Here is what I think the LC does for variable ignition timing. I don't know any of this to be a fact, so take this for what it's worth. The variable ignition timing is controlled by the computer using the MAP sensor and the TPS sensor. I discovered that the TPS Ω2 resistance climbs as you increase throttle, mine went from 1.0Ω closed throttle to 4.2Ω at WOT. 3.89Ω would be factory for WOT on my bike. This leads me to conclude (however erroneous it may be) since my bike achieves the factory WOT of 76% (3.89Ω at about 3/4 throttle) my bike is advancing the ignition a little ahead of what factory specs call for. When I started to test mine I had already made the decision that I was going to advance it about 5% from 76% to 81% to see if I could tell a performance difference. Turns out mine came from the dealer set on 82% already (mine is a 2001 model). Performance wise my bike has always been strong. My brother has a 99LC and when we did some field dyno testing (road testing) when both bikes were identical, ie. V&H pipes with no additional changes. Doing a throttle roll-on at 55mph my bike would pull his bike anywhere from 5-7 bike lengths. Same held true for most any speed/gear we started from. My bike has always had this 'place' in the power band where it really starts pulling hard. I don't know how to describe it really other than at a certain RPM the bike really comes alive. After doing this field dyno we took his bike apart and did a stage 3 conversion. K&N high flow filter, 170/170 jets. Then we went and did some more dyno testing. The stage 3 on his bike made it run just about even with my bike with factory carburation. Seeing the difference the stage 3 made in his I decided to do it to mine except I went with 170/170 jets (112.5 and 110.0 are factory) and a different type of K&N filter. It made a significant difference on my bike although I ended up backing down to 160/160 jets which seem to make it run better. Is the difference in the TPS (76% vs. 82%) the difference between his bike and mine? I don't know. Will you see a perfomance gain by setting the TPS to a higher value than the factory 76%, again I don't know because I'm not going to lower mine to 76%, nor am I going to raise it above the dealer prepared 82% because of detonation issues. I'm certainly not going to suggest or advocate that anyone set their's to a higher than factory % but if you decide to do that I would certainly be interested in hearing your results and I would be happy to post your findings here. E-mail Comments