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Steady State Vs Ramp up tuning

Road Tuning

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Discussion and questions related to the course Road Tuning

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The Whole Idea of Steady State tuning is for you to have a complete fuel table for Part throttle, that way you are 100% sure you have all cells tuned properly weather you need them or not,

A normal ramp run or power run is full throttle, the load will be way different from steady state where you tune to 3/4 of full throttle range, if you find hard to tune using steady state, if you have a way to datalog, you could just drive the car the way you normally drive it up to say 5,000 rpm for 20 min or so, then review you log and see what the AFR says if you are either lean or rich, you can fin those spots in your data log and see where your at regarding load and rpm to make the changes, this takes more time to complete, but you will just change the cells that you are actually using if that is what you are after,

Short answer to your question, Ramp run will access if you are at sea level to your last 3 load colums close to 0 Map pressure where steady state will reach lower load,

one if for your normal driving (Steady State and one is for max power)

Thanks mate, Yes i can datalog. I use Honda P28 with Neptune. I got the point that steady state will access the load points. The higher end ECUs such as link, motec etc might point to exact load cell being use. In my case, i can see nearby cells being always picked up. So it is an average of all the cells under consideration or something like that. Do you have any suggestion on how to tune such ECUs?

Hi Magesh,

I have no first hand experience with neptune, although i do have experience with Crome which are pretty similar,

Yes cells are an average what you do in that case, is review your data log check where you are in the fuel table a select the 4 shaded cells not only the red or the pink one, (Red is the darkest and means you are in that cell, other color is an average) after you have done all you changes on the fuel map according to your log, check the 2d map plot all lines should be smooth if one is ok but the upper or lower one is not is because you just selected one cell when doing all your fuel changes,

every line should be spaced in a similar way to the next one, except when vtec kicks in and you go higher on the RPM's one line should be off buy a bit form the lower one but the upper one should be spaced similar, when tuned properly.

If you have more questions feel free to ask

Thanks Javier ,

Much appreciate it. Neptune should be pretty much same as crome (although i haven't used crome). I got the idea of checking the 2D map plot. I will check that after changing the cells. For now, i have changed the single cell on which the recorded AFR against that cell. I didn't get the idea of VTEC 2D map spacing. If you have a picture of the VTEC region can you please post it?


What I meant to say is. That your 2d map plot lines should be smooth and symmetrical, against the next upper or lower line, (which indicates your engine load through the RPM's) if they are not smooth you should check those spots for fueling changes,

I will upload 2 files, one is the low cam and one is the high cam or vtec cam, notices next to my Fuel table i have displayed the fuel map in a 2D plot, that way is easier for me to check all my fuel lines against the others, you are aiming to have a very smooth very symmetrical plot with fuel lines that have pretty much the same shape as the one next to it, just slightly higher (for the Upper) or lower this indicates more fuel needed for higher ones as you are making more power and less fuel for the lower ones.

but the whole idea is that they are smooth have a look at the pics if you still in doubt I'll try my best to explain


Attached Files

Thanks mate..you have hondata and neptune is very similar. I even have same.laptop as yours. Anyways your 2d plot looks smooth. I did some data log on the road, calculated the correction factor and changed fuelling. After which when i looked at the 2d plot, it was all zig zaggy. I think the easiest way to change fuelling is to drag the points on the 2d graph and make it smooth. The other way is quite painful. So how and when do we depend on afr and correct fuelling based on target afr and expect graph to be like yours? Did you correct the fuelling by depending on afr correction method?

Thanks Mate,

My is tune on the Road only,

As I said if it is all Zig zagi is because you tuned 1 cell and not all 4 you need to do corrections on all 4 highlighted cells, unless you have a access to a dyno.

I always depend on AFR all cruise is tuned around 14.7 transient is at 13.5 and Wot at 11.8, what i do, is to tune first the low cam, up to 5k rpm or even past it. with Vtec disable, so it doesn't switch to the high cam.

I ride the way i normally drivee my car for about 30 min datalogging all the time, trying to get all sort of condition, I.e traffic, stop and go, 50% Throttle and so on. it takes a while, but I just did the Steady state tuning course, so i never tried that before, seems easier but i need to find a really not busy road, which i do not know of, so for me this has to do,

After a few 30, min rides, the fuel curve start to emerge, You can not just jump and drag lines up and down, as that will change your fueling, so first you need to know if it is lean/rich and lets say you have tune all cells, and you find a dip in your 2d map, then you take the next fuel point and the previous pone and you interpolate, a valid data as a reference, otherwise you will make it real hard for you.

once low cam has been tuned you enable Vtec and move on the power runs. to tune high cam.

Hope that clears some of your doubts

Thanks mate, Got the point. But when i am tuning a cell for fuel based on its corresponding AFR, i can't touch the neighbouring cells due to their AFRs being too different. Also my AFR for a particular cell is showing totally different values at the very next moment. Is it due to slight variations in throttle? I will attach a few pictures. I will also attach the log file (17062018.dmg). You can simply open it in neptune rtp exe. (you can download from www.hrtuning.com support). For attaching purpose i have renamed to 17062018.txt.

Attached Files

You're not going to have much luck with a scattershot approach, datalogging and then changing a few cells at a time that are too rich or too lean. You have to figure out the VE curve of the engine and make the fuel curves smoother.

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