boost controller problem........

[Brunoboy]

Hi guys, I hooked up my Hallman Pro on my old gsx no problem. well now that i tried setting it up on my galant, it wont function properly. My mbc is hooked up to the wastegate on my 14b, and the other to the j-pipe. Is there anything wrong with this? I switched the lines and it still boost the same. If I turn the boost up all the way its boosting 9 psi, and if I turn it down its the same, If i switch the lines opposite, it does the same, so What have I done wrong???
-shane

 

[jepherz]

I think you need to post up pictures...

 

[BoostedAWD91]

everything working properly? wastegate working? u running a internal or external gate

 

[mikus]

Did you see higher boost beforehand? If not, it could be a variety of things ( ^ WG definitely suspect)

As far as boost signal for MBC, there's various factors at play in your choice - but J-pipe is arguably the safest way to go. Keep it there until you resolve the issue.

 

[Brunoboy]

Quoting BoostedAWD91:
everything working properly? wastegate working? u running a internal or external gate


internal, i have seen higher boost with the mbc before, stupid question, does the 14b have a nipple on it besides the wastegate that I need to cap? lol....

 

[mikus]

no, nothing else on there

you could pull the WG line off and see if it boosts higher (be careful of course, just a quick pull) that way you know for sure it's the MBC...

 

[Brunoboy]

what do you mean? how will it boost higher if nothing is regulating it?

 

[mikus]

With nothing regulating it at all, a turbo will boost until it maxes out, or something else gives (the latter in most cases)

the turbo spins as long as exhaust gas has no choice but to flow past the blades in the exhaust housing. The wastegate opens a new path for air to go - letting teh turbo slow down again. If there's no boost signal telling the WG to open, and exhaust gas keeps flowing, the turbo will spool until.... well usually bad things.

This can be quite handy for troubleshooting, just need to be very careful as you can overboost quite easily. give it a bit of gas and let up as soon as you have your data, and you're done.

 

[Brunoboy]

so leave the wastegate free and the j pipe free?

 

[mikus]

disconnect the MBC to j-pipe, and cap teh J-pipe so that system is closed. Now, no signal tells teh WG to open, and in theory the car would boost as high as it could. You can see if it's able to get up to... whatever you need to see.

Don't go past maybe 12-13psi on a stock system, and be careful. if it still can't make higher boost like this, something else is wrong, the WG system is next on your hit list.

 

[Brunoboy]

what do you do about the wastegate i mean

 

[Brunoboy]

i unhooked it, the wastegate must not be opening. it still only boost 6-7...........-___-

 

[solidviper89]

Exhaust leaks?

 

[mikus]

a closed wastegate allows boost, you want closed not open.

you say you've seen higher boost with teh MBC which is good, but have you seen higher boost with the 14b?

If you have not, money is on the turbine housing being cracked at the wastegate flapper. VERY common on 14b. Also check your exh mani for cracks while you're around there, especially if it's an original 1G mani.

 

[JNR]

I think he used the MBC on a different car?

What was the psig you were getting before putting this on the 14b (car); was it higher then? I was going to suggest doing a boost leak test, to make sure the system is capable of producing (at manifold) higher pressures than 9 psi. If the leak's bad enough, it won't.

 

[Brunoboy]

Quoting mikus:
a closed wastegate allows boost, you want closed not open.

you say you've seen higher boost with teh MBC which is good, but have you seen higher boost with the 14b?

If you have not, money is on the turbine housing being cracked at the wastegate flapper. VERY common on 14b. Also check your exh mani for cracks while you're around there, especially if it's an original 1G mani.



i did see cracks along the wastegate flapper.......uhm my exhaust manifold is the GT highflow manifold tapped for egt. and it works, its not cracked..........so what do I do?

 

[Brunoboy]

Quoting JNR:
I think he used the MBC on a different car?

What was the psig you were getting before putting this on the 14b (car); was it higher then? I was going to suggest doing a boost leak test, to make sure the system is capable of producing (at manifold) higher pressures than 9 psi. If the leak's bad enough, it won't.


I had it on my GSX eclipse. I was boosted 17-19 all day. that too was a 14b ported. my car does seem to be pulling timing though, I can feel when it revs higher it pulls back some. and I remember that happened when my gasket blew between the turbo and the mani or when I wasnt tuned............

 

[mikus]

Here's a list for to do:
- confirm no piping leaks (boost leak test as above, great suggestion)

- confirm Wastegate actuator/flapper is functional:
>> disconnect WG flapper at arm, check that arm is adjusted to just at the end of flapper 'closed' position
>> check flapper and arm - flapper should move freely, arm shouldn't move easily and should not bind up against anything
>> when you do a leak test, you can run ~15psi to the WG actuator if you want, to confirm arm fires out proper (although this wouldn't cause your current issue)

If that all checks out, it's time to start looking for cracks in exhaust mani and turbine housing. i'd pull the exh mani first and look down the housing, if it's real bad it will be quite apparant. Cavernous cracks are not uncommon. You can maybe get a finger into the flapper area to feel out for cracks too, but you won't be able to see them unless you pull everything and split the turbine housing/o2.

It's still not clear if you've seen higher boost on THIS VERY 14b. If you have not, again my money is on big cracks in housing/flapper area. If you have had higher boost on it (recently) then I'd be less gung-ho to disassemble everything.