too much boost from joe p controller

M

m-speedy jerm

Member
my buddy and i just installed the xz mbc controller tonight, and we twisted it out all the way, and i'm still hittin' 11psi everytime, we can't seem to lower it. this of course not a good thing if i want to keep my engine, so any ideas would be great:wtf:
 
Probably a kinked line somewhere...you should be seeing 1-2 pounds more boost than stock with the MBC set to the lowest possible setting.
 
I bet it'l start to work right once you get some more posts under your belt! I mean, 1 post??? what do you expect??? Joe P's stuff only works if you post a lot so get going!!!



all kidding aside. 11psi is NOT cool!!! if it's not working, you're better off taking it off and sending it back for a new one. then again, I took mine off (GIB YSSUP) so what do I know? one thing I DO know is... I'd rather get blown, then blow up my engine! good luck!
 
yeah, checked the lines, no dice, i thought thats what it might be reading through the forum

and yeah, haha, i should have more posts, i've had the car for 4 months, but i've just recently started working on it, so maybe my posts will start to rise now:0

but yeah, i'm not sure if its the controller, the car is virtually stock except for the joe p equipment, its the 2k3.5 and its unflashed, not sure if that has any bearing, but if i can't fix it, i'm goin' to remove it, which is of course a better option than a blown engine as you said...
 
What is the gauge reading without the MBC? The gauge might be off.

If the temperature is fairly low, you shouldn't be able to hit 11psi without hitting fuel cut. People around here hit cut at ~9psi in cold weather (<35 degrees or so)

WHICH would lead me to believe your gauge is off.
 
i have the blitz dual tt hooked up, so its reading in bars, it hits .76, which looking at the table is equivalent to 11.02psi, the weird thing is when we tested the car, we didn't hear the fuel cut, so maybe the reading is off, which of course would lead to a whole different prob, wouldn't know how to test if the reading is accurate or not though
 
At stock boost (MBC off) you should be be reading max boost of 7psi or lower.

It's supposed to be somewhere between 6 and 7 psi, but it ranges from car to car...some people are at 5psi, some are at 7.

If the TT is reading 9psi with the MBC off, then it's probably installed incorrectly or defective.

IMO if you're not hitting fuel cut you SHOULD not have any problems with blowing your engine...the cut was set at that certain level by Mazda for a reason. If Mazda didn't think it would be safe for that amount of air to flow into the engine, then why wouldn't the cut come in sooner?

Oh, and you don't hear the fuel cut, you FEEL it. At WOT, the car will stop accelerating abruptly...it will feel like hitting a wall. Trust me, if you hit the cut you will know it :)
 
haha, yeah, you have a point, i certainly haven't felt it, so maybe i'm aight..... we did run the car w/ only the fcd and the fuel pressure reduction kit and it hit around .55 bar or 7.9, and w/out that it was 7.4psi, which i'm guessing is normal, so it seems accurate, but i'll double check to make sure i'm not missing the fuel cut, haha
 
Good point...if it's installed backwards, it will vent nearly all of the pressure...meaning little pressure will go to the wastegate actuator (higher boost)

Try installing it the other way. Oh, and make sure you keep the FCD off for all of this, so if you mess up, you won't overboost.

Once you get the install done correctly, and you decide you want to run higher boost then it's your choice. But keep it off until you figure out what's up with the MBC.
 
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hmmm, okay, i believe we have the bottom portion of the xz to the wastegate and the turbo outlet connected to the middle portion of the controller, is that right??
 
im the one that help speedy jerm install this. We took the wastegaute side of the MBC and found the T comming off of the BPV. Hooked the hose coming from the bottom of the T to the wastegate and then hooked up the vacuum source to that T. We know that this works b/c we tested it.

When we set the boost controller up we set it to the max by accident and at 3/4 throttle we hit .86 bar and backed off so i went and adjusted the MBC. We got it down to like .71 but when him and i would go race he would hit .76.

I have the blitz tt ran to the vacuum line coming off the back of the intake manifold. So im pretty sure that it's done correctly.
 
maybe too much on one vacuum line? ( I don't know...just theorizing :) )
 
doesnt the mbc need to be relaly close to the vacume source or else it will have a abnormally high low setting?
 
m-speedy jerm said:
my buddy and i just installed the xz mbc controller tonight, and we twisted it out all the way, and i'm still hittin' 11psi everytime, we can't seem to lower it. this of course not a good thing if i want to keep my engine, so any ideas would be great:wtf:
Click to expand...
you should remove it, too much pressure like that will not be good for your rods.
 
Re: Re: too much boost from joe p controller

DiscreetSpeed said:
you should remove it, too much pressure like that will not be good for your rods.
Click to expand...

my girlfriend says the same thing all the time to me
 
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