?????????????

 

Not a good idea, the BAC maintains your engine's idle throughout different loads applied to the engine, and most guys that remove theirs run into idle problems...

Having said that, some guys claim to have no idle problems whatsoever with no BAC...

 

depends on what kind of accesories are still on your car and how well its running.

if you still have the p/s the BAC is a must!
if you have no p/s but still have the a/c you can get away with out the BAC if you only run the air occasionaly and remember to hold the gas when coming to a stop to keep the engine from stalling under the load of the compressor at idle.

if you have neither p/s or a/c, and your engine has a strong idle and no vacum leaks, you'll be just fine without the BAC. the electric loads of the car (hedlights, windows, stereo etc) are not enough to significatly disturb the idle so long as the engine is in a good state of tune.

however, there is no reason to remove the BAC unless you are doing a full emisions removal AND the throttle body mod. otherwise just leave it in.

if you do take it out, make sure to reroute the coolant line to the rear housing under the intake mani's. if you just plug it off your engine will get hots spots &lots of bad problems.

 

what is the tb mod that you talked about

 

Do a search, it's been discussed several hundred times

 

I'm running no BAC valve and have no idle problems. But I also have no AC or PS or any other real load on my electrical system/car other than the e-fan.

 

Sorry to bring up an older thread, but what in the hell does this mean? You just feed it underneath the IM? as in you just let it run underneath and you don't mount it to anything?

Also, what the hell is the p/s?

thx guys.

 

You run the line that connects to the block that came from after the TB mod and run it into the nipple on the water pump housing right above the plug on it.

PS = Power Steering.

 

You've got that backwards. Power steering loads are taken care of by the ASV; A/C loads are taken care of by the BAC valve.

Since the emission controls, TB and BAC valve have nothing to do with each other, it makes no difference if you remove them together or not.

 

Not true. I've seen and worked on plenty of engines where these were blocked off, and never had any problems. Like e-fans, this falls in the realm of "old wives tales".

 

But you can't argue the fact that with that entire coolant circuit routed back to the water pump, more VOLUME of coolant flows through the system...

 

the TB thermo wax uses the same coolant line as the one running through the BAC, so if one or the other is gone the line needs to be rerouted accordingly.

i know that the emmisions equipment have nothing to do with the bac, however IMO just removing the BAC and leaving everything else on the engine is kinda pointles.

removing the BAC onbly becomes worthwhile after lots of other stuff has been removed from the engine since removing it on its own has next to 0 advantages.

 

In the absence of both the Thermowax and BAC Valve - you can block off the line supplying these two In confidence. I have done this on s5 TII setup and It has not come back to plague me. I really do not know where people get these "you can't do this" from or If doing so there will be consequences In doing so.

 

i stand corrected then. i rerouted mine just to be safe, so i geuss ill leave it on for now/

 

The only purpose of that line Is to have a thermal effect on the Thermowax ie. wax expands than causes the pin to fall. As for the BAC Valve, It prevents the Coolant to freeze rendering the Valve useless, atleast temporarily.

Using a Hanson Tap - 1/4-18, part # 8203, I tapped It In the Water Pump Hole, after removing the pressed In sleeve. Using a Watts 1/4" brass squared plug, part # WCA-737, I plugged It up using some threaded teflon sealant. I got all this at Home Depot, fwiw.

As for the Rear Iron Plate, I can't remember. Aaron Cake, Snrub and I drilled and tapped the hole after removing the sleeve. Maybe they will remember the specs.

 

its good to know they can be be tapped and plugged, but i dont like my chances tapping into one of the housings, especialy while its still part of an assembled engine.

did you do a full coolant flush after tapping the holes, or was the engine already apart?

 

Rerouting the line is obviously required if the BAC valve is removed, but that's not what you said. You said there's no reason to remove the BAC valve unless you are doing the TB mod and removing the emisions, which is not true. The BAC valve can stay and keep doing it's job just fine.

IMO removing the BAC valve is pointless.

This is one of those old wives tales Aaron mentioned. If the BAC valve is so cold it can freeze, then the engine is obviously not running, in which case the coolant will be just as cold as the BAC valve.