Custom exhaust tuning...help needed!

[Dave Hord]

Car: 1989 audi 90 quattro

Earlier this year I decided to do some custom tuning of the exhast system on my 
car. (look for a webpage coming up soon...i'll drop a URL to the list, photos 
will be taken on friday)

I replaced the stock rear muffler with a 12 inch resonator (2.5 inner dia). The 
result was a pretty darn sporty sound!  It's loud, but not super-rice-boy loud. 
It does, however, have a very annoying drone right at 3000rpm. 3000rpm is right 
where I end up sitting for normal driving.  

The result of the modification was a large increase in throttle response, the 
car now pulls all the way to the redline...it used to just die at 4500-
5000rpm...continually adding revs but not increasing the power much at all.

I'd like to 'tune' the sound, but without an exhaust lab that isn't the easiest 
thing to do! All I want to do is get rid of the drone at three thousand rpm. I 
don't mind going a little louder, I'd be happy just to 'move' the drone to a 
higher or lower rpm range too.

I haven't touched the centre muffler yet, it's an aftermarket stock replacement.

I have easy access to:
12", and 15" resonators
15" long universal mufflers round or oval shape
I can have anything custom made with an 8-14wk turn around (so, if I wanted a 
6" resonator...)



Any ideas as to what I should start playing with?  Now that my job requires 
lots of highway driving, I REALLY need to do something about that drone!

-Dave




There are two ways to live life.
I choose to no longer live in fear.