Yes! My Forge UNOS MBC is working great now. Its turned all the way down with the stiff spring and holds boost at 20 psi tapering to about 19. It did jump once or twice to 21,22 but thats okay with me as long as I don't see any huge spikes. When re-installing it last night, I made sure the spring was secure on the nipple. I might have over looked this initially when changing out the soft spring with the stiffer one but its not something I'd do. I did not lube or grease the bearing either. The ball sits in a cone shaped recess, and I think grease would cause it to stick if any. So I left it alone since it moved easily as I blew into it. Overall, I would strongly recommend for anyone having problems to make sure the spring is securely snug onto the nipple. I even had use very small needle nose pliers to get the coils on the nipple. As far as temperature goes, not sure it affected me too much. It was 31 last night when testing it out and 69 today as I drove around and I didn't see any difference in boost so who knows. Anyways, I hope this helps.

 

I had the same problem with the stiff spring. I can only use the soft spring b/c of the erratic boost levels on the stiffer spring.(I mentioned this on a previous post... and I was told that 25psi was not possible at a setting of zero w/the stiffer spring...interesting) I will def. keep an eye out for a permanent fix. The craftsmanship of the Forge is excellent, I just hope this gets resolved soon so the unit can work up to its full potential. Keep us posted Mike.

 

TEchause, that only happens when the spring is not seated on the nipple. If you seat the spring, it does 17-18psi on the minimum setting. I've had to fix several of them in the past 2 days, because the springs were not seated when the owner switched to the stiff spring from the weak spring.

 

Here's my update:
I took my MBC apart and inspected & cleaned same. After taking it apart, I noticed that the ball was stuck in it's base, I had to use the allen wrench to gently tap it loose. Upon inspection of the lower half of the MBC, I noticed that it appears that the SS ball had gotten wedged in it's base and was likely the cause of said spikes. I decided to compare the seat & ball of the Uno to an AMC that I have. while their SS ***** look identical, their seats are very different. The base of the seat in the AMC is wider and has much less taper, whereas the tapper on the base of the forge is much more steeper and made out of aluminum. I'm speculating that it appears to be a machining difference in the base of the unit and may be allowing the SS ball to get wedged into the base, thus causing the aformentioned problems.
Again, this is pure speculation.
I greased said ball w/ Synthetic bearing grease, re-assembled , installed and road tested. all spikes to date have been eliminated and same is holding @ 21-22 psi w/ no spikes. I was abel to get my MBC dialed in within 2 passes using only 7-10 clicks negative(I received said unit with heavy spring installed from Al and am using same, no other spring was sent with unit).
I have driven the car several times again today w/ same results. if there is any change I will post.
On another note, I've spoken w/ Forge on two occassions and was very pleased with their advise and willingness to remedy the problem. Life happens, it's what we do with it that sets us appart!

 

Sorry bout ma poor spellin. LOL!

 

Warrtalon, this issue is not caused by the spring not being seated properly on the nipple, it's the ball that gets stuck on its base. I had a hard time getting the ball out of the MBC when I was about to grease the spring, that's how I found that the ball was causing the spikes. I still believe that the ball sits so perfectly on its base that gets stuck, and using a slightly bigger ball would solve the problem without having to use grease.

I went to my local autoparts shop and Home Depot trying to get a ceramic (or SS) ball, but none of them carried them.

 

Mike,

I figure adding to this thread is probably the easiest way to get your advice, other than just calling you guys (next step ...).

I had the Forge UNOS MBC installed on my IX yesterday. The first problem that I had was an immediate spike to 25+ psi with it set all the way to the -. I pulled it apart and of course the stiff spring was not seated on the nipple. That was a reasonably easy fix to get it seated and back together.

Then with the knob all the way to the - I hit around 14psi or so. Great. I started cranking it up attempting to hit a spike of around 21-22psi. Now the problem that I have is very erratic boost.

It usually goes like this:

Full throttle, boost builds to a spike of anywhere from 20-24psi ... boost then immediately drops 2-3psi, then starts creeping back UP to around 20-21ish or so, then it starts tapering down from there. All the while the boost occassionally bounces up and down a bit.

I have no clue if I have a boost leak, leaking BOV, weak WGA, bad install of MBC, bad MBC, bad boost guage/install? Not sure which of those could cause the erratic boost behavior that I'm seeing bouncing up and down?

By the way, Warrtalon rode in my car for a quick second gear (not as bad) and third gear (problem definitely noticeable) run, so he can verify the behavior as an independent observer. Unfortunately, I think he was mostly looking at my stock gauge, which is reading low (doesn't zero when car off) since the autometer guage was installed, but I think he observed the 'initial spike, then drop, then creep up, then drop again' behavior.

Thoughts?? Where should I begin the troubleshooting?

Thanks,
Josh

 

I would suggest trying to slightly crush the BOV - The spped factor knows how to do that procedure and see how it is then

 

Since I've been dealing with this problem I think I can help you somehow.

First of all I'd try to get a different boost gauge just to make sure that you're reading accurate numbers (you already know that your gauge is not accurate, not reading zero when it's supposed to).

After greasing the ball I haven't had too much problem with the Unos, spikes are "almost" gone. It may happen once in a while, but not as bad as before. If I have a spike now it quickly drops to the the dialed PSI. Before the grease the story was totally different! I could recreate spikes whenever I wanted, even worse... without wanting them!!! If from a roll I pressed the gas pedal too quickly, at 50% throttle I was at 25 PSI or more, and with just little movements on the gas pedal I could go up and down the 25 PSI mark. No matter how many times I took the MBC apart and reseated the spring on the nipple, the problem remained.

For me (and some others) the problem has been solved by greasing the ball with full synthetic bearing grease. Give it a try and let us know your results. But remember to try another gauge, don't put your engine on risk.

 

OK, thanks Al. We were going to try that yesterday but ran out of time. Also Warrtalon wasn't sure if the symptoms I was seeing were consistent with the leaky BOV problem. He seemed to think it might be different.

If we did a pressure test of the system looking for boost leaks, would we be able to see for sure if the BOV was opening prematurely?

 

Thanks for the advice.

Do you get a spike, followed by a drop and then a creeping back upwards??? I also hit a different peak each time ... kinda scary. I'm running it low now just because it's very unpredictable it seems.

When I took mine apart (for the 3rd time or so), the ball came out with no problem at all and didn't seem to be sticking in the least. I'm willing to try a little grease though ...

 

Well, I've wanted to chime in and say I have a Forge UNOS BOV and LOVE it - no problems, and this post has convinced me to do it - so there! *LOL*

Just my $.02 - if you have a question about what your boost is doing do a thorough boost leak test FIRST. Sorry, a bit off-topic, but I see this alot. I made my own tester and got an air compressor just to help me sleep at night when I'm trying to figure out if I really have a problem or not. My car was a COMPLETELY different animal when I fixed a number of leaks I was having and wasn't aware quite a while back.

Back to your regularly scheduled thread...

 

Well anytime you have a mod which is free and takes 10 mins that would be my first step

BTW - your boost should be set at 20 psi MAX

 

Uh, yeah. Pressure testing and BOV crushing will likely occur tomorrow if I have time. I thought I would post here for advice from the manufacturer especially since my symptoms (spike then fall then creep up again) seemed a bit different than what has been reported by others. I thought it might trigger some thoughts from Mike@Forge or other knowledgeable people besides the obvious pressure test ...

 

What does "crushing the blow off" mean?

Plus, just wanted to say my UNOS is working great and totally consistant now. Its turned all the way down (stiff spring) and hits peak boost at 20, 21. It doesn't usually taper either. Holds it all the way to redline in any gear. I just made sure the spring is SECURELY snug on the nipple.