Running ITB mode backward?

All questions about MS2/Microsquirt/Microsquirt module. See also MS2/Extra manuals

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Running ITB mode backward?

Postby yellow-fever » Sun Dec 24, 2017 4:28 am

So if I understand correctly, itb mode blends map based at low load with TPS based at high loads. This is done for more accurate load sensing because of the way ITB's work so you only have to tune one VE table and Tunerstudio autotune will work when set up correct. Can I reverse the curves so it uses TPS at low loads up to 100kpa "normal off boost" and then swap to map based from 101kpa to 250kpa? It's a fuel injected two stroke that currently runs alpha-n TPS based and I need to add fuel when I add a turbo, so map based would work best high rpm and TPS at low, the oposite of ITB on a four stroke. Can I just reverse the curves and have it work correct?

I can turn on second load source in tunerstudio vs ITB mode and a second table option shows up so table VE1 is Tps vs rpm and VE2 shows map vs rpm, the autotune feature then also has the choice to tune VE1 and VE2 in separate windows.
How does it autotune with two different VE tables? I used autotune with a map based system only with a single VE table and had great luck but that was a smooth 4 stroke not a finicky two stroke with a weak low load Vac signal.
Any info is greatly appreciated!
Thanks :)
Turbo BMW E30 MS3X
Turbo Skidoo 670 Microsquirt
Skidoo 1000SDI Microsquirt with future turbo goals
http://www.dootalk.com/forums/topic/147 ... k-install/
yellow-fever
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Re: Running ITB mode backward?

Postby muythaibxr » Sun Dec 24, 2017 5:32 am

Your best bet is to use ITB mode the way it was designed, and use table switching with a second table to handle boost. ITB mode can’t currently be reversed the way you are asking.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.

:msq:
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Re: Running ITB mode backward?

Postby yellow-fever » Sun Dec 24, 2017 5:49 am

Thanks for the quick reply! :) Wouldn't running my engine in ITB mode not work well since it runs the oposite of ITB with weak low speed map signal where ITB has strong?

If I set the main fuel algorithm to Tps and secondary to map it now shows two VE tables. I set the TPS based ve1 table from 0 to 100% Tps angle and the second ve2 table from 101kpa to 250kpa. Can I tune VE1 with autotune with table 2 locked and then lock VE1 table and tune ve2 table with autotune when I add the turbo? I know autotune cannot do it all specially on a 2 stroke but I had great luck on my strictly speed density based turbo BMW e30.
Turbo BMW E30 MS3X
Turbo Skidoo 670 Microsquirt
Skidoo 1000SDI Microsquirt with future turbo goals
http://www.dootalk.com/forums/topic/147 ... k-install/
yellow-fever
MS/Extra Newbie
 
Posts: 32
Joined: Sun Feb 10, 2008 12:20 pm

Re: Running ITB mode backward?

Postby yellow-fever » Sun Dec 24, 2017 3:06 pm

I just connected a Microsquirt to a Jimstim and simply tried it with autotune. You can tune one table at a time or both at the same time. If you turn the simulated wideband up or down it chages the VE tables up and down nice and steady like it should. This looks extremely promising! I think I can tune the alpha-n off boost table VE1 close to perfect and then just lock it and tune the second VE2 table when I am ready to add boost. The flexability of this product line absolutely amazes me all the time. I swear the people that crap on it just don't really know what they are doing or how to properly work out bugs that are a normal part of any custom one off build project. I think people that hate it are maybe more of an expensive plug and play type of person verses cost effective version for someone who likes to tinker.
Thanks for the input! :)
Turbo BMW E30 MS3X
Turbo Skidoo 670 Microsquirt
Skidoo 1000SDI Microsquirt with future turbo goals
http://www.dootalk.com/forums/topic/147 ... k-install/
yellow-fever
MS/Extra Newbie
 
Posts: 32
Joined: Sun Feb 10, 2008 12:20 pm


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