Hi, could anyone help with this problem please?
I've had the standard turbos reconditioned, when this was being done it was recommended to fit a slightly larger compressor wheel to each turbo & machining the housings to suit. The car is standard apart from air filters & a larger exhaust (HKS dump pipes, HKS front pipe, cat replacement pipe & 3in cat back)
Now when driving at a cruse/light acceleration (0 vac/boost) at anything below about 4,500rpm the recirculation valves are constantly cycling open close open close. When this is happening, if the throttle is opened a little more it gets worse (manifold pressure surges from 0 up to 5psi & back to 0 again & again)
if the throttle is opened almost fully, this surging stops & the engine begins to accelerate. It also seems to be running allot richer when accelerating with these turbos.
Most things have been checked & the only problem seems to be that the turbos are pumping too much air at the wrong time or something like that.
Has anyone had there standard turbos reconditioned and had bigger compressor wheel's fitted with no problems?
Does anyone know if something could be done to correct these problems without going back to original size compressor wheels?
Thanks