In the process of putting my car back to stock intake, I unwittingly installed my JDM DV backwards, or upside down. When I took it for a test drive I could tell right away by the reversion shushing sound that the turbo made.

Anyway what I'm getting at is that the turbo spooled noticably faster since the DV wasnt opening at all. Does this mean that if I want to optimize spoolup I should replace my JDM DV with an adjustable one like the Forge RS, or something else with a stiffer spring?

 

Well normally it is a trade off. If you get a stiffer spring the valve will hold more but then under low boost let offs it could flutter.

I would say leave the DV there and get a LICP if you want quicker spool.

The MR DV is a pretty good unit. It is one of the only ones I recommend. The full list would be APS, MR, Forge, TXS RBV, and some other DVs.

 

Any idea at how many lbs. of boost the JDM DV starts to lift off its seat? The diff in the spoolup rate was very marked, so I may swap it out for something with a heavier rate spring that's adjustable and easy to install and recirculates. I already did the LICP upgrade and have the TiAl turbo. Do the aftermarket diverters and BOV's which you recommend have a larger diameter valve than the JDM DV?