Pete @ Stratmosphere

<center><img src="http://www.stratmosphere.com/valved_585.jpg"></center><p>Looks like Automobile Magazine posted up their video. It's on their home page and on YouTube.

http://www.automobilemag.com/index.html

-Pete, Stratmosphere. 1.866.533.1777<ul><li><a href="http://www.youtube.com/watch?v=vOYkjK_SIEs">YouTube link</a></li></ul>

RI A6

Great exhaust, made even better with downpipes!

McGyver

Those are the sounds I hear during my commute. . . talk about "getting your mind right"

quattrothatcould

Oh wow. That sounds amazing

SteveLRS4

In the early dynos people were saying that the intake flap not opening was affecting the dyno results. Hopefully by now someone who deflapped has confirmed the 20hp gain. Sound is nice and all but for $1700, I'd want the gain confirmed before purchasing. Isn't this something that Stratmosphere should do if they are selling Milltek?

RI A6

I deflapped (actually put in a switch to open the flap) and looked at before/after MAF readings. There is a difference. It does not account for 20 hp, but it turned my attention to another issue. My engine is pulling 12 degrees of timing retard at high rpm now (with and without flap open). But in January it was pulling only 3 degrees. That would easily account for quite a bit more power. I think the timing retard is temperature related, and/or may be the mechanism by which Audi engineered the ECU to keep from increasing power with mods (as was theorized by some exhaust tuners).

The downpipes do make more power in the midrange. It can be seen in my dyno plots, and in MAF reading comparison between my car and Bob's.

ELEVENS

Cross-filled underground storage tanks, winter vs. summer-blended fuel, contaminated fuel. Another idea -probably a stretch - the aftermarket exhaust installation/rigidity/noise fooling the knock sensors? For example, tapping on the block is a service-manual method of testing them.

I agree that temperature is the most likely, but now that it's cooler, that shouldn't be a retard issue.

Sorry Man, I'm not yet buying the Audi engineer-anti-modding ECU programming theory.

Cheers!

drvbiker

Pete:
DOES STRATMOSPHERE HAVE UPGRADES FOR AN S5?

Greg @ Stratmosphere

We hope to have catback systems here late December/Early January. Perhaps sooner. Looks like $1799 for the catback. DP's still undergoing durability testing

-Greg

RI A6

Although I did try a tank with MMT additive, and saw no substantial difference in logging. Now that temps are cooler, I'll so some additional logging and see if the timing retard comes back down.

I mention the ECU programming, only because it has been mentioned previously. In lieu of any other issue, that would be the last possibility. The interesting thing is that the retard only kicks in around 5000 rpm. Below that, there are substantial torque gains with the Milltek downpipes and catbacks.

You idea about the knock sensors is also a possibility.