1999 996C4

I finally put my fabspeed exhaust in the car - sounds pretty nice, however at ceratain cruising speeds on the HW it is LOUD - any way for me to get that resonating sound less extreme or completely gone? I installed the sport cats and mufflers - Is it because of the sport cats that I think it sounds like a jet engine trying to take off?

Any suggestions for dampening the resonation would be greatly appreciated - also, if go back to the stock cats will the exhaust by Fabspeed alone (just the mufflers) be more mild?

Thanks for any suggestions you may have.

1999 996C4

To put it simple, it sounds like I didnt invest all the money for the sport cats and exhaust, and I simply put the muffler bypasses on - sounds WAY too loud and nothing like what is in the videos by Fabspeed - any help please?!?!?

gota911

No mufflers = LOUD!

Keep the sport cats and add some the mufflers of your choice based on sound. This will be louder than stock but not nearly as loud as the muffler bypass set up.

1999 996C4

I actually do have the Fabspeed mufflers installed - as well as the cats - but it sounds AS IF I do not have any mufflers...so I am wondering why it sounds this way? I followed all instructions obviously and the only part I can think of that I didn't do was replace the gaskets from factory - they looked pretty good though, but perhaps something is leaking there?

gota911

Sorry, I read your second post and thought you had installed muffler bypass pipes.

ivangene

I listened to the sound bytes on the muffler by-pass.. bought them, and they sounded awesome!! They sounded so awesome that I had to remove them because my ears were going to be falling off if I didn't. The sound bytes are not accurate, just go watch Nitro Funny cars run down the 1/4 mile - then compair to a video....major differance..

GL, but i bet we see a "FS fabspeed cat and muffler" post soon... you and I will be looking for the "less loud" option together
Ed

Meister Fahrer

Sounds like the sport cats are creating the extra noise in your case.

Did you do the install yourself, you could put the stock cats back on and probably notice a difference.

Good luck!

medtech

I'll trade you for a set of 3.6 PSE modded cans by Fister D...PM me

1999 996C4

Yes, I did install myself - I will put the stock cats back on and see what type of difference it makes - I just don't want to lose out on any extra power

And yes, you will probably see a "FS - Fabspeed Sport Cats" post in the near future!

Thanks for the tips!

redridge

are the fab cats 200 cell or 100 cell, the stock is 400 cell and will reduce the noise to a nice "livable" level... lucky you didnt sell you stock cats yet

1999 996C4

Ridge - yes, they are the 200 cell - had no idea that "cell" = noise level (probably doesnt) but it explains why they are twice the volume that I would prefer them to be - and it sucks because all I wanted was the muffs and the guy on the phone DEFINITELY sold me on the cats as well - and I had to wait 2 weeks for the cats because of shipping errors...not fun and lots of time & money wasted at this point.

Anyways, thanks for all the help everyone, sounds like I need to take the cats off and ultimately go with just the mufflers, hoping it won't take away from the fun sporty sound and feel that the car now offers - just too much excess noise at this point!

Very grateful I didn't ship the cats yet! Sorry for the confusion.

BlownC2

i had the same problem. changed to quieter mufflers and solved the problem. i think i replaced the fabspeed mufflers with fvd sport mufflers.

1999 996C4

Sounds like you kept the cats then and just replaced the mufflers? I think I am looking to switch back to the stock cats and keep the Fabspeed Mufflers for the louder sound, hopefully only when doing WOT.

Malakas

interesting. I didn't realize the sport cats made such a sound difference..

Patrick

If you have cats and fabspeeds, and think they are too loud, you should probably go back to the stock mufflers. I have fabspeeds and they are way quieter than the monty mufflers I was running. I did have a pair of supersprints that were slightly louder than stock. The Monty's fell apart on me, (multiple times), but I am looking for something with similar sound. The fabspeeds are way quieter, with or without cats.