VF34 Subaru Wastegate install

Off the back of the webinar about Wastegates I have a couple of questions specific to my application.

the car is a Impreza rally car (S5), engine is the EJ20 with a VF34 turbo (had a VF22 but these are unattainable now), when first on the dyno we struggled to reach the desired 1.5-1.7bar of boost so switched to a turbosmart Wastegate where we could control both sides of the diaphragm with the use of a 4 port Mac valve. The car also runs anti lag in stage mode.

over time (less than 100km stage use) all the preload from the actuator rod has been lost and understandably a drop in boost pressure from 1.5 down to 0.9, we reset the preload and went again, same thing happens, this time I paint marked everything and checked nothing was bending on the Wastegate mount. Can confirm that nothing had moved but still lost the preload we had started with.

I've been told that it’s the shaft that goes through the exhaust housing and connects the gate flap to the arm is bending/twisting with the heat in operation, does this sound feasible and has anyone overcome this issue?

Hi Scott,

That may be happening, I would measure the length of the rod from the base of the actuator body to be sure.

Are you running anti-lag etc? as this will generate a lot of extra heat which could cause the rod to soften

Yes anti lag is used in stage mode, EGT’s vary from 450 degrees on the road, 750degrees on stage with a limit of 900 where the anti lag turns of if it reaches over 900 from what I can see. And normally that would only happen if there is lots of off throttle for a prolonged amount of time