Adjusting HX40 boost

[pwknapp]

Installed a PDR HX40 with a wastegated 16cm. I'm at 7300ft and getting only 35-38psi boost. What boost should I be getting at this altitude and how many turns on the rod to get there ?

 

[BPonci]

Invest in a regulator and bleed of your w/g to fit your needs. You should give it a break in period. Rule of thumb is never go over 40 psi. But i have seen much higher! BEWARE!

 

[jwilliams3]

I was safe up to 46lbs with my PDR 40.



--Justin

 

[Jetpilot]

The boost you are seeing is where it should be. Piers sets these turbos not to exceed 38 psi and if you take it higher you probably are your own warranty station. Also trust me when I say that you really are NOT going to get more HP from boost higher than 38 psi from a HX-40, the heat and backpressure derived from the higher boost more than offset the higher charge number.



Doug

 

[pwknapp]

Thanks for the responses. I'm really confused now. Took off a PDR 35 because it was maxxed out at 35psi. Now with this 40 only 38psi??? Anybody running the PDR40 at altitude?? What boost numbers are you running?? . My head is oringed and ported, 370's,Scheid tuned pump etc. , Just looking to get all I can out of the 40.

 

[Jetpilot]

35 psi of boost coming from a HX35 is not the same as 35 psi boost coming from a HX40... ... The 35's air will be hotter hence the oxygen molecules will be farther apart. Also you have the issue of backpressure, tthe 35 will creat more backpressure hence raising egt's and cutting HP.



Doug

 

[BPonci]

The hx40 at 38 psi has more denser volume than a hx35 at 34 psi.