GDeen

I can't decide if I like the stock or MTM sound better comparing on youtube. That said, more power may tip the scales toward the MTM. Anyone notice more seat of the pants power? Other benefits? Happy you did it?

blinger

Do it.. Don't be scared

CovertW12

Hard to quantify the power gain if any, but the seat of the pants leads to believe that there's sometihng - it's certainly more responsive and revs freer on the high end.

The change in tone alone was worth it for me.... I've also uplugged the "valves to allow it to flow freer all the time. Not a huge change but a bit more snarl down low.

It passed the wife test, but still is growly enough to turns heads a it revs up.

it is however VERY spendy....hard to justify the cost for new ( I luckily found a light used on - thanks to HTK). Miltek supposedly has a system as well but fitment can be challenging with their stuff based on my past two experiences.... MTM is close to perfection.

overall I love it, but would struggle to justify it unless I was into the car for the long haul.

regards,

E

GDeen

I do mean D3 - couldn't figure out how to correct the typo once it was in there...

Thanks for the thoughtful answer.

MP4.2+6.0

on this where think I recall you reporting the twitchiness/sensitivity of the throttle had been reduced some. Still have that sense? Any sense what it may have done is drop the back pressure some and shaved off some low end RPM power in favor of more higher up when freer flow kicks in?

And, I guess you disconnected the vacuum switches for the rear muffler "secondaries" if you will, which I'm betting would result in a bit more yet of this shift. I need to play with that again on mine to check it against the torque feel.

Car has power to burn so not too concerned on the low end loss, but then it has serious get up and go already up higher too... Might actually hurt city mileage a bit, but that's not the W12 altar anyway...

Wickedated

I was also skeptical especially since theres no power gain, its purely a sound issue.
That being said, I hate how subdued the stock exhaust is. It's just not worth of the S in S8. My buddy drives a brand new S63 and boy, that thing revs. Side by side, when you put both cars in neutral and throttle it up, the S8 sounds almost electric next to the Benz. Not good.

So I'm on the same boat, but I really wanted the upgrade in sound, so I just went for it. It'll be installed by the end of the month hopefully.

SENS8

The earlier post you reference may have been mine of 25JUN08.

In my recent 25,000 miles with the MTM exhaust, after first 22,500 miles without it, I feel rather confident in having substantiated at least 1.5 mpg fuel mileage improvement (though "aural satisfaction" was entirely the motivation).

I'm not able to attribute that (or, not) to any such technical explanation as you're mooting here. It *may* well be that at every (or most) RPM and throttle setting there's more power; I dunno. What I do know is that before (with standard S8 exhaust) I couldn't hear the engine pulling (and I think it wasn't, with mushy throttle response after twitchy tip-in), so I always had to have my foot further in it, or tip a lower gear, to get down the road as if there were 10 cylinders helping.

In my case the S8 followed two RS6's (each with factory "sound enhanced exhaust"), which no doubt relatively spoiled me in terms of expecting throttle responsiveness. Now with the MTM exhaust, the S8 SOUNDS far more "throttle-y" than the RS6 (or anything else I've heard on the road), even though it still lacks for torque compared to the turbo cars (such as my "weekend" car). The S8 is as much sport to drive now as any of these others, because the better MTM sound experience makes up for S8's torque deficiency, in "normal" driving.

Lastly, I'm afraid we still haven't reached the gas price level at which the 1.5 mpg improvement justifies the MTM's initial "spendiness"... over any lifetime of the car.

But to me the MTM exhaust has entirely made the difference between trading after a year as I otherwise would have done, at such sacrifice in resale value, and my current plan to keep the S8 through 100,000 miles. If such a consideration could help you rationalize the MTM purchase: go for it!

Wickedated

Actually, if you post MTM exhaust on your resale ad, you'll for sure get hits

RoninWheels

As most have mentioned, the main reason for upgrading the exhaust to the MTM is because of the sound. There is no question that the s8 acutally sounds like it has a v10 w/ the MTM but as for pwr increase i can't tell you from experience as i have yet to get a before and after dyno #'s.

The MTM system is a well made piece of equipment... from the fitment to the bends and welds. It is lighter than stock and less restrictive on flow, which in theory should free up some HP/TQ. Up to date the only significant hp/tq gain from exhaust work i have experienced on an Audi NA car was from MTM.

I will have another system installed by the end of the month... Pics__Video_ coming soon.

CovertW12

I did dis-connect the "valves" after driving it for a week with them engaged - a bit more "growl" at lower rpm's and I like that the tone stays constant, versus a tangible change in pitch when the valves opened.

overall I couldn't be happier....