Adjustable Hi/Lo boost problems

[ttsrq]

Ok so I was looking through the dsm tuners forums and found this mod and thought it would be cool to try it. http://www.dsmtuners.com/forums/showthread.php?t=196100 and http://www.dsmtuners.com/forums/showthread.php?t=220530 so I did what it said and its not working. For the wiring I took a wire from the ACC on my switch and wired it to one of the male connectors from the BCS.. then I wired the positive on my switch to the red wire in my stereo wiring harness...then wired a ground to the other BCS male connector. Then I wired the ground from my switch to the ground in my stereo wiring harness. After I did this all nothing worked..the switch did not work aswell as my stereo..I checked the fuse and it was blown I then replaced the fuse and it still wont work and the fuse is fine.
I then took the car for a test drive to see if maybe the switch light was burnt out and I boosted to 25 psi EEEEEK.... So heres how I rigged up the BCS and the MBC.... The MBC is connected to the waste gate and the nipple coming off of the turbo...I then put a T in the line between the turbo nipple and the MBC and connected it to the flared side of the BCS I then put another tee in the line between the waste gate and the MBC and hooked it up to the other side of the BCS. Any help would be GREATLY appreciated.

 

[kspharris]

It all sounds like it is hooked up right. What type of switch do you have? Do you have a VOM? If you do test the lines, ohh and make sure that you have the proper wiring on the BCS you may have that backwards.

 

[wret]

You obviously created a short. I hadn't seen that write-up before, but now that I look at it, it seems very safe. Even if you screw something up in the wiring, you would still be running on the MBC. Check for a leak in your tubing somewhere and be sure your MBC is not set too high.

 

[ttsrq]

My switch looks like this but it is red http://www.positiveoffset.com/Parts/on-off-switch.jpg dont know if this helps but before I saw this mod I was just running my MBC but it was hooked up differently it was hooked up to a line off the BOV and the other end was connected to the waste gate and it worked perfectly fine held at 15psi. Then when I did this mod I reconned the hose from the BOV to its stock form and hooked up the MBC from the wastegate and the nipple thing off the turbo. The car has no boost limit it hit 25psi when I stepped on it and I figure it should run off the MBC because the BCS wasnt hooked up properly or something and my MBC was set for 15psi. So I wired some of it to my stereo and the others to the BCS and then a ground and my stereo no longer works and either does the BCS switch.

 

[ttsrq]

Ok so uppon further inspection I found out that my setup keeps blowing my radio fuse I even put a fuse 5amps larger into it and it still blew it. So something must be wrong with my wiring. This is EXACTLY how I wired it. One male connector off the BCS runs to a good ground in my engine bay, the other male connector from the BCS runs to the positive on my switch. I wired the red wire from my radio harness to the ACC of my switch. I wired the ground on my radio harness to the ground on my switch. And it keeps blowing the radio fuse. Is the load too big of a drain on it? Or is it not wired properly..where should I wire it too. I also installed the MBC differently now and still have the same problem with it boosting to 25+ psi. One end of the MBC is connected to a line off the BOV, the other to the waste gate...I put a tee in the line from the wastegate to MBC and put it onto one end of the BCS. I put another tee in the line between the MBC and the bov and connected it to the flared end of the BCS with still no luck its not boosting to what my MBC is set at (15psi) I need help REALLY badly.

 

[wret]

So you have returned your MBC to your orginal configuration and it's still overboosting?

I'm sure you have read that running an MBC off the BOV line is not preffered, but I doubt this is the cause of your problem. Be sure your tubing is good and connect the MBC from the turbo compressor nipple. Bench test your MBC if you can with an air source and gauge to be sure it's releasing at the proper setting. Once you know your MBC is working you can go back to sorting out your BCS short.

 

[ttsrq]

OK so my MBC is working properly and everything and ive gotten closer to the problem with the BCS short. So I wired up the BCS a little differently but every time I try and connect the possitive I get huge sparks and I cant connect it because the wire starts melting. I wired the postive to the battery now because I kept blowing fuses when I wired it to the radio harness. I dont understand why its doing this though and not letting me hook it up with out sparking madly. Whats wrong with it?

 

[ttsrq]

Ok so now im really confused for the most part things are working SOMEWHAT properly...the switch turns on and off but when i turn it on the positive wire heats up REALLY fast and starts melting so I disconnect it... is there any reason why its heating up and not working?

 

[kspharris]

The reason why is because something is not working properly. It is probably your switch. The reason why it is melting is because it is trying to pull to much current and that is what is melting the wire. I would check for grounds. You should hook up the positive part of your switch to the hot side of your battery and not use the acc. You should run the acc. to the BCS. What gauge wire are you using? Do NOT use your BOV as a source for your pressure. If it is still boosting to high just try to turn your boost controller down, you may have bumped it or something. Let us know.

 

[Ceddy]

I wired the red wire from my radio harness to the ACC of my switch. I wired the ground on my radio harness to the ground on my switch.

You don't ever wire the positive and ground to a switch! This is a dead short.
Your drawing insane amouts of current to melt the insulation off wire.
This is bad for your battery and you car's electrical sysyem

 

[Ceddy]

Positive from Radio
to
Switch
to
BCS
to
Ground

 

[ttsrq]

The reason why is because something is not working properly. It is probably your switch. The reason why it is melting is because it is trying to pull to much current and that is what is melting the wire. I would check for grounds. You should hook up the positive part of your switch to the hot side of your battery and not use the acc. You should run the acc. to the BCS. What gauge wire are you using? Do NOT use your BOV as a source for your pressure. If it is still boosting to high just try to turn your boost controller down, you may have bumped it or something. Let us know.

AHHH so I wired up the wrong thing from the BCS to my switch I have it all wired up good now and when the switch is turned on the boost will stay at 10psi!!! YAY but when the switch is off im still boosting to like 25+ PSI.. I know the MBC is working fine and everything because when I was just running it would hold perfectly fine at 15psi and everything. So maybe I installed the BCS and the MBC wrong heres what I did. One end of the MBC goes to the BCS and then the wastegate through a tee. The other end of the MBC goes to the BCS and then to the bov line. What did I do wrong?

 

[kspharris]

Try taking the boost controller out and turning it around. Also DO NOT use the BOV line to source your MBC or BCS use the line coming off the j-pipe( by the turbo). That may be the problem there. Try that stuff and let me know. It will be awhile before I can get back to you but I will try tonight, if not tomorrow. If turning it around does not work then just try turning the knob down and see if that works. Hope that you can get that working. Thanks.

 

[ttsrq]

Ok wtf.. I got all of the electrical stuff working now...so when the switch is on it uses the BCS and stays at 10psi.. then when I switch the switch the other way it doesnt stop at 15psi like its suppose to, it just keeps going up and wont stop till I get off the gas.. the mbc is a ball and spring style and looks like this |--
|

the bottom end is connected to the turbo and to the flared side of the BCS and the sideways flange is connected to the waste gate and the other end of the BCS.. Why is this not working why wont my boost stay normal?

 

[kspharris]

Are you doing anything that we have said to do? Did you try turning the boost controller down??????? Did you flip the boost controller around????

 

[ttsrq]

Ok so I hooked the boost controller to the nipple of the J pipe and then to the waste gate and put tee's in the lines. So now im running 15psi(to what my mbc is set at) but then when I flick the switch im still getting 15psi. What could be the problem?

 

[ttsrq]

Anyone else got any ideas now? No matter whay way I flick the switch im still staying at the boost my MBC is set at whys it doing this?

 

[kspharris]

Thread bumping is bad, just a FYI, the moderators do not like it. Did you connect the BCS also? How did you do it, just like the MBC? Let me know and I will try to help.

 

[ttsrq]

I didnt bump it on purpose I just fixed one problem and then ran into another problem. The BCS is connected like this one end of the BCS goes into a tee between the waste gate and mbc the other end of the bcs goes into a tee between the jpipe nipple and the mbc.

 

[ttsrq]

Im boosting like 15 psi no matter what way I am flicking the switch I know its wired up properly because I can hear the BCS turing on and stuff when I flick the switch why isint this stupid thing working?

 

[Low Impedance]

ive wanted to try this myself, but i dont get the logic of how the BCS can override the MBC based on how the vac lines are hooked up. i might be just not seeing it correctly in my head or something. but problems like this make me not want to bother...

 

[kspharris]

The way it works is that when you have the BCS active it is open and allows air to flow through to the wastegate and hold whatever boost the wastegate is set at. When you de-activate the BCS then the air path is blocked and the air has to travel throught the MBC which will allow you to set it at whatever you would like.


I do not know why it is not working though. Did you change anything since last time? Recheck all the electrical connections, maybe something is loose. Is the BCS hot to the touch when it is on? Pull off the hoses and check for obstructions, there may be something blocking the path of the BCS. You can check it by just connecting the BCS to the wastegate and the J-pipe nipple and see how much boost you build and then flip the switch and it should drop off pretty good. Let me know I will try to help you the best that I can.

 

[wret]

It's really quite simple. Here's a diagram. The black represents the normal path for the MBC. The BCS (now just a solenoid valve) is used to bypass the MBC when open.

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[ttsrq]

Thats so ####ed that boggles my mind because thats exactly like I have it set up! Why would it not work and go to the setting my MBC is at no matter what way I flick the switch?! I can hear the BCS clicking on when I flip the switch a certian way but im yet still boosting at 15psi(MBC is set at that) thats so crazy!!! WHY WHY WHY :'(

 

[ttsrq]

Do you guys think its electrical maybe? But when I flick the switch on I can hear the BCS flickering is that what its suppose to do?