Scooterotica

this explains it quite well ,although there is a bit more to it.

http://www.motorcycle.com/how-to/how-tw ... -3423.html

also ,the width of the straight/belly section is pre determined by the angle and length of the divergant /diffuser cone..which normally would be approx 2.5 times the diameter of the exhaust port.but going to say 2.7 or 2.9 would help spread the power range whilst suppressing max power slightly.
but that may often be to big to physically fit and give good ground clearance etc .
2.2 would equate to approx 110/115mm which most scooter race pipes seem to be

drunkmunkey6969 wrote:

bizzly wrote:.....I ask this question because I have been looking at the Franspeed tour pipe and cant see any difference from the race pipe in the photos......

If you are looking at Andy Francis website, last time I checked (a month or two back) he had the same pic on for both the JL3 and the Franspeed Race. I did tell him....

Yea I was.....thats that sorted then....lol....thought they looked similar

Biz i have a jl3 you can try if u want to loan for a week

Darrell Taylor wrote:Biz i have a jl3 you can try if u want to loan for a week

Cheers for the offer Darrell....I have a Taffy pipe that I was going to try, see what thats like. My other scoot has one on, and It rides really nice at about 65 to 70+, whereas the Race pipe doing the same speed always sounds like its gonna blow....lol...probably cos Im getting an old bugger...lol....The taffy pipe seems to go on forever without any hassle
Is there much difference between the Taffy pipe and a JL3 ?

If it's the "newer" Taffspeed Road Mk IV exhaust, then it's an even better touring exhaust than the JL3, which is a copy of the older Taffspeed Road exhaust. They are built like tanks and will last longer than your engine, real quality. I think the main differences are the Taffspeed Mark IV road exhaust makes even more power lower down than the JL3 and makes better torque. It won't rev as high as the JL3 but can pull pretty tall gear ratios. They are also very quiet with fresh wadding in the silencer. Very little noise comes from the expansion area as the entire exhaust body is double walled mild steel.

GP Kevo wrote:If it's the "newer" Taffspeed Road Mk IV exhaust, then it's an even better touring exhaust than the JL3, which is a copy of the older Taffspeed Road exhaust. They are built like tanks and will last longer than your engine, real quality. I think the main differences are the Taffspeed Mark IV road exhaust makes even more power lower down than the JL3 and makes better torque. It won't rev as high as the JL3 but can pull pretty tall gear ratios. They are also very quiet with fresh wadding in the silencer. Very little noise comes from the expansion area as the entire exhaust body is double walled mild steel.

I think its the older Taffspeed.....how can you tell the difference between the two ?

I stand to be corrected but I think the newer Taffy exhausts have the Fresco type big circlip arrangement in the endcan, whereas the older Taffy Road pipes, like mine, just have the rivets like the JL3 does now.

I think you may be right. Also the later Taffspeed road exhaust had swappable down pipes while I think the earlier (and JL3) do not.

So...is this an old one or a new one ?