I'll let someone with more transaxle experience than I help there but as for exhaust... 2 into 1 will work better in the low to mid range and 2 seperate will work better in the higher rpm ranges so for trails and mud I'd suggest going with a 2 into 1 as it will provide a better all around powerband. I'm not sure if a X or H crossover would make enough difference on a small engine to be worthwhile, maybe/maybe not?
To make a 2 into 1 perform the best it can without 10 pages of math, keep these things in mind:
- Size matters! That doesn't mean bigger is better though, try to match the size of your pipe as close to the size of your exhaust ports as possible to keep flow velocity up.
- Equal length header tubes that merge into a collector that is about 1-1/2 times bigger than a single header tube will aid exhaust scavenging and keep flow velocity up.
There's more I could go on about but it'll get boring! Lol.
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