Blow off valves

[dilyanyordanov]

Hi guys,
I wanted to purchase blow off valves when my milltek catback was installed but the Shop contacted forge and they said that there are 3 sizes and they are not sure which one fites rs6 c6...which is kind of funny buy anyways...Does anyone know what size fits ? I believe it was either 34mm, 36 mm or 32mm maybe...Thanks

[IanH755]

The RS6 blow-off valves are molded-in to the lower half of the plastic airbox so there is no ability for a direct swap to Forge etc. Instead you have to cut out the plastic OEM ones, buy the aftermarket ones and glue them into the holes left in the plastic airbox by the cut-out OEM ones.

It's been done by a few people on here before and at least one has taken photos of what they did - their thread with pictures is here - viewtopic.php?f=47&t=128908

[RS6-T28RPH]

These are the ones I have fitted to mine (obviously make sure you buy a pair!) : https://www.forgemotorsport.co.uk/Turbo ... --756.html

20k miles on and still no issues, had a play with swapping the springs out, seem to have found a happy medium with the blue spring with MRC Stage 2 tune (https://www.forgemotorsport.co.uk/Valve ... --826.html) and gives a nice modest whoosh back into the airbox when backing off full boost, nothing crazy like a scoobaru or and jap thingy but a nice noise, just to let everyone else know you have backed off

[Per_S]

You can use these as well. https://www.gfbuk.com/product.details.c ... uctid=1027
No springs to swap in them.

[dilyanyordanov]

Thanks a lot for the help guys. When does one actually need aftermarket bov if mine haven't failed yet. I am at 773 hp and 1039nm. Stock turbos ...

[IanH755]

When the boost pressure you are running exceeds the amount the OEM valves can cope with, usually if you increase the boost on the OEM turbos or buy new turbos running higher boost, or alternatively just because you fancy something more user friendly for altering than the "molded into the airbox" OEM ones.

At 773hp you're slightly higher than a Stage 2 tune level but still within the operating range of the OEM ones.