tune pipe ajustment in or out

[Tantrum]

Hi Their fellas
just a quick question on adjustable tune pipe (Lee Tietze design )on a yamato 302 out of the corners should i lengthen or shorten the pipe
Thanks Darren

[blueskyracer]

After last years post on C Mod all I can say is that folks will tell you that on that design just put the pipe against the header flange and leave it there. Work with props and set up.

[blueskyracer]

Read this thread from last year. It has a lot of info on pipes and a lot of C mod infomation in general http://www.hydroracer.net/forums/sho...threadid=18594

[sam]

In the corner and just out you want the pipe long. On the straight, you want the pipe short.

This is because when the motor rpms are down you want the sound wave to take a longer time bouncing in the pipe because the time that the piston has the exhaust port open is longer when running slower.

The length of the pipe makes the sound wave synch up with the exhaust port open duration.

[Boatracer4fun]

After last years post on C Mod all I can say is that folks will tell you that on that design just put the pipe against the header flange and leave it there. Work with props and set up.

I agree also. After long phone calls inquiring about the same, i was toold by more than one to do as above.

[Sonny]

Dump the pipe when you hear the motor straining into and before the apex of the turn. Use the steam (momentum) generated from the pipe being in to carry the speed through the corner. What makes the corner so critical is that your needs change half way through. The torque coming off the turn is everything. the pipe should be long coming off of the turn. if the motor is finding the pipe and the pipe is finding the prop it will pull like crazy out of the corner...as it stops pulling ..probably about 1/3 of the way down the straight away and you are at full throttle feed the motor the pipe and listen to it. accurate RPM and top speed readings will tell you if the wheel is too big or too small. Hope it helps

[JBM]

In my opinion, the sliding mechanisim failures are not worth the minimal gain, if any.

[Sonny]

a lot of the pro stuff trickles down to influence the mod stuff. the same way that the old Mercury stuff has everyone mixing there fuel wrong. The pipe can be a pain in the ass. You dunk the pipe, trap a little water and blow the candles out and that sucks. Me personally... I cant even imagine racing with out it. The Oxygenated fuels like methanol produce a more significant exhaust signal so they respond more aggressively to the pipe. There is no doubt that the pipe could produce more power. We are giving a little away by sliding it at the header. I am working on a pipe that is fixed at the header and when you pull the pipe it shrinks the canister only. Also trying to play with an Iris that changes the diameter of the stinger at the same time, similar to a jet engine The science behind the pipe has always been intriguing to me and I spend way too much time thinking about it.lol