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White Lightning
13-04-2007, 03:30 PM
Well, I need to get my finger out and get my downpipes sorted. Can anyone confirm for sure what the bore of the standard downpipes is? Both from turbos to the joint and from the joint to the cat?

Also, any thoughts on what would be the best size to go for if I get a custom solution made with my 2 1/2" cat back system. I know the standard cat is 2 1/4" but that will be replaced at some point with a sports cat or decat ...

Axeboy
13-04-2007, 06:06 PM
Im sure its 2 1.4" from the two turbos...

White Lightning
13-04-2007, 07:41 PM
Im sure its 2 1.4" from the two turbos...

So two lots of 2 1/4" go into one 2 1/4" . That seems like a silly design :thinking:

bradc
13-04-2007, 08:49 PM
I thought it was 2x 2" going into 1x 2.25", I might be wrong though.

White Lightning
13-04-2007, 10:40 PM
I thought it was 2x 2" going into 1x 2.25", I might be wrong though.

That would definately make more sense Brad.

bradc
14-04-2007, 05:32 AM
Well not really because the area of 2x 2" pipes is a lot larger than 1x 2.25" pipe which is what the rest of the exhaust system is.

2" = 3.14sq inch area
2.25" = 3.976
2.5" = 4.909
3" = 7.07