BAC and FMIC..... stupidity
 

OK... So i put a custome FMIC in my car, a Haltech, a BNR turbo and fabricated all the intake pipes myself......

Well.. After fabricating all the pipes, i decided that I was going to use the stock BAC for cold starts and to set the idle....

Works GREAT.. except one smal thing..... i left the BAC open to the atmoshpere.... I kept wondering why in the hell my turbo was making such and ungodly phweeeeeeeeeeeeeeeeeeeeeeeeee sound at 14 PSI and why it was so difficult to make 15 PSi of boost.....

I always thought that the BAC was noisy and annoying as it sat there sucking air in, anbd was a bit worried about it sucking unfiltered air in and was planning on plumbing it into the filter....

WELL,, the other night it hit me... HEY DUMBASS... you have the friggin set screw on the BAC cracked open to allow extra air in at idle to control the idle speed, when the intake pressure goes positive.,.. the friggin setscrew is still open, thus allowing air to escape out the BAC intake nipple.... which would explain why the factory setup has the BAC plumbed into the intake system after the turbo ans why it sounds like someone just poked a hole in a high pressure air tank when you hit boost.....

So... I took a N/A BAC valve i had laying around, yanked the intake elbow out of it and welded it into my 90 degree pipe going from the turbo to the FMIC and connected it to the BAC with some half inch VAC line and.... BINGO

Problem solved....

Now you can all relax and realize that ol YOD is a flawed human after all and not the diety you were all worried he was!!!

Just looking at your mod list i am guessing you dont hav ps/ac. If you dont have ps/ac you dont need a bac it seems.

I use the BAC to idle the car up to 2.5K until the water temp reaches about 125 degrees and the will idle at 850 smoothly.. You can set the haltech to whatever RPM and shutoff temp you want. Its also more convienient to adjust the idle at the BAC than to adjust the throttle stop everytime you want to mess with it. Its a necessity here in PA in the winter!!!

Well that is just cool:)

What? Tell me more about this, it sounds important! I'm putting a 3rd gen intake manifold/TB on my S5 TII motor. I was told the Haltech won't run the BAC and I was just going to block it off. What do I need to do/keep to keep the idle up cold? I hate the AWS and will get rid of that, I don't want it going to 3,000rpm cold, I'd like it to idle at 2,000 for a bit when 1st started.

my haltech controls the BAC just fine.....

E6k (what I have) or newer?

Yeah.. its an e6k..

You just give the positive side of the BAS 12V from a switched power source and then connect the negative to one of the PWM outputs. Then you go into setup and set that pwm for BAC operation. I have to re-adjust my MS time since it got colder.. i'll do that tonight and let ya knwo whay my settings are.

Thanks, I appreciate it :)!