james-wrx

guys this has got me stumped.
My car is quite heavely modded it's got a 2.33 forged engine and has stand alone boost control etc, it's been mapped for 1.3 bar on VPower.
The problem is it used to rev really well, when it got to 6.5k it would surge to 8k and pop the limiter no problem, there was no activity on the knocklnk, recently it has started to light up amber at about 7k revs
I have lowered the boost to less than a bar and it still does it, it's been happening for quite a while now so i had a look at the Fule pressure gauge and im pretty sure it has dropped from 4.2 bar on idle9all vacuum hoses attached) to 3.2 bar so anyway i have adjusted it back up to 4 bar and it seems better, it still doesnt surge across at high revs but im only running 97 ron fuel at the moment so im not pushing it, what is cayusing this knocking?
I have a looseheatshield on the uppipe but it wouldnt be causing this would it ?

Thanks for all the help

Luke-Avfc

You sure it's not just the fuel your using ?

Never forget when i got caught short once in my old wrx and put sainsburys unleaded in it ( mapped on Optimax at the time ) I didn't think i was going to make it home it drove like a bag of spanners.

james-wrx

I have amanged to get some super in it but not Vpower yet!

I have ran it with the boost controller turned off and just running 0.85 bar boost (97 Ron) it's better but still at 7.5k revs its lighting up orange
I have tilted the intercooler forward as well as it's not a perfect fit it's off a WRX newage so its a lot bigger but the flow into it doesnt look good !