INDRA G........cat bypass pipes

[993inNC]

When those "other"pipes don't fit correctly or look right, I'd be happy to make you a set of these for a little more $$

Those are beautiful!

[Bill Verburg]

One still wonders what is happening to exhaust gas flow at the conjunction of the pipes and what effect that junction may be having on pressure waves in the exhaust system.

These are even fire engines which do do benefit from siamesed exhaust like odd fire V8s

[993inNC]

Bill, not really that different from the factory cat which is a collection chamber. These have been on my car (and others) for some time now, have been to the track many times (on my car alone) and have had no adverse effects. In fact as I've explained before they offer more down low punch without suffering on the top end (muffler dependant of course). This all comes down to flow rate and when/where and if there is restriction. There is also no more heat at my collection point than there is at the heatexchanger flange location, so excessive heat build up doesn't seem to be an issue.

Don't knock it, try a set, you won't be disappointed

[Bill Verburg]

yes and no, the collection chamber of a stock 993doesn't have the gas flow directly colliding bank to bank.

In addition subesquent versions(GT3) went to great lengths and expense to separate the flow paths.

It's like the kinematic adjustment which was elimeinated on subsequent versions.


they tried something and found it wanting and then moved on.

I don't even like the way Flowmaster and magnaflow are conjoined.

As I said, I really don't know, just wonder

[993inNC]

I'm not sure it matters considering the exchanger tubes aren't equal length. If the factory was that concerned about exhaust pulse, I would have expected them to create "real" equal length headers.
These motors don't seem to like through, unrestricted flow because it allows for to much valve float, but again, my pipes have been on for a couple thousand miles. The only effect has been a richening of the A/F mix because the secondary O2's aren't registering a siphoned exhaust. Therefor it thinks the motor is running lean and richens the mix. Other than that, they are great! Sound is amazing, wieght is only 11 pounds and they look really cool!

[indra gunawan]

thanks for your offer 993inNC, but i made the cat-bypass already with reference to Fabspeed model.
More over it will be easier to make it here in my country , since i live far away from usa.
Anyway, thank you very much