Really enjoying my RS6, but a few questions...

[jbtexas]

I am doing my best to put miles on this car (almost 2k now!) :rs6kiss:

A few questions/comments though...

1) why does the car feel so much more powerful/grunty at lower RPMs? It feels like it runs out of juice in the upper RPM band. I swear that it feels like at 5k or so, it goes onto engine only. I mean, not really...there is boost there, but feels very anemic. I am sure that this is my amateur status with turbos, and that there is a logical answer...(?) I love the way the car feels in the lower RPMs.

2) Is there any secret to "teaching" the tranny? It is by far my least favorite part of the car so far. Putting it in "S" just makes the car very unpleasant, there seems to be no rhyme or reason to when it holds revs, doesnt hold revs, shifts, etc. Putting it in tiptronic mode of course cures all this, but part of the reason I bought this car is for the convenience of leaving it in auto. So far, regular "D" seems to be the best answer for controled auto driving, but even then the car seems to really have a mind of its own...I can just tell that the tranny is trying to figure out what to do and not very good at it. I really liked the new S6 auto tranny, wish this was similar.

3) I know many on this board have discounted the "heat soak" factor, but I have to say that I have noticed a significant difference in driving this car at 80 degrees vs. 50 degrees. I have tested this on several occasions and I am convinced that the Texas heat is not great for pulling out the best of the engine/power...so I do think that I will investigate a cooling option for next summer.

[SpinEcho]

1. This car is all about torque and traction, so it feels strongest from a standing start or during acceleration from low revs and low speeds. Maybe this is why you have the impression it runs out of puff at high rpm, although I can assure you that it needs to be revved to near red line to get maximum acceleration! If you are getting a really noticeable drop-off in boost your diverter valves could be shot. When mine went I got a sudden loss of boost at mid to high revs that was quite dangerous (scared the living @#$! out of me once while executing a pass).

2. The transmission on the RS6 is pretty primitive by today's standards (but then again it seemed pretty good when the car was new - how quickly things get outdated)! I haven't hit upon any magic formulas to teach it. Like you, I find 'S' mode something to generally avoid, and I pretty much stick to auto or paddle mode, switching to the latter if I want instant control.

3. It doesn't get hot enough here to make heat soak a significant factor, although I have noticed it a few times in the summer and at track days. It's not exclusive to the RS6; I've noticed it with my past and present other boosted cars, too. Such is life with forced induction...

Hope this helps a little!

[DHall1]

Jonathan,

1. I agree with the statement about low revs, ect...

2. Driving habits teach the trans over time. How much time depends on several ecu factors. 2 days..no, 2 weeks...closer. I also use D more than S. S is good for spirited driving and corners.

3. "Heat soak" well its a 3 headed monster. I would not change anything with the car or cooling system. Why? The engine fuel and tuning maps in the ECU will select the best parameters baised on a whole host of sensors. One of which being IAT, intake air temp. If its 95 degrees out in Texas....there is little you can do to make the IAT cooler. Heat soak has nothing/very little to do with IAT. The ECU could care less how hot your engine block is. The intercoolers are already placed low and out of the main engine bay. You can make IAT improvements by making the IC more efficient...that is the better route. But still.....95 or 105 is hot and you will never improve the ICs enought to make it drive like 50 degree ambient. The "big" tuners of other makes tend to go with water or water/meth injection to help the IAT. I would never trust a 2, 3 or 4 hundred dollar gizmo with my 40,000 dollar engine. Never

That said, I would do lots of testing to verify if you even have a problem. Have you considered the VAG-COM? I will buy one shortly just to data log tuning parameters. I like spreadsheets. haha

:cheers:


I am doing my best to put miles on this car (almost 2k now!) :rs6kiss:

A few questions/comments though...

1) why does the car feel so much more powerful/grunty at lower RPMs? It feels like it runs out of juice in the upper RPM band. I swear that it feels like at 5k or so, it goes onto engine only. I mean, not really...there is boost there, but feels very anemic. I am sure that this is my amateur status with turbos, and that there is a logical answer...(?) I love the way the car feels in the lower RPMs.

2) Is there any secret to "teaching" the tranny? It is by far my least favorite part of the car so far. Putting it in "S" just makes the car very unpleasant, there seems to be no rhyme or reason to when it holds revs, doesnt hold revs, shifts, etc. Putting it in tiptronic mode of course cures all this, but part of the reason I bought this car is for the convenience of leaving it in auto. So far, regular "D" seems to be the best answer for controled auto driving, but even then the car seems to really have a mind of its own...I can just tell that the tranny is trying to figure out what to do and not very good at it. I really liked the new S6 auto tranny, wish this was similar.

3) I know many on this board have discounted the "heat soak" factor, but I have to say that I have noticed a significant difference in driving this car at 80 degrees vs. 50 degrees. I have tested this on several occasions and I am convinced that the Texas heat is not great for pulling out the best of the engine/power...so I do think that I will investigate a cooling option for next summer.

[Hy Octane]

To add to the above, next time in for service ask them to check the MAF sensors readings. I had one of the two go bad and it did something similar to what you describe. Also, you might try adding a few gallons of 100 octane racing fuel to the tank to let the ecu keep from retarding the timing as the revs go up to prevent preignition from lower octane gas/hot ambient temps and thus possible damage. It is a highly tuned engine with more sensors built in to protect it than the Starship Enterprise..Here in So Cal we can only get 91 from the pump which is the absolute lowest you can go for this motor,, by raising up the octane a few numbers it really wakes her up...Dont use octane booster additives tho.
Hope this helps..

[DHall1]

That is actually a very good point. I doubt Jonathan's MAFs are having an issue but a very good point to check the readings. One of the reasons I will pickup a VAG-COM and do some of my own data logs.

I also agree with 100 octane addition to the fuel. Any detonation detection by your ECU will kill your cars performance for weeks. Yes, I said weeks. Dont make me explain. Yes, weeks. :doh:


To add to the above, next time in for service ask them to check the MAF sensors readings. I had one of the two go bad and it did something similar to what you describe. Also, you might try adding a few gallons of 100 octane racing fuel to the tank to let the ecu keep from retarding the timing as the revs go up to prevent preignition from lower octane gas/hot ambient temps and thus possible damage. It is a highly tuned engine with more sensors built in to protect it than the Starship Enterprise..Here in So Cal we can only get 91 from the pump which is the absolute lowest you can go for this motor,, by raising up the octane a few numbers it really wakes her up...Dont use octane booster additives tho.
Hope this helps..

[DuckWingDuck]

MAF failure will INSTANTLY result in a CEL. My right MAF seals broke and the CEL light came up. But ya, wouldn't hurt to plug in and check; incidentally, the function group 32 :D

[jbtexas]

Guys, thanks for all response. I seriously doubt that there is anything wrong here. Rather, I suspect it is a combination of hot weather and that there is more (punch) feel in the lower RPMs. I will definitely have them check all codes, sensors, etc. when I get the oil changed...planning to do that again in the next 1k miles or so given the unusual break-in with this car...

[cornishmoocher]

Along with the MAF get the N75 changed. And a map and then get 600ftlbs all the way to 6500rpm :D :wo:

Also the transmission doesnt learn.....:vhmmm:

It adapts from throttle angle and speed of travel (of pedal). Each and evry time you drive her, So if you are just pootling away, it will change up to the highest gear asap. But if you drive in sport mode the car will hold lower gears longer...untill you touch the throttle, where it will drop down to the lowest gear permtted by revs/mph. The throtle sensor becomes more active and sensetive in sport mode as you would expect, so a 1/4 inch lift off can result in adown shift of two gears.
I also hate this, and it is why unless i am on the m,otorway,when the car is in D, at all other times the car is in happyflappymode.

Sorry to put the dampner on the intelligent tranny theory, but if you think about it- it can't learn, only do what it is told.

CheeRS Alex

[DHall1]

I think we are talking about the same thing. The tranny is a just a mechanical device that does what its told. We agree.

The TCU works with the ECU to send that said message to the tranny. The TCU and ECU have smart learning built into its function.


Along with the MAF get the N75 changed. And a map and then get 600ftlbs all the way to 6500rpm :D :wo:

Also the transmission doesnt learn.....:vhmmm:

It adapts from throttle angle and speed of travel (of pedal). Each and evry time you drive her, So if you are just pootling away, it will change up to the highest gear asap. But if you drive in sport mode the car will hold lower gears longer...untill you touch the throttle, where it will drop down to the lowest gear permtted by revs/mph. The throtle sensor becomes more active and sensetive in sport mode as you would expect, so a 1/4 inch lift off can result in adown shift of two gears.
I also hate this, and it is why unless i am on the m,otorway,when the car is in D, at all other times the car is in happyflappymode.

Sorry to put the dampner on the intelligent tranny theory, but if you think about it- it can't learn, only do what it is told.

CheeRS Alex

[DuckWingDuck]

I'm not so sure about it "learning" but rather there are ~200 shift programs that the TCU knows about and I think the "learning" that we're talking about is really the TCU adjusting to one of its pre-programmed functions.

[jbtexas]

It depends what "is" is.... :D

(tis the political season)

[cornishmoocher]

Why must I have 8 characters??

Original reply to JBT..... :);)

[DHall1]

Tell me about it. I am scared to death about higher taxes. We make too much money. I might have to make some huge company purchases next year to lower my net/net. I will not give 50% to uncle sam.....more if this Obama character gets in, and its looking like it. I have to bust my ass to make a go of my own company. Sucks.


It depends what "is" is.... :D

(tis the political season)

[Hy Octane]

As far as the tranny learning, I inquired as to if it was possible to identify and isolate a certain shifting program and then lock it in . The problem with the learning idea is that once it learns a certain pattern of your driving, if you encounter a bit of traffic, it abandons that program and switches to another based on that moment of traffic you had to deal with. There is no way for the user to re-select the previously 'learned' program (say # 165 for example) and recall it as your preferred auto shift program at will. You have to teach it all over again .
Thank goodness for the paddle shifters..

[peiserg]

I went with the highest end aquamist setup there is. Total install incl a custom water resevoir was about $2800. But it made a HUUUGE difference. And I live in phoenix, so I'd say i'm familiar with hot days.

It certainly was not a "$300" part.. it is seamlessly integrated into the system, keyed into not only boost levels, but injector pulse width/duration and throttle position! This setup is awesome, worth every penny.

[jbtexas]

I went with the highest end aquamist setup there is. Total install incl a custom water resevoir was about $2800. But it made a HUUUGE difference. And I live in phoenix, so I'd say i'm familiar with hot days.

It certainly was not a "$300" part.. it is seamlessly integrated into the system, keyed into not only boost levels, but injector pulse width/duration and throttle position! This setup is awesome, worth every penny.

I would like to learn more about this...can you post here or send me a PM? thanks

[DuckWingDuck]

There was a thread a while ago on the aquamist thing but I don't recall anyone getting one at the time, would love to hear more about it as well.

[Copper]

Here's an interesting article on modern transmissions:

http://cars.about.com/cs/autoenthusiasts/a/tranny_choices.htm


"But it's with the automatic transmission that the most changes have occured, led by computer-based electronics which give it a "brain" that recognises driving situations and adjusts almost instantly. In this case the added gears are a real benefit, for automatics have always lagged behind manuals in efficiency. Whatever number of gears a car's manual transmission came with, the automatic option always had one less. And with many cars it still does, the manufacturer assuming that since the buyer doesn't know the difference, why bother with the cost of that extra gear?"

[Mr Balsen]

There was a thread a while ago on the aquamist thing but I don't recall anyone getting one at the time, would love to hear more about it as well.

+1

Frederic

[snoopra]

There was a thread a while ago on the aquamist thing but I don't recall anyone getting one at the time, would love to hear more about it as well.
RS6 POWER has an aquamist setup installed and he said he got a 32F degree reduction but he hasn't been on this site for some time now. peiserg, more info on your setup, PLEASE! ALSO, has anyone looked into using the liquid CO2 air intake cooling system by DEI?http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300239870039&sspagename=STRK%3AMEWAX%3AIT&viewitem=
And I'm still unclear about this trans "learning" issue. I'm doing the IPT upgrade and wondering if the TCU will allow for a higher torque output (say, 700lb-ft:hahahehe: ) or will I end up having to do the MTM upgrade?:vhmmm: