I have a 99 convertible. I installed an SLP catback with the regular SLP muffler, not the loudmouth, and its still a little annoying as far as decible levels go. I know i sound like a wimp to the ears, but i need something that isnt this lound but with solid performance. The convertible doesnt hide noise as well as the hartops. Right now its borderline too loud for me, and i know it will be when i upgrade to headers and Y pipe. I was wondering if anyone has ever put a glasspack from an old hotrod or anyhting inline with their muffler to quiet it up a bit. i'm curious as to how it would sound because i know it will show little to no performance drop, can anyone help?

Update: i'm planning on ripping out the carpet and Dynamatting everything, so if anyone has experience with dynamat and a loud exhaust, let me know if it helped interior noice levels.

Thanks everyone!

 

something like and 18" (or bigger if you can find it) bullet muffler or maybe a borla XR1 muffler right behind the Ypipe should help out quite a bit with little to no affect on performance.

whether it will be enough for your needs...hard to say....but judging from how much it helps quiet down the Loudmouth (in place of the resonator) it should.

 

The SLP dual/dual is one of the most quite catbacks. Its barely louder than stock.

But ya, what Teke said should help. If you go w/a stick muffler make sure the internal diameter of the muffler doesn't neck down. Most will be a 1/4" smaller than their inlet diameter.

 

Assuming you got a 3" complete cat-back and not just the muffler, you should get this and install it in the y-pipe. It'll help and there won't be any loss in performance. Just make sure it's installed as far back in the i-pipe as possible.

http://www.jegs.com/cgi-bin/ncommerc...26&prmenbr=361
p/n 289-24219

 

SLP has the dual/dual on clearance right now - excellent flow and fairly quiet.

I did the dynamat thing on my convertible and it helped very little - save the weight, time and money and just get the dual/dual.

 

Thx for the suggestions everyone! i'll let u know how it turns out, i think i'll upgrade the y pipe and put in the dynomax bullet.

 

fyi:

Trying to quiet my GMMG;
Installed dynomax bullet - gave it a bit of a glasspack sound but didn't quiet it enough.
Installed the car chemistry cone - did a great job of quieting but lost too much power.
Installed a chambered section from SW didn't quiet it enough.
Installed the Borla XR1 - quieted it nicely but I got tired of dealing with the muffler in the way of the drive shaft every time I jacked it up.
Installed the Dual/Dual - nice and quiet and good sound, clearance, and flow.

 

Except he ALREADY HAS THE DUAL/DUAL, and is wanting to make that quieter.

 

I have the same concern as my header install approaches. The loudmouth and headers without cats will sound like the end of the world, so I think I am going to try that Borla XR1 first, and go from there.

 

Yea especially if your planning on putting headers on yet. I have the original loudmouth and after putting on the LT's and OYP its loud as hell, gonna throw a bullet style in place of that resonator. But taking out the stock cats; and i heard throwing that larger y-pipe in can make a noise difference. However much quiter it gets with a bullet muffler thrown in, is gonna be quickly offset if you do headers and even high flow cats and y-pipe,...keep that in mind.

 

YA i should've added in the first place in the future, headers are a definate upgrade. i might just tolerate the noise untill o do full headers and y pipe, then go from there on installing a bullet, or maybe something more drastic in noise reduction. Thx for the info on the silencer cones, i never heard from enyone using them, good to know they totally suck before trying them out.

 

If he thinks the Dual/Dual is too loud he shouldn't be driving one of these cars.

I know "loudness" is subjective but Jesus H Christ...if someone thinks the Dual/Dual is way too loud they should buy a Lexus or something.

 

agreed arnt these muscle cars? Arnt muscle cars characterized as big badass loud motors? if you didnt want the muscle car package then buy a bmw

 

My bad, thought I read he had the loudmouth.

Bullet will help a little, XR-1 will help a lot. Dynomax makes a nice 4" round (not the bullet) but they only have the 3" in steel, not stainless.