SARGEPUG

Long story short, I bought the car from a friend that said the previous owner modded the exhaust, but he misplaced the receipt. Here are the pics of the Fabspeed unit below. My confusion is that it looks like a cat bypass that runs thru the stock muffler. If it's a cat bypass, how did it pass inspection? Also, does this enhance the exhaust note or only gives power gains, due to the fact that the stock muffler, is still "muffling"?

wildcat077

What you actually have is a Fabspeed pre muffler which still retains the O2 sensor contrary to the cat bypass which is smaller in diameter and,i believe does not have the O2 sensor bung ...

All you need now is a nice Fabspeed two out muffler and you're in business

Cheers |
Phil

Amber Gramps

Was it a visual inspection or was it put on a sniffer? I'd say you have a clean running engine if it passed the sniff test.

SARGEPUG

Thanks for the info, so does what I currently have,enhance the note or it's only for hp gains?
Two out system sounds great, but I don't have a cutout for the second pipe. I could go w/ the capped off single exhaust system. I am def ordering one or the other tonight!

http://www.fabspeed.com/911Carrera.html

Caferacer

There's a video on the Fabspeed site of them cutting out the rear valance for a second pipe with a sawzall. Takes about 30 seconds. Just saying.

Also, NYS doesn't use the expensive sniffers they made all the inspection sites purchase a few years back anymore.

Finally, video before and after so we can hear the difference!

Robey

wildcat077

I have the Fabspeed one in two out muffler on my 89 911 and after 3 years i have to say i'm very satisfied with the sound,which by the way is not overbearing and the excellent quality of the Fabspeed products as compared to some cheaper "louder" brands ...

As for cutting the extra hole on the right side of the rear valance, like Robey says,there is a complete how to video on the Fabspeed website !

Cheers !
Phil

Ed Hughes

Let's not get hung up on terminology. They are all "cat bypasses", some have the O2 bung, some of the cheaper ones don't. They only differ in throughput/back pressure, constuction and sound quality. Way back when, in TX, Ruby passed smog with a Fabspeed bypass on a stock engine/chip. TX standards weren't very lax.

SARGEPUG

Thanks for all the info guys, I just ordered the Dual Outlet MAXFLO Catback Exhaust Muffler!

wildcat077

Ed,

For what it's worth,they aren't all the same ...
Although i have the Fabspeed muffler i installed Ben's MK pre muffler which i found to be better because the O2 bung captures both banks rather than only one with the Fabspeed and it looks a whole lot better in my opinion
As for smog tests on our cars,we don't have that in Canada ... yet

Just sayin ...

Cheers !
Phil

wildcat077

Sarge,

Congrats on the purchase of your new muffler.One piece of advice i can give you is to install
EVERYTHING LOOSELY at first and i mean it otherwise you will find that lining up your two exaust tips evenly will be a "not so joyful experience" ... lol
That means to loosen your pre muffler as well,then you line everything up loosely,adjust as you go and then you could start tightening things as you move along !

If you need any tips,feel free to ask !

Cheers !
Phil

SARGEPUG

Thanks, but I'm going to give it to my mechanic!

Ed Hughes

That was my point. There are several styles that all provide the same function, but in various ways and levels of results. In essence, they all replace a cat. But "pre-muffler" "cat bypass" "test pipe", or whatever moniker, are just names. I was only responding to your statement noting the different names.

There is only one O2 sensor on the stock car setup-since both manifolds feed into whatever bypass unit is used (assuming it has the bung), they woull all capture both banks, just as a stock cat does. I'm not following your statement here, as anything replacing the cat will see all the exhaust from both banks going through it.

My headers only allow one bank to be picked up, as there are two distinnct manifolds feeding each side of the 2 in/2 out muffler, and I've been tio lazy to modify or go to a wideband setup.