Could you send me a picture of the piston? We are on our second redesign and you may have one of the earlier styles... Loosing boost in 5th with the stiffer spring makes me think that you might have one of the ealier pistons that could get stuck slightly crooked allowing the valve to leak.

 

I'll get some pics of it asap, btw it's not just 5th gear, it's pretty much any partial throttle situation where you're making boost and trying to maintain a speed too, it can't make up it's mind whether it's supposed to be closed or not.

 

hey Chris i got one of these as well and..... well not impressed one bit.
you have to drive the car like an on off switch.

I have the red spring now installed and the flutter is less pronounced but i hear comp surge if you don't boost to much to allow the valve to open.
basically it does not open at the lower boost.

yes it hold boost fine and if you go WOT throttle and change gear between 3500-4800rpm as boost builds up it will spike like a ****!! It giving my HKS EVC 6 a hard time controlling the boost.
Even worse with the blue spring and at my altitude 5000ft the flutter at partial throttle 5th gear is unbearable. People look at me like i am crazy.....(cant this plank drive WTF).
So i am gonna slap in my Plastic IX valve and live with the boost leak, trust me the driveabilty is that bad with the FORGE 15.
Gonna throw this POS BOV in the trash.......

oh well time to install my autronic and Slap in my Tial with the AMS 30r and be done!!

 

guys, try the red spring with all the shims. . .it's worked for me so far, and you learn how to part throttle it for DD. . .i wonder if the RS is easier since you can "click" your stiffness out. . .??

 

This subject has been beat into the ground many times, Forge stopped making this valve a long time ago because of problems and it was never intended for use on the evo.

The IX valve holds boost just fine if you add the Dejon Tools leak stop kit and drivability is way better.

 

cfdfireman1,

We still make the valve. It was designed for the EVO.

Mellon,

I've been trying to work out a viable solution to this in the slow periods since I started with the company. So far the absolute fix has been to drill a EXTREMELY small hole in the center of the piston... works but isn't really a realistic fix.

I think that a restrictor in the vacuum line will cure issues with transient driving but steady state high load situations (low vac or low boost) will still have issues.

The odd thing is we make a valve for the 2nd Gen eclipse which is nearly identical that doesn't suffer from this issue... at least not on the Eclipses. So either it is something peculiar with the EVOs or there is some difference in the two valves that accounts for it.

Whoop_ass,

No need to junk it, we warranty our parts. If you are unhappy we will refund you. If you bought it through a vendor initiate the refund through them and have them contact us if there is any problem. BUT I would prefer it if you could wait a while as I will be attempting to find a solution over the next few weeks.

 

I will hold onto it bro thanks!!
besides the flutter issues there is nothing wrong but it is a PITA to drive on the freeway with this valve in(you either have to be on boost or not).

Workmanship is top notch bro

 

mike@forge in a post about 1-1/2 years ago or so when someone was trying to sell one of these, it was about the same time your new rs came out. seems as though that post has been pulled or I would show it to you.

 

Mike is a dork...

 

I didn't know that.

 

Patty, I pulled the Forge DV out today and got some pics of the piston for you to examine.

I put the stock BOV in and driveability is back to normal, no more on/off switch after part throttle and the 4th / 5th fluttering is all but gone. It's 200% more enjoyable to drive again.

I think spoolup is slower with the stocker, I'm used to seeing ~ 20+ by 3000-3200 and now it's more like 3400-3600 which is what I originally expected from this evogreen turbo.

I hope there's something you can do to improve the Forge unit and let me know if there is something I can do to help. If this can't be resolved I'll be asking Buschur Racing for a refund but I do want to give you a shot at it first.

pics:

 

I did the same as well chris
put the stock plastic valve back, at least i can drive the car and enjoy it.
to much effort to drive the car like that

the little bit of boost it holds is not worth the ball acke to drive around it.
i am on the other side of the globe so i doubt i will be sending my unit back.

oh well i am sure i can use it hold papers down on my desk in my office..LOL!

 

I can't explain it but my EVO feels much stronger with the stock BOV...even my son said something when I got on it the first time after changing the BOV without his knowledge. It might be the way the boost comes on a little later with the stocker. I'll have to do some DLL logs to find out for sure.

 

hmmmmm!
i am gonna pull some logs but i think i hit boost sooner and it more agro with the Forge BOV!!!

Maybe have a look at the works valve, i think it the same as the JDM one

 

my previous best with the Forge BOV after dozens of attempts was 372awhp and now within 3 attempts the best was 382awhp in DLL which is a new best for me.

I also did a 1/4 mile run to see if the g-tech agrees:
my previous best after dozens of runs was 12.20 @ 116.5 and a 1.7 60' and today with only one attempt I got a 12.20 @ 116.6 with a lousy 2.0 60' (clutch didn't hold) so 3 tenths were thrown away easily. I think it's got 11's in it all day long with a good clutch.

I did some 5th gear part throttle pulls with the stock bov and the fluttering is there:

at 10psi it's hardly noticeable
by 15psi it's very bad and difficult to maintain speed
at WOT it's fine.. the problem is when you're trying to do some light acceleration that it starts pulsing. I never had this problem with the stock turbo so I suspect it's the evogreens fault and the forge bov just amplifies the problem.

again the stock bov is still worlds better in most situations, it's just the 5th gear part throttle acceleration that neither do very good.

I did notice that the stock bov, like the forge isn't able to keep the air from crashing into the turbo, I get a really bad choo choo choo after any boost where I let off the throttle and the higher the boost, the worse it is.