LS1 Boost OS - Development

For discussion and distribution of custom code and hacks
bubba2533
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Re: LS1 Boost OS - Development

Post by bubba2533 »

Yeah, it a tough market right now for stock PCM stuff. I really don't think it's worth much effort with how inexpensive the Holley Terminator is.

I would love to have a RSLS1, but I really don't think it would be worth it unless it was very inexpensive. If it was open source that would be awesome and might significantly revive some interest in stock PCM things.
LS1 Boost OS V3 Here. For feature suggestions post in here Development Thread. Support future development ->Patreon.
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Gareth
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Re: LS1 Boost OS - Development

Post by Gareth »

The Holley stuff is rubbish

[youtube]https://www.youtube.com/watch?v=k0hOVIT1RuA[/youtube]
According to chemistry, alcohol is a solution...
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NSFW
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Re: LS1 Boost OS

Post by NSFW »

kojab wrote:What saddens me is the technology that was put into the RTLS1 is wasted unless I pass on RTLS1 source code to someone who will not profit on our hard work.
RTLS1 is really cool project. Have you considered posting it on GitHub under an open source license? This is what I do with all of my home software projects that turn out to be useful (and some that don't).

And even for the rare project I work on that might be sellable, like PCM Hammer... I still never wanted to sell it, because I don't want that job. I'm too busy already with my day job and hobbies. Also, those of us who worked on it could not get it done individually, so we had to collaborate somehow, and collaborating under the open source model ensured that nobody could get ripped off. It's very hard to profit on something when somebody else is giving it away. :)

GitHub works for hardware projects too - there are plenty of schematics and PCB layouts and CAD files up there for project that aren't strictly software.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
kojab
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Re: LS1 Boost OS - Development

Post by kojab »

Thank you NSFW for your input. GitHub is something I will look into.
bubba2533
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Re: LS1 Boost OS - Development

Post by bubba2533 »

Gareth wrote:The Holley stuff is rubbish

https://youtu.be/k0hOVIT1RuA
Seems like they’re selling pretty good. More so I was talking about the terminator. I would never put TBI on any engine.
LS1 Boost OS V3 Here. For feature suggestions post in here Development Thread. Support future development ->Patreon.
bubba2533
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Re: LS1 Boost OS - Development

Post by bubba2533 »

bubba2533 wrote: I got lucky! It's working on the bench already. As far as giving a signal. It's kind of weird because the interface is requesting a position instead of a duty cycle, but I can change all that when I write new code.

I also quickly figured out a way to modify the frequency. I may be doing it wrong, but it is only going down to 60hz. I'm not sure if that will work very well for a boost control solenoid.
So I did some more digging into the code and there seems to be some limiting of the frequency deeper into the code. I wasn't doing it wrong, but I don't think the EGR output is capable of a lower frequency. At least I don't feel confident hacking the code to modify the range. It may just cause it to crash or get into an unknown state. For all I know the hardware isn't capable of running at that low of a frequency.

I also found some info on boost control solenoid frequency here: http://www.circuitse7en.net/page26.php
Based on that info 60hz would provide a very small window of useable duty cycle and it's possible it could not even work since they only tested up to 40hz.

I'm not really sure if there is an ideal frequency, but I've seen that 25-30hz is very commonly recommended.

Next steps for me are to investigate other outputs to see if they are capable of running that frequency range.
LS1 Boost OS V3 Here. For feature suggestions post in here Development Thread. Support future development ->Patreon.
kur4o
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Re: LS1 Boost OS - Development

Post by kur4o »

I bet the frequency is hardcoded in the code. I think also it is some prescaler of the main tpu running frequency.

If you know a command to actuate egr solenoid some experiments will get you there.
bubba2533
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Re: LS1 Boost OS - Development

Post by bubba2533 »

Yeah it was hardcoded. I added a parameter so I could quickly modify it.

Before:

Code: Select all

0x2E424  move.l  0x1F9 , d1  ;move frequency to register
After:

Code: Select all

0x2E424  move.l  (0x1FEF2).l  , d1  ;move frequency parameter to register
I was able to get the actuate it with HPTuners. But the frequency of the output was ~60hz even when I set it to 30,15, etc.

I measured the frequency at 128hz with my scope with the factory setting. And worked out the scaler to modify it.
LS1 Boost OS V3 Here. For feature suggestions post in here Development Thread. Support future development ->Patreon.
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NSFW
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Re: LS1 Boost OS - Development

Post by NSFW »

I'd try it at 60hz just to see what happens, but I'll admit that it is suspicious that most sources I could find say 15hz or 30hz. My Subaru is 15hz from the factory, and I've heard of people getting better results at 30hz, but it's not something I've experimented with myself.

For cars with manual transmissions, there are solenoid outputs for the automatic that could be repurpose. But I'm sure there are plenty of people with turbos and automatics, so that approach would be less than ideal.

It's also worth considering a manual boost controller in parallel with a solenoid. The MBC governs peak boost level, and the solenoid opens at part-throttle to solve the part-throttle-full-boost problem that happens with an MBC alone. I run my Subaru that way just because it's dead simple to tune. I do ramp in the MBC, but I'm pretty sure it would almost as well if the MBC was just an on-off switch at around half throttle or so (whatever throttle level makes enough boost to surpass the wastegate spring).
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
bubba2533
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cars: 03 Chevy S10 Turbo V6

Re: LS1 Boost OS - Development

Post by bubba2533 »

I’ll have those as backup plans, but I hope to get something better to work. I’ve seen secondary fuel pump relay control in wiring diagrams and I may have found the code that controls it. Not sure if the hardware in the PCM will run the boost control solenoid since a typical relay coil is fairly low current.
LS1 Boost OS V3 Here. For feature suggestions post in here Development Thread. Support future development ->Patreon.
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