Hi,

I would like some advice.

My Coupe has just had forged internals, has a GT28RSR turbocharger, Apexi boost controller and Forge wastegate actuator. I am now trying to get everything running properly before upping the boost.

The set up is working well, and controlling the boost very accurately, which I have currently set at 0.9 bar, but in the future should go up to around 1.4 bar.

The problem is this:

If you accelerate from, say 2000 rpm, in one fixed gear, the boost will increase steadily to 0.9 bar. It will reach this level of boost at around 3200rpm and will hold it accurately right up to 7000rpm.

However, if you are cruising at say 4500rpm with only a moderate level of boost, and then put your foot down, you get a brief boost spike of up to 1.2 bar before the boost returns to 0.9.

Is this because the actuator is unable to move the wastegate fast enough? If so, would adjusting the rod length help? If so, longer or shorter?

Any other suggestions?

cheers

Got it in one. at 4500 rpm the turbo is already spinning fast so when you get back on the throttle it spins up quicker than the actuator can keep up with. a brief 4 psi boost spike in those conditions isn't anything to worry about.