Exhaust types. ?

[grahamb]

Hi 

I am trying to get my old head around the 2 stroke exhaust minefield.

Here is a factory exhaust for the engine type I am using . 
As you can see it is a long way from the types used on most scooters and other 50cc 2 strokes.




The overall length is 350-400mm .

I am looking to adapt this car boot find into a performance exhaust , (any thoughts on it's suitability)
Also does the length work against me as in the pressure wave having to travel further. 

It could end up over twice the length. 





Cheers Graham

[aeroxbud]

The Leo vince is a good exhaust. Your standard exhaust does not really have performance goals. The next step up is a half wave type exhaust. It will give you quite a performance increase. While looking basically stock. www.pedparts.co.uk/product/1161/stage6-street-exhaust--aerox-minarelli
The exhaust like the one you have is a true expansion chamber. Will probably double the original power, and give a substantial increase in speed. Google two stroke expansion chamber.

[grahamb]

Nov 22, 2020 18:45:55 GMT -5 aeroxbud said:

The Leo vince is a good exhaust. Your standard exhaust does not really have performance goals. The next step up is a half wave type exhaust. It will give you quite a performance increase. While looking basically stock. www.pedparts.co.uk/product/1161/stage6-street-exhaust--aerox-minarelli
The exhaust like the one you have is a true expansion chamber. Will probably double the original power, and give a substantial increase in speed. Google two stroke expansion chamber.

Hi Aeroxbud
Thank you for your reply 

I would like to use an exhaust with an expansion chamber . The one fitted is about the same length as the Lea vince and  seems as an exhaust, but not sure if adapted the Leo vince it would be a better option.? 
 
With the moby the engine pivots backward as it revs  and the exhaust has to pivot with it . So length and pivot points are a consideration.

The existing pipe fitted has a 16 x 200 mm stinger  ( inside the chamber to reduce the overall length,) for a 75cc motor would you consider that to be a bit on the small side . 

Last question, after the engine exhaust has passed through the stinger , does the silencer on the end have an influence on the   
overall performance.

Having ordered a new cylinder that should (after I find out about port timing ) perform better I would like to get the exhaust right 
as I think it i just a important .

Many thank Graham