350 @ 6200

[20psimitsu]

Finally put the car on the dyno and peaked 19psi @ 6200 which gave me 350 on a Dyno Dynamics. My problem is at 6200 rpm's the boost starts falling off. Then when I tried turnning up the boost, she did nothing so I turned it some more and it gave me less boost. I thinking the wastegate is hose'd wrong. Anybody got any ideas???????????

 

[ThingyNess]

You need to give us more information -- what wastegate you're using, how you have it hooked up, what spring you have in it, etc.

Your profile says you're running a T66, so you're obviously external.

If you have a low pressure spring in there (like 7psi or so), you will only be able to increase boost so much with an MBC before the manifold back pressure blows the wastegate valve open. The solution is to use a much stiffer spring (say 14psi), or possibly to hook up the wastegate differently, depending on which one you have.

 

[20psimitsu]

I have a HKS 50mm race wastegate and I have the purple spring (14.2psi). One of my couplers has a slit in it that wasn't noticeable. Fixed the hose and she hits 30 psi with no problems.

 

[2gAWDTalon]

In the future, a boost leak test (would have shown the split coupler) is a standerd test before a dyno session...

 

[20psimitsu]

Yeah, for some stupid reason I didn't think of a leak being a possibilty. Just thinking it was the MBC or the wastegate. I'll keep that in mind for next week.