WHICH SPORTS EXHAUST ?

[Guest]

my superdooper stainless exhaust and silencer bypass pipe have been flattened beyond repair.I want to replace with a stainless steel item without jeapordising power.Please note this car has been dyno tested at 251 runs superchip,stage1 cam,polished heads and now a trashed exhaust.ANY SUGGESTIONS WELCOME.THANKS IN ANTISIPATION,chris[8|]ps I am a member but why does it say i am not?

 

[carreracat]

There is a post in the general discussion forum about the non member thing which should see you straight courtesy of Mark Bennet. http://www.porscheclubgbforum.com/tm.asp?m=70284
As for the exhaust, I've just had a Cargraphic back box and bypass fitted. Not sure on how it would effect the performance of your machine, but it looks and sounds great and the car certainly seems quicker lower down the revs.

 

[Guest]

Why not get the same as what you had pre-flattening?

I like the SSIs and early style 2-in mufflers but that means a whole new exhaust rather than just a pre-muff and final muffler.

Essential Styling made up a nice custom 1-in 1-out muffler for a race client that looks fairly stock but is really just straight thru on the inside. Pics are posted on this board if you search. You may have to call Simon if its not on the website. I also recommend (on the basis of the experience of many on Pelican BBS) that people use a std shape pre-muff rather than a bypass pipe in order to keep the full compliment of midrange torque. The standard pre-muff design is not at all restricting but the perforated expansion chamber type design seems to suit 3.2s very well. There is no benefit in going to the by-pass pipe.

RB

 

[Guest]

This is an example of what I was thinking re the pre-muff:

"very little can be gained by disconnecting stuff from a motor
from how Porsche made it. BUT, that said, what else are you going to do to
the engine? The engine is designed to like a bit of back pressure - helps
with mid rev torque with valve over lap. Not enough back pressure and a
goodly amount of intake charge remains out of reach when the piston starts
its down stroke and the exhaust valve shuts too soon. However, if you
richen up the mixture, this will (read - may) be negated. However, the
sound will be a nice throaty sound."

So without the right mapping, a "sports" exhaust is often buying you no more than sound and perhaps less torque into the bargain. This lack of mid range torque makes it feel like there is more top end horsepower. Sad but true.

 

[carreracat]

Hi Shirish,

The exhaust looks great (will post pictures eventually!) and the sound is wonderful. My new hobby is driving around with the windows open in all weathers!
Hard to say what effect it's had performance wise because I had to get a lot of other work done (it turned out to be a litle bit more costly than my normal annual service!) so the car is now a lot closer to what it should have been in the first place.
Before the work I didn't get a lot of power below 4000rpm but this has improved a lot and there's a good pull from about 2500rpm onwards, although the best noise still comes after 4000rpm!