B8 RS5 4.2 FSI exhaust discussion - share what you know

Post by **sakimano** » Mon Nov 12, 2012 8:03 pm

Not looking to discuss which aftermarket catback sounds best, but rather I would like to know what the stock setup is like in order to gauge whether there could be some improvements had by addressing any potential weaknesses.

Interested in the following:

1. diameter of downpipes and catback exhaust sections
2. is there a crossover (xpipe or hpipe) in the catback section?
3. how many catalytic converters are there, and where are they located?
4. what is the setup for the manifold...is it a log style manifold, or short headers..or other?

The B7 RS4 had the following setup from the engine back

manifold - tri-y headers
downpipes - 2.5" downpipes that tapered to 2.36" just before it mated up with the catback
catalytic converters - 2 in each downpipes...pre-cat up at the end that mated up with headers and main larger cat down before the mate-up with the catback. Gutting out the pre-cats yielded strong gains for the car while retaining the main cats and their ability to help a car pass sniffer emissions tests. You could also DIY it for free, so this was a great mod. Main cats were very good and flowed well.
catback - no crossover, with a resonated section. 2.36" diameter on the exhaust

As I mentioned above many RS4 owners found gutting the pre-catalytic converters to be a great source for efficiency improvement. The next level of performance gains to be had involved larger diameter exhaust and downpipes. 2.75" was the choice of MTM in EUR and JHM in the US, and we have seen very strong power and performance gains from cars with the 2.75" setups. Other companies went with a repeat of stock size with changes including the relocation of/deletion of catalytic converters or the addition of crossovers or adjusting the flow/shape of the exhaust. These stock sized systems mainly yielded sound gains and modest power gains.

Post by **sakimano** » Tue Nov 20, 2012 5:49 am

So either...
A) nobody saw this thread (but the numbers of views would refute that)
B) RS5 section owners are shy (again unlikely)
C) Nobody knows anything about the stock exhaust...but if that is true how do you guys make decisions on aftermarket products before you know what you are removing?

Anyway any help would be appreciated.

Post by **SteveCuz** » Tue Nov 20, 2012 2:13 pm

D) Not too many RS5 owners on this forum and due to it having little activity, noisy non-rs5 owners click on a new thread.

Steve

Post by **Nickyboy** » Tue Nov 20, 2012 2:53 pm

SteveCuz wrote:D) Not too many RS5 owners on this forum and due to it having little activity, noisy non-rs5 owners click on a new thread.

Steve

Like me.

Post by **sonny** » Tue Nov 20, 2012 3:13 pm

E) you was being ignored

Post by **northernpar** » Wed Nov 21, 2012 12:46 am

F) Too busy driving the RS5 and couldn't be arsed

Post by **bam_bam** » Wed Nov 21, 2012 12:55 am

G) for Gangnam Style!

Post by **Nobby** » Wed Nov 21, 2012 11:43 am

H) from STEPS

Post by **DanDB** » Wed Nov 21, 2012 3:56 pm

I) Dont give a sh!t

Post by **sakimano** » Wed Nov 21, 2012 6:06 pm

Lol

only one reply from an RS5 owner, and...

northernpar wrote:F) Too busy driving the RS5 and couldn't be arsed

Hopefully someone will have some info to share at some point. Is there a Milltek rep that posts here ever?

Post by **brice9** » Wed Nov 21, 2012 10:34 pm

seems to be the quiet est forum on here??? ...why is that?
i love mt RS5

Post by **philipwalker** » Thu Nov 22, 2012 6:20 pm

I have a miltek on my RS5 get a bit noisy in dynamic other wise OK.

Post by **sakimano** » Fri Nov 23, 2012 4:56 am

brice9 wrote:seems to be the quiet est forum on here??? ...why is that?
i love mt RS5

Car is super new...takes time to build up a base. Also first owners (generalizing) aren't always entirely active in forums.

Post by **brice9** » Fri Nov 23, 2012 3:28 pm

Phil
were did you buy your exhausts...what type did you go for catback? non res etc?

i am thinking of going with MILLTECHS AS I HAD EM ON MY rs4 and loved the noise.....i just want that growl all the time...i must say dynamic is a great thing to have, but i dont use it much at all except for acceleratng onto motorways after a few miles the suspension just drives me mad...too hard!!!

loving the car though only had it 4 weeks,,,but i do need some more noise...so let me know what you went for.

many thanks

Post by **MSLRS5** » Fri Nov 23, 2012 4:00 pm

Hi Brice9,
Like you I came from the B7 Rs4 to the RS5...and I'm still enjoying the new motor. I agree that in dynamic mode the suspension is too hard to be useful on anything on anything other than a track so this is a possible suggestion:
If you like the exhaust note but don't like the early down shifts then set up as this perhaps: Using drive select choose your engine and gearbox to dynamic and steering and Suspension to auto (for example) and then use the gear lever in the left hand gate. This way you can change up when you want to and it will only down shift automaticaly when the engine needs to. You don't get the throttle blip if you let the car change down..but if you use the paddles then you can still get that blip if you wish. I drive like this all the time as I prefer to use the paddles but if you "forget" to change down the car still does it for you...and you don't get a broken back everytime you go over a pothole.
HTH.

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