ClayBob

Is there a formula (ofgeneral theory) about how much boost = how much hp? For example - 10#'s boost = 10hp? Just curious as to what my mods are adding.

Thanks
Claybob

Lil Dog

With a stock HX35 turbo with a 12cm housing, the general rule of thumb is 10hp per psi of boost. But if you have a boost elbow installed etc, it starts to go out the window. Doing the calculator dyno usually sets one up for disappointment on the rollers..

ClayBob

Thanks, going out the window as in the boost elbow negatively affects the rule of thumb?

Lil Dog

Well your boost elbow limits your boost to a safe level of say 36psi, when you have the fuel for more. BUT.. The turbo is really not very good at letting you use that power above that pressure anyway as it starts to restrict flow through the engine, basically choking it. So the ramp sort of levels off after that. HTH...

ClayBob

Awesome response...I expect with my mods I wont quite see 30 so sounds like I'm good to go. Leaving (with my camper on) now, so I'll know a bit more (at least according to the butt dyno) when I return. Gonna mess with the xzt settings as well. Thanks again.

Lil Dog

If you have only 30 psi now, you have room for another good 50 hp. The XZT should be good for that. I am not that familiar, does the XZT come with the boost elbow? (not to be confused with boost fooler)

ClayBob

Stock the truck is wastegated at 20 psi. The XZT does not come with a boost elbow but does boost fool. I've purchased and installed a boost elbow and now see 24-26 with the XZT off. I expect I'll see a bunch more when on turn on the fuel....

scottsjeeprolet

With my Adrenaline with Comp tune on Level 10 i have hit 44psi. Waiting for the HX35 to implode.

Tate

I ran my stock turbo there for months with no ill effects.

The 10hp per psi of boost rule as worked decently well on my trucks when the turbos aren't over extended. When I was pushing my HX35 to 43 psi, I made 330hp. Pushing the 62mm to the same, it is 440. Driving my dually tonight, at 50 psi wasn't all that strong, but I was only about 1/4 of my pedal. Push the pedal further, boost didn't move much, but there was a definite kick in the pants.