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Accelerating From engines to gearboxes--tuning the parts that make your car go.

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  #1  
Old 07-09-2010, 09:58 PM
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Default Exhaust tip diameter dynamics?

What role does the exhaust tip shape, diameter, and length play in things like performance, back pressure, and noise?

The reason I ask is because every clubman exhaust comes with a giant 3"-4" exhaust tip and I have a strong distaste for giant exhaust tips. Would there be a downside to hacking them off and installing a smaller diameter tip?

The exhaust in question runs 2.25" pipes throughout, but then turns into a 4" tip.

Should the tip be equal to or larger than 2.25" or could you go a little smaller like 2"?
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Old 07-09-2010, 10:34 PM
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Do it, they're just for the looks. I don't think I'd go smaller than the actual exhaust but you certainly could without too much effect.
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Old 07-10-2010, 03:53 AM
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i was sort of wondering the same. Ive got 3" single wall straight cuts now, and was wondering if i did some sort of double wall, if it'd quiet it a little???

Wish they made some of those silencers in 3"
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Old 07-10-2010, 04:53 AM
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Rally, as long as it is not smaller than the previous diamiter (you said 2.25) then no adverse performace issues will arise. although the last 12 to 4 inches really shape how a car sounds. anything smaller that 2.25 and you start to run into pressure changes, these can sometimes SERIOUSLY affect a cars performance.

recomendation: do anything but put a smaller tip on
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Old 07-10-2010, 05:24 AM
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Nowadays, exhaust tips typically do nada - just an outlet to point fumes in a particular direction.

Days past it was more common to find packed tips (resonator tipss), and with those the diameter effected the tone ever so slightly. Essentially smaller tips helped make a sharper bark and a bigger tip would give a more mellow tone. Pacesetter is one of the few aftermarket makers around that still offers decent resonator tips.

That aside, like FG notes, just go with a tip that is equal to or larger than the exhaust pipe for best results.
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Old 07-10-2010, 07:25 AM
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Here is my new exhaust

4.5" Tip
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Old 07-14-2010, 12:22 AM
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so long as you dont go any smaller than the diameter of the exhaust itself ur fine
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