View Single Post
Old 05-27-2012, 12:19 PM   #8
Reino OP
Gnarly Adventurer
 
Reino's Avatar
 
Joined: Nov 2011
Location: namibia
Oddometer: 206
The load i am referring to is throttle opening which is measured by a tps in % or vacuum by the map sensor in pascal.

ignition curves for cr500 below

http://i870.photobucket.com/albums/a...396/graph9.jpg

A 2stroke ignition sees most advance in the early parts of the rpm range (30 degrees) to get the exhaust temp high to maximize scavenging and drops after max torque to something like 9 degrees btdc to maximize over-rev, this is for a 2d map of coarse but you get the point.

I thought about this topic for a while and realized an expansion chamber's scavenging effect is optimized for a certain temp, so with less load you can effectively increase advance to increase exhaust temp for throttle response. under load you would retard to decrease temp to decrease chance of melting the piston.

this is why i love 2strokes, deceptively complex bastards.

Reino screwed with this post 05-27-2012 at 01:41 PM Reason: forgot info
Reino is offline   Reply With Quote