whats a good blow -off valve?

 

Stock diverter valve.

 

If you can find a legitimate HKS SSQV, they are among the best made. Exhaust Depot sells a hard pipe with a flange mounted HKS SSQV on it. They are relocating right now so the lead time is a bit long. Beware there are many copies out there because of some issues with the company right now... and no they aren't quality issues. So the lead time is even longer because of that.

Stay away from the HKS SSQV's coming from Riss Racing. A couple of people have found they were counterfeit!

Helix and Alta have BOVs that mount on the rubber pipe coming off the throttle body tube that connects to the "noise maker". They work perfectly fine but it is more worthwhile to get rid of that pipe, and replace it with a nice smooth continuous pipe like the ones made by NM-engineering or if you are really patient Exhaust Depot. Smoother motion of air will give you a little torque gain.

The Forge BOV is another alternative. It's actually a sandwich adapter that works with the factory diverter valve. I couple of people in my local MINI club have them and don't have any issues.

Thumper is correct in his statement though. For the most part the stock diverter valve does its job perfectly on the R56. Our little turbo can't push a large rate of air very fast and problems with compressor surge really don't exist. I have noticed a small decrease in turbo lag between shifts but other than that, adding a BOV is mostly for show on a R56. There are a lot better things to modify out there for the money.

 

^If your just after sound, the Forge piece is great for the money. Fairly easy to install too. Ive compared to many Subie BOVs and the Forge piece sounds just as good without being a legitimate blow off valve.

 

thanks appreciate it

 

HKS is the best. Exhaust depot also makes a hard pipe with a fitting for it. Could also get the RMW tune and get some fluttering BOV noise.