Hey all,

I plan to make a fun project out of a proper trail-tuned power commander FC map for the MCM with a slip on and no lid.

I might be the right guy to do it, but who knows? anything is better than nothing and I don't see a lot of maps for this really ideal combo out there.

My background is I'm a hobbyist automotive ECM hacker and have written some pretty major tuning/logging/reflashing software for some niche market platforms, and I've reverse engineered a decent amount of ECM fueling code, so I do understand at a very low level how ECMs work.

My particular bike is just 2018 KLX250 in perfect running condition, -1 front sprocket, no airbox lid, yoshi slip on, MCM, power commander FC, so a good baseline for what most of you guys seem to be running. Honestly it runs pretty okay with a zero map but I know there's a lot on the table.

Anyway while I'm working on that please tell me your experiences or input, has anyone already done a map? People running the EJK please tell me your experiences/settings as well.

I'll let you know the progress.....hopefully this results in anything someone can download that makes their MCM/slip on bike run awesome.

 

@rfesu , what tool are you going to use to determine your fueling - a dyno or a logging wide band AFR meter ? Surely you are not going to attempt fuel curve creation via DynoButt !

We know the engine will run "perfectly fine" with insane fueling - as fat as 10's and as lean as 14's - but always with reduced performance compared to proper fueling..

Are you aware of the relationship between a fueling curve and it's ignition curve ? Since we do not have the ability (?) to alter the stock ignition curve, the fueling curve must stay within the "operational envelope" of the ignition curve. ( E.G.Within 12 - 14 to 1 AFR's, leaner AFR must be ignited earlier and richer AFR must be ignited later...) So the stock ignition curve must be determined as well as the stock fueling curve - as both, together, form the baseline tune that can be "built on"..

 

as anyone who has ever tuned an engine will, i'm absolutely going to use all the information and feedback available to me, including how it feels and how it sounds, those are important inputs. i've been working with engines long enough to know whether it's begging for more or less fuel and my 'dyno butt' is pretty well calibrated too, thank you for asking.

if i feel like i need more data i'll try to get a probe or two in there.

definitely will start by adding a bit o' fuel where i feel like it's gained VE and removing a bit where i feel it's lost some, and see if the change is positive or negative. i've tuned plenty of bikes with and without dynos and widebands and they all end up running great, this way just takes a lot longer, but i have lots of time, and no dyno.

it's just a toy dirt bike. i'm not going for perfect since i'm not racing and i do hope someone does get it mapped on a dyno, but i will definitely get something that's better than what we already have available, which is literally nothing as far as i can tell, and since we're a community maybe we can revise it from there?

yep, sure am. on a small low horsepower engine such as this, it's far less important than you're making it. no use worrying about what you have no control over or no complete knowledge of. i'm just going to go ahead and work on tuning it the best i can, while you're thinking about how you could do it better.... but are not.

 

Rfesu- having done some engine building and modification myself, your kidding yourself, and others if you think your " dyno-butt" is going to be an accurate measurement of performance improvement.
And it is even more important to use an actual dyno with DOCUMENTATION to display increases or decreases in the performance on our relatively low HP engines.
Two-five HP increase or decrease on a 300 HP engine is hardly noticeable but may make a significant impact with an 18 HP engine.
We are so fortunate to have several people on this forum who at their own expense, have dedicated countless hours on improving the performance of our bikes and have unselfishly shared their vast knowledge and experience with others. The knowledge they have shared has saved hundreds if not thousands of dollars for many members on this forum. How many members have run out and purchased a new exhaust system because it really sounds cool so it must make more power. Later finding out someone did a dyno test and discovered the brand new pipe makes the same or less power than the stock system.
Let's show them the respect they deserve and not let our egos bite the hand that feeds us.

 

if you're telling me a fuel map developed for a bike without a dyno is useless, you are the one who is kidding yourself, and so is that other guy that told me without a dyno i should just not bother. ego has nothing to do with it.

people have been tuning all sorts of engines since well before dynos and widebands were available to the common man. i use what is available to me. i don't have a dyno where i live right now, only lots of road and trails and various sensors and electronics, but i absolutely take observations such as 'pops a wheelie now after adding a bit of fuel in this range' as a useful measurement and so do most people tuning bikes.

i will tune my bike accordingly, and willing to put the time into developing the best remap i'm capable of, and wanted to share my experiences doing so for the benefit of others.

if you really think my practiced hand in tuning is worthless to you since its not on a dyno, and you think that EJK crap is going to somehow be better than my hand tuned bike, i guess i could keep to myself.

just trying to help.

 

ya'll do what ya'll gotta do. mine's staying bone stock