I have had the forge RS blow off valve and wanted to share my experience with others. The valve was put on the car so that I could boost 30psi while drag racing. For that purpose the valve is wonderful. My problem is that I drive up a mountain road 14 miles going from 1000ft to 6000+. While driving up the mountain road the car uses the turbo to make the climb and when driving normal the valve is unable to release air smoothly. The car jerks like crazy and is impossible to drive smoothly as the turbo spools just enough to cause the bov to try and release some of the presure. When driving spirited it is impossible to go wot through the turns and this causes a major problem when trying to drive fast..... while using partial throttle driving fast the car once again can not release the pressure smoothly causing the car to drop on its face for just a second. A very scary thing when you are driving very fast through a turn. I also notice that while on the freeway at about 100 (I know its speeding) the car requires turbo and once again jerks because of this problem. I contacted Forge and they said it is normal. If it is normal how could you possible road race with this valve??? Any help would be great I am about the put the valve in a box and put it on only when drag racing. I have tried different settings from stiff to loose on the adjustment.

 

Welcome to the club - my experiences exactly. A reseller on here suggested going with an upgraded spring - in other words, take the next higher spring than what your boost would suggest. I had been running a blue spring for my 24psi, but went with a red spring instead. It did help on the street, but I still get the flutter when trying to feather the throttle (like up thru the esses at Watkins Glen).

My mechanic is trying to address this further with some added shimming, adding a restrictor (a NOS nozzle machined down) to the small diameter hose going into the valve, and relocating the valve further away from the exhaust manifold so it doesn't heat up as much.

If that doesn't help, then I'm switching to a JDM MR valve for track days.

 

please let us know if any of your testing helps. Thanks for the reply

 

Is yours the one w/the knob on it right? If so, i also experience this only when i'm in 5th and going 60 or higher and try punching it a little, getting that sputter.

 

did you change the springs dude? it has like a xx-23psi spring for that kindof stuff

 

Hello Tad,
1st, make sure you set it at its softest setting. It takes a ton of clicks to get it to full soft. Other than that, you could just put an Evo9 diverter valve on there and see how it changes your driving experience...
Good luck.

 

I had the same problem when I had mine. My fix was sell it and got myself an APS.

 

Yea the Forge valves are super sensitive to changes in the plenum. Feathering the throttle causes these changes and the valve picks up on it, causing the annoying(and possibly dangerous on a track) condition. The RS valves are also known for completely blowing of under boost during tuning of big cams or meth setups as you normally incur a few misfires during then, these cause plenum changes, and the valve blows open. Ever have a valve dump at WOT on a dyno running 28lbs of boost? It's fun

I've spoken with Forge about this and have been working on reducing the sensitivity of the valve. Inline restrictors are one way, but must be "tuned" to work with your valve and flow requirements(boost level). Start at a .060" bore and drill out from there. On the RS valve, you really can't change springs as the internals are not like that of the standard FDV. It uses a beehive style coil spring to prevent binding and valve limits while turning up the tension. The standard FDV uses a round coil, and can be tuned/shimmed accordingly

 

I also have this valve and the car has absolutely NO part throttle driveability due to it. Even traded PM's with Forge about possible trial and error stuff, and honestly. There is a very very simple fix to all of this.

Buy a different bov. Its junk. Why would you change bov's for different conditions? Listen to you guys!? Buy one, that does its job correctly. Which is exactly what I'm going to do. This thing is crap.

It should do its job thru the entire range of conditions on the vehicle. You shouldn't have to mod a bov, to make it do what it should do out of the box.

 

this is why i got rid of the forge and went with the APS, it is almost identical to the stock metal mr valve

 

1. Guys the RS is the knob adjustable one -- not the one with different springs.

2. Ive tracked over 300 miles with it - no problems. Which could be my style of driving (and about 20k with it in my car).

3. Gotta keep playing with it to get it adjusted right. Yes the car will buck some if I part. thod. lift or flutter in 5th under low load. On the softest setting it will flutter more (think about it - the spring will be weaker in that setting). So it needs to be stiff enough to not open under you boost psi but not so stiff that it opens for a short period and then closes...just takes some time to get it right on.

I did trade my friend an APS for this RS. We both are happy now

 

Amen

 

Which brings up another good question. Has anyone tried or taken apart the Works valve? It looks suspeciously like the IX valve and when i questioned them about getting the parts/springs they use to mod it, they came back with "all our valves are brand new so we don't sell the parts or core it out." Which makes me believe that its just a 9 valve new from Mitsu without anything special done to it.

 

Luckily I didn't personally fork the money over for it, or, trust me... my previous post would seem very tame. I'm at my absolute boiling point with this thing.

I got caught up in the, well I'll try this, maybe this, adjust this... and to be real honest. I thought about it for a second and went. Are you kidding me? Why am I doing this? Every forge product I've ever encountered, on any car... has always been a problem. Its not me. Its not the car. Its just junk. There are too many options out there to pull your hair out over an ebay quality bov.

So here's my brief synopsis;
Sounds good.
Uglier than hell.
Works for shi**.

Easiest fix? Sell it.

 

if you know how to adj. a bov then this valve works fine...