I had basically a 6 pound spring in my 38 mm wastegate and it would spool up to 6 no problem. Well I put a boost controller on it to set it to around 9 or 10 pounds and as soon as I hit around 8-9 pounds I get bad boost cut. I have a stock map sensor and my chip is set to 11.2 pounds for boost limit on the map sensor. I also recently bought a new spring for my wastegate to eliminate the boost controller. The spring is a small blue spring which is 8.7 psi. Now it cuts everytime I boost to 8-9. I don't understand why it boost cuts there. Anybody have any ideas?

 

what do you mean "boost cut"? If you have the boost controller set for 10 psi and it hits 8-9 on your gauge and stops, then your gauge is most likely inaccurate. As for the second part of your post, i'm no genius but i'd say it's working properly there. If it seems like the boost trails off you more than likely have a decent boost leak, check all couplers, welds, etc...You can make this easier and more accurate by building a simple boost leak tester.

 

Boost cut as in soon as I hit 10 usually, the boost cuts out and it feels as if it's serious fuel cut. My friend uses Hondata s300 and there is an option for boost cut and that's what mine feels like. I think my gauge is correct because when I had the 6 psi spring in, it read 6 psi everytime before the boost controller. My AFRs are somewhere in the 11s full throttle so I don't think it's anything to do with fuel. Also have a Walboro 255 in right now.

 

Anybody have any ideas? I'm completely lost..

 

try posting it up in the forced induction section, my thoughts are boost leak but you may get some more helpful info there.

 

on 7 psi i get boost cut at high rpm thats bout it. stock map sensor