Air & Exhaust

Boost Controller Designs For simplicity's sake, we'll say the wastegate opens at 20 psi and regulates the boost pressure to 20 psi. The way any mechanical boost controller works is fool the wastegate into thinking you are are making less boost then you actually are. So if you want to build 40psi, you need to make the wastegate think that you are only building 20psi at your set pressure, so in this case, you want it to think the boost is ha

Don's Head Porting Extravaganza Special Thanks to Don (Drothgeb) For the Time, Information and Pictures present in this article.  Thanks Don! There are different stages of porting, as Don describes below. Stage 1, is removing the collar in the bowls just below the valve seat. It's pretty easy to see the area I'm talking about in the pictures below. Just removing that without removing anything around the valve guide

Oversized Wastegate and Regrinding When we're trying to get as much out of our turbo as possible, it is very common to port the the wastegate out to help keep drive pressure in check.  However, we are limited to how much we can port the wastegate out by the size of the wastegate flapper.  The size of the little HX35's flapper could use some serious help, and it wouldn't hurt to give a HE351 a little love as well.  So what we're going to do is install a larger flap