PDR 40 boost readings...

[DEZLPWR]

Just curious what boost psi you PDR40 guys are seeing @ hwy cruising & @ wot. I am seeing about 4psi @ 70mph on level ground. My PDR35 w/12cm housing @ same speed was 7-8psi. WOT with my DDIII's and Comp on 5-5, I see 38psi, which I hear is normal.....

PDR35 was 45+ psi!

Is it normal for the PDR40 to have lower cruising boost psi, and why is this?

Sometimes driving around town, I see 0-2psi often..... I thought it would be higher than that.



Just wondering.

 

[markdixon]

Higher drive pressure it takes more exhaust pressure to spin the turbine. Just like changing the exhaust side from a 12* to a 16*cm housing. You probably also have higher egts due to the lower boost @70mph hope this helps.

 

[Vaughn MacKenzie]

DEZLPWR, with a lot less backpressure and bigger exhaust turbine on the PDR40 it's not going to drive the turbo as much as your HX35 when driving at light throttle. Basically since it's designed for an engine with greater displacement (which moves more air at 0 boost) it won't generate as much boost when hooked to a smaller engine like the 5. 9L. Everyone who's gone to the HX40 comments about the significant drop in boost pressure and slight increase in EGTs seen at cruising speeds and driving in town. Certainly doesn't sound like there is anything wrong with your PDR40 or you truck



The fact you can crank more boost now at WOT is because you're not way outside the efficiency map of the PDR40 like you were with the HX35



If you were to port your head and throw in a Piers cam, you may see your cruising boost increase and EGTs drop because you'll effectively make it act like a larger engine :dance:



Vaughn

 

[C. Harlan]

My PDR HX40 is wastegated at around 44-45 PSI... WOT, see siggy for BOMBs. .



-Chris-

 

[zjones]

As far as around town, 0-3 +/- psi (depending on trailer/no trailer, Furds/no Furds, ect).



At the time I bought a PDR Hx40-16cm I had a TST #11 plate in stock position & a light TST afc spring installed. I could barly get 34 psi. shut off the wastegate & lowered my egt's 100* & easily hit 42psi. I now have -see sig- & have the wastegate set to get me 44psi max. Sounds like you need to set your wastegate.