[ QUOTE ]
Markey said:
I have the forge fitted to my car and instantly noticed better holding of the boost.
[/ QUOTE ]
If your OEM DV was broken then fair enough. If the OEM DV was working normally then I very much doubt there would be a difference, in fact there can be no reason for there to be a difference.
I think the aftermarket DVs are a con. They are marketed as performance enhancements whereas in fact they can do little other than (in some cases) improve reliability. They cannot improve performance unless OEM valves are torn or otherwise broken. I have several DVs sitting in my garage that I have tried on 1.8T engines and my S4 and I can say with confidence that they make NO DISCERNABLE difference to sound, performance and if anything I found the aftermerket valves on the 1.8T to slow down throttle response and turbo spool up. They make no more power on the dyno, and now my local tuner is recommening the latest revision bosch with uprated internals over all the aftermarket stuff. I think the placebo effect of spending £70+ on a beautiful shiney aluminium DV is leading to these fabled performance increases. If you look objectively I doubt there is a difference, and I for one, could not tell on a blind trial which was which.
Add this to the stories of some aftermarket DVs coming apart in use and sending bits into the intake system, I think I'll continue with my two £20 bosch valves with some spares in the boot along with the spare TBB....
