Cannot raise boost with MBC

[Catbox_95]

I installed a Hallman MBC, correctly I'm pretty sure. I installed it according to the following thread:

http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/237982-best-way-install-mbc.html

The car is pretty much all stock, 2G, stock turbo, stock BOV.

To start, I backed the bleeder all the way out and made a run. To my surprise, I hit 13 psi of boost, which is what it ran with the stock BCS connected. So I made about 20 runs, each time screweing the MBC in 1 turn, all the way up until it was all the way tight, and it behaved identically each time - 13 psi.

Is it possible that the stock 2G BOV is not allowing any more boost to build? I have a 1G BOV but I'm waiting for the flange adapter in the mail.

 

[alex209]

I would swap the 1g bov in, 2g bov leak around 10psi ,I had same problem swaped bov and mbc worked great .make sure you do a boost leak test too

 

[PieEyedPiper]

Even a leaky 2g bov should allow 15psi spikes. If the mbc is hooked up correctly and the turbo is in good health move on to replacing the bov. Yours might be extra terrible or something.

 

[Catbox_95]

Yeah I've done a boost leak test and all seems well. I'm putting my money on a crappy stock 2G BOV. Thanks for the replies.

 

[Lofty]

You dont have the BCS installed still do you?
A bad turbo can also do this. Its pretty rare but Ive seen it happen on my buddies 3000gt.

 

[DSMxJB]

I installed a Hallman MBC, correctly I'm pretty sure. I installed it according to the following thread:

http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/237982-best-way-install-mbc.html

The car is pretty much all stock, 2G, stock turbo, stock BOV.

To start, I backed the bleeder all the way out and made a run. To my surprise, I hit 13 psi of boost, which is what it ran with the stock BCS connected. So I made about 20 runs, each time screweing the MBC in 1 turn, all the way up until it was all the way tight, and it behaved identically each time - 13 psi.

Is it possible that the stock 2G BOV is not allowing any more boost to build? I have a 1G BOV but I'm waiting for the flange adapter in the mail.

I recently installed my Hallman pro and had the same exact problem. I though I did something wrong and tried everything. When I boost leak tested my car the stock 2g bov wouldn't build more than 10psi and started leaking at 8. I put my GReddy bov on and the boost controller started working.

 

[honda_burner]

Don't hallman boost controllers have to be hooked up the opposite way of the common boost controller set up because they are the bleeder style, not the typical ball and spring set up?

 

[bryanwheat]

Don't hallman boost controllers have to be hooked up the opposite way of the common boost controller set up because they are the bleeder style, not the typical ball and spring set up?

If it is a bleeder style than it will need to be hooked up like the stock boost control solenoid so that could be the problem. According to this they are ball and spring and should be hooked up like the link above. http://www.hallmanboostcontroller.com/ES New Instructions.pdf

 

[honda_burner]

Sorry for the misinformation then.

 

[Catbox_95]

You dont have the BCS installed still do you?
A bad turbo can also do this. Its pretty rare but Ive seen it happen on my buddies 3000gt.

The BCS is still on the car, and the wires are running to it, but no hoses. I was told to leave it on the car, although disconnect all hoses, or the CEL will come on.

 

[PieEyedPiper]

The BCS is still on the car, and the wires are running to it, but no hoses. I was told to leave it on the car, although disconnect all hoses, or the CEL will come on.

You're fine.

I recently installed my Hallman pro and had the same exact problem. I though I did something wrong and tried everything. When I boost leak tested my car the stock 2g bov wouldn't build more than 10psi and started leaking at 8. I put my GReddy bov on and the boost controller started working.

This might indicate how some of the older members information can be outdated in respects to such things. "Back in the day" it was commonly understood that the 2g bov leaked, badly, new or old, but I don't think I can recall that everybody was getting <=8psi performance out of them. More like 12, or 10 on a real bad one. Age is a bi***.

I know you have another thread going but I'd go evo8 or stop futzing about and just get an rre/dave brode uicp if you aren't going fmic.

 

[DSMxJB]

You're fine.

This might indicate how some of the older members information can be outdated in respects to such things. "Back in the day" it was commonly understood that the 2g bov leaked, badly, new or old, but I don't think I can recall that everybody was getting <=8psi performance out of them. More like 12, or 10 on a real bad one. Age is a bi***.

I don't see how my information is wrong? I have a boost leak tester with a gauge and just did this not even two weeks ago. The boost leak test would go up to 10psi but air started coming out of the bov at 8. The op asked if the bov was causing his Hallman not to work an if it was the bov. I just had the same experience and almost posted because I was worried my Hallman was faulty but ended up Blt and finding out my bov was garbage. The first drive with the new bov I turned the boost controller and instantly my gauge went to 1.2 bar and I let off but my Hallman worked perfectly after the 2g bov was replaced.

 

[Trix96gst]

Swap the BOV the stock 2g leaks at 10-11psi. I had this same issue late last year. Swapped the 2g bov out with a hks ssqv bc that's what I had laying around with my fmic and I slapped the upper pipe on with bov and was able to raise boost. But a boost leak test wouldn't be a bad idea just to make sure you aren't having issues elsewhere

 

[JusMX141]

Your BOV is acting as a wastegate.

On a friend's stock 2G a few summers ago, no matter what we did the turbo made and held 14psi solid as a rock. I fabbed a flange and we swapped one of my spare 1G valves on the car- instantly went to 18-19psi and trailed off to around 15psi by redline.

 

[turboglenn]

WHen my 2g was new i couldn't make anything over stock boost until i replaced the BOV and opened up the exhaust with a cat-back... the exhaust was too restrictive and the BOV leaked anything it could make..very dissapointing when i bought the car near 13.5 years ago and had to immediately spend what equalled "big money" at that age, to buy the thermal cat-back and upgrading the BOV, just to see the boost gauge read a 'lil higher ...it was ok though, more boost and the ECU just took more timing and the car got slower...hence me ripping the ECU out and installing a haltech by 24k miles on a car i got with roughly 16k on it.

 

[Catbox_95]

Resolved the issue. As some of you suggested, yes, it was a BOV. replaced it with a 1G BOV, and I have to say the car has NEVER run so good. Both in performance, and every day drivability. I can't believe the old stock BOV was causing so many other little problems as well. Thanks for the help. Sorry, I don't know how to make the thread read "Resolved".