Exhaust size question

[gnxtc2]

Is a 4" exhaust system legal? or does it have to be 3.5"? I read the rules it says 3.5" measured 4" from the flange. What flange? where the cat "used" to be or the the turbo exhaust housing flange? I know the DP is 3.5".

Here is the excerpt:

• Any single or dual exhaust system allowed. Must muffle and exit in stock location. 3.5" max size, including downpipe - measured 4.0" from the flange. Downpipe must be routed down through the stock location, no flex pipe allowed.

Billy T.
gnxtc2@aol.com

[Scott231]

Is a 4" exhaust system legal? or does it have to be 3.5"? I read the rules it says 3.5" measured 4" from the flange. What flange? where the cat "used" to be or the the turbo exhaust housing flange? I know the DP is 3.5".

Here is the excerpt:

• Any single or dual exhaust system allowed. Must muffle and exit in stock location. 3.5" max size, including downpipe - measured 4.0" from the flange. Downpipe must be routed down through the stock location, no flex pipe allowed.

Billy T.
gnxtc2@aol.com
One of us needs to brush up on our grammar skills...When discussing the Exhuast System you are limited to 3.5" maximum diameter pipes and single or dual systems can be used. As such, you can run a maximum of a dual 3.5" system.

The downpipe is also limited to 3.5" maximum diameter with one alowance --To measure the downpipe diameter, you first move 4.0" downstream from the turbo flange and then the pipe must be no larger than 3.5inches in order to be legal for the TSM Point Series. The racers did agree to allow you to run any size downpipe at the Bowling Green (and BG Only) race this year.

So some smart cookie will probably show up with a custom made dual 3.5" exhaust system and a 6" downpipe...and just might go a little faster as there will be very little backpressure.

[gnxtc2]

One of us needs to brush up on our grammar skills...When discussing the Exhuast System you are limited to 3.5" maximum diameter pipes and single or dual systems can be used. As such, you can run a maximum of a dual 3.5" system.

The downpipe is also limited to 3.5" maximum diameter with one alowance --To measure the downpipe diameter, you first move 4.0" downstream from the turbo flange and then the pipe must be no larger than 3.5inches in order to be legal for the TSM Point Series. The racers did agree to allow you to run any size downpipe at the Bowling Green (and BG Only) race this year.

So some smart cookie will probably show up with a custom made dual 3.5" exhaust system and a 6" downpipe...and just might go a little faster as there will be very little backpressure.

Maybe one of us could learn how to spell....allowance:owned:

So what your telling me, I could run a 4" exhaust and still run TSM but not for the TSM points series.

Billy T.
gnxtc2@aol.com

[Scott231]

Maybe one of us could learn how to spell....allowance:owned:

So what your telling me, I could run a 4" exhaust and still run TSM but not for the TSM points series.

Billy T.
gnxtc2@aol.com
No, the GS CA rules also limit you to 3.5" max diameter exhaust systems.