I could use some help from the techies on the board. Some background:

I was testing the car for boost leaks and found one on one of my diverter valves (I believe they are evoms billet valves, installed prior to my purchase). I believe the leak is on the outlet side (not were the piston seals the inlet), apparently the outlet threads in to the diverter valve body and it was leaking as it was not tightened properly.

My question is, if I want to bench test the valves prior to installing, if I blow air in through the inlet, should air pass through the outlet if the piston is sealed? I think not but I am not sure.

If any of the above is technically incorrect (i.e. I am mixing up inlet versus outlet) feel free to correct me, still learning...

Thanks for the help!

 

I had the same issue with the aftermarket ones that i bought. I think that a 1-2mm thread seal is bound to leak as even under ideal conditions a metal thread won't provide a good gas seal.

I decided to abandon the aftermarket DVs and replaced mine with a Bosch 710N. Haven't had any problems, but i get the impression i may have to replace them every few years.

Best of luck... PM me if you need the part #. The bosch ones are a paltry $45 a piece.

 

Wow 45 bucks. Are you running any engine mods?

 

Hey... i'm really sorry i didn't respond sooner. I totally spaced on this one.

I don't have many mods. An exhaust and I'll be flashing shortly. I'm not an expert so take what I say with a grain of salt, but I know that there are plenty of guys on this forum that make 700+ hp that use the 710N's.

If you think about what this part is doing, it's really a binary thing, either it works or it doesn't. If you're on throttle, the diaphragm is closed and all of the pressurized air goes to the intake manifold of the engine. If you let off the gas, a vacuum is applied to the line at the top of the valve, opening the diaphragm and circulating the pressurized gas back into the intake (thereby de-pressurizing it). This is done to avoid large amounts of backpressure to the turbo compresser which might damage it. Indeed, the previous owner of my car had a damaged turbo because his DV had gone out.

So, given all that, the only reason to go with an aftermarket part would be if that part were more reliable or would last longer. I have serious doubts that the way more expensive aftermarket parts are any better. for $45 a piece, i could buy 8 of the 710N's which would easily outlast the car.

Hope this helps.

 

Thanks for the info. Turns out my DVs were fine and I had a batch of Bad fuel in the car. Running much better now!

 

Wow, how'd you get bad fuel? I didn't know that sorta thing actually happened!

 

Do we need 2 710N diverter valves? Are the 710Ns a direct replacement for the stock ones? Nothing else needed?

 

Yes, you need two of them and they are a direct replacement. I've had them in my car for a few months without issue.