Tuning your MegaSquirt - Speed Density V Alpha-N

[Reynard923]

MegaSquirt MS-11 Fuel only. (Megatune 220-1 old version)

I have finally built my EFI system ( replacing twin 48mm webers) for my 1600cc single cam 8 valve VW Golf engine.
This is a full house race car engine with its only intent is to produce maximum power - usable rev. range is 7000 to 8500 rpm.

Installed and programmed MegaSquirt according to the manual, I am able to:
1. start the engine
2. get it to idle cleanly at between 1600-1800 rpm (much better than the weber's)
3. some limited afr tuning for idle.
4. no load - will rev cleanly to 4000rpm with out any hesitation ( a single seat race car is not something you take out onto the street).

Next step is some 'rolling road' time to have it tuned in the power band so it will work on the track. I will have to pay for this.

My problem is this:
I managed to get this far using the Control Algorithm - Speed Density. I only discover this when I went over all of my tuning imputs.
I have no MAP input. There is nowhere on the 4 Throttle Bodies to take it from and besides the huge overlap on the cam would make it
impossible to get a stable measure.

I then changed the Control Algorithm to - Alpha-N with 2 injections per cycle and Simultaneous staging.

I cannot get it to start. Does not won't to know about it. If I change back to - Speed Density - starts and idles as if nuthing had happend.

Has any one else experienced this problem and does any one know what I am doing wrong.

[Peter Florance]

datalog starting attempts of each setup and post them along with their msq's

[grippo]

There is more to it than just switching the algorithm. There is a table that maps tps to an equivalent map that you can use, under Other Tables, AlphaN MAP table. This table allows you to enter values of equivalent map for each tps and rpm combination. Then this table is used for the map entry into the VE (map, rpm) table. If you don't want to do this, you can set all the table entries equal to the tps values and then VE will become a function of (tps, rpm). The other thing you need to do with alphaN is to select an rpm range under Other Fuel, AlphaN Blending. If you want alphaN everywhere, and you do if you don't have a map sensor, then set both rpms to 10000 rpm, you will never exceed this, so you will never enter speed density.

[Reynard923]

Hi Peter,

In responce to your query regarding dataloging. I have paid for MegaLogViewer
but have some issues reading any of the data from MegaTune.
I have asked for help on another thread. I think it has something to do with
Firmware !!!!

Hi Grippo,

I will digest the information you have provided, apply it and return with the results.

Once again, thanks for your inputs.

[Reynard923]

Hi Grippo,

I have just compared your suggestions to my Megatune 220-1 software.
It does not contain the tables (other tables, AlphaN MAP Table)

On the old software I can only find - Settings - VE Table - Controller VE Table.
I am aware that this is old software. Here's the thing - my Dell has old Windows 2000 Professional,
but it has a serial port. The Old Windows will not allow me to download the new Megatune software.
My new notebook has the latest Windows Vista 7 software, but only 2 USB ports. It will not talk to my
MegaSquirt ECU. ( this is why Bill Gates is the richest man in the world ).

Can I open the Controller VE Table and manually fill the 8 RPM bins to 8500rpm and fill the TP% bins
with 10 to 100 and burn to the ECU. Will it stick, and most importantly, would it work.

Your responce would be most appreciated.

[trakkies]

Hi Grippo,

I have just compared your suggestions to my Megatune 220-1 software.
It does not contain the tables (other tables, AlphaN MAP Table)

On the old software I can only find - Settings - VE Table - Controller VE Table.
I am aware that this is old software. Here's the thing - my Dell has old Windows 2000 Professional,
but it has a serial port. The Old Windows will not allow me to download the new Megatune software.
My new notebook has the latest Windows Vista 7 software, but only 2 USB ports. It will not talk to my
MegaSquirt ECU. ( this is why Bill Gates is the richest man in the world ).

Something odd going on. I had an old laptop running Win98SE and managed to download everything I needed.
Now one with Win7. For that I have a USB to serial adaptor.

[Peter Florance]

Hi Peter,

In responce to your query regarding dataloging. I have paid for MegaLogViewer
but have some issues reading any of the data from MegaTune.
I have asked for help on another thread. I think it has something to do with
Firmware !!!!

Hi Grippo,

I will digest the information you have provided, apply it and return with the results.

Once again, thanks for your inputs.

Hi Reynard
I recommend TunerStudioMS (same author as MegaLogViewer) instead of MegaTune
Note the version of Megatune is not the same as the firmware version that is in the MSII. TunerStudio will tell you what firmware version you have.