Bare with me, I have a tendency to write long paragraphs. So everyone says that Hallman and Forge MBC's are the best. I'm sorry, but I'd hate to see the worst then! My first Hallman Pro RX wouldn't control boost. CBRD will tell you. Lasted a good while (2 years), then quit. I tried a Forge and oh my god, talk about problems. At least when the Hallman malfunctions it doesn't boost to 35 psi! Well, all in all, back with a brand new Hallman Pro RX, I have another issue. Randomly, I will hit 22 psi and hold, and suddenly drop to 15 by, say 6 grand. Like hitting a "soft" wall. Not like fuel cut! You get the picture. To fix it I turned the MBC all the way down, then back up and good, 22psi - 19 taper. It will happen from time to time with no other symptoms.

I have been flashed twice and have done logs. No knock whatsoever, so no timing pulled.

No boost leaks. It would have to be a big leak. And the fact that it operates normally most of the time would rule this out.

Wastegater Actuator is almost brand new, stock replaced once. When these go bad, usually they overboost, not underboost.

I've been reading hundreds of threads about MBC installations for 3 years, so I know how to install one. I'm tapped on the turbo outlet.

My conclusion is the ceramic ball must somehow be "sticking" to something inside.

I'm out of options... I do not know what to look for in the internals. Maybe lube up the ball? I'm running the heavy spring. Boost hoses are fairly new. No I'm not reusing the stock hoses. I'm not a newb, I know my boost! And the gauge is dead on! I compared it to a mustang dyno's readings. Within 1/4-1/2 psi!

Mods: HKS downpipe, Works Hi Flow Cat, HKS Catback, GSC S1 cams, HKS RS intake, Whinebro 255 FP, Greddy IC piping, JDM Evo MR BOV, and minor other goodies.

Now that I think about it, I'm still running the stock Iridiums. My third set, so they're brand new, gapped to .026 or around there. Would a misfire cause boost issues? I wouldn't think so, but I'm not familiar with misfires. And a big miss usually throws the P0300 or around there.

Thanks for the help experts.

 

Where's Warrtalon?

 

If you are going off of the turbo outlet and not the BOV line than it would have to be the MBC, hoses, WGA, or a leak somewhere in the intercooler piping.. Nothing else should have an effect on it. At least not that big of an effect.

If they are new hoses and a new WGA I would try to find someone local to borrow thier MBC and see how things go.

 

Clean the spring and ball. Sounds like the spring is not seating correctly on the ball at times. Clean it with MAF cleaner or the like, Brake Cleaner even, over a paper towel. Then squirt a little WD40 onto the spring and ball aswell as into the MBC (shake out the excess).

Otherwise get an mbc that works like a JoeP.

 

thanks, I will try the cleaner and lube!

 

I had a forge and it worked perfectly. Also if you have problems with Forge they'll send you out a new one asap if you contact them.

I'm using an aem truboost now though and hell will have to freeze over before I go back to a twistie boost controller.

 

im wondering if the wga may be not up to par...

hmm...the new one should be perfectly clean.. but as stated you may want to spray it...

cb

 

LOL!!!

 

Why not just buy a Hallman Pro...is there any real need for the ceramic ball and extra cost of the RX...

 

I didn't have an option the second time. I was told by the vendor the first time, that the ceramic ball helps spool quicker or something. A funny thing is that whenver Al flashed my car two years ago he told me that the RX was not as good as the steel ball one. (I thought that it was just because Al only sold the Pro's and not the RX's.) He may know his stuff though.

Update: - I haven't had a problem since. I cleaned and lubed the old one and man it was dirty, but the new one was fine. I don't understand.

Chad: - It could be something with the Wastegate. But when tested open, it shot up to 30psi+ and I lifted. Then bypassing the MBC it boosted to 11-12 psi perfectly.

I think I'm going to make a warranty claim for at least one of the two.

 

don't have a problem with my hallman, but man that forge mbc is a piece of you know what...