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Megasquirt Alpha N Table
prelude1980 - 4/7/10 at 09:31 AM

I was just wondering on megasquirt alpha N table is it the same figures across each line? i know it changes as you go up the table but i was wondering about as you go across the table?


omega 24 v6 - 4/7/10 at 10:56 AM

Not sure what you mean really??

Along the bottom you will have RPM up the side TPS or MAP and in each box between these points a wildly differing set of figures none of which you can guess correctly.


prelude1980 - 4/7/10 at 11:25 AM

this is the part i can't seem to find, nowhere seems to give guidelines on what the numbers in the table should be


MikeRJ - 4/7/10 at 11:41 AM

The numbers are simply the optimum amount of ignition advance for that specific combination of engine RPM and engine load.

You won't find anywhere that tells you exactly what numbers to put in the table - every different engine and installation will be different. A rolling road session is by far the best way to create a good map.


prelude1980 - 4/7/10 at 12:12 PM

but it's the Alpha-n table just a fake map table, how do you determine the numbers to put in a fake map table?


flak monkey - 4/7/10 at 01:17 PM

Alpha-n is the fuelling algorithm it uses throttle position and rpm to determine the fuelling.

Speed-density uses MAP (manifold air pressure) and RPM to determine the fuelling.

Which version of MS are you using and what are the full details of your set up? Someone can then give you a basemap to start you off.

If you are as stuck as you sound, are you sure MS is the correct direction to go in?

I would thoroughly suggest reading the relevant MS manuals, especially the software setup and configuration for a basemap.

David


omega 24 v6 - 4/7/10 at 01:25 PM

If it is the ve table you are speaking about the you can generate one using megatune (not available in tuner studio i don't think).

you will need to set everything up to suit your build/hardware/software etc etc it is not just a case of plug and play I'm afraid ( hope i'm not teaching you to suck eggs)

just keep asking questions you will always get answers regardless of how silly you MAY think they are. 3 years in I am still asking.
you will also get a quicker answer on here than the ms efi site ( mostly yank cars on there).

ETA as flak says you really need to READ READ READ. If you don't or if you cannot understand what you need to do then you really will struggle.
It's been a struggle for me ( still is at times) but all the info is out there all you need to be is patient and VERY interested to work it out. it is a trial but will give you a MUCH MUCH better understanding of all things EFI

[Edited on 4/7/10 by omega 24 v6]


prelude1980 - 4/7/10 at 04:26 PM

Sorry it's my usual thing of not explaining. I'm running speed density on ms2. I got a zetec on bodies. BUt due to the problem with the map range I am having a playing with alpha n


paulf - 4/7/10 at 10:10 PM

I ran speed density for some time but was never happy with it although i still think it could be the better measure of engine load.
I changed to Alpha-N and guessed at some figures for the map based on the speed density maximum and minimum figures and by looking at similar maps .
It was good enough to get it started and then i data-logged it and adjusted by trial and error and feel whilst driving.
The MAP is nowhere near the shape of the speed density one but is much smoother to drive,I also changed to RPM throttle enrichments which is a big improvement and easier to set up.
To make the base MAP you need to get an idea of the TPS range that most of your driving is done in, You will need a couple of rows near idle a couple spaced apart for full throttle and the rest in the middle closely spaced for mid range and cruise points.Do the same for the revs across the MAP also.
Paul

quote:
Originally posted by prelude1980
Sorry it's my usual thing of not explaining. I'm running speed density on ms2. I got a zetec on bodies. BUt due to the problem with the map range I am having a playing with alpha n


flak monkey - 5/7/10 at 07:14 AM

Change to alpha-n - you'll never get a good map on speed density on throttle bodies.

For the throttle bins (y-axis) they work on % as well in MS2.

I would suggest rows as follows:

Top line 100%
Bottom line 0%
Then from bottom up:
1.5, 3, 5, 8, 12, 15, 25, 40, 55, 75, 90

You need lots of resolution around your cruising area which is normally up to around 15% throttle and just off closed throttle. Then above that everything else is fairly arbitrary as its nearly linear with TPS.

Your 0% line is your idle line.


prelude1980 - 6/7/10 at 05:04 PM

quote:
Originally posted by flak monkey
Change to alpha-n - you'll never get a good map on speed density on throttle bodies.

For the throttle bins (y-axis) they work on % as well in MS2.

I would suggest rows as follows:

Top line 100%
Bottom line 0%
Then from bottom up:
1.5, 3, 5, 8, 12, 15, 25, 40, 55, 75, 90

You need lots of resolution around your cruising area which is normally up to around 15% throttle and just off closed throttle. Then above that everything else is fairly arbitrary as its nearly linear with TPS.

Your 0% line is your idle line.


Thanks Flak that's very helpful and does make sense.

I have 1 table "Alpha N Map Table' that i'm not sure about it's a 6x6 table


prelude1980 - 10/7/10 at 07:56 PM

been playing all day with the map and got it drivable finally. Now using tunerstudio ve analyzer to tune it up a bit better.