Another Baffling Question....

[DocDirk]

Using an exhaust diameter calculator the rough ID allowing my engine to breathe fully is 2.8", with 2.5" being an 80% capacity second place. I like the looks of my sidepipes and would like to use them, but haven't yet found anything of 2.75" ID.... I'll call around to see if anyone would make that... I'm wondering if filling the remaining 1/4" surrounding space with fibreglass would make any sound muffling impact. I've driven the car with open sidepipes and it's a gas, but whoa...too loud for me!

Can't have my cake and eat it too....but maybe have half my cake and eat the other half lol

Dirk

[Balance_Point]

Originally Posted by DocDirk

Using an exhaust diameter calculator the rough ID allowing my engine to breathe fully is 2.8", with 2.5" being an 80% capacity second place.
Dirk

I am unfamiliar with this calculator. Is this some kind of minimum flow # that it generates based off of cid and ve?

[DocDirk]

I'm unsure how such a calculator as this would take into account unknown engine variables, but such as it is.... here it is. Any constructive feedback would be appreciated. My engine is a BB 533 with 650FWHP, 2" headers, Trickflow heads, ported, Vic Jr. Intake, Demon 850 annular carb. I don't have the cam specs at hand.

http://www.mk5cortinaestate.co.uk/calculator5.php

Sure would be nice to make more than gobbledygook out of the mess of information in my head atm re exhaust lol

Dirk

[CHANMADD]

I have run different ID's over the years and stuck with a 3" ID and a 4" OD on the muffler. I used glasspack mufflers and welded up the sidepipes with chrome turnouts. It might not be the best looking pipes but they sound awesome and perform great. The bigger the ID the lower the exhaust tone, and the the smaller ID will give a higher note.On your size motor I would'nt go smaller than 3"ID