RI A6

Here's the partial writeup of the flap switch mod. If you are not comfortable slicing into your wiring harness or using a soldering iron, don't do it. If done correctly there are no ill-effects to the car.

Currently when the flap is opened the ecu control signal is disconnected causing an open circuit code. This is a minor code and does not effect anything, nor does it light any dashboard lights. This weekend, I will implement a fix to cause the ECU to think that the solenoid is still connected and add it to the write up.<ul><li><a href="http://www.teraspeed.com/RS4/flap%20switch%20mod.pdf">Intake Flapper Switch Modification</a></li></ul>

Fluffhead

Great write up, I'll be doing something this weekend :-)

bhvrdr

can you do some of the same day datalogging on this scott?

Fluffhead

I don't see the need for keeping the flap closed all the time. I would only want to be able to keep it open all the time or keep it stock.

I would like to route the switch to the dash using one of the blank buttons (most likely the "S" b/c the euro wheel is used for this now). If I'm going to have a switch on my dash I would prefer

A rocker switch
<img src="http://rsk.imageg.net/graphics/product_images/pRS1C-2160443w345.jpg">
<img src="http://rsk.imageg.net/graphics/product_images/pRS1C-2160432w345.jpg">

or even this for fun :-)
<img src="http://rsk.imageg.net/graphics/product_images/pRS1C-2160402w345.jpg">

A friend who is a lot better then me with wiring is going to help me with this, but if I go with a two-way switch what would I need to do with the wiring to get it to work.

TIA

RI A6

If you use a SPDP switch, then you'll get the intake solenoid open code in your ECU log. This does not seem to cause any issue, but I'll know more once I come up with a resistor to trick the ecu.

RI A6

There's a gain in MAF, but increased intake air temperature is definitely reducing the potential gain.


<img src="http://www.teraspeed.com/RS4/mass%20air%20flow.jpg">

<img src="http://www.teraspeed.com/RS4/temperatures.jpg">

bhvrdr

I guess your already looking for remedies for that i'm sure.

daveak05

there is addtl airflow, and intake temp rising confirms warm air being pulled in(location).

question: are you feeling a noticeable difference in low end giddyup?

RI A6

flap open vs. closed doesn't look any different. But there's a huge difference in timing from last winter when I did my FATS run and was on the dyno. Top end MAF is down from before and it's pulling more timing.

I'm now beginning to wonder if the ECU update that Audi did messed with timing. I need some other people to run some logs.

bhvrdr

ambient temps. you can get MAF readings that will vary up to 20g/s or more just from not using same day/same ambient and same road grade/surface testing as well as of course same coolant temps (which overall timing takes into account). Timing can be thrown off by just a change in coolant temps of a few degrees. Coolant temps dont need to be inlcuded in what you show the forum but you better run in concurrent in the background during a log session to make sure they are the same for both runs if looking at timing. It all needs to be held constant. Otherwise you end up attributing little variations in MAF of 5 g/s or so or little variations in timing of 1 or 2 degrees to the changes in your mod when really it is just normal statistical variance or due to other confounding variables.