kutter

I am thinking of getting chipped in the future and was considering MC's bypass valve. But APR and others have told me that the stock BPV is fine on the A4 even when chipped. I've heard nothing but positive things about MC's BPV and will probably change the stock unit when I chip. But the question is, do I need to?

Someone said that the stock unit is rated for 7 psi - 10 psi (roughly). Where are you guys getting these numbers from? Audiworld has been a great place for me to learn more about my Audi, but sometimes I feel that mis-information or undocumented info is spread here without any true facts to back up some claims.

Until recently, everyone chipped with GIAC, APR, Wett, etc have not mentioned the stock BPV being a problem. Can some of the old timers who have been chipped using the stock BPV comment on your experiences? Are you still chipped using the stock BPV, or are you chipped and have swithced to an aftermarket BPV?

Thanks again for all your comments fellas,

kutter
'00 A4 1.8T Q-tip
'00 Passat Variant 1.8T tip

BOOSTD

I got APR'd two weeks ago and don't think I have a "problem" with the stock BPV. I do, however, think there's merit to putting on a BPV that is rated for higher boost. Per MC, the stock unit will handle .8 bar while his will handle 1.5 bar. If my APR chip is minimum 1 bar, with spikes a little higher, I want to make sure I'm getting my money's worth of boost I bought with the chip. MC has a BPV in the mail to me now, can't wait to install it. FWIW Ed P. says that his chipped A4 is smoother under boost with MC's BPV, and I do agree that under heavy acceleration my boost could be smoother. There tends to be some flutter in the acceleration that doesn't quite match what's going on with my gas pedal. I would guess this means I'm losing some precious PSI. Any comments from Ed P., MC, or others with the new BPV would be appreciated.

tird

I was only seeing 15 in Hg of vacuum at idle. I installed MC's new BPV and now am seeing 21 in Hg of vacuum. The car runs alot better now and the boost is alot smoother. I would definitely recommend it to anyone that is chipped.<p>Ed
99.5 1.8TQMS, APR v3.0, APR Exhaust, K&N, MM Spyders, LLtek Induction Kit, MC BPV

kutter

I know that MC knows a great deal about the A4, but who is his source for the info that the stock unit can only handle up to .8 bar? I spoke to APR today and they said that stock unit can handle their 1.0 bar chip without problems. I'm just baffled as to why people are only recently addressing the stock BPV weakness when 1.0 bar chips have been out for the A4 for so long now. I rode in a friend's '00 GIAC'ed GTI 1.8T and it was the smoothest, fastest 1.8T cars I've been in. He has the stock BPV in his car, and I did not notice any hesitation or fluttering at WOT through all gears. Eurotech Atlanta chips all 1.8T cars with the GIAC chip and I don't know of anyone changing their BPV from the stock unit. I'm not trying to start a controversy (again). I'm just trying to learn more before I choose to chip my A4.

-kutter

CraigB

<p><a href="http://www.users.uswest.net/~craiger/a4main.htm">
<img SRC="http://www.users.uswest.net/~craiger/cwb_ottosig.jpg" BORDER=0></a>

RS

Here is my experience. I have a APR stage III car and a Porsche 944 turbo S. Both cars use a BPV that is interchangeable between the cars. I changed my 944 turbo valve about a year ago to the 993 TT valve primarily because the OE valve was 10 years old.

So when this whole BPV thing came up I swapped the 993 TT valve in my A4 as I knew the Porsche valve was good. Guess what? Absolutely NO difference! I even put the 10 year old valve in the A4, again NO difference. The Porsche holds 17 lbs of boost until redline with either valve, with no boost lag between shifts. I did not try the A4 valve in the Porsche.

Here is what I think is happening, the BPV gets dirty, does not close and hence the "failures"

The Bosch part number for the Porsche valve is 0 230 142 102 You should be able to get it for about $30-$35 dollars.

If you think your valve is not functioning properly, I would remove it, soak it in some hot soapy water, manually cycle the diaphraghm, blow it out with compressed air and retry it. If that does not work put the Porsche valve in.

BOOSTD

Email him

JeffDavison

Have new Bosch BPV box in my hand. Rated @ 20psi from my source


Jeff Davison

audimods

i have a MC BV and have yet to install it. but i'm convinced the fluttering in acceleration is the fluttering in the stock valve.

yes, some people have it stock, others have it when chipped.<p>2000 A4 1.8TQMS

EdP

Perhpas it's wishful/hopeful thinking, but I do notice a difference, however slight. I DO hear the difference from in the cabin, and can tell when the valve is bypassing the turbo. I DO NOT feel the surging that I felt before replacing it with MC's valve, and my "old" one (incidentally is the revised AUDI part) is not dirty. It feels much smoother under heavy throttle, part throttle, and quick throttle release. I'm satisfied, and that's all that matter's when I spend my money.