Thanos_RS4

Hi guys! I'm on the path on installing the full kit from Milltek (DP, cats..) and one thing that I don't have much info or experiences is the 100 vs 200 cell High-Flow sports cat.

What are the differences (apart the cell number!) in HP, compliance with emissions, sound etc.. Has anyone had the chance to get to use either one in his RS4_B7?? The price is negligible between the two, hence my need to put the best for the RS4...

Many many thanks :-)

Pete @ Stratmosphere

The 200 is likely to operate within the factory specs for a longer time all things equal. -Pete

wankeldude

question asked was how they compare to each other with respect to horse power, emissions, and sound

being "likely to operate within factory specs for a longer time all things equal" means what?

shonobi

It means it may not and can cause CELs with read outs like "low threhold pressure" etc.....like the problems one can experience with OEM as time goes on.

The Aftermarket with the increase cells will increase the flow of gases post-combustion from the engine. Also the aftermarket DP has one "CAT"/ DP, unlike the stock DP which has 2 per DP which also reduces restriction of exhaust gas flow.

If I am wrong someone please correct me.

thanks

Thanos_RS4

Now that wording explains it for me :-) Many thanks ! It's clearer now on what and why to install on my precious :-)

wankeldude

please compare and contrast a 100 cell vs. 200 cell catalytic converter, with respect to horsepower, emissions, and sound.

From what I understand:

the lower the number of cells per inch, the higher the flow, louder sound, and more potential horsepower. The compromise is decreased longevity, and increased emissions.

A 200 cell catalytic converter will do a better job of scrubbing exhaust gases than a 100 cell. It will likely last longer than the 100 cell. It will however restrict exhaust flow more than a 100 cell and thus provide less horsepower.

craiglieberman

Just curious...lots of questions about air flow and such...but does anyone care about hp? Doesn't anyone care to see dyno numbers of JUST the downpipe mod for this car?

Having no CEL issues is great, and the sound of the DP mod is SUPERB, but isn't anyone remotely curious about whether or not the mod makes power, or does it lose torque down low?

Speaking with some other Audi tuners, the general consensus has been that the DP mod affects low end torque and that the trade offs do not justify the modification.

I couldn't find any stated dyno charts on the system. I'd happily consider the mod myself, if I could substantiate power gains with it.

RI A6

There is no loss of power at the low end. In fact, I'm now making better than 25 lb-ft more torque below 4500 rpm, and the engine pulls much better starting at 2K.

I could not get a good dyno reading on the high end above 4500 rpm, because of the intake air valve staying closed. But, my Milltek dyno showed more torque against a same day benchmark at about 77F and a different day benchmark in the winter at about 40F

Thanos_RS4

So that I have proof that I didn't waste (?) 5800 Euros (!!!) for the full kit just to get nothing or even lose power!! I will -of course- post the dyno results here :-) Sound is good, HP/Torque is better! I'll go for the 200-cell CAT. Timing.. October-November time frame!