TunedFlow

Can someone please explain to me the different dynamics of a tuned pipe? I fully understand the concept of back pressusre and pipe length and such but I don't fully grasp the differences in pipe composition. So can someone please tell me the differences or properties of a one piece pipe, dual and three chamber and the ringed rib pipe?

armedtotheteeth

I pretty much go by looks on my car [:'(] but I'm a hobby 1:1 scale mechanic, with quite a bit of knowlegde about cars. Backpressure is basically what differenciates one pipe from the next. Backpressure is the force your engine has to produce to push the exhaust gasses out of its ports. On a 4-stroke or rotary engine this is much more significant, because it is actually one of the driving forces that continually turns the camshafts. On a two stroke engine however, it is not as crucial because, obviously, the exhaust is pushed out on the stroke that also compresses the fuel/air mixture. This is why 2 strokes run dirtier and hotter than a four stroke, and why the oil has to be mixed with fuel. Different pipes offer different backpressure, so different performance occurs, and different tuning is required. On a pipe with a lot of backpressure, like a 2 or 3 chamber pipe, you are going to have more bottom end torque as a result of higher compression rates and healthy temperatures. On a pipe with little or no backpressure, you will have signifantly less bottom end but a faster and smoother top end, because the extreme amounts of exhaust the enginge puts out at high rpms will not be restricted.
If you have already put a few tanks of fuel through your engine and plan on switching to an aftermarket pipe, retuning the carb is nesecary. You should basically do what you did when you broke it in, just start rich and work from there. This is why most knowledgeable sources will tell you to break in your engine with the pipe you plan to use.

Hope that helped at least a little.

RcSuCkA

check that out

http://rcnitro.com/rn/articles/tuned.asp

TunedFlow

Thanks a lot that cleared up a lot for me.