Interestingly that Sportec replaced my aftermarket blow off valves on my rebuilt tuned 996 TT with the OEM Bosch items, noting that they better for the car, which I find a tad confusing, any thoughts please. They left on the Evoms wastegates ??

 

When I had my UMW turbo upgrade, Kevin also recommended returning to the Bosch DV's. Been ok so far (2 years).

Jon

 

Ok so I am certainly not alone here, Kevin ??

 

Ive found that the aftermarket ones were poorly made and worse than stock theyll fail every few years, but theyre fairly cheap to replace

 

Kevin is no longer on 6speed. Try him over at rennlist.

Jon

 

also running bosch MS units here. Tony@EPL swears by them.

 

Yep. Bosch 710N's..don't run anything else.

 

The aftermarket ones tend to leak more due to their design. Last time I pressure tested my system both were leaking badly. But after tightening the tops they work well.

 

interesting that this took so long to come to light as most of us probably have after market versions, as we all thought they were so much better !!!!!

 

I had the exact same experience. They couldn't even hold 3 psi. The ones that I used had this crappy metal on metal seal that was imposible to seal correctly. My dad (a fluids expert) was appalled at the metal to metal seal for gas. At any rate 710N's for me.

 

Forge are good...

 

+1 on forge their customer service is awesome

 

hey guys thought there was a difference between blow offs and dvs ? have had three sets of dvs am noe running one blow off .... your thoughts plz

 

I think that everybody is only talking about DV's which are recirculation valves. I haven't heard of anybody running a true BOV on the 996TT. The only difference is DV's dump the pressurized gas back into the intake stream vs. into the atmosphere.

I think the primary reason people go with BOV's is they like the hiss. The DVs are too small (a consequence of there being two) and too far behind you to properly hear the hiss.

 

that why i changed... had forge and they made a great sound until i installed pipeing to the turbos then it was gone !!!!! car ran way better but i missed the sound so i went to blow offs , now it sounds like i,m opening a window when i shift, not the sound i had but it's better than no sound