Hey bud thanks for getting back to me! I've not yet installed the bovs, I'm having trouble removing the plug on the inlet manifold, so I may just tap into the vac pipe which the ZAC guys use. I'm actually trying to run the bovs on my Aston Martin Vantage which uses the m177 engine and the manifold plugs are both a ***** to get to.

I did ask PTG about the correct spring, they said the one it comes installed with should be fine with stage 2. Did you try the original spring? Im pretty sure if your spring is too hard it won't release the pressure built up in the turbos. I'm only changing from the stock recirc valve because I'm getting compressor surge after installing intakes to the car.

How is the noise with the PTG valves? I'm still using the stock bypass valve with the hoses reconnect to the intake pipes and it still blows off pretty hard!

Hey bud, I've noticed that you're using the PTG race bovs so I thought I'd give you a shout. I've just ordered a set for my c63 too and wondered what spring you ended up using? I'm currently only running stage 2 (downpipes & intake) and didn't want to use the wrong spring just in case. Any help/advice on these bovs would be super helpful!

Thanks!

Rick