RageHard.. Running thought experiments as my knowledge on the subject increases, I've come up with a map suggestion for you. Basic premise is that as your particular setup (slide, spring, etc) begins to uncover the K152, the curve must not over-advance the richer AFR. Key points are 25° at 6500 rpm with a slow ramp-up to just over 30 at 10K with the target value of 32@11k.. I assume you feel Max TRQ start to come on around 6500 ?

 

Very interesting, yes still feels like peak trq is around there somewhere. I have thought the straight 40deg may be losing a bit in the mid rpm range based on a long 6th gear climb I do all the time. Hard to say when the top end feels stronger though. It's pouring with rain today but I'll try and upload this map and go for a ride tomorrow.

Thanks!

 

Ok, I didn't include the file - just a sceen shot.. From what you're saying, I might need to tweak it some before uploading it..

I expect PEAK TRQ on your bike to be 7K-7.5k.
I expect you to feel the beginning of the big TRQ ramp-up at 6k-6.5k
.. Am I close?



Editing done.. I suk,,

 

Your 6th gear climb is going to be invaluable for this tuning - what a stroke of luck..

 

Progress Progress... Our combustion chamber design is typical in todays' ICE design and provides the shortest, therefore quickest, path during combustion. It is a 4 valve pent roof with centrally located spark plug (very important). It provides the shortest, therefore quickest, burn rate of any other mainstream chamber design. (Major point of this design is that it does all this "goodness", even in high compression applications, without the need for domed pistons - which "screw up" everything.)

While the AFR controls how fast the flame front travels, the chamber controls how "far" it has to travel. Get it?

So it becomes easier to understand - running performance AFR's (12-13:1@WOT), will create very quick flame speeds in a very quick chamber. Big advance numbers won't be tolerated during the 80% of max TRQ curve, I.E. 6-9k, if AFR in that range is as above.


I found one site that suggests 28° could be a max advance target, when using a crude "plateau" mapping, with such a chamber/AFR combo.

 

OK so the rain eased enough to go for a quick ride yesterday evening. Here is the map I created based on your suggestions.



I did keep the 5 deg initial advance as I feel it makes the bike easier to start especially when hot. I was also trying to pay a little more attention to the tach on the 6th gear hill. Basically hitting the bottom of the hill at 6500rpm and going WOT to the top so it seems like a good gauge.
There does seem to be a marked improvement with the current map over the straight 40 deg advance from 3000. Was definitely pulling stronger in the mid range yet the "extra" power I was feeling at 3000 and up towards redline is still there. Still early days but it seems like you on the right track here.

 

Ok! For further tweaking, move the 25° point left or right.

I tried to put it at the point where your CVK setup goes below 13:1 AFR which, I think, also happens to be the point where your TRQ starts to really rise.
( I am basing all this on the assumption that the stock lift hole and slide spring are delaying or "easing into" the "full effect" of your K152 somewhat - even with the N1TC at 2N..)

For instance: You could attempt to place the 25° point directly "over" max TRQ (probably somewhere closer to 7.5K) ,, If you do, check for "flatness" or "dullness"(over advancement) in the power ramping between 40°@3k and the RPM value you put the 25° on..

Or you could move the 25° point to the left, perhaps getting it closer than I did to the very beginning, OR just ahead of, the "big pull on your arms" TRQ ramp..

At any rate - As time goes on, I'll know more.. But as of now, it seems advance should be increased VERY gently or not at all during the "80% of max TRQ" area of the power curve - perhaps(I'm guessing here) 5.5k to 8.5k on your bike.

 

Another "thing" I'm interested in Rage.. I kept the huge ramp to 40° because 1. you said it's working.. 2. I think your CVK setup is maintaining a healthy 13.5 AFR below about 5K rpm@WOT and even leaner AFR's in normal riding, which would allow "biggy" advance and improve low rpm throttle response and power..

So is that the case? Do you have "biggy" power and throttle response from idle to about 5K that is far better than stock?

 

Another tidbit of knowledge: If you are running a restrictive exhaust, regardless of all other factors, you are increasing the exhaust gas dilution of the "charge" the spark plug ignites. This causes slower flame fronts which means you can run more ignition advance.

More advance will offset the power loss from the restrictive exhaust. Probably more than offset it.

Surely the Aussie 35° curve will greatly benefit any KLX running the stock exhaust.

I know the MCM makes a dead stock bike leap - it was my first mod on mine - You gotta wonder if those who must keep the KLX quiet should do only two things - MCM and Aussie curve..?



We need more "testers" !

 

By the bold you mean the increased backpressure from the stock exhaust pushes a little more exhaust gas back into the cylinder as the intake cycle begins, right? This dilutes the air in the charge thus slowing the speed of the mixture combustion, correct?

How are you taking into account the speed of the engine, in combination with the presumed speed of the combustion to figure a given advance?