Hi my rs turbo has an issue with boost. It boosts lovely on 1st 2nd and 3rd but when you get to 60-70mph in 4th or 5th it struggles like its hitting a wall then suddenly it will drop revs to 0 then do a massive back fire then engine with go back to normal and go back to the revs it should be. Just wont boost properly. Did it all before head gasket was done and also its setup. What else can it be now? Cheers in advance

 

Chipped?

Sounds like its hitting a boost cut?

 

It got setup this week but was told boost cut was sorted and o it's a standard ECU mate

 

What boost are you running? Some stock ECUs will run up to 10 psi, others 9 psi

if you're close to that you will be hitting boost cut.

 

Well he told me it was 12 psi so maybe I just need to chip it?

 

Sounds like it to me, 12 psi on stock ecu is too high in my opinion, that said it's about 20 yrs ago since I had my RSTs

Before I had mine chipped with a Bayjoo chip I had an incar bleed valve which was a balancing act between having loads of boost then the sudden boost cut, which was interesting while overtaking...lol

Before having the bleed valve, Mine used to spike about 15 psi but then drop down below 10 psi so not to hit boost cut.