Quote:
Originally Posted by renault_megane_dci
Since we are dealing with engines with high specific power, we can assume they are a little cammy with quite some overlap which means they get more efficient at higher RPM.
usually an engine is consuming the least fuel a tad under peak torque with WOT.
I bet your peak torque is 8K and peak power 9K.
What I get from your testing is that there is an optimal compromise of gearing for every size of engine and that longer gearing is not always the best compromise when dealing with smaller engines.
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It is 50cc engine with around 3hp at 8000rpm and has peak torque at 6000rpm, but I don't know how torque curve looks, torque might not drop right after 6000rpm, it has not much pull at 5500rpm though, so maybe advertised specs are not what I'm actually getting.
I could get hotter cam that has 40 degree more, but same lift, big bore kit comes to mind also, hills are quite long and there is lot of weight to be drag around.
With CVT system rpm is quite constant most of the time, especially when power is needed so narrow power band would not be big issue, but should I try to optimize thing to higher rpm? As it can't really well climb hills at low rpm, I would guess I have to.
Noise is just something I really don't like and above 6000rpm it starts to make quite bit of noise, with BBK it might be possible to have bit more civilized noise and perhaps economy would improve too as climbing hills will not put so much strain and hill climbing would be shorter time.
It would cost around 70 to swap cam and move from 50cc to 80cc, which is of course bit on illegal side, but perhaps law was made for bit different users in mind.