http://audirevolution.net/addons/albums/images/181983073.jpg
If I remember correctly the Milltek RS4 exhaust isn’t even 2.5 inches. Its less then that. Just like the S4 4.2 the RS4 4.2 Milltek offering is just a shade over stock size. Not enough to justify the 2000$ price tag or even the thought of putting on a new exhaust
oh snap, you’re right.
Milltek RS4 catback is 2.36". Great. More restrictive than stock.
Milltek S5 ‘large bore’ (lol) downpipes are 2.36" as well. The catback? Also 2.36"
That’s not even trying.
Bumped because its so interesting. Also, a new member pm’d me asking some exhaust questions and this thread was particularly relevant.
I hadn’t seen this thread yet. Its always nice to start the day with a chuckle… 
It’s pretty eye opening.
http://www.millteksport.com/exhaust.products.cfm?variantid=194
Stock Rs4 downpipes = 2.50" necking down to 2.36" at the end to mate up with the stock catback. Precat upstream, main cat downstream.
Milltek RS4 downpipes = 2.50" necking down to 2.36" at the end to mate up with the stock/Milltek catback. One cat, downstream.
Basically Milltek eliminated the precat…and created piggies (with cats that are worse than stock main cats). Piggies are free with 3hrs of DIY work in your garage. Milltek catted downpipes are $2,500!.
Stock RS4 catback = 2.36". No crossover, decent bends, but a crimp right near the mufflers.
Milltek RS4 catback = 2.36" H-pipe crossover, worse bends than stock and eliminated the stock crimps at the mufflers.
Again, nearly a stock replica with the exception of the h-pipe. Stock is free on your car. Milltek is $1700.
This is why I get a laugh when people say things like ‘THAT CAR IS NOT STOCK…IT HAS A MILLTEK!’
From a sound point of view, Milltek is fantastic, but from a performance point of view? I don’t get it. I REALLY don’t get when people are tuned…then they get Milltek downpipes and catback, and get a ‘custom remap’ then gain boatloads of power. As you can see here, that’s really not possible. You can also see why saying you need a custom tune to take advantage of your Milltek is also bunk.
Stock downpipes
http://jhmotorsports.com/shop/catalog/images/JHM-VAST_B7_RS4_Piggies.jpg
[b]Milltek downpipes/b]
http://www.audizine.com/classifieds/data/24/photo_111.JPG
Stock catback
http://audirevolution.net/addons/albums/images/650780120.jpg
Milltek catback
http://audirevolution.net/addons/albums/images/668062472.jpg
And as technical assiantant pointed out. Those crimps are not necisarily a bad thing.
Contrary to a bad bend which affects airflow and dynamics, the crimp gives the same pipe diameter, just oval instead of round. And its 2 inches away from the muffler so any “turbulance” it might cause is irrelevant at that stage since its at the end of its path anyways.
the reshaping of the cross sectional area will cause some pressure loss, same with a bend. I wouldnt say one is worse than the other.
The key is to not think turbulence, think pressure loss
The stock cat back isn’t that horrible for performance as I did trap 113 on it. Horribly restrictive , I think not. I do have home-made dp’s an let me tell you when I start the car it shakes the everything In the garage!
It’s horribly restrictive relative to a well designed 2.75 setup
P.s. someone on rs246 doesn’t think it’s possible you ran 12.26 @112.98. Named Arthurpe… He did some math and has decided it’s not possible
Enjoy!
oh god, not this shit again
Hahaha, this happens over and over with every car I own…
Thanks for the lol , saki!!
Fwiw , I have a anoth video of my best run from the stands, I’ll check and see if the time is visible.
Still I’ve had a quite a few compliments on my exhaust note. But I will never put a full exhaust on the car as I don’t want to spend money twice, since boost is around the corner.
What A fucking mathematician…So much work to discredit someone. I don’t get why instead of being pumped most RS4 guys don’t congratulate each other. Prolly just another guy that loves CC threads and hates the drag strip.
I also enjoy his shade tree engineer comment talking about JHM on page 1…
Lol^^^^ yes must be a engineer of some sort . Lol shade trees !!! I do like saki said you will never modify your car.
Haha saki tore them up like always, but most of the haters will never admit defeat. They’d rather prove they are different by either being in 2nd place, or calling everyone liars and contributing nothing to their platforms!
Lol I like the parts how he says LW rotating parts won’t help anything. I just put on my LW wheels (41.3 lb/corner) and LW front rotors and I can say it made a HUGE difference over stock wheels and rotors. I have all the LW parts and my car RIPS through first like a raped ape. I’ll post some logs to compare to my before run. That will shut him up
ironically he’s actually been saying carbon buildup isnt a problem for years now
[quote=“B6JoeS4,post:36,topic:2694”]
Honestly, it probably won’t. If you’ve never interacted with him you’re in for a treat.
nothing will shut him up…he’s a smart guy who remains emboldened by his knowledge. I think he gets caught up because lots of the knowledge he has doesn’t directly apply here, however his convictions are strong enough that he posts like they do. People get intimidated by that in many cases, so people think he must be right. It didn’t work for him on Audizine where a good bunch of people who are really knowledgeable about producing acceleration gains in these cars saw through the math from the get go, but it has seemed to earn him some loyal followers on rs246 (lots of engineers there actually).
Who knows. I think engineers get trapped by their training a little bit…they want to focus on what would or wouldn’t pass muster in an engineering proof, rather than look at the big picture and see the cars making improvements. i.e. I showed them jnaut’s time and rather than say ‘oh wow…so with mostly LW mods, he shaved quite a bit of time’…they will say ‘he had gutted his downpipes so none of this means anything’. Thats why I asked the one guy for ‘what would you consider proof of gains for a lw part’. They will never give you an attainable method of proving you are right…they will instead shoot down anything you put in front of them. For carbon clean, I believe one of those guys said to prove carbon impacts power, they would only accept ENGINE dyno results, and only if done at one engine dyno, before and after, and for at least 10 cars to have a proper sample size. Right…so you’re right unless we get 10 RS4 owners to pull their engine, find an engine dyno and do before/after dynos with carbon cleans in the middle? OK…coming right up.
If you really think you the LW parts do next to nothing, that means you think jnaut can run 12.26 @ 112.98 with just gutted stock sized downpipes and some race gas mixed in. If so, you’re not so familiar with RS4 performance.
haha, Arthur"PE", smart guy, just stubborn with tunnel view issues. Close the book, throw the parts on your car and test the “theory” for yourself. Always an entertaining read.
What kind of engineer is he? Not beig able to think outside of the box, or rather the equations, is no good for an engineer.