For sure. I was thinking if maybe i should add a little lube to it? compress it in my hand a few times with some sort of light oil or something? Maybe put a drop onto the ball itself as it seems very tight in its spot. I'm not sure it should be able to wiggle in it's spot when taken apart, but i asked Mike to make sure on this. If he doesn't post on this, i'll let you guys know his comments. Also, when/if i can fix it, i'll be sure to post so.

Edit: Also, fuel cut. Does Al at Dynoflash remove fuel cut? If i was boosting to 26psi, shouldn't i have reached it? I only hit it for half a second before i shut it down and pulled over.

 

I have bad news for you walkedu, after a couple of days using the soft spring I decided to go back to the stiffer spring. I made sure it seated correctly, and for a day it worked as it was supposed to work (just perfect), then all of the sudden I started experiencing crazy spikes again. These spikes are so unpredictable that they can happen any time, and then they can just go away.

This past Saturday I had my Evo flashed by Al on South Florida, after the flash we went for a ride and Al drove my car. At the first shot at the throttle we got a pretty bad spike (maybe around 26 PSI) and Al immediately said that I had my boost set too high. I told him about the problem I'm having with the Forge MBC and the stiff spring, and as explained above the following runs were fine just below 22 PSI. Also I talked to Calvin (the next guy in line for the flash) and he told me that he just installed the Forge MBC and experienced bad spikes as well.

What I think it’s happening is that for some reason the stiff spring is getting stuck inside the MBC, and that's why I asked before if it was safe to lube the spring. Nobody answered, so I didn't do it. I don't want to go back to the soft spring because I can only see 19 PSI at the maximum MBC's setting, so I don’t know what to do…

 

I just got a PM back from Mike@Forge and he said it should be alright to use a VERY little amount of synthetic grease. It's too late to try it now, but after work tomorrow, i'll see what happens. When you took your MBC apart, how was the ball sitting? Was it stiff and made no noise or movement? Being that I bought my UNOS used and had only the stiff spring, Mike is actualy mailing me a soft spring FREE of charge. I couldn't believe it. I didn't even buy my unit from him and he's going out of his way to help me out. Amazing...Simply Amazing.

 

I'll do the same think, I'll try to lube the spring tomorrow after work. The ball fits fine on the MBC, I don't think that is the problem.

 

I was just asking about the ball for the sake of mentioning it because i have no idea either. Just trying to bounce ideas around. I mean, shouldn't it move just a little bit? Or i guess when you "click" it down, the ball should move then so maybe it should be stuck TIGHT like mine was? I don't know, either way, i'm going to lube it up a little bit.

 

Welp, i just tried to oil it down a bit. Took it all apart. Ball and spring both came out. Used a little Mobil 1 5-30 and put it back together. Did a quick pull and wouldn't you know it... 25psi again. I made sure it was wound all the way negative. When i instaled this the first time, this got me about 16 psi. What gives? It's not like this part has alot of pieces to it? What could possibly be making this happen?

Edit: When i took this thing apart yesturday and today, both times the spring was on there solid and over the nipple with about 2 1/2 coils wraped around it. The ball and the spring are the only parts inside the chamber correct? Like i said, i didn't buy this new and don't know what it looked like new. It worked fine for about 3 weeks after i bought it and then this.

 

We should merge this thread with this other one:

https://www.evolutionm.net/forums/sh...d.php?t=177505

The problem has to be the stiff spring. When using the soft spring, no matter how hard I drove my car or what I did to it, I had never got a spike at all. Unfortunately I don't have the time to do more testing, when I leave the office is pretty late...

 

I wish that other guy would have just posted in this thread to begin with.

Anyway, Mike is sending me that soft spring, so i'll just switch to that for the time being. I can't imagine that any other portion of my car would be causing this due to the fact that nobody else is spiking like this with other MBC's? I'm going to check my WG actuator to be safe, but when i did the oil thing, everything appeard to be ok down there. I'm at a loss??? Maybe i'll take it apart YET AGAIN, and take a GOOD LOOK at it. Maybe rince it out or something?

 

I was thinking about using a little bit of teflon grease instead of oil.

While you take the MBC apart again, try if possible to take pictures of the inside of the MBC's body. I'm not sure but I think there are some grooves inside that may be worn out. I'll do the same.

 

Ok, i can take some pics. What grooves would wear out? I tested the clicky part when i had it all apart in my hands and it appeard to work just fine. When you tighten it down (turn it towards the plus) it pushes the spring up harder and harder against the ball. I don't see how mine could be worn out as the UNOS just came out and with only 8 clicks from the bottom, it's not like i turn mine a whole lot. Granted i bought mine used, it came with the heavy spring so i doubt he turned it much either? Like you, i don't want any other MBC and would like to fix this one rather than buy a different one.

Mine will spike when i punch the throttle. If i just ease into it, it still boosts way higher than the lowest setting should go. hmmmm

 

Wear is not caused by the clicks on the MBC, I think it's caused by the spring traveling up and down at different boost levels.

I bought mine new, and the crazy spikes started after 2 weeks of using the MBC.

 

Well with the spiking that we're seeing, that would mean the ball is being held shut correct? So.. all of the sudden, both our ***** are stuck during WOT right? It just doesn't make sence to me that it didn't do it at all, now it won't stop doing it. I don't suppose you have a warrantied turbo do you? Cause both myself and that other guy both do. What other mods do you have?

 

Still can't figure anything out. I took it apart and cleaned it with q-tips. Thing was DIIIIIRTY! Thought that might help, but nope. Still acts real crazy and spikes to nearly 25psi on the lowest setting. It seems like it wants to work, but the very next pull it just spikes again. Did you figure anything out Juan... or that other guy?

 

Well, I just got back from a test drive and have some news. Once again I took the MBC apart and checked the stiff spring, it couldn't be seated any better. Then I proceeded to check the metallic ball and I found something interesting... it was stuck on its base!!! No matter how hard I shook the MBC or how hard I tried to suck the ball with my mouth, the ball just didn't move. I used a q-tip trying to get the ball loose, and after a lot of attempts I finally manage to get it out of the MBC's body. I realized that the spring is not the issue because there is plenty of space inside the MBC for the spring to go up and down; I don't think it even touches the inside walls of the MBC. On the other hand I think the ball is too small, and knowing how quickly boost raises on the EVO, and then goes into vacuum, so no wonder the ball gets stuck. I mean when you punch the EVO boost quickly reaches ~21 PSI, then you let go the throttle and the car goes below 20 in Hg, that quickly up and down on pressure may cause the small ball to get stuck on the MBC (when in vacuum), so that's why when you punch the car once again we got crazy spikes.

I may be way off, but since nobody else seems to care about this problem I'll keep troubleshooting this issue. Just for the records, after I realized the ball was getting stuck I decided to put some grease on it (synthetic grease) as well as on the spring. I drove the car for about 30 minutes, with partial throttle punches as well as hard launches, no spikes so far.

 

Thats funny you say this^ when I took mine apart I noticed I had to tap it upside down when it was taken apart to get the ball out once, good find