I am looking at getting some GHL Headers on my
91 C2Turbo. Along with the headers I am looking
at either placing a muffler by-pass pipe or
placing a performance muffler. IN both cases I
am leaving the Cat. I would appreciate any info
on this, ie..is the muffler by-pass "too" loud,
does it make our Porsche cars sound like an
American V8. thanks, Tom

 

I am planning to do the muffler bypass.
Have been told the sound is just right and not to loud.

I will remove the muffler and start the engine to hear for myself before ordering that elbow joint, shouldn't be more than a few minutes work.

Good luck
Staffan

 

i have a ghl bypass on my 3.6 turbo and the sound is not to loud its just right ( maybe a little to quite )... my friend has all the same mods on his 3.6 turbo and has a performance muffler... the sound is in a way louder or more resonated... its just a matter of prefference or $$$, the bypass is more cost effective and saves 30lbs of weight. <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

 

I have the bypass, Simple,light and sounds perfect. I don't think I would go with a muffler.

91 C2 Turbo

 

I have had a muffler bypass on my 91 c2t since I bought it in Jan 2001. I have recently replaced this bypass and the tips with Fabspeed equipment. Very nice. I have also just replaced the cat with Joe's cat bypass. The car is loud but not too load for me (removing the cat made it much loader than with the muffler bypass). The cat bypass makes quite a bit of (subjective) difference to the performance. The workmanship of the Fabspeed pieces is first class.

 

On 965 C2 Turbos sound and power levels after the turbocharger are in 4 versions.
#1 stock cat and stock muffler-quietest version with most weight and the least power
#2 stock catalytic converter installed with 2ndary muffler bypass pipe (replaced stock muffler behind passenegers car RR tire)- power gain and sportscar sound.
#3 Catbypass pipe and KEEP stock 2ndary muffler on the C2 Turbo. ABSOLUTE most power available and not too loud sportscar sound. Quieter than version #2 above. This is the very best and smartest value for maximum power for all C2 Turbos and works with all aftermarket headers systems. Headers are an independent decision vis a vis final exhaust after the turbo.
#4 B&B/GHL?/ Mille Miglia muffler bolted directly to the turbo. This method is the loudest BUT not as efficient in terms of power as a catbypass pipe. Also over time all muffler BOLTED DIRECTLY to the Turbo (3-4"s away) will get destroyed and get superloud over time especially if you goto the racetrack.
The answer if you want maximum power and quality sportscar sound and no resonnace and the best value for your money--all you need is a catbypass pipe for any & all C2 Turbos!Performance for the next millenium

 

There's another option which is, as I said, to do the cat bypass and the muffler bypass. The picture in the prior post shows the Fabspeed cat bypass. Both myself and my Porsche technician were very impressed with the quality and fit of this piece.

Usual disclaimer, just a happy customer. YMMV.

 

[quote]Originally posted by 993 RS Clubsport:
#4 B&B/GHL?/ Mille Miglia muffler bolted directly to the turbo. This method is the loudest BUT not as efficient in terms of power as a catbypass pipe. Also over time all muffler BOLTED DIRECTLY to the Turbo (3-4"s away) will get destroyed and get superloud over time especially if you goto the racetrack.
The answer if you want maximum power and quality sportscar sound and no resonnace and the best value for your money--all you need is a catbypass pipe for any & all C2 Turbos!Performance for the next millenium[/QB]<hr></blockquote>

No offense but this is nonsense. Do turbo charged racecars (look at any 935 engine diagram or photo) run cat bypass pipes or direct of off the turbo's? You will get more power running direct off of the turbo than off of a cat bypass pipe through the stock muffler or any other muffler for that matter. My 964 Turbo S with a B&B muffler running direct of the turbo is quieter than my 993 with - guess who's - exhaust.

 

Hi Mark

no arguing...you have a beautiful rare car!
HERE IS UNDENIABLE 100% PROOF on why a catbypass pipe makes the most power without being too loud on C2 Turbos&gt;

Regardless of what type of headers a C2 Turbo owner has installed on his/her car- stock or aftermarket or stock ........ The absolute best sportscar sound and MAXIMUM POWER without being too loud for ALL C2 TURBOS (965 TURBOS from 1991-1994 including the "S") is simply installing a catbypass pipe that dumps into the STOCK Porsche C2 Turbo 2ndary muffler. You simply install a catbypass pipe and then reinstall the original equipment muffler supplied new on each & every C2 Turbo ever manufactured to have the most power possible on these wonderful C2 Turbos.

HERE IS why a quality T304SS catbypass pipe used in conjunction with the stock muffler makes the most horsepower, is the best value, never EVER breaks and isnt too loud.

1st) In terms of power the Fabspeed C2 Turbo catbypass pipe used with the stock C2 Turbo 2ndary muffler has the least amount of backpressure as you ACTUALLY can roll a golfball "from the turbo right out the back of the car".

The 2ndary Porcshe stock muffler is just a straight perforated tube that is straight thru....truly performance designed. Fabspeed has completely cut the stock C2 turbo muffler open to verify this.

You can ALSO prove this to yourself by "getting a golf ball or ping pongball and drop it in one side and it will roll out the other side!!!!"

YOU cant do this with any of the following exhaust systems that are mounted after the turbo: the stock catalytic converter, B&B fabrications muffler, GHL 965 muffler, MIlle Miglia.....they all have baffles and chambers. Turbo cars dont want nor do they need backpressure.

Therefore with a Fabspeed catbypass pipe on a C2 Turbo the exhaust has an unrestricted flow path out of the Turbocharger and thru the catbypass pipe and then straight thru the 2ndary stock muffler right out of the right side exhaust tip.

Instant boost, more power, great value and the 100% most beautiful thing is that its not too loud and its NEVER EVER BREAKS NO MATTER how hard you drive on the street or on the racetrack.

If you want the systems even louder then a 2ndary muffler bypass pipe can be bolted directly to the catbypass pipe......this is the exact exhaust system used on the "FACTORY racecar that ANDIAL PREPARED for BRUMOS RACING. C2 TURBOS" THAT DOMINATED and RULED the COMPETITION IN THE SCCA BRIDGESTONE SUPERCAR CHALLENGE until the series ended.

Fabspeed Motorsport makes the finest C2 Turbo catbypass pipe in super polished T304SS and we include all the proper hangars or clips for the stock Porsche sheetmetal heating system and the AIR injection port is located in the correct position. Its fit and works great and ..........best of all its super easy to install and "REMOVE & REINSTALL' to get your car inspected every 2 years where ever you live.

check it online at our website. Have a great day.
<a href="http://www.fabspeed.com" target="_blank">Performance for the next millenium</a> <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

RS -
&lt;p&gt;
Who do you work for? Joe?
&lt;p&gt;
The next time I take the B&B muffler off I will try to roll a golf ball through it. Maybe you're right and I'll have to use a marble. But then by your arguement all I need to do is have the baffles in the B&B cut out and then I would have equal or better power than the Fabspeed bypass with the stock muffler. Food for thought!
&lt;p&gt;
I will tell you that any racing turbo's I've ever seen have the exhaust (admittedly w/ no baffles) running directly off of the turbo.

 

[quote]Originally posted by Mark S.:
<strong>RS -
&lt;p&gt;
Who do you work for? Joe?
&lt;p&gt;
The next time I take the B&B muffler off I will try to roll a golf ball through it. Maybe you're right and I'll have to use a marble. But then by your arguement all I need to do is have the baffles in the B&B cut out and then I would have equal or better power than the Fabspeed bypass with the stock muffler. Food for thought!
&lt;p&gt;
I will tell you that any racing turbo's I've ever seen have the exhaust (admittedly w/ no baffles) running directly off of the turbo.</strong><hr></blockquote>

 

Mark,

Don't bother...I was so intrigued by the discussion of these two potential configurations because I am running a cat bypass with a B&B muffler on my '91 C2T, that I decided to dig out my stock 2ndary muffler collecting dust in the garage. Here's the deal...I actually was foolish enough to begin believing that this muffler would be less restritive than the B&B...so I tried to pass a marble thru it!! NO WAY!! If 993 RS Clubsport is talking about the huge stock muffler that locates next to the right rear wheel then there is no way he's correct. The inlet and outlet are on the same side of the muffler and there was no way I could get a tiny marble to pass thru this thing no matter how much I tried. There is one thing that he is correct about..the B&B muffler has cracked but this is because it is a big piece of junk!! It has split at the seams about six times and has needed to be TIG welded. But, I believe that the explanantion for this is just that it is a terribly designed piece. In confirmation of this both a local Porsche performance shop has told me that every B&B he has encountered splits the same way. Also, a friend who is a member of the local BMWCCA chapter has said that EVERY ONE of the M3 owners that have used B&B exhaust parts on their cars have had problems with them cracking. He said that it is a standing joke of legendary proportion with the BMW club memebers.

 

Hi Mark S,

993 RS Clubsport IS "Joe". I guess you are not familiar with 993 and 996 message boards. He is on there all the time with the same kind of messages posted above....

I've had the primary muffler bypass on my C2 Turbo for over 6 months now and I love it. I love the sound. I love the throttle response and it it not too loud with cruising on the freeway.

Unless you want something louder than the bypass J pipe, why would you willing to paid a bunch of money for an aftermarket muffler.

Best regards,

Sonny Vo
ps: The J pipe can be had for a lot cheaper than a few vendors out there want you to believe.

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

Try rolling a Golf Ball through the C2 Turbo stock muffler....a marble is too small.

Ill post a picture of a C2Turbo muffler cut open..... as soon as I finish the 930 systems were are working on for the early cars.

Have a great day.
joe