Forge Bypass Valve Owners!!!

Nothing like that. It wasn't even a complete batch that had the problems, just a smattering of valves.

The best thing to do is ask for the valve to be inspected when you order... if you order from one of our dealers just ask them to verify that the side port and the lock ring are tight. The valve should NOT rotate on the flange. If it does it is too loose.

So what should we do if we have an affected build? Send it back to forge for a replacement?
 
if you can spin the valve around the flange you just tighten it up with needle nose pliers. if the release port ( the part the bypass hose connects to) spins inside the valve itself, remove it slap some thread sealer on it and screw it back on. there is no need to send it in. both are really simple fixes.
 
So now its being said we can replace the BPV with an aftermarket one from Forge, and we "should" get better performance from it?


- How much boost are we talking here that we need to run in order to make the stock BPV useless? 20psi? 25psi?
 
if you can spin the valve around the flange you just tighten it up with needle nose pliers. if the release port ( the part the bypass hose connects to) spins inside the valve itself, remove it slap some thread sealer on it and screw it back on. there is no need to send it in. both are really simple fixes.

Thanks TB
 
laloosh is running...18psi? and he said he found that he got more boost with the forge, so he thinks the stock one may be leaking. So maybe as early as 18? If i do anything to up boost, I'm going to get some sort of new valve (Forge is at the top of my list), whether it be MBC (which is very unlikely) or cobb AP.
 
even when my car was 100% stock i noticed a huge difference in my spool up time. when using the blue spring the valve shuts faster than the stocker. the faster it shuts, the faster you start building boost ! not to mention there have been many members who have found their stock valve to be leaky.
 
even when my car was 100% stock i noticed a huge difference in my spool up time. when using the blue spring the valve shuts faster than the stocker. the faster it shuts, the faster you start building boost ! not to mention there have been many members who have found their stock valve to be leaky.

How can you test the stock valve for leaks...? I'd like to know if mine is leaking...
 
you can make a boost leak tester. i made one with a PVC cap and a tire valve stem. you can pressurize your intake system and check for leaks everywhere.
 
Different car but the same principals apply. Stock car brought to the same temperature with the only change being swapping the factory valve for one of ours:

So, from my impressions from the graph, the change in performance is somewhat earlier boost equating to torque and power available a little bit sooner?

Also, the ability to go to higher pressures with no leaks?
 
Correct. There are two ways in which a valve can leak: at boost onset and at full boost. From what I've been reading on this forum the factory Mazda valve does both...

"Bench" testing won't necessarily show either of those problems.
 
Correct. There are two ways in which a valve can leak: at boost onset and at full boost. From what I've been reading on this forum the factory Mazda valve does both...

"Bench" testing won't necessarily show either of those problems.


So basically its good practice just to change out the OEM valve...

There goes another mod...:rolleyes:
 
LOL at least it's not a super expensive one (unless you baller up for an HKS Type II that Supras like to run - it's around $350).

BPVs by design are great for stock cars, but I think the whole drive by wire thing screws up the purpose, because as the ECU is fluttering the TB plate going all whacky (esp at WOT in these cars) is allowing the BPV to maybe open just ever so slightly, enough for a little boost to squeak out.

Usually factory BPVs don't fail so fast when upping the boost too. At least most of the metal housing ones don't (1g DSM holds well up to 20psi many times before you have to crush it). I'm wondering if the engineers at Mazda almost didn't purposefully design the stock BPV to start "leaking" after 1-2 psi above the stock amount, as a safeguard. Not that it's gonna thwart someone from throwing on an MBC and trying, but it's another option in the fight against an unexpected overboost from a line coming off or something.
 
I'm wondering if the engineers at Mazda almost didn't purposefully design the stock BPV to start "leaking" after 1-2 psi above the stock amount, as a safeguard.

So if you're not running higher than stock boost pressures the OEM valve is OK/does not leak? I was in the understanding that even at stock boost levels that the OEM valve still leaked...?
 
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