Well I have been without the a4 for a few days, and have been wondering. Mike, you could help with these probably. Im 01, so I have the AWM and DBW. I know on the NDBW cars the Intake nipple closest to the radiator goes directly to the DV, but on DBW it goes to a valve under the intake. I was originally going to run a hose straight to the DV, but a4_2000 pointed out when you do that on DBW, your boost drops to 5psi. So someone tell me whats going on? Can you somehow allow the DV to not be ECU controlled, and get factory boost?

-puts on flame suit-

Hellz yeah I want a BOV, flame me. Save me the "N00b, you cant run a BOV" speech. Ive read about it, and you guys know ive been around for a while. Now in theory, whats stopping me from making a custom IC to Intake pipe, that will allow me to put a MAF sensor in there? Seems like a valid solution to the unmetered air issue. However I dont know how the aux systems would react (SAI, EGR, PCV, etc)

Thoughts?

 

I can't see why it wouldn't work in that location, other than (potentially) the fact that the air passing through the sensor at that point would be significantly warmer than the air passing through it in its stock location. I don't know whether the sensing element is susceptible to damage from heat in that way, but that is really the only downside I can think of. Interesting idea really.

 

You were going to run a hose directly to the DV from where? the nipple on the intake mani? I run a line diectly to my DV. I put a T into the line from the intake mani to the FPR and then hooked in my DV line. I'm AWM also and did not notice any psi drop when i did that. You can also bypass that valve (N249 i believe). That will allow you to have a smoother boost delivery.

For the BOV, that doesn't sound like a bad idea. Your theory is correct and I'm not sure why it wouldn't work. Just delete the SAI sys and be done with it anyways lol.

 

I might get a salvage maf and just try this out, it would be really interesting to see how long it lasts.

So the only thing connected to that front IM nipple is the N249? Thats odd, ill make a video after I toss my boost gauge back in, because im rather sure I loose a couple psi with it unplugged, and I dont understand why (except that it has to do with a reading from the n249)

 

http://audizine.com/forum/showthread...-bov-dv-or-maf

Looks like at least one person accomplished it

 

the only problem other than heating with the MAF would be that the air it is metering is now under pressure, idk if that would matter or not. i actually thought about doing this, but just ripped it out instead. i didnt feel like cutting and splicing the wires. as for the n249, the way that works is that there are 2 of them, side by side, connected to a vacuum resevoir through a system of check valves. then you hit the gas, they close, so that that resevoir holds only boost, when you let off, they open, making that vacuum go to your diverter, which is faster than the time it takes for all your boost to get used and go to vacuum in your IM. i ripped all that **** out, SAI, EGR, when i still had my k03 in. it wont do anything at all for performance really, just make your engine bay look sexy. if you want to go BT, this will give you alot more working room

 

BEFORE

AFTER

BT

 

It will not cause a limp issue if you keep the N249 valve plugged in but just remove the vac lines from it. Basically doing the same thing when bypassing the N75 valve for a boost controller, you still leave the actual valve harness plugged in.

Plenty of DBW A4 owners have done this mod without any issues. I even ran it that way back when I was running GIAC tuning.



If you really want to run a BOV just do it, if you want to do it right just end up going with a mafless tune.

As for putting the maf sensor after the turbo, doesn't work well since our maf sensors dont work correctly when used as a "blow thru" setup. Not good to push very high temp air thru a maf sensor and expect it to read correctly or even last long.

SAI has nothing to do with the maf or even the intake system between the maf and the turbo. It just sucks in fresh non metered air thru the exhaust side of the head. EGR is part of the SAI system and if you go mafless you can just go with a vented catch can. Mafless is the way to go if your trying to clean up the engine bay.

 

people used to try to crawl in my engine bay cause of the big empty spot haha. i took the stock TIP and put it going down to where the SAI pump used to be, essentially a cold air intake.

 

Mike is the best.

I honestly have no use for this, since im FWD and tiptronic. I could run an elim kit, but id rather just save up for a 1.8TQM