Motec M1 Build Alpha-N

Hi everyone,

I have just put my in engine in the car (hopefully do a write up once it's all complete) and have been playing around with the idea of changing the engine efficiency (fuel) map to be based off "Engine Load Normalised", which, when set to TPS, will mean the fuel map will use TPS for the Load Axis - alternatively, I can just set that axis to be TPS.

I have seen between this forum and the motec forum that this has been done, but not having a lot of experience with build, little hesitant to load the modified firmware onto the car and find it messes with something else on the ecu. Has anyone here had any experience with build and doing something like this? Any feedback on how it went, or the application you did it for would be greatly appreciated.

The engine has big (ish) cams and lots of overlap - idles at 75-85kPa (absolute). Still single plenum and TB, so I think it should be ok at full noise on MAP, but not sure about the part throttle stuff when driving it on the road.

I do this on my custom firmware, I just made the axis of the efficiency table be Throttle Position. When I first loaded that firmware, I did need to re-tune the efficiency table.

Thanks Dave, I had seen you say you have done it in some other threads.

I guessed I would have to re-tune it. I have just taken the car for the run up and down the street with the standard set up and there's no much vacuum to play with.

So it's just as simple as changing the table? It doesn't have any adverse affects else where?

You can always load the other package if it doesn't run on your newly built version. Why don't you try it, and see if you can get the engine running and idling. Then work on making it respond to free-reving. You may see enough of a trend to make changes to your table and give it a try on the track (or road).

One thing should be constant -- the full throttle curve should look alot like your existing 100 kPa line (I am assuming normally aspirated).

Of course, tuning on a dyno is ideal -- what's your plan?

Here is a screen shot of my Engine Efficiency Value table setup to show what axes I used:

Thanks for your help David.

The engine is NA and it'll be tuned on a chassis dyno in the next few weeks all things going to plan.

I gave it a go yesterday afternoon. I changed the engine efficiency and fuel mixture aim main tables to Engine Load Normalised - the idea was that engine efficiency, ign timing main and fuel mixture aim main tables would all have the same load axis - maybe it might be better changing them to TPS. I also wasn't sure if I should have left the lambda aim to MAP, but we'll see how this goes. I know there are other tables for the lambda aim using inlet manifold pressure still.

I used the VE values I had from the engine idling, and the short drive I had done to start the new map, and it was only a few cranks before it started. I have driven it around up to about 60km/h, then would park the car up and go back through the logs and adjust the fuel map. At the moment the ign table is set to a flat 20* - enough not to be too sluggish, but not enough to cause knock - I'll be setting up the knock sensor once it is on the dyno. I have the rev limit set to 3500 for the moment. I'm reasonably happy with that part of the map now, so I'll up the rev limit and start getting a few of the higher sites.

It's pretty much impossible to drive under 2000RPM, I expected that, but it's worse than I anticipated.

I'll have to work on the throttle compensation a bit, but hopefully this will get better as the table is tuned.

One question - might be worth starting another thread, I am seeing values >100% for ve. It's not a problem as such, but it leads me to believe there is something up with the set up somewhere. Is this something common in NA applications with the M1? I wouldn't be surprised if I saw up to 105 at the top of the map, but I have seen up to 130 at 2500. Any thoughts on this?

Just some info about the engine for those who might be interested:

Mazda BP05

250* at 50 thou duration

10mm lift

Inlet: 3.7mm lift at TDC

Exhaust: 3.4mm lift at TDC

1mm oversized valves

SR20 beehive springs

ported head (obviously)

11:1 compression - fuel is 98RON

It made 180 is HP on the engine dyno, comparable to other class cars - bit down on power and torque though. Most of the classes engines run a slightly different camshaft (less duration and 11mm lift) and more extensive porting. So hoping to see 150-160whp, 30-40 more than my old engine.

My max VE is around 128 - 132 on my NA Mazda 2L MZR, with AT Power ITB's and a really good custom exhaust (otherwise stock) -- I get just over 200 whp on my Dynapack dyno (efficient straight-cut Hewland gearbox). The VE number is just a number -- it is what it needs to be to get the proper fuel calculation for the given air calculation.

Give the engine what it needs, and don't sweat it.

You do realise that the GP Packages in M1 will do throttle based mapping out of the box.

The Engine Load Normalised Mode set to Throttle Position, and the Inlet Manifold Pressure Estimate Main table correctly populated will allow for the Engine Efficiency tables vertical axis to be based on throttle position.

I had found some stuff about using the Inlet manifold pressure estimate main table, but from what I understood, this didn't change the efficiency table. I'm happy to have a look at doing it that way.

From what i have looked at and read, you would set inlet manifold pressure mode to estimate. I get a bit lost with the inlet manifold pressure estimate mode - so I would get another pressure sensor for ambient pressure, and set inlet manifold pressure estimate mode to ambient relative?

Then I would populate the estimate table with a% of air pressure in the manifold - so if I am getting 85kPa at 1500rpm @ 0% TPS, I would populate that cell with 85% - and that value would 85% of the ambient pressure?

So on the engine efficiency table, I would change my load axis from 0 to 100kPa? Sorry, I don't quite follow how this changes the engine efficiency table - or how i would set it up to work correctly.