NefMoto

Technical => Tuning => Topic started by: ddillenger on December 22, 2012, 06:31:11 PM



Title: variable runner intake map location? A6 vs S6
Post by: ddillenger on December 22, 2012, 06:31:11 PM
So the a6 4.2 has a 3 stage runner setup, whereas the s6/s8 has a two stage. I'm assuming there's a map somewhere in the ecu controlling this. I'm trying to find a decent definition file (for any 4.2 c5 a6/s6), but so far no luck. Anyone taken a look at this? The bin I'm looking at is attached.


Title: Re: variable runner intake map location? A6 vs S6
Post by: prj on December 23, 2012, 08:33:01 AM
Search for SUMODE in the FR.


Title: Re: variable runner intake map location? A6 vs S6
Post by: ddillenger on December 23, 2012, 08:50:14 AM
Thank you sir!


Title: Re: variable runner intake map location? A6 vs S6
Post by: ddillenger on December 23, 2012, 10:32:57 AM
(http://i1217.photobucket.com/albums/dd385/silverd22/intakechangeover23a.jpg?t=1299429139)

So the A6/A8 have 3 stages, shown above. What I'd like to see (If I had an s8 manifold in front of me it would make this much simpler) is the effect of using s8 values in URLSUNM, URL2SUNM, and URL3SUNM on an a8/a6 40v manifold. Does the s8 even use all 3? Being a two stage I would assume that the runners are either LONG or SHORT, and the vacuum pods won't operate independently of one another.When the changeover occurs they both open, shortening the intake tract in one motion rather than 2. The intermediate stage is eliminated-correct? If that's true it would stand to reason that there would be a very big hole in the powerband between 3360 and 5200 rpm when running an s8 program on an a8 manifold.

Does the s8 use one, or two vacuum pod actuator valves? If there's only one it doesn't appear that this problem can be overcome without code changes. Anyone have any experience with this?

(http://i1217.photobucket.com/albums/dd385/silverd22/intakechangeover24a.jpg?t=1299429139)


Title: Re: variable runner intake map location? A6 vs S6
Post by: ddillenger on December 27, 2012, 03:23:12 PM
Having a hard time without a definition file, If I had a known map to compare I'm sure I could find it, but it seems 4.2 info is scarce. Anyone?  Suggestions would be welcomed (not just asking for a definitive location). Thanks guys.


Title: Re: variable runner intake map location? A6 vs S6
Post by: prj on December 27, 2012, 04:24:59 PM
To get some info about the general map locations you can look at the RS6 stuff.
However, it does not have multiple KFURL maps or anything of the sort.
But my guess would be that the maps are one after another.


Title: Re: variable runner intake map location? A6 vs S6
Post by: ddillenger on December 27, 2012, 04:26:04 PM
Thank you again. Appreciate you taking the time.


Title: Re: variable runner intake map location? A6 vs S6
Post by: cerips on December 27, 2012, 05:37:41 PM
The D3 A8 self study program 282 has the following information on the standard engines:-

4.2l 40v
Changeover from long to short runner 4480 rpm.
Changeover form short to long runner 4320 rpm.

3.7l 40v
Changeover from long to short runner 3280 rpm.
Changeover form short to long runner 3120 rpm.

Changeover from short to shorter runner 5120 rpm.
Changeover form shorter to short runner 4920 rpm.


I can't see any mention of load determining the changeover points BUT the 2.0l I4 & V6 SSP from around the same time  (SSP 255) does mention that the changeover on the I4 occurs between 2000 & 3700 rpm at 65% load. The text also mentions temperature dependence.


Title: Re: variable runner intake map location? A6 vs S6
Post by: matchew on December 27, 2012, 07:26:50 PM
Looking at the S8 file, as far as I can tell, it has a 2 length manifold and state changes at 5400rpm

Looking at the S6 4.2 file it seems to have a 3 length manifold and states change at 2900rpm only at load greater than 48% and 5400rpm.


Title: Re: variable runner intake map location? A6 vs S6
Post by: ddillenger on December 27, 2012, 07:33:22 PM
Sounds about right. I'm still muddling my way through it. Care to share the basis of your observations (location)?


Title: Re: variable runner intake map location? A6 vs S6
Post by: matchew on December 27, 2012, 09:00:26 PM
Sounds about right. I'm still muddling my way through it. Care to share the basis of your observations (location)?

No, its obvious and takes about 30 secs to find.


Title: Re: variable runner intake map location? A6 vs S6
Post by: jordant_111 on September 22, 2014, 08:06:51 PM
What about running a D3 A8 intake manifold since it is only two stages and should be a closer match to the tuning of the Euro file? I am seriously looking at this option for my B5 4.2 swap.


Title: Re: variable runner intake map location? A6 vs S6
Post by: RS-MAD on September 27, 2014, 02:01:24 AM
What you search is 189C5 if I'm right.