[V8] exhaust needed for 90 V8 quattro

quattro + 5 or 8 = fun thequattroking at yahoo.com
Fri Feb 13 02:35:02 EST 2004

I have had about 4 or 5 different combos of mufflers and pipes on my car.
Basically, what I found is I could NOT stand the noise it made with the rear
one gone.  It rattled my brain.  Horrid.  I do have a 5 speed and at highway
RPMs, it literally gave me a headache.  Next, I put two glass packs back
there and a dynomax up front.  Wonderful.  Sound was so intoxicating I could
not keep from driving around with with the windows down.  ESPECIALLY in the
winter when I could keep the revs up and the tires spinning.  Soon after
that, the car hit a retread dead on the road.  I messed the cats up.  So, I
decided to put new cats and pull the rear glass packs.  The dynomax stayed.
Very nice.  A bit more "snarly" but not headache quality.  Then, I decided
to move the position of the dynomax from center to rear.  Wow, that really
changed the sound.  Deeper and almost no snarl.  Then, the final system that
I have today.  I took the whole system off from the x-over pipes and started
from scratch.  Front to rear 2.5" duals.  Including cats.  One flow pro at
the rear position.  Nearly perfect.  I discovered increasing the pipe
diameter really mellowed out the sound of the car.  It now sounds like a
massaged GM small block at idle and a big bore ferrari at readline, only
deeper.  Inside the car, there is almost no increase over stock.  When cold,
it is kinda raspy.  But, when warmed up, it makes all the noises described
above.  My overall impression of the flow pro is not as positive as the
dynomax in terms of sound, but it sure is a sturdy unit when compared to the
ultra flow.  I really like the sound now.  So much, that I copied it on the
coupe 20v.  However, I put a center resonator on the 20v as the 5 cylinder
is so raspy.  Sounds like a "Honyota" on laxatives.  It is still to raspy
for me.  So, I bought a supersprint tip with a resonator.  Will see if that
helps at all.  If not, I may remove the center resonator and install another
flow pro.  Non V8q, but I also have a MBZ 4.5 liter that I built like the
V8q.  I am very happy with that system too.  Another thing that I discovered
that really helps keep cabin noise down is to make sure the tip extends past
the bumper.  If not, my no technical description would be sound waves are
getting caught in the trunk and resonated through the cabin.  I stuck a piec
of pipe on exhaust system of the 20v to test the theory.  Currently, the tip
ends just about 1/2 inch before the most extended part of the bumper.  I put
it out about 1 inch past the bumper.  Really made a diff.  Hope some of my
trial and error gives a few ideas.

Take care,  


Bay Area, CA
Eastern WA State

PARTING:  1972 Mercedes Benz 280 SE 4.5
PARTING:  1986 Audi 4000 CS quattro

> I have actually had zero resonation in the cabin at any speed, and have
> had no "Toyonda" like effects.  I do have a slight rumble, but other
> than that no problems.
> I actually went to the exhaust place to have the rear cut out and have
> straight pipes put in the same way yours is, but I had a decent size
> rust spot in the center muffler, and the guy said that it was a
> resonator anyways.  He also said that if I removed the rear muffler that
> it would be too loud for what I would want.
> While I have heard keith's exhaust with the rear muffler removed, I went
> with what the "pro" recommended.  It would have cost me the same either
> way. Bummer.
> Shawn

>> Count me in on the buy for catalyst test pipes.  Also, Keith at
>> Audiconnection told me that there are gains to be made by removing the
>> resonator at the end of the exhaust system but not by pulling the
>> muffler  located behind the cats.
>>  Laurel Audi quoted me "about" $750 to do the timing belt two months
>> ago.
>>  John
>>  73 MGB
>>  89 1cq
> So far I've stayed out of this discussion but since I've been
> quoted..............
> The center muffler is really a muffler, it is not a resonator as has
> been suggested. It's an outstanding high flow design. It consists of two
> straight pipes with a pattern of holes to allow sound absorption by the
> packing material. Simply replacing it with another set of pipes is a
> simple and effective way to make the car faster by lightening your
> wallet. It also makes the exhaust tone very loud/harsh (something akin
> to the sound of a pair of Toyonda's with 5 inch fart cans out the back)
> and it resonates in the interior of the car to the point that at highway
> speeds it interferes with the enjoyment of simply listening to the
> radio. (I know some people like the sound, but I, and I beleive most V8
> owners would not)
> The rear muffler/resonator on the other hand is entirely suited for
> removal by those who want a power increase and like the sound of a high
> reving european V8. Replacing this muffler with straight pipes does not
> require suffering resonation in the cabin, in fact during highway
> cruising the exhaust is only noticable when you're beside one of those
> concrete walls or have the stereo volume way down. Replacing this
> muffler does allow you to annoy the neighbors at will as well as make
> the Toyonda drivers think twice about annoying you.
> Just my $ 0.02
> Keith

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