MWTB: cat bypass pipe
10-11-2011 | 06:56 PM
#17
Rennlist Member
Joined: May 2001
Posts: 9,632
Likes: 543
From: Solana Beach, CA
I haver been down nearly every iteration of muffler for the 993:
B&B muffs and a stock cat,
Factory Motorsound and a stock cat
RSR Mufflers from Robin Sun and a stock cat
Fabspeed Cat Bypass into RSR mufflers
Fabspeed Super Cups and a stock cat, 3 different times,
FD Motorsports Stage III and a stock cat
FD Motorsports Stage I, Fabspeed X pipe and Fabspeed 200 cell cats
Fabspeed Super cups, X pipes, and Fabspeed 200 cell cats.***
If you want to set off alarms in parking garages and impress Junior High school kids, the Super Cups with Cat Bypass pipes are the ticket, nice and loud...
What I found to be the best sound combo for me was the Fabspeed X pipes with 200 cell cats connected to FD Motorsports Stage I mufflers (The quietest ones). At Laguna Seca, I passed 92 dB sound the first time I went there. The next time I flunked and had to install diversion pipes as well as adding duct tape to the intake grill. That got me to 91.2 dB, a passing grade.
I have a AVI clip I can send to an e-mail address. the AVI format will not work on this message Board.
For situations where I need stealth such as Laguna Seca, I have gone back to factory mufflers refurbished by FD Motorsports hooked into my Fabspeed X pipes and 200 cell cats. Failing sound at Laguna Seca quickly becomes a big hassle and can get you sent home.
*** In unlimited sound situations, I replace the stock mufflers with Fabspeed Super Cups. I am just hooking this set up tomorrow. I imagine it will be incredibly loud. I can live with it as the car is 99% track, 1% street. The Super Cups are a little lighter than stock muffs.
__________
B&B muffs and a stock cat,
Factory Motorsound and a stock cat
RSR Mufflers from Robin Sun and a stock cat
Fabspeed Cat Bypass into RSR mufflers
Fabspeed Super Cups and a stock cat, 3 different times,
FD Motorsports Stage III and a stock cat
FD Motorsports Stage I, Fabspeed X pipe and Fabspeed 200 cell cats
Fabspeed Super cups, X pipes, and Fabspeed 200 cell cats.***
If you want to set off alarms in parking garages and impress Junior High school kids, the Super Cups with Cat Bypass pipes are the ticket, nice and loud...
What I found to be the best sound combo for me was the Fabspeed X pipes with 200 cell cats connected to FD Motorsports Stage I mufflers (The quietest ones). At Laguna Seca, I passed 92 dB sound the first time I went there. The next time I flunked and had to install diversion pipes as well as adding duct tape to the intake grill. That got me to 91.2 dB, a passing grade.
I have a AVI clip I can send to an e-mail address. the AVI format will not work on this message Board.
For situations where I need stealth such as Laguna Seca, I have gone back to factory mufflers refurbished by FD Motorsports hooked into my Fabspeed X pipes and 200 cell cats. Failing sound at Laguna Seca quickly becomes a big hassle and can get you sent home.
*** In unlimited sound situations, I replace the stock mufflers with Fabspeed Super Cups. I am just hooking this set up tomorrow. I imagine it will be incredibly loud. I can live with it as the car is 99% track, 1% street. The Super Cups are a little lighter than stock muffs.
__________
So I saw a thread about a cat bypass pipe in the 964 Forum, but I was wondering what the pricing would be for a 993 one new/used, and if anyone here has one to sell.
What is required to remove the cat? I've never done any exhaust work, but we have a floor lift (the one that looks like an X) so I could lift the car pretty high in the air
I did my emissions test back in February, how often do I need to smog the car in CA?
Also, how much louder would it make the car, I want it to be loud during acceleration, but relatively quiet going through the neighborhood.
Sorry for all the questions, but just trying to be informed before my decision
What is required to remove the cat? I've never done any exhaust work, but we have a floor lift (the one that looks like an X) so I could lift the car pretty high in the air
I did my emissions test back in February, how often do I need to smog the car in CA?
Also, how much louder would it make the car, I want it to be loud during acceleration, but relatively quiet going through the neighborhood.
Sorry for all the questions, but just trying to be informed before my decision
10-13-2011 | 09:02 PM
#20
Burning Brakes
Joined: Jul 2009
Posts: 1,064
Likes: 3
From: Vista, CA
Martin S and Harvey,
You are both running X-pipes in your cars. Have you done any dyno research with that?
I made a set of X-pipes for mine but I wasn't happy with them (resonated like crazy at 2500-3000RPM) and moved to an H-pipe style setup.
I know that Bill is an advocate of separating the exhaust banks completely but does anyone have dyno evidence to prove either theory (x-pipe VS seperate)
I am in the process of building another system and I am trying to decide whether to keep the H-Pipe (mostly to get O2 readings from both banks) or to go with completely separated banks and stick the O2 sensor in just one side.
Bosch's 993, sorry to run so off-topic
You are both running X-pipes in your cars. Have you done any dyno research with that?
I made a set of X-pipes for mine but I wasn't happy with them (resonated like crazy at 2500-3000RPM) and moved to an H-pipe style setup.
I know that Bill is an advocate of separating the exhaust banks completely but does anyone have dyno evidence to prove either theory (x-pipe VS seperate)
I am in the process of building another system and I am trying to decide whether to keep the H-Pipe (mostly to get O2 readings from both banks) or to go with completely separated banks and stick the O2 sensor in just one side.
Bosch's 993, sorry to run so off-topic
10-13-2011 | 09:30 PM
#21
Rennlist Member
Joined: May 2001
Posts: 9,632
Likes: 543
From: Solana Beach, CA
I have just installed Fabspeed Supercups to match up to my Fabspeed X pipes and 200 cell cats. The sound is awesome and very loud. Note this is a track set up. NOT for the street.
I will put it on the dyno tomorrow.
About 6 months ago, with the X pipe, 200 cell cats and a FD Motorsports Stage I muffler, the car made 245 to the rear wheels....but note I only took in to 6,200 RPM. This time we are going to Red Line...hope it doesn't blow!!!!
The car has been on a diet. I have been able to get it to 2,937 almost dry, a wee bit of gas an no driver. I have to make 3,204...add in gas and a driver + driver suit, cool shirt cooler, helmet, shoes....I'll make weight with some Lbs. to spare.
I will put it on the dyno tomorrow.
About 6 months ago, with the X pipe, 200 cell cats and a FD Motorsports Stage I muffler, the car made 245 to the rear wheels....but note I only took in to 6,200 RPM. This time we are going to Red Line...hope it doesn't blow!!!!
The car has been on a diet. I have been able to get it to 2,937 almost dry, a wee bit of gas an no driver. I have to make 3,204...add in gas and a driver + driver suit, cool shirt cooler, helmet, shoes....I'll make weight with some Lbs. to spare.
10-14-2011 | 09:58 PM
#22
Thread Starter
Instructor
Joined: Dec 2010
Posts: 134
Likes: 0
Martin S and Harvey,
You are both running X-pipes in your cars. Have you done any dyno research with that?
I made a set of X-pipes for mine but I wasn't happy with them (resonated like crazy at 2500-3000RPM) and moved to an H-pipe style setup.
I know that Bill is an advocate of separating the exhaust banks completely but does anyone have dyno evidence to prove either theory (x-pipe VS seperate)
I am in the process of building another system and I am trying to decide whether to keep the H-Pipe (mostly to get O2 readings from both banks) or to go with completely separated banks and stick the O2 sensor in just one side.
Bosch's 993, sorry to run so off-topic
You are both running X-pipes in your cars. Have you done any dyno research with that?
I made a set of X-pipes for mine but I wasn't happy with them (resonated like crazy at 2500-3000RPM) and moved to an H-pipe style setup.
I know that Bill is an advocate of separating the exhaust banks completely but does anyone have dyno evidence to prove either theory (x-pipe VS seperate)
I am in the process of building another system and I am trying to decide whether to keep the H-Pipe (mostly to get O2 readings from both banks) or to go with completely separated banks and stick the O2 sensor in just one side.
Bosch's 993, sorry to run so off-topic
Thanks for the feedback everyone, do any of you guys who have ran multiple set ups have an extra set of fisters for sale?
