I am getting ready to dyno in a couple of weeks and I can currently hit 38 PSI in 5th gear, going up a slight hill. What are the limits of an HX-35 as far as boost? I have read that a pull on a dyno can make trucks generate more boost than on the street. Will I exceed my turbo's limit and cause damage? I have a Big-Head wastegate which is part of the Banks kit. Can i adjust the wastegate a little to keep it safe? I don't want to be the one who blows up something this year, it was a Duramax last time.

 

I always thought the limit was around 35 psi.

 

If it's an inertia dyno you will see less boost on the dyno than on the street. You ought to back it down some and see if it runs cooler, 38 psi out of an HX-35 is just hot air.

 

The boost limits of the 35 are a function of altitude as well.

The turbo works much harder to make 35 psi at high altitude than at sea level.

Generally, I've read that the efficiency limit is about 35psi @ sea level, lower at higher elevations. In other words, you can run more boost than 35, but there's no benefit to doing so (discharge temps are super high and EGTs will skyrocket).

The "mechanical" boost limit is the point where the charger is spinning so fast it may grenade. I've read that this is about 42 psi.

I'd adjust your WG to lower boost to around 35 psi. Ideally, a larger housing would be the "proper" way to lower it. Your Banks Power Pack should have come with a new turbine housing that is 14cm WG. With that in mind, I would just stick with WG tweaks.

You are apparently nearing the limits of your charger's capabilities. I larger compressor wheel from Hi Tech Turbo should help the breathing.

JLH

 

mine has been hitting 42lbs for 50k miles or so. it would smack 50 plus when i had the 12cm ex housing on it. i don't think i would worry about 38, but others it may worry badly.

 

Mike,

if your turbo looks anything like that clutch I got from ya, I feel sorry for it!!!

thanks again for hooking me up!

Forrest

 

I do have the 14cm housing. I have never looked at the WG, can someone briefly explain to me how I adjust it? Thanks, --Neil

P.S. the dyno is a Mustang......

 

Anybody know how to adjust for less boost? Bueller....Bueller......

 

The 35 is a tought turbo because it has small wheels on it. I ran mine above 50PSI many off times. Its not really makeing any more HP but I had too much fuel for the turbo. I worrie about EGT's more than PSI.
DM01

 

I have heard and read on here

32 PSI is the most optimum for an HX 35 turbo, anything over 38 PSI is just producing hot air which is actually robbing your horsepower.. and increasing your EGTS i personally wouldnt risk running the turbo above the 35, even though i peg my gauge that reads 35 out like its nothing. I try and keep it between 30-32 even though it sometimes hits 35, i just watch the pyro when it does and let off when i have to.. But my truck wont be "stock" for too much longer... he he he he When i graduate im gettin a good gift from me to me..

good luck and hope this helps...

Tx

 

I realize that running the turbo at 38 psi is not optimal. I need to know how to adjust my wastegate to bring it back down to around 35. Thanks

 

If your wastegate actuator is spring loaded you only have to loosen the spring tension on it to allow it to open sooner and lower your peak boost.

 

CTD_Neil, Does the Banks actuator still use the boost elbow from the compressor side of the turbo? If so, an adjustable elbow would work and let you manipulate the max boost for the situation.

 

I'll take a look at the wastegate setup and see what it has. I figured it was something easy like, "lengthen the shaft a turn" guess it's more involved. I'll see if the actuator uses an elbow. Thanks

 

it's that easy... lengthen the shaft a little or adjust your elbow.

Forrest