Scooterotica

Despite the array of expansion pipes on the market, I have never seen one advertised with details of it's tuned length.

As the first thing you need to calculate when building an exhaust is the tuned length, why do none of the manufacturers quote their own tuned length?

If we knew the tuned lengths of the exhausts on offer, it would be easier to decide on which pipes might be best for your tune.

With the cheapy clubmans I buy, wouldn't make much difference really I would have thought :baddevil: :baddevil:

I remember asking Dave Webster what was the tuned length of one of his pipes I bought in the 80's. I got no answer

I think its even more strange that dealers/manufacturers dont advertise the port timings that the pipes were designed for in the first place?

I think its such a complicated subject, that the best most scooter riders could hope for is to find out at what RPM a production pipe produces peak power at and match your port timings to suit......after that is starts to get a bit demanding.......

The exhaust length, cone angles, and exhaust volume variables are extensive...practically every production pipe out there is an average assumption made to work across a broad range of engine variables and performance conditions.

Only when you whittle and engine down to its narrowest and finest of details, can you fabricate an exhaust of similar stature to match....and that is then destined to produce peak power within a desired power and RPM range, in a specific manner, for a specific purpose............outside of that, it has to be an average, and the thousands of scooter riders and hundreds of engine builders that want more 'performance' will be restricted in their search, by the result of their findings.

i think its fair to assume that taffy pipes for Eg were made to suit their tunes,likewise for DJ pipes...etc...most other after market pipes are made to suit a whole range of set ups and are so just a compromise...some higher/lower revvy ...some more suited to race ..others to touring...
MB pipes ,suit MB tunes..
more info would be good as per tuned lengths ,but that isnt really the whole story anyways ...

Forget 'duration' what about time/area..
Why dont someone try to find out what a pipe maker was thinking when the made a pipe? Call em up and ask. I bet most in our scooter world cant give you an answer Ask them where the torque will start and finish for example on a standard Ts1.
Then call Adspeed... he'll give you an answer .. he knew what he was doing and what he was trying to achieve.

i think you will get a very comprehensive answer from simon at b race too

This was a post on a recent thread re the ADS range of exhausts....a basic look at it but all anybody needs really.

http://scooterotica.org/forum/viewtopic.php?f=7&t=11771

The current Rally pipe peaks between 6.5-7k and tops out about 7-7.5k dependent on tune.

The up coming Fast(er) Road pipe will peak between 7.5-8k and top out about 8-8.5k dependent on tune......thats on paper testing to start soon.

The Race is a bit further again, peaking 8-9k and topping out 9k+.

So hopefully three pipes to cover all tastes.

Hopefully before long have all three on a TS and a simple graph to show the results from the three different pipes.........

so out of curiosity adspeed, can you answer knowledge's question? im not setting you up to explain the meaning of life but just interested to see what info you can give and how knowledge would use it.