or Bosch (on the right).

its got the one on the left