daveak05

I'm just poking fun at a whopping maybe 7hp on a 420hp car.

Jenner

One of my vacuum lines was repaired due to an issue that trigged a CEL and prevented the airbox flap AND the intake mainfold flaps from opening/changing. This causes a noticeable loss in power at 5500rpm+

Seems like too much of the RS4 is vacuum controlled.

This is only the front half of the car:
<IMG SRC="http://www.jlosee.com/images/RS4/PDF/RS4_vacuum_diagram.jpg">

Here are two TSB's dealing with vacuum issues:
<A HREF="http://www.jlosee.com/images/RS4/PDF/TSB-RS4%20Manifold-1.pdf">
http://www.jlosee.com/images/RS4/PDF/TSB-RS4%20Manifold-1.pdf</A>
<A HREF="http://www.jlosee.com/images/RS4/PDF/TSB-RS4%20Manifold-1.pdf">
http://www.jlosee.com/images/RS4/PDF/TSB-RS4%20Manifold-2.pdf</A>

daveak05

especially that much interdependancy.

I'm just saying that deflapping doesn't solve the problem, and may cause some of its own.

Jenner

The intake manifold flaps make a noticeable performance difference where the power flap open or closed is minimal.

The two are linked, thus the deflap mod was born. The process of removing the power flap and tugging on vacuum lines may have removed any kinks or binds in the system that were causing the two flaps to not work correctly.

daveak05

I don't know about tangled vacuum lines though.

Jenner

So it can't be THAT bad.

Also the additional coolant radiator in the passenger side air dam has it's own thermostat. This tells me that it's only getting hot coolant if the t-stat is triggered to open.

Would be nice to know what temp that triggers at. For all we know regular driving doesn't cause it to open, only driving in extreme heat or on the track does(and you'll be in the 5500+ rpm zone all the time anyways so the flap will always be open).

So the air flowing over this radiator might not be hot or even warm during normal operating temps/conditions.<ul><li><a href="http://www.jlosee.com/images/RS4/PDF/Audi.ssp.921603.pdf">RS4 coolant diagram on page 19</a></li></ul>

Jenner

smashtheqube posts:
<I>"Just deflapped the airbox... THIS THING IS A ROCKET!!!"
"I seriously think I've gained at least another 25HP or so by doing this"
"I was setting ASR off in the car just by flooring it in 1st... that's how powerful this car is now" </I>

I drove my RS4 for 1-2 weeks with my intake manifold flap and power flap not working. When it was fixed the car felt like he stated said above.

This wasn't "new" or "added" power. This is the RS4 engine performing the way it is supposed to. But if one gets used to the performance WITHOUT the two flaps functioning, when they start working again it feels incredible.

Assume his flaps weren't working, and he didn't realize it. During the deflap process KTR(tuning shop that did the deflap for him) either noticed a kinked vacuum line and fixed it but didn't mention it, or just tugged on the lines enough that it removed any kinks.

Suddenly smashtheqube has a car that feels like it is making more power when in reality it is making the normal power it should have from the factory. The only think he can attribute this to is the deflap process, but that's not where it really came from.<ul><li><a href="https://forums.audiworld.com/rs4b7/msgs/66922.phtml">https://forums.audiworld.com/rs4b7/msgs/66922.phtml</a</li></ul>

daveak05

per Audi's official explanation.

There will be more airflow through the engine bay at cruising speed, and less engine heat buildup than at idle or slow speeds.

There's another major heat source close by, the exhaust manifold.

daveak05

one would ahve to hope that Audi would route and tie off vacuum lines properly though.

Jenner

Since you don't have an RS4 I have to ask if you have seen the way the airbox is set up.

There isn't a way for the exahust manifold heat to get to the airhorn for the power flap.