Paul H. (near Annapolis, MD)

Just saw xr4tic's comment below about his Forge DV valve fluttering a bit on low boost acceleration.

If I go to part-throttle acceleration from a vacuum state, I am getting surging when the boost rises to between ~8-12 PSI. This is especially apparent at lower RPMs. I was beginning to suspect a leaky hose, but if I open the throttle all the way, I get a solid 15-16 PSI of boost.

I have a HyperBoost (non-adjustable) BPV I recently got from Stratmosphere to replace my TT225 (710N) valve that I suspect was toast.

When I first installed the HyperBoost, there was no surging at all, but after a week or so I started to see it again, although nowhere near as bad as with the TT225.

Could this be the BPV? I don't see a lot of testimonials here for this BPV, but it seems to be constructed pretty well, and the few comments I did see here were all positive.

Is is possible there is something else? I guess this is not something that can be armchair diagnosed easily, so just looking for suggestions at this point.

The car is a 1.8T with just an APR chip and Borla exhaust. I have a VDO boost gauge installed, and the vacuum line from the intake manifold to the BPV was replaced a while back with some Samco silicone vacuum hose (the factory one had a hole burned into it near where it passed the turbo) and this hose is in good shape.

Any suggestions would be appreciated.

Thanks,
Paul