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Well - I was thinking about this the other night - I don't think the ECU really knows what is coming

Posted by: zapco98 on 2002-09-24 10:43:09
Account #: 3926

In Reply to: what about metered air dumped between shifts? posted by BOOSTD on 2002-09-24 09:39:49

back into the system. For example, once it passes through the MAF - its now being compressed by a turbo, but does the ECU know how "much" air is going to be coming back on an off throttle situation? I am not sure the Motronic system is smart enough to calculate turbo 'efficiency' - but hey, who knows... The reason I don't think so is that from swapping to K04s, I have had no such issues, and the volume of air being recirculated has definetly changed from what the K03s used to do. Also have to keep in mind, that with a BPV, you're recycling "Hot" air - so that may be a slight performance hindering issue - probably not too noticeable, but for the one who wants 100% performance, that .1% is everything I guess.

I just don't think the ECU is smart enough to know how much air should be coming back, I mean when you're at different throttle positions at different RPMs, the compressing of the air's efficiency is always changing so the amount of air bled off is a constantly changing factor.

2001 MTM STG4 S4
2004 MB E55 AMG

AIM:zapco98

Thread:

BOV's...a little tip - DonIstook 2002-09-23 20:07:41 (19108 views)

Re: BOV's...a little tip - pythaguras 2003-10-02 23:02:40 (277 views)

does anyone know if the .... - just_a_kid 2002-11-19 22:14:19 (1539 views)

NEWBIE to Audis...been a Honda/Acura guy since high school...NEED HELP! NEED GUIDANCE! - t4t3hybrid 2002-11-01 14:24:47 (2171 views)

Just Bought One, I will have a writeup this upcoming friday (Oct 4th) - STKSKI 2002-09-29 20:20:31 (1452 views)

Don - some comments for your consideration - LONG - shortyq 2002-09-24 23:09:39 (1684 views)

Very interesting, as are your cars : ) - what's that smell?st 2002-09-25 10:08:32 (962 views)

Interesting info - thanks Scott. BTW I've been practicing my left foot braking. =) - markbradford 2002-09-25 07:16:49 (997 views)

Okay let's review: How much sheer abuse did BOV folks endure here before this? - sans-audi 2002-09-24 16:11:49 (1233 views)

A ton. Why? Because they were FULL OF CRAP. - nyet 2002-09-24 16:13:37 (1370 views)

Some people admitted it, in their defense : ) - what's that smell?st 2002-09-24 17:05:17 (798 views)

Well, yeah. - sans-audi 2002-09-24 16:18:08 (707 views)

Don what about "engine wash" - WJM 2002-09-24 14:52:35 (1373 views)

All cars are subject to the same emission standards, both high and low rpms - DonIstook 2002-09-24 19:30:47 (1053 views)

very true A/F ratios are what they are... - WJM 2002-09-25 12:28:38 (837 views)

Thanks Don! I still have a question about the design with a MAF though. - Joshua (wishbone) 2002-09-24 10:54:23 (986 views)

I think he is saying it only runs overly rich during idle (if the valve is misadusted and open) - nyet 2002-09-24 11:12:15 (937 views)

Naw, the car runs rich in essense because say for example you take your Forge valve - zapco98 2002-09-24 11:23:15 (1311 views)

ah got it. - nyet 2002-09-24 11:24:22 (654 views)

Yeah I got what he was saying with idle and non-boost applications.. - Joshua (wishbone) 2002-09-24 11:15:51 (811 views)

Don, can you confirm that these are the right ones? - DABearS4 2002-09-24 10:28:27 (1042 views)

Thanks for the info! Now my S4 will be perfect! - DABearS4 2002-09-24 10:25:35 (869 views)

bless you for these informative posts... - SameerP 2002-09-24 09:45:59 (1024 views)

what about metered air dumped between shifts? - BOOSTD 2002-09-24 09:39:49 (781 views)

I was wondering that too. Must run rich during shifts no? DOn, would you recommend this for...... - markbradford 2002-09-24 13:06:48 (879 views)

Well - I was thinking about this the other night - I don't think the ECU really knows what is coming - zapco98 2002-09-24 10:43:09 (851 views)

the mix getting to the O2 sensors is probably how it knows... - TRM @ velozt.com 2002-09-24 11:09:27 (842 views)

Does it matter how much is coming back?? - Joshua (wishbone) 2002-09-24 11:07:16 (741 views)

Right - but figure that if it goes back through the MAF, and say you're off throttle for a couple - zapco98 2002-09-24 11:13:39 (844 views)

Well... - Joshua (wishbone) 2002-09-24 12:38:34 (615 views)

[edit] but now the extra pressure in the INTAKE system will prevent MORE air from passing the MAF - nyet 2002-09-24 11:17:51 (728 views)

*and the whole S4 group moves to BOV's* ;) great info Don! - Audiboy 2002-09-24 08:51:28 (971 views)

;-) - TRM @ velozt.com 2002-09-24 08:59:59 (618 views)

Would this valve also work in the TT? Is all the information accurate also for the 1.8t? - Power5 2002-09-24 05:37:21 (840 views)

track this thread FOREVER! good stuff Don - thanks for sharing. - TRM @ velozt.com 2002-09-24 04:58:09 (577 views)

so can you tell us exactly how to setup the valve to keep it closed at idle? (amount of washers etc) - andre d 2002-09-24 02:27:36 (725 views)

Trial and error, but it is easy - DonIstook 2002-09-24 04:46:52 (842 views)

Did you use software to measure any particular value? What did you use to confirm that you had - what's that smell?st 2002-09-24 05:50:04 (716 views)

The software was my finger on the valve to feel if it opened or not at idle. - DonIstook 2002-09-24 05:56:41 (838 views)

Cool, thanks. - what's that smell?st 2002-09-24 05:57:27 (670 views)

Yeah, that would be my next question also. - what's that smell?st 2002-09-24 04:17:03 (602 views)

So what parts do i need?? - dohc 2002-09-24 00:18:16 (860 views)

Twin Greddy Type S.... - EP : Dark Cloud S4 2002-09-23 23:31:06 (2979 views)

Re: Twin Greddy Type S.... - pythaguras 2003-10-02 22:59:03 (135 views)

I WANT BLOW OFF!!!!..... - nicz28 2002-09-24 13:55:45 (2381 views)

With a DSM adaptor I do believe!! hjahahaha nice! - Milpitas2.7T 2002-09-23 23:32:58 (854 views)

Hi, so basically any BOV would work on 1.8T as long as I get the adapter kit from Turboxs? Thanks. - Jack Wang 2002-09-23 22:44:28 (1134 views)

no meng.... - wnut 2002-09-24 09:53:19 (903 views)

Oh, Ok, so for 1.8T the BOV will be where the BPV is..am I thinking right? - Jack Wang 2002-09-24 11:49:08 (1876 views)

there's about 3 ways to mount a bov on a 1.8t - wnut 2002-09-24 12:12:22 (1247 views)

Is there much to do with the H valve to install it? Or is it just "plug and play"? - naptownnogaro 2002-09-23 22:16:47 (843 views)

iirc they're about $150 a piece... - wnut 2002-09-23 22:20:53 (1184 views)

thanks - naptownnogaro 2002-09-23 22:24:41 (619 views)

You are the man. - nyet 2002-09-23 21:59:45 (707 views)

this is what i've been saying all along... - wnut 2002-09-23 21:53:58 (1021 views)

Saw this on rookie Edwards car . . . look a mechanical throttle valve . . . . ! - boscoj 2002-09-23 21:11:56 (1542 views)

i'm 99% sure that it's a forge bov. - wnut 2002-09-23 22:29:32 (1709 views)

You can barely see the pop off valve on Galati's and Bell's car in this pic - boscoj 2002-09-23 22:38:57 (1759 views)

Yup, they have a single BOV (which Subaru folks use) - Audiboy 2002-09-24 08:54:07 (828 views)

by jove I've think you've got something . . . - boscoj 2002-09-23 22:36:56 (719 views)

This is the one that I found on the site is this the right one??? - FAS4T 2002-09-23 20:53:09 (1919 views)

that bov is crazy loud! - wnut 2002-09-23 22:31:39 (1419 views)

As Stealth4 says-I think he means this one. You're going to order two of them tomorrow, aren't you? - gr 2002-09-23 21:06:32 (915 views)

I could buy them right now, tempting! but what about the mounting hdwe? - FAS4T 2002-09-23 21:12:32 (923 views)

I think its the regular H one, unless ur making ajoke - Stealth4 2002-09-23 20:54:50 (660 views)

no really I think I may be blind this is the only one with an H that I found on the site.... - FAS4T 2002-09-23 21:06:48 (892 views)

Damn you and my credit card bills!!!!!!!! - Giga2Envy 2002-09-23 20:23:25 (689 views)

So... how much do these bad boys go for? ;-) Where can I get em? - zapco98 2002-09-23 20:15:20 (843 views)

http://www.turboxs.com/ - DonIstook 2002-09-23 20:17:28 (1938 views)

How about the mounting hardware? Is it the same as they have for the "1.8T?" - zapco98 2002-09-23 20:30:41 (795 views)

you are awesome, thanks for the real life tested info. - Stealth4 2002-09-23 20:12:58 (793 views)

hey, you said a "little tip" - Odorless-Clandestine 2002-09-23 20:10:59 (922 views)

Well, the tip itself is small, but it took a while to get there - DonIstook 2002-09-23 20:16:02 (1077 views)

Well, it's tremendous to see someone take the time to post up such concise and useful info (truly). - Odorless-Clandestine 2002-09-23 20:21:47 (916 views)

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