Table switching to Alpha N MS2

Stubbe · Post by **Stubbe** » Sat Aug 12, 2017 4:21 pm

Tell me if you need more info, v6, ITBs, running MS2 and exta code. NA engine. I have a rough tune for cruising right now.

I'm trying to tune my motor and started with speed density. It works pretty good while cruising,but I could never get to anywhere near half throttle since it goes to atmosphere instantly. I tried doing the IBT mode like I should but for some reason it wouldn't work. I would be below the switch curve and tps and it wouldn't run my speed density table that worked before. I couldn't even get it to start.

Then I see the secondary load and set that to Alpha N (primary is still speed) and it works that I can now accelerate with more throttle. I set a filter in Veal to >90 kpa thinking it will lock it out before that. However I find the more I tune this its adding to my primary table and messing it up at points. It seemes even though I am below first cell it still adds that value in the total fuel calculation. I saw the table switching and can set it to switch to >90 KPA but the table itself is map referenced.

What I would like is to run one table below 90kpa with KPA as the load axis and then switch to another table at greater than 90KPA that loads off of TPS.
How would I go about this?

Thanks, Stubbe

Moody · Post by **Moody** » Sat Aug 12, 2017 4:52 pm

Honestly they way your trying to setup SD with alpha-n is the same thing as itb in the end. If you would take the time to setup the ITB switch tables it will work awesome and be easy to tune.

With that said, I have done it both ways. Although, I advise you use %baro instead of SD for your primary. This is currently how I'm running my boosted ITB motorcycle. The reason for %baro is because this is an engine that it street/highway driving and altitude changes don't change your fueling during altitude changes. %baro and SD are tuned the same but %baro helps with baro changes where SD is not near as easy to tune with of you go up some mountains. Even if your don't plan to change altitudes much I still would use %baro, not really a reason not too....

I wouldn't do table switching. I would setup %baro/SD as primary and then setup Alpha-n as secondary table.

I added a couple photos showing my two tables on my boosted bike to give you an idea how you may want to go about building a table. I only use the alpha-n table to ad fuel in those high load low rpm areas. Once you get into high roms with %baro/SD table shouldn't have much problem fueling on its own.

Hope that helps,
Dustin

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Stubbe · Post by **Stubbe** » Sat Aug 12, 2017 5:13 pm

I'll try the % baro. I have it set to an Alpha n additive right now. The problem i noticed is my second table is adding fuel when I don't want it to. Ex my second tables lowest cells are set to 2000 rpm and 15% tps. However when I am sitting at idle it is richer than it was and I found out the second table is adding even though its not above 2k or 15%. It seems like it continues the lowes cells value off the table.

Stubbe · Post by **Stubbe** » Sat Aug 12, 2017 5:18 pm

Just saw your lower section of the alpha table is set to zero fuel. That might be what I needed.

Moody · Post by **Moody** » Sat Aug 12, 2017 5:19 pm

Stubbe wrote:I'll try the % baro. I have it set to an Alpha n additive right now. The problem i noticed is my second table is adding fuel when I don't want it to. Ex my second tables lowest cells are set to 2000 rpm and 15% tps. However when I am sitting at idle it is richer than it was and I found out the second table is adding even though its not above 2k or 15%. It seems like it continues the lowes cells value off the table.

You will have to manually adjust the tps table for what the engine likes. Any cells set to 0 shouldn't add any fuel based off of tps.

Switching to %baro won't should change anything in your tune. It's just something I suggest for future driveability issue with altitude changes. And it works better with a dedicated baro sensor. But currently I use it with taking baro measurement from map sensor on power up....

Dustin

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Moody · Post by **Moody** » Sat Aug 12, 2017 5:22 pm

Stubbe wrote:Just saw your lower section of the alpha table is set to zero fuel. That might be what I needed.

Correct. I basically have the tps table adding fuel when I noticed the engine wanted it on the datalogs. Make sure to smooth your tables to make smooth fuel transitions.

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red-racing · Post by **red-racing** » Mon Aug 14, 2017 12:04 am

switch to alpha-n primary, multiply map. no secondary. tune your ve table.
I`ve done this number of times, without any problems.

Stubbe · Post by **Stubbe** » Wed Aug 23, 2017 6:54 pm

The dual table thing seems to be working for me. Not perfect, but its working. Does the alpha primay/multiply just make it one table. Hows is cruising/daily. I'm not really at WOT all the time so cruising matters some. All I could find is that it does "hybrid alpha n" which I don't really understand.

Also it seems like past 4k on my speed density table I"m at 90kpa and map doesnt matter. Should I max that table out at 4500 and rely on Alpha N for higher rpm/WOT. It seems my table could have more clarity then since I have half my bins are pretty well unused

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