what size exhuast piping?

Q&A regarding engines, turbos, and intercoolers and power upgrades

Postby Conrad_Turbo » Tue Oct 19, 2004 3:57 pm

Well going from a 2.25" stock system to a 2.5" system your exhaust gas velocity is going to be 25% slower as the pipe cross sectional area will be 25% larger. Going with a 3" pipe you will be getting 75% slower velocity and thus a 75% increase in cross sectional area as compared to the stock exhaust.

So if you are putting down 75% (rough guideline) more Hp than stock then go with the 3" exhaust, but if you aren't I'd go with a 2.5" as a 3" diameter exhaust has a greater surface area. More surface area means there is more heat transfer and your exhaust will become more dense and prone to more turbulance (and backpressure). Also denser exhaust will cause more backpressure on the system when it goes through the muffler.

Note: % were rounded down to nice even numbers. :)
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Postby alltracman78 » Tue Oct 19, 2004 4:05 pm

Never thought of it that way...
Good info.
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Postby Cormudgen » Wed Oct 20, 2004 2:00 am

I think for now I'm going to try and take the cheap way our and wrap the part that is hitting with exhuast wrap. I hope that I may be able to get some free firehouse hose.

Anyone have any other suggestios for cheap heatwrap?

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Postby alltracman78 » Wed Oct 20, 2004 2:10 am

Might have something at Lowes, or almost any auto parts store. You shouldn't need much.
You could also try coating what ever the ex is hitting with some kind of rubberized undercoat [Nothing flammible though].
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Postby BraveUlysses » Wed Oct 20, 2004 2:30 am

alltracman78 wrote:Might have something at Lowes

We don't have anything like this at Lowe's.

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Postby 91redst185 » Sun Oct 24, 2004 11:49 pm

this is a little off the topic but does anyone know where there are blueprints for the ST185 exhaust
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