Exhaust and frame questions

[TwoHundredEx]

First off, these questions are related to my 2 stroke X project. The first one is, since I need to modify the stock bike pipe to fit the 200X, the area of the pipe that goes from the beginning of the expansion chamber to the head, is a certain length for a reason right?
Basically, if I shorten it, or lengthen it, it will perform differently right?

Well, lets say I keep it the same length, but straighten it out a bit, or twist it to fit the frame for example. Will that have an effect on the performance, or will it stay the same because it's still the same length as stock, only a different shape?
Lets say, I need to shorten it, how much will that effect performance? if at all. Same question, but lengthening it?

Onto the second question.
The engine is tilted back a bit in the frame because the front motor mount on the engine hits the downtube, our origional idea was to cut the section of downtube that is being hit, find another tube the same size and cut a piece like this " ) " to clear the engine mount. Does that seem like the only reasonable idea? We can't tilt it back because then the carb would hit the rear shock.

Now, ...If those questions made any sense to you then give yourself a pat on the back! Because for some reason I can't seem to communicate anything properly right now. :lol:

[RedRider_AK]

I think your frame idea would work great given some reinforcement. You'll have to slide a smaller-diameter pipe into your frame section to give you better weld surface.

I read somewhere that the longer the header on a 2-stroke pipe is, the higher RPM's the powerband will be. I'm sure it's not that simple though, but I think you could get away with slightly shortening it. How much do you need to take off? Twisting it will probably make even less of a difference.

[TwoHundredEx]

I think your frame idea would work great given some reinforcement. You'll have to slide a smaller-diameter pipe into your frame section to give you better weld surface.

I read somewhere that the longer the header on a 2-stroke pipe is, the higher RPM's the powerband will be. I'm sure it's not that simple though, but I think you could get away with slightly shortening it. How much do you need to take off? Twisting it will probably make even less of a difference.

I'm not sure how much we'll need to take off, or add on yet. The mechanic working on the motor mounts/exhaust said that he's having a hard time trying to find angle where the expansion chamber clears everything, so now he's waiting on me to come in and see what I want to do. I'll be heading in on Tuesday so I'll know then. Basically, I only wanted to know how much of a difference adding/subtracting length would make, so that if we have to do that, I could judge wether or not it would be a good idea.

[jeffatc250r]

I wouldnt worry about the pipe, do whatever it takes to make it work, for what little tweaking and trimming your gonna do, you wont even notice a difference. and as far as the frame mod, i think that will work fine so long as its welded good.