Well, after grinding a stock plate to a #100 I can peg my boost gauge at 40#'s. I installed a boost elbow that came with the #10 plate I bought a while ago, and the truck has a Banks "Big head" wastegate and exhaust housing already installed. From what I read the stock HX 35 runs out of its efficiency range around 35#'s. The truck spools very quickly and I enjoy the new power, but I'm not wanting to damage the turbo or the head gasket. So, my question is, how much boost is o.k. for a stock turbo and stock head gasket? Also, which way will I have to turn the screw on the boost elbow to bleed off the excess boost? Thanks for your help.

MIke

 

I was told you want to keep it around 35# or so...

 

If you already have the Banks Actuator there's no need to use the brass elbow. The Banks actuator is actually nicer because it's fully adjustable...the elbow is really not.
with that said, the max efficiency for the stock turbo is 36psi. Any more than that
and all it's doing is creating excess heat that you don't want.

Take out the albow and adjust your actuator.

 

12cm HX35 is good to 35 psi.......occasional WOT spikes past this are fine.........when you begin to fuel a bit more you will find that the waste gate begins to become ineffective because it only dumps exhaust from 3 cylinders instead of 6 and this is not enough flow control to limit boost well..........exhaust housings can be drilled out to wastegate all 6 cylinders if required..........cylinder pressure is what lifts heads and blows out head gaskets so depending on who you talk to and how their truck is set up and used, 50-60 psi is the limit for head gaskets........a truck with a lot of timing advance and run hard may only put up with barely 50 psi where as others get away with more.........

 

Thanks for the reply's fellas. The only reason I put the boost elbow in was because I was spiking the gauge at WOT and it didn't seem like the "Big head" waste gate was doing anything. I got the same result with the wastegate line plugged and without. I do feel better about the headgasket, though. I'll have to go mess with the adjustment on the wastegate to see if I can get boost down to around 35#'s. Thanks again.

MIke

 

The HX35 efficiency is lost at about 35psi, it becomes in danger of overspeeding at about 38psi, and it is generally accepted that the head gasket can take 50-55psi reliably but it may go into the 60s before it blows short term.

 

the stock wastegate actuator is adjustable too... just loosen the adjuster on your elbow.

Forrest