Initial Fuel Map

[whizzo944]

Hello All,
I have a bike engine which I have chucked the carbs and installed throttle bodies. The bike is a Honda VFR400 which has a 90 deg. V4
engine. My question is this, is there a way to calculate an initial fuel map? I know roughly how much horsepower and torque the engine produces, there are loads of dyno traces for this bike on the 'net. There is an initial map calculator for Megasquirt (sorry for swearing )
but it objects when I tell it the max. RPM is 15000. Any and all suggestions gratefully received.

Thanks in advance,
Dave.

[Fred]

Is this map for MS and if so, which variant, or FreeEMS, and if so, why didn't you tell us what you were doing??? :-)

The code for that from MegaTune is available on not2fast.com and you can take a look at the algorithm. It's pretty messy, but kinda clever. Reality is that you don't need much of an initial map, something flat that is correct in the idle region is sufficient and your prime/post start stuff and dead time is key. Once you have it running, it's easy to push it into those areas that aren't right, and see in which direction they are wrong, and adjust it to suit.

Have a read here: http://issues.freeems.org/view.php?id=461

Fred.

[Fred]

You could also just lie to the tool and then move the axis values around ;-)

[whizzo944]

Hello Fred,
You must know that the map is for an MS, I haven't even begun to fully understand FreeEMS yet.
If I can make a suggestion to you, could you possibly do a "FreeEMS State of the Nation" address to your followers,
so that everyone knows where the latest hardware and firmware developments are, of course not wanting to divert
your attention from firmware development, which seems to be your main focus at the moment, if I'm reading between
the lines correctly.
The bike has a MS2 on it, ultimately I would like to try FreeEMS on it. The MS2 thinks that it's running a V8,
the engine has a 360 deg crank, i.e. both rear and both front pistons are up together, so I am just using spark outputs
1 & 2 and just ignoring the other 2. The ultimate aim is sequential injection, I can run the engine sequential spark or
wasted spark, it doesn't make much difference. When you mention a "Flat Map", do you mean just a slope in the load
axis , or totally flat, which wouldn't make much sense to me? The load sensor is the TPS, not the MAP sensor, so I assume
that the slope won't be linear.
Sometimes I am very hesitant to ask questions here, I feel like I'm taking without giving anything back. Do you have a beer fund
that I can contribute to, that is if you ever find the time to drink beer !!
The reason for not telling you what I'm doing is because I thought my project vehicle doesn't have enough wheels to be interesting
to people here )))
A Thousand Thanks for your help,
Dave.

[Fred]

OK, for MS2, I'm going to assume that you mean MS2E and I'm also going to move this thread to the appropriate location. MS2E when in speed density mode had the option to have a proper tuning setup or a hack job MS standard one. Lances curves only work for the MS hack job one anyway, which doesn't matter because you're in speed density mode.

I've no idea how to estimate the curve for an alpha N setup, except that you'd expect that at low throttles it would have lower fuel demand, however at low throttle openings at low RPMs you'd expect to reach full fuel demand well before you reached full throttle. Lance's stuff is no good for that, though, that much I DO know.

I hope the reason for your hesitance to ask questions isn't my aggressive no-bullshit nature and way of writing. If it is, I apologise. If it's just that you don't want to waste time, you're probably not. If you don't ask questions you can't learn some things. Docs are thin, and good questions = good answers = good stage-one docs which is good for all.

I find the time to drink some 1 euro wine most nights while tapping at the keyboard :-) If you want to feed the "vino" fund, the paypal links on most of the websites (such as http://freeems.org) head for my account. If you prefer to deposit into a British account, I can give you details for one of those too.

Re your bike being a bike, don't be silly! I *LOVE* hot bikes, I'm just too paranoid to ride one. My nature is "balls to the wall" and I'm afraid I'd last less than a week on a quick crotch rocket, so my interest is purely in staring at others bikes in carparks :-) FreeEMS may be going on a quick race bike here in Spain pretty soon, FYI, and although I won't be getting on it, I'll be heavily involved.

Throw up a thread in users rides if you want, I'm interested, I *LOVE* high RPM too <3 :-)

Fred.

[whizzo944]

Hello Fred,
I thought you lived in New Zealand? Don't know why I thought that, I was going to ask you to say Hi to Aaron Slight for me, one of
my heroes. Yes, I am using MS2Extra.
My hesitation at asking questions has nothing to do with your no-bullshit philosophy, in fact I'm a big fan of a BS-Free zone. I hesitate because I feel I can't contribute anything to this project and I don't like taking without giving something back.
I will take your advice and just get the thing running at idle and go from there, I have a WBO2 sensor and see how it goes from there.

Thanks again for your help,

Dave.

[Fred]

I'm a real 100% full blooded kiwi, bare foot, number 8 wire and everything, but a certain Spanish lady tempted me away from my home shores yet again. I've vowed never to live in Europe again, though, if this should go wrong, for whatever reason, and if she doesn't like NZ when I drag here there, same applies. In any case, right now, I'm in Madrid with her family, and we live in Barcelona for the time being, at least. If you're taking a summer holiday in a few months, hit me up and we'll have a pint/glass of something.

One more piece of advice, you will probably be better off using their blend mode for some of the cells. You tune your TPS table till you're happy with it, note the parts where it's not very good, and use map for those, or vice versa. You can swap to that post getting it up and running TPS only, though.

Thanks for the little something :-) I'm not legally allowed to work here for several more months, so every bit helps, most appreciated!

Fred.

[Spudmn]

Hi Dave

I was going to ask you to say Hi to Aaron Slight for me, one of my heroes.

I live in NZ and Aaron Slight is my neighbor. I will let him know you said Hi.

Just kidding

[Fred]

You (funny) bastard! LOL, I was thinking "wow, what a coincidence!", then I looked down :-p

[Fred]

Dave, I just realised that we had this, it may be useful to you: viewtopic.php?f=54&t=1271