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fred43
12-01-2010, 7:59 AM
So i'm thinking about switching pipes 86 sporty and can't decide on upswept or 2-1. I need some opinions. what are the performance differences between a long exhaust pipe and a 2-1?

cntrhub
12-01-2010, 8:35 AM
Long individual pipes on their own probably are no different than a slight smoothing advantage are the tied-in pipes.

See, the tied-in bike helps the pulse sort of smooth out. The mid-connect has the breathing effect where that slight connect farther up the chain has less time to reverse direction farther away at the end of the pipe.

So, there you have this over-lap of the valves [both being open] and that pull at the connection or tie-inn has that quicker ability to lend a hand to some reversion more at a shorter distance and that abrupt pulse traveling so far has now a short distance and that smoothing effect sets the more quicker opposite pulse; it more has a smoother running pulse is all [tied in].

You WOT both pipes on the dyno, you'll probably see a little added grunt down below being that speed event at the mid-pipe. Other than that, I would guess at WOT, you might have close to the same HP curve at the top... Being the pipes are muffled the same, meaning, no extra packing to slow the flow.

jwhite
12-01-2010, 10:32 AM
I cannot speak from experience as far as the 2 into 1's go, but everyone I know how runs them claims a performance boost. My buddy who's had extensive motor work done to his 883 - hopped up to 1200 with cams, etc - his runs like a raped ape.

I went from straight drags to upsweeps and noticed it ran a hell of a lot better. Then I cut them down into short shotguns and noticed a considerable drop in performance and ran like shit until I got my carb idle mixture readjusted and dialed in.

That's my .02 for what it's worth.

fred43
12-02-2010, 8:16 AM
Thanks for the help guys