Fabspeed Cat Bypass

Hello all, I am new to this forum and I have a 2003 C4 Cabriolet. I am looking to get some more sound for the exhaust without breaking the bank at first. I am considering the fabspeed cat bypass pipes and O2 extenders. I was wondering if anyone is running this set-up with stock mufflers and what your opinions are on the sound, also if there are any sound clips. (I did do a search but didn't come across any clips). I figure if it doesn't give me enough sound I can always go to the Fabspeed mufflers as well, but I figured I will start with one thing at a time. Thanks in advance!

Category: Engine - Exhaust Price: $900 Private or Vendor Listing: Private Listing Part fits: Porsche 911 996 Turbo Location (State): GA Item Condition: Used Shipping Information: Item can be shipped Hello fellow 6speeders. I'm selling my hardly used Fabspeed exhaust GT2. It comes with 100 cel cats. All is complete and no damage other than your typical scratches from install/removal. I purchased this from my old mechanic, put under 10,000 miles over two years and now I have a Kline exhaust from Sam. I took it off my X50 in March and has been sitting in the garage.Take it off my hands. Sam thank you! XCUDB

I haven't heard this setup, but I suspect it will be quite loud. You might try some high performance cats in place of the stock cats. Another good, inexpensive way to get some nice increased sound is the Fister D muffler modification. I did this to my C4S, and it sounds great. It adds a little growl without adding any drone. I've also heard that the Fister D mufflers sound very good with sport cats.

I have this exact same exhaust system. Generation 1 single canister. I here that the original gen 1 systems are becoming very sought after, since fabspeed doesn't make a single canister version anymore. Very rare... You don't see a lot of these anymore.

Quotes source post: 3096568

Quote: Hi 2300cc, if you go with the cat-bypass pipes and your stock mufflers, it will sound a little more aggressive but not too loud since the stock muffler cans are big and restrictive. The only problem with cat-bypass pipes is that you may have issues passing emissions in your state and you loose some low end torque without the cats. I would go with Sport cats unless you are tracking the car, so let me know if you have any questions and I can offer you a member discount on the part. Thanks,

Bump

Alex, Thanks for the reply. The car is going to be used on the street mostly, and as long as the O2 extenders keep the cel off I should have no problems with inspections. Thanks again!

Bump

My set up is Fabspeed X pipes cat bypass + Fabspeed muffler bypass. Very loud. "I" Like it like that. Most people don't but I do. I live by the Police station about half a mile. Never got anything for it. Instead they wave at me. But if you're more conservative then I would take Alex's advice.

you don't happen to still have this exhaust, do you? I'm also located in Atlanta.

Dyno , cat bypass :

Hey devil I have one for 850 shipped. Text me at+15133026014 This thread is a year old.

Alex, what kind gain does X pipes cat bypass with muffler bypass put out, not 200 sport cats. This one.

Quotes source post: 4615713

Quote: Is this still for sale?

They have the wrong site. Link: http://www.fabspeed.com/996_GT3.html

what do you mean?

I posted the dyno wrong because the site is' wrong.

If you run a straight pipe setup (cat and muffler bypass) don't you lose power at the low end, but gain at the high end? I've been trying to dig through posts but I can't find any examples. Does anyone know at which point you start to gain power?

I believe the chart posted is correct for a cat bypass pipe, it is just labeled wrong within the chart. You can see the low end drop off in torque between about 2700-3500rpm. I'm sure Alex would know if this is definitely the correct chart.

OK I am going to jump in here with an opinion that is not always popular. If what you are striving for is a better sound for the car go don't go with the cat bypass but try the Fister D mod to your mufflers. This can be done for about the same price as cat bypass pipes and has several advantages. First it does not effect the low-end torque like cat bypass pipes will. And it will not effect the drive ability of the car as the O2 sensors will still be functional as they won't be modified. Or try another muffler set up, although they can be pretty expensive. With the cat bypass pipes you are disabling the pollution control system on your car which IMHO is a bad thing, and you have to deal with the O2 sensors, CEL's and drive-ability. issues. . It is also strictly illegal for a street car and makes you subject to pretty onerous fines if you are caught.

+1 Dharn55

Someone has just put the original exhaust with cat bypass or fister d?

Alex so those numbers are right? 285whp?

Quotes source posts: 3097519, 3097828

Quote: Quote: Hey Guys, yes that Dyno chart is correct for the Cat-bypass Pipes with stock mufflers vs a totally stock exhaust. It was done on a 996 C2 and the car made 285HP/295TQ to the wheels with the cat-bypass pipe only. Yes it will loose some low end HP and TQ as you can see in the graph but the gains are great from there on. The Cat-bypass Pipe is designed for track use due to the power loss down low and emissions purposes but you can use it on the street as well. thanks,

Hey Alex thanks for the replies. I am going to have to figure out which route I would like to go. Once tax returns come we'll be in touch! Do you welcome people to the shop? I live in NY so I could just take a ride out to pick up the pipe rather than have it shipped.

Quotes source post: 3098628

Quote: Hey 2300, yes you are always welcome to come to Fabspeed and check it all out and see how its all done. Give me a shout when you want to make the trip and I will have the bypass pipes ready for you when you get here and then give you a tour of the facility. thanks,

Alex when you say 285HP/295TQ to the wheels with just cat bypass only. Meaning with the factory exhaust? Will adding muffler bypass lose/gain any power?

Quotes source post: 3100798

Quote: Hey Nine-Eleven, yes the factory mufflers were on the car. The muffler bypass pipes will make more HP at the mid range to top end but loose HP/TQ down low, due to the loss in backpressure. The car does need some exhaust restriction in order to make power everywhere. thanks,

So it's not bad running cat bypass with stock mufflers then right?

Hello Alex, if I use the bypass x cat, how many hp gain at medium / high? How to lose hp low? Then if I change the ECU, the low return to the original hp or more horses?

Quotes source posts: 3103383, 3103427

Quote: Not at all, its just another way to run the exhaust system and get a different sound. Quote: You will lose some good HP and TQ down low to the mid range and then it will come back up and make a nice Increase. If you do the ECU tune, we can bring the power back up a little to level it out but not too much. if you are looking for overall HP gains, go with the Sport Cat and if you are looking for a nice sound and want power in the mid range and on, but also want to keep the stock mufflers, you can go with the catbypass pipe only. I recommend going with the Sport Cat X Pipe and the Maxflo mufflers for a good HP increase and a nice sporty and deep sound, that you will like. thanks,

Alex, I have the Fabspeed X cat bypass and Fabspeed muffler bypass. So I'm at 285rwhp 295tq. What does it take to bump it up to 300-320rwhp? Talking about all motor bolt ons stuff. I'm going to stick with bolt ons instead of F/I it gets complicated there. What would you suggest? Headers? EVOMS intake? Plenum spacer? Tune? ECU upgrade? Weight reduction? Full exhaust instead of muffler bypass? Thanks!

Your e 'a 3.4? Are 285 hp at the wheel?

PM Sent.