2.5" ? Gay.

I don't see all the need to do this. If it is for a track, just bolt a flanged straight pipe in (test pipe if you browse american forums). Have you normal cat flanged and bolt in when off the track.

If you think this is so you don't get defected or some crap, you can smell the difference between a straight pipe and a catted pipe. Also, if we get crap like over east, they just put a probe on your exhaust to measure emissions... Looks don't come into it.

Only reason for straight pipes is flames. For a street car, you can get a high flow cat which will perform within a bee's dick of a straight pipe.

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]