hey everyone,

I recently had to replace my turbo after the last one blew up at the end of the season last year. While getting the new one installed and ready to be tuned in the next month I did a boost leak test to make sure everything was good. All of my couplers were good but the stock evo 9 BOV started to bypass around 26 psi. From what I've read that is about the max the stock valve will hold. I have been and will be running around 24 to 25 psi for around 350 whp. I think that is a little close to the pressure the BOV starts to bypass at.

So I am looking to get something that will hold a bit more. From my research the synapse was the best recirculating BOV but sadly it is no longer made. The Tial QRJ and Turbosmart Kompact are readily available but i have read that there is some part throttle drivability issues. Most reviews and information that I find is mostly street or drag racing not circuit.

So i turn to everyone here.
what recirculating BOV are you running and how is drivability with it on track?
Any other options or are those 2 pretty much it?

Incase it makes a difference I'm not trying to make massive power somewhere between 325 to 375. The turbo is a dominator 1.0 XTR, 1050x injectors, intake, exhaust, and IC

Thanks in advance

 

did you have the plastic BOV or the RS metal one?

 

Its the stock evo 9 metal one

 

I crushed mine but not sure how much psi it can hold

 

Synapse Engineering Synchronic Blow-off Valve. Recirculated. It opens at .5 PSI and 50 PSI the same. Could be my favorite mod no stuttering or flutter at all I won't even look at another BOV.

https://www.evolutionm.net/forums/ve...evo-ix-mr.html

 

You cannot buy that anymore. He is looking for another option that works as fantastic.

 

Just crush the stock bov down about 5mm. It'll be fine.

 

We have had great results with an old school genuine type S with a single spring mod top port only. Also check out the type FV.

Not on circuit but used at autox.

 

I think this is the way I will be going. I'm still on stock frame turbo so I don't think it will be an issue if it decreases flow just a bit from crushing it

 

Are you talking about the greddy type s or type fv?

 

Stock crushed surged terrible for me when going from full to part throttle. The Synapse, while a **** company, worked amazing. The boost release is so progressive and smooth with throttle lift in push mode with the big port plumbed to IM and small port vented.

Ive heard the Turbosmart kompact valve also works well but havent tried it.

If I ever have a failure on my Synapse, I'll probably just reverse engineer it and remake the broken parts.

 

The trick is only crushing it 4-5mm or less. Just a smidge. If you crush it to the point you're bending the hose barb, yeah they flutter.

 

Its been a while but IIRC I crushed mine down to the hose barb touching but then bent it up to get a hose on it. But were just adding preload here where we really need more pressure area on the holding side of the valve.

I would say the 2nd best option I've experienced is the super duper old school Dejon BOV solenoid (RIP). Not quite as good as the synapse for small lift response but 30psi holding like NBD on a 1g BOV in DSMs was amazing.

 

I thought that the Tial QR was the one to get with the Syncronic off the menu. Is this not true?

 

No it surges even with the supercharger spring
In stock frame turbo. Works great if you go to a vband turbo kit though