It might no be until next weekend but my plan will be to paint a couple lines on the road, I have a long incline on a quiet road about a 1/4 mile long that works out pretty well for a rolling start 4th gear pull from 20-60+.
My plan is to do 3 runs 70,80 and 100% TPS to see how the ECM manages the fueling for each mod.

 

It would be good to fully define when the ECM goes from closed loop to open loop.
IF this trigger is simply TPS controlled, then a run with TPS held steady below the trigger will show closed loop fueling (14.7) , TPS held steady above the trigger will show open loop fueling ( probably in the 12's)..
IF the trigger point is controlled by more than just TPS, then we have a problem that needs to be solved. Such would likely be a simple implementation of a load based fueling solution using computations based on a VE table, TPS, Gear sensor, tire speed sensor, etc, maybe even a "modeled airflow thru the throttle body" table in lieu of a Mass Air Sensor.

If your preliminary assessment of a hard 75% TPS trigger (from open to closed loop) holds true, it explains everything. And it fits in with being able to pass emissions testing without having to use (more) complex software.

 

Here you can see we have 76%TPS and we have just left stoich. Lean? 13.1 is okay in my book.




Here we are at 79% TPS still 13.1



At 81%TPS we have 12.9 still very happy with that.


100%TPS we get 12.3 safer side of rich. But not pig rich.
I just hope I can find a combination very similar with the 351.

 

What would be cool to see
AFR during following conditions
1) below 70% TPS,
2) 75-85% TPS
3) 100% TPS
And for the following RPM
1) idle (~1200-1600)
2) 2000rpm - 10000rpm)

And following mods
1) standard klx300 ecu + lidless
2) standard klx300 ecu + planetklx2 snorkel
3) JDM ecu + 270cc injector + KDX snorkel
4) JDM ecu + 270cc injector + 3d printed snorkel

 

The weather here just won't give up. No progress until the weekend. I have a KTM injector to try also, can't find a good cc/min on it but I believe it's around 350...

 

I ran 3 different scenarios tonight.
1. KDX snorkel shortened. 4th gear pull to redline.





Lidless 4th gear pull to redline.




A little lean for sure. The horizontal line looks to be 13:1 AFR.
Not to mention it is so annoying I wouldn't do it for a 10 HP gain.
Well maybe for 10 😄


Finally, the PlanetKLX2 LID.
QUIETER for sure.






More to come.
I also did a couple of long 6th gear pulls with both lidless and PlanetKLX2 LID verying throttle position I will share later. Mr Sandman is throwing sand in my eyes at the moment.

 

With the AFR a know factor stock, could the timing be off on these bikes to make the header glow like that?
I know when I built a few circle track engines if the ignition timing wasn't advanced far enough on cam break in, the exhaust would glow.
Theory was it was still burning when leaving the combustion chamber.
I know we can't change it, but what if we could??

 

Long 6th gear pulls open air box.
File https://drive.google.com/file/d/1vOe...w?usp=drivesdk
Application is listed in first post to read the files.
Even with open airbox, other than being very annoying, no real threat of damage due to extreme lean condition.

 

Long pull with PlanetKLX2 box lid.
File https://drive.google.com/file/d/1vmOTdf6vInd8vAmgKfcTOendQbUC6Ux3/view?usp=drivesdk

 

Ahh, drawing conclusions from the "long pulls" is not possible. Those charts do not create usable data.

The charts showing 100% TPS from 3XXX rpm to 8XXX rpm do create useable data - and they show that a lidless aribox creates much too lean AFR's over too much RPM range to be safe. Same for the 3d printed lid.

If you can make a chart/run showing a linear throttle progression from 60% TPS to 100% TPS, we can better see how the ECM transitions from closed loop to open loop.

Your data shows that running a KDX snorkel on the stock ECM is safe.