Boost Control

Testing and development of Megasquirt 3

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jarods7920
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Boost Control

Post by jarods7920 »

Does anyone have a preview of what the MS3 boost control set up is going to look like? I would love for it to be set up to where you can do it similar to a more advanced ems. WIth MS2 its only 8x8 which is terrible IMO. In working with other EMS systems even piggy back, their are boost control features that allow you to bring boost on by as much as a pound per 100rpms. Now i am not sure what this new processor is capable of, but it would be amazing to see something a bit more advanced. Or even gear by gear would awesome as well.
muythaibxr
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Re: Boost Control

Post by muythaibxr »

Why would you want to change the boost by 1 psi per 100 rpm? What is the use-case for that?

We plan gear-based boost and a couple of other options that we don't currently do in ms2/extra.

However, I don't see any need to allow boost target to change every 100 RPM. Most likely the controllers you're talking about most likely do not interpolate, and instead compensate by creating overly large tables.

With interpolation 8x8 is way more than is probably necessary.

For example to gain a 1 psi change over 100 RPM, you just set up two bins 700 RPM apart and make the boost change by 6-7 kPa between those bins.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
jarods7920
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Re: Boost Control

Post by jarods7920 »

Well, where it becomes useful is in lower gears. Say for example first and second. You add a pound or two per 100 rpms or so that you can keep the car from spinning instead of just throwing 20 psi at it all at once. In higher gears its not so much an issue. Having a FWD car makes this a very desirable feature. I mean a 100 rpms is just an example i am not saying it has to be exactly that, just a reference point.
muythaibxr
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Re: Boost Control

Post by muythaibxr »

OK, but that would work fine with the 8x8 table and interpolation, just as my example above says.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
jarods7920
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Re: Boost Control

Post by jarods7920 »

Will there be any sort of scramble feature, say you want to turn up the boost for a run or two. Rather that going into megatune and changing the map just flip a switch or something like switchable tables and it switches?
muythaibxr
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Re: Boost Control

Post by muythaibxr »

Yes, I believe that switchable boost target tables are already in. I think once I get the code responding better to target changes that'll work better, but even now it should work fine.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
jarods7920
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Re: Boost Control

Post by jarods7920 »

Hmmm....maybe i wont be switching EMS' then. I guess i will give the MS a try and then if it doesnt work then i can go from there. Thanks for your help.
jarods7920
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Re: Boost Control

Post by jarods7920 »

Ok, one more question. Is the boost still going to be set my TPS? Or is there going to be a way to set it based upon MPH or perhaps maybe using the traction control system. Say be able to cut duty cycle back to the solenoid when the car sees the speed from a front wheel speed sensor rise faster than the one from the rear or visa/versa? There would have to be a way to turn it off during the burn out of course.

Just trying to think outside the box and get the best control for launching the car. I went the my MS2 stuff and i could not find the traction control, it was only in ms1.
muythaibxr
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Re: Boost Control

Post by muythaibxr »

It'll be settable the way it is now in ms2/extra, VSS, or gear.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
jarods7920
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Re: Boost Control

Post by jarods7920 »

Boost control or traction control?
UnaClocker
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Re: Boost Control

Post by UnaClocker »

I think traction control and mappable water injection were the only two things that never came over from MS1 into MS2.. Judging by the lack of discussion about it there, I imagine it was because nobody used it.. ;)
edit: oh yeah, 3 stage shift lights didn't come over either, but that might have been possible with some clever use of the generic outputs. :)
Brian
'84 Dodge Rampage
muythaibxr
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Re: Boost Control

Post by muythaibxr »

A few people used them, but considering that we didn't bring them over, and very few people said anything, I'd say that very few people used those features.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
jsmcortina
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Re: Boost Control

Post by jsmcortina »

jarods7920 wrote:Just trying to think outside the box and get the best control for launching the car.
Please continue to do so - the more ideas and discussion we have, hopefully the better we can make the MS3 feature-set.

James
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muythaibxr
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Re: Boost Control

Post by muythaibxr »

jarods7920 wrote:Boost control or traction control?
I was thinking about boost control.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
Matt Cramer
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Re: Boost Control

Post by Matt Cramer »

Una wrote:I think traction control and mappable water injection were the only two things that never came over from MS1 into MS2.. Judging by the lack of discussion about it there, I imagine it was because nobody used it.. ;)
edit: oh yeah, 3 stage shift lights didn't come over either, but that might have been possible with some clever use of the generic outputs. :)
I'm not sure the traction control really worked, but there's now an effort at bringing it over to MS2/Extra.

I do get occasional requests about water injection with MS2.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
UnaClocker
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Re: Boost Control

Post by UnaClocker »

Yeah.. I wasn't saying it was a bad thing or anything, just noting that out of all the features, those were the 3 I had found that hadn't come over.. Most of that missing stuff can be implemented on a GPIO or Jean's IO Extender board now (well, once one of those starts shipping)..
Brian
'84 Dodge Rampage
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