Exhaust Fab Question

[bealsey]

Hello I am going to fabricate my own exhausts, i was just wondering if you could keep both exhaust systems completely seperate instead of linking the pipes together? Each cylinder will have its own system and silencer then!

[Zakalwe]

Hello I am going to fabricate my own exhausts, i was just wondering if you could keep both exhaust systems completely seperate instead of linking the pipes together? Each cylinder will have its own system and silencer then!

I think (but I aint no expert) that the reason that they are linked is that the pressure pulses from one side either help to scavenge the gases from the other side, or are timed to prevent the cylinder charge from escaping down the exhaust.

[sirch345]

I think (but I aint no expert) that the reason that they are linked is that the pressure pulses from one side either help to scavenge the gases from the other side, or are timed to prevent the cylinder charge from escaping down the exhaust.

I'm inclined to agree with Steve (Zakalwe) and you could end up with less BHP going down that route.

Although after saying that I think I'm right in saying that some after market full exhaust systems do run separate exhaust headers, but to help with the scavenge make their headers tapered. It appears you need a certain amount of back pressure (although it may not be a lot) to get the best from the big V twin.

If you look into the header joint where the righthand side (rear brake lever side) link pipe connects, you will see some restriction there. It's not a bad design where someone couldn't be bothered to remove it before welding it up, but helps with back pressure, as some have found out when they've removed theirs.

Chris.

[Zakalwe]

Pretty much every performance V-Twin that i can think off has the headers joined, even when employing twin end cans. Think Ducato, Aprillia, KTM. There must be a sound reason for this. Even racing twins have linked headers, and go to some lengths to achieve the same header lengths (ever see the price on a titanium Ducati racing zorst??? Think upwards of £1800 ).

In fact the only V-twins that I can think of that doesn't have a linked header are Hardley-Ablesons. In my book that's a good enough reason to steer clear!

[bealsey]

Cheers that is exactly what i thought, i will just have to make the exhaust the hard way!