I recently purchased and installed the Forge diverter valve from Buschur Racing.

quick shipment, good packaging etc.. no problems with BR

I installed the Forge DV and immediately notice a few things different:

1) during part throttle the car was building much more boost than normal which required me to back off the throttle significantly to keep it under control.

2) when I barely lifted off the throttle, everything was dumped violently and the car nose dived, no smooth transitions.

3) normally with the stock plastic dv I was seeing a spike to 24psi max and holding about 20psi to redline. Now it's spiking to 26psi max and holding about the same best I can tell (analog gauge and no logging)

unhappy with the driveability I pulled the DV apart and saw that it had the blue spring installed. It came with a yellow and a red. The yellow is slightly softer than the blue and the red is very stiff. I installed the yellow and it's still building big boost without much throttle, same as the blue, but the transitions are smoother, much less of an on/off switch. However, in light acceleration at 20+psi it's cracking open and causing the boost to flutter badly and in higher gears like 4th and 5th it can't stay closed at 26psi and flutters through the pull to redline.

I spoke with Nick@Buschurs and he explained the difference in the springs which confirmed what I suspected about their stiffness:

green 5-15 psi (may not be shipped with new units)
yellow 15-23psi (what I'm currently using that's having trouble handling 4th and 5th gear)
blue 23-30psi (violently blows off when you barely lift off the throttle)
red 30+psi (I didn't try this one)

Nick also reminded me that the kit came with a couple of shims you can put under the spring to make it slightly stiffer, so I'm going to try that to see if I can find a happy medium between the yellow and the blue, so I'll report back with my findings and some pictures I took.

p.s. the sound is fine, nothing obnoxious. I have a HKS VTA BOV on my Stealth TT and it sounds like a chirping bird at < 20psi but at 25 to 35psi it sounds much deeper and tolerable and the driveability is perfect.

Here's a pic from www.BuschurRacing.com 's website for those unfamiliar with this unit:

 

No doubt this valve holds like a mother, but the issues you identified will, sadly, never go away no matter how many times you take it apart and put it back together with the various internals. You end up having to use your throttle like it's an on/off switch. Probably okay for the dragstrip but a pita for the daily driver. I really liked mine at WOT, but hiway and interstate runs were not fun.

 

I have basically the same unit. For daily driving in the 20-21 psi range I use the red spring. Virtually no driveability issues. Reference this thread for more impressions:

https://www.evolutionm.net/forums/sh...d.php?t=271834

 

JFTR..... its www.buschurracing.com




Thanks for the post!

 

This was the first thing I got when I first got my evo. Its a solid piece I use the blue spring which came already installed with it. I have never had any driveability issues.lol It is pretty damn loud though now that I have the buschur air filter on.

Def a great product

 

whoopsie, fixed the url...I was sending people to a pr0n site or some crap haha

 

hmm I didn't try the red spring because I figured it would only make that on/off feeling worse. I'll try it and the shims this weekend.

 

Look forward to your final opinion on this Forge DV, Chris. I finally gave up on mine.

After testing and retesting different DVs on my car, I have found that for me the IX DV (which I think is a/k/a MR or JDM DV) is the most satisfactory. I think ALL DVs flutter, the IX DV seems to flutter the least, or is the least obtrusive. Next least is the Forge RS, next the regular Forge. I don't consider the OEM plastic a to be a real DV. FWIW. YMMV.

 

isn't that the old model blow off valve,i have the forge rs and it is adjustable,i thought they stop making that bov,becarfull how many times you change the spring because i did the same thing witl my old blow of valve and it start leaking from the screws on top...

 

I tried the red spring this morning..still has some flutter if you do light throttle and it's having trouble staying closed in 5th especially if you don't go WOT. I suppose I could shim it to make the spring stronger but I'm already hearing some surge at low boost where it isn't releasing the air before it crashes into the turbo.

I guess I'm spoiled by my HKS SSQ BOV on my Stealth, it works perfectly in every situation, but it's about twice the price too.

thus far I think the forge bov is great for a 1/4 car but I don't think it's very good for a daily driver or autox car where you're going to be doing quite a bit of part throttle driving.

 

i had this DV on my 8 and do mountain runs 2600ft to 10000ft...drivibility sucks. The problem with it is the "high mass" piston

 

I still haven't shimmed the red spring to make it tighter yet... been busy busy,

here are the pics I promised:

 

and you bypassed the IX BOV because?????


Great pictures by the way, look like you took them for a magazine or web catalog shoot lol

 

because they leak at the pressure I'm running.

lol I looked back at the pics, they do look a little artsy fartsy

 

i'm in the same boat. I currently run25psi, and I plan on upping it to 27-28psi...the IX BOV is not the right choice for me 2.

Glad you reviewed the Forge on the EVo. I had forge DV on my VW 1.8T and it worked like charm...2 different cars though.

I will keep my search going. DD over here too