ACS exhaust write up - The Unofficial BMW M5 Messageboard (m5board.com)

TriflowM5+M3 · 21st June 2003, 17:52

Well i got the exhaust yesterday...wow what a package. I think the reason that you pay so much for ACS is because of the packaging. It came in a huge box with all sorts of foam and fabric in it. Quite interesting.

So i took it to have it installed today at the same shop that installed my M5 exhaust. They gave me a rip because they hated the M5 exhausts but i told them this should be much easier.

Well they took off the old one and just about cried because it was so heavy. They made numerous BMW engineering comments, all in good humor.

As for the ACS exahaust...went right up with no problems. Looks good from straight behind but the tips look a little long from the side...nothing a ACS rear diffuser cant help but certainly not bad at all.

As for sound,

idle- slightly if only louder but deeper. Very nice, you can tell it has an aftermarket exhaust but it does not have the aftermarket exhaust tone (did that make sense?) due to the deeper note.

moving- it sounds great when below 4000rpm, deeper and more pronounced but zero resonance. I tried to make it resonate but it didnt want to, a welcomed departure from the B&B's on the m5. Very established sound..very close overall in sound to the stock one but with a deeper set of complex tones.

BUT. Above 4000rpm the exhaust just gets drowned out with the rasp from the rest of the exhaust system. Its not that bad but it certainly needs to be addressed. (I could deal with it, but the girlfriend might not like it). I think this exhaust in conjunction with the rasp-x pipe would be nothing short of amazing. I take a guess that adding any exhaust is going make it worse but im glad that now there is a fix.

Thinking now, the B&B's might have had a slightly better overall sound but generally they loose the aftermarket exhaust sound and sound exactly like stock in the upper range...so for the m3 it would be like 4000rpm and might have led to resonance. I have enough of that with the M5, no need for more. Now im not 100% sure the B&B's would have been like that but, thats their characteristic market sound. At 4000rpm is where the ACS takes shape but with the overtone of rasp. Clean that up and it should be music to the automotive junkie ear with the beauty of the tips. Im sure that the ACS/Remus will have much better overall quality as well.

performance-ahh dont care. It didnt feel like much although im sure it may do 2-3 hp but the reduction in weight makes it seem like more although i cant judge 4 hp...can you? Also the whole aftermarket exhaust mental thing might be there too...not sure but im not looking for performance.

wish i had a digi cam to take some pics and make a vid..but i keep spending money on mods.

TriflowM5+M3 · 23rd June 2003, 06:49

So no one with the ACS exhaust for the m3 wants to back me up or contradict me?

pride355 · 23rd June 2003, 14:08

Triflow,

I remember reading a post on AC Schnitzer muffler which actually states that it decreases the power at the peak. I think it was member Phoenix.

Personally I don't like Schnitzer muffler but everyone has different tastes.
However, it is obvious that you have the cash so if I were you, I would get Eisenmann Titanium exhaust which weights 1/3 of OEM exhaust. Further more, a few weeks ago, I met a guy who has AC Schnitzer muffler on his E46 M3, I didn't notice a difference in sound although it is hard to comment without driving.

Here is Kevin's titan. exhaust without tourched tips. My favorite exhaust.

(because it is 17 lbs at 2500$

)

TriflowM5+M3 · 23rd June 2003, 14:45

pride..

when you are talking about having the money for the ACS...how bout the TI exhaust! Thats more than double what i paid for the ACS. The ACS was the second least expensive exhaust next to the B&B's.

The ACS is certainly louder than OEM as the exhaust is slowly starting to break in...

Just like i stated in my write up..i dont care about the power, thats what the m5 is for.

Although im going to be adding the RaspX pipe to the ACS..if that doesnt clean it up....the B&B's should be off backorder at that point.

pride355 · 23rd June 2003, 14:56

Quote:

Originally posted by TriflowM5+M3
pride..

when you are talking about having the money for the ACS...how bout the TI exhaust! Thats more than double what i paid for the ACS. The ACS was the second least expensive exhaust next to the B&B's.

Triflow,

You get me wrong.
I know that AC Schnitzer exhaust is one of the cheapest in the market and Eisenmann titan. is probably the most expensive one.
Its biggest downside is its price which is 2500$. However it is approx. 35-40 lbs lighter.
I didn't say that you have the money to buy Ac Schnitzer; actaully you have the money to afford both for M3 cab and M5. So if I were you, (and it is important to live in the states to get eisenmann titan. since it is only for US market), if the money is no subject (I assume that it is no subject for you for a 2500$ exhaust) I would have bought eisenmann titan.

Sorry, it is wrong to make assumptions but you said that

Quote:

So no one with the ACS exhaust for the m3 wants to back me up or contradict me?

so I post my opinion

TriflowM5+M3 · 23rd June 2003, 15:16

its all good, i wasnt trying to put any bad feelings out there.

I know that the Ti exhaust is good and its light but, im not really worried about the weight or the performance of the exhaust...just purely the sound performance. So adding the TI exhaust would be great if i was looking for total performance...power without all the weight.

no hard feelings?

KaOTiKM3 · 23rd June 2003, 15:45

any sound clips out there of either the Eisenmann Ti Exhaust or the GruppeM Ti exhaust?

TriflowM5+M3 · 23rd June 2003, 16:30

check www.eisenhaus.com for the eisen TI one...

none that i know of for the gruppe m one...

kevin034 · 23rd June 2003, 17:58

Here's some interesting facts for you guys ... amazed me at first too. When I first received my titanium exhaust, I put in on a large weighting machine (w/ digital read outs, my cousin owns a computer store and frequently ship things via UPS, thus the weight.). The titanium exhaust weighted in at 14.5 lbs, not 16lbs as I had expected. I looked into the box for mounting brackets, thinking maybe that accounts for the missing 1.5 lbs, but there was nothing.

After getting the exhaust installed, I weighted the stock exhaust. Provided that there may be dirt deposits in the exhaust, it weighted at just shy of 60lbs.

60 - 14.5 = 45.5lbs savings = 4.55HP gain just w/ weight alone.

It think it's pretty sweet!! However, as tri mentioned above, the rasp drowns out all exhaust noise once you get above 4000RPM. However, I've noticed that this is only true if I am in 1->3 gears. Once I am up in 4th, the exhaust is actually louder than the rasp, very deep and mean sounding!

TriflowM5+M3 · 23rd June 2003, 18:11

kevin,

very cool...im going to call UUC at like 3:30 and talk to them about the raspx pipe and find out details. Right now its on back order so i have no idea when it would be avail.

Sounds interesting though...it drops another 20lbs off the total exhaust system