1 hp? Crude, maybe-- but sounds effective non the less. You were running about 23.5 before-- you are hitting 24.5 with the Aussie timing?


About the ramping, that is what I was trying to understand-- does it stay at 10° until 5K then switches to 35°? It sounds like that is what you are saying.

Good luck with the continued testing, cant wait to see some more results!!

 

This might be a good read to get everybody up to speed on the topic and the specific cdi box mentioned...

https://www.kawasakiforums.com/forum...cdi-klx-37214/

 

Thanks Hoot. I haven't seen that thread in years. Readers can see the stock curves as I see them.

The Aussie curve - on my bike - enhances as much as 1hp on top after Max HP. It did not raise Max HP - it created and allowed "bigger" HP to be carried out longer toward redline. In other words, TRQ is created , in the top end, that is not there with the stock mapping

 

It seems max chamber pressure needs to be reached 14-17 degrees ATDC (From research). These crude stock curves, with set constant values, will allow/create this "perfect timing" only in a small RPM range. Flame fronts travel at a set speed and fill a chamber in a set amount of time regardless of how fast the engine is turning. So as engine speed increases, there is less time available to reach max pressure at 17-20 ATDC yet the flame front will need the same amount of time to do it as it did at idle. Begin to understand the problem? All we can do is move the spark up(advance it) so as to try to keep that flame front producing max pressure at 17-20 ATDC.

I hope that made sense. Point is, at a "set advance value" you will see on a Dyno chart where this "perfect timing" occurs - it's a sharp change of increased TRQ/HP ..

 

So the goal is to maintain this perfect "Max pressure at the exact proper point" throughout the RPM range - obviously with a constantly changing ignition curve. I have no idea how quickly or slowly to increase the values - there is the math, but it is engine specific, very complex, and only provides theoretical guidance.. Unless members can provide "enhanced information/guidance" I'm just going to have to keep learning, tweaking, and testing..

 

subscribed.

hoping for non-MCM data.

 

Informative thread, his dyno results were disappointing though, it seems like 25 would be too little for optimum power. At least I see how the timing advances linearly from 10 to 35 before flattening. The thread seemed to die off rather quickly, I guess no one was able to prove it made a measurable difference?

KLXster-- perhaps the KLR/Mojave stock curves would be worth a try? BTW, I just got hold of a KFX450R service manual just to see how an engine of that type is tuned-- here it is:

KFX450R
Timing Advance Electronically advanced
Ignition Timing From 10° BTDC@1 800 r/min (rpm)
to 39.5° BTDC@6 000 r/min (rpm)
Spark Plug NGK CPR8EB-9
Valve Timing:
Inlet:
Open 26° BTDC
Close 70° ABDC
Duration 276°
Exhaust:
Open 82° BBDC
Close 24° ATDC
Duration 284°

 

Turns out, there is a reason you don't have all kinds of options and information about ignition curves, like you do with jetting mods. A curve for one bike will not perform as well or at all, on another bike. The variables involved are staggering.

Kawasaki determined that the combustion chamber design/cam profiles and timing/induction and exhaust systems/ of the KLX would perform quite adequately with all fuels and altitudes, with a simple 25° curve.

A performance ignition curve that eeks out every bit of power, is practically specific to A bike. My curve will only apply to an identically modified KLX at the same altitudes, running the same quality fuel, to get the same benefit.

For instance, I'll share one factor that is of primary significance - AFR @ WOT must be kept 12.5-12.8 to one in order to produce the quickest flame front speed. If you don't know it already, that's one heck of a big main jet - at least a DJ140/K152 for lidless with slipon, or at least a DJ144/K158 for lidless with full performance exhaust. Leaner AFR's have slower flame speeds - so the ign. curve would need to be different - it would need to be advanced more.

 

However, I hold to the belief that a high performance "generic" curve/map can be found for the most popular "mod combos".

 

Wish I had access to a dyno, I'm still running 5deg @1500 ramping up to 40deg @ 3000 and the bike seems to really like it. As you say I think getting the correct AFR first is key. I know from tuning turbo charged cars that advancing the ignition can mask/compensate for a rich AFR, a slower burn can still occour at the correct time