Coping with a Crappy MBC - My Struggle

[Polyol]

So I bought that cheap MBC from e-bay. Only 20 bucks so I thought W.T. hell.

I installed it following various posts from this forum and in no time she was in. Went from the BOV/Mani line...plugged off the turbo housing and intake...unclipped the BCS. I took her for a spin and she is pushing way too much pressure...up to 17psi or more. I thought "great" then the check engine light popped on real quick.

Great...I take her home and turn that puppy down counterclockwise as far as I can and still no dice. Now my car is dying and the check engine light is turning on after reset. Ahhhhhhh...it starts to rain and I call it a night. That night in my dreams I was having boost nightmares.

The next day my buddy shows up and he is good help. We try to go to the compressor housing for a boost source and we replug the wire harness running to the BCS and cap it off. We go for a spin and she spikes up just like before but no check engine light. Nice. I assume that my ECU didn’t like having the BCS unhooked.

My friend opens up the MBC and tears out the guts. No spring or ball. We go for a spin and only 11-12 psi. Hall-al-loolua. At this point I get the wire cutters and start hacking off coils on the MBC. Took off two of them and FINALLY I have control of my pressure. What an ordeal.

Just thought I would share my experience of trial and error with those cheap ass e-bay MBC's. Sorry its so long. Overall, they do work but be ready to modify and keep close tabs on that boost pressure. Im still using the turbo housing as a source for boost. I may switch to the BOV line later but for now it seems to work pretty good.

 

[L2RTSiAWD]

Yep that can happen when buying a home deopt special off ebay. They just get springs and balls and don't test them.

 

[Polyol]

Here is the one I bought...if you buy one of these be careful of overboost. Be ready to cut some springs.

http://cgi.ebay.com/ebaymotors/ws/e...tem=2474258276&category=33742&sspagename=WDVW

 

[blcknspo0ln]

or you can just buy a joe p or hallman and call it a day

if not, check out a guy called proboostmbc.. i think that's his name.. good stuff [ ball and spring, non bleeder valve ]

 

[mitspro]

no joke i bought the same thing. all i had to do was open it and flip around the spring inside and no more problems

 

[TurBoGs-T]

Originally posted by Polyol
Here is the one I bought...if you buy one of these be careful of overboost. Be ready to cut some springs.

http://cgi.ebay.com/ebaymotors/ws/e...tem=2474258276&category=33742&sspagename=WDVW

I have that exact same one and it holds fine. Clipping the spring sounds like a good fix.

 

[Grn95GST]

You said you unclipped the BCS, you are just supposed to unplug the hoses off of it and cap the nipples but still leave it plugged in. That may be the reason your CEL is on.

 

[Polyol]

Originally posted by Grn95GST
You said you unclipped the BCS, you are just supposed to unplug the hoses off of it and cap the nipples but still leave it plugged in. That may be the reason your CEL is on.

Well I read from quite a few people that they unpluged the BCS with no problems. But yah, I plugged it back in and the CEL was gone...I stated that in the original post.

and we replug the wire harness running to the BCS and cap it off. We go for a spin and she spikes up just like before but no check engine light. Nice. I assume that my ECU didn’t like having the BCS unhooked.

 

[DSMeclipse4G63]

The cheap home depot racing mbc's are tempormental, mine can turn the boost up 10psi with a 1/4 turn...but then I adjust it 3 turns and no change in boost. You get what you paid for....It took me about an hour to get 14.5-15psi from 8psi. The best way I found to hook up a mbc is run the vacuum line from the bottom nipple on the t25 to the bottm nipple on the mbc(which ever end has the ball). Then hook vacuum to the wastegate, I always got decent accuracy with this setup. Now with the b16g is harder but I finally got it to sit at 15psi in all gears at wot.
Andrew