LS1 Boost OS - Development

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Re: LS1 Boost OS - Development

Postby NSFW » Sat Jun 04, 2022 4:48 am

bubba2533 wrote:I am pushing towards variables seen in most aftermarket ECU's. So I've actually considered creating a new set of spark tables that are based on MAP and not g/cyl. This would also allow for the removal of my Boost Spark Adder table since I could just increase the size/range of the table.

Cool. I started with tuning stock ECUs so I'm just used to having a g/cyl axis... but as long as fuel and spark use the same axes, then it doesn't really matter which.

I might switch to this OS for my car, even though it's naturally aspirated, just so I won't have to deal with power enrichment. I'd much rather have a proper fuel table instead. :)
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!

Posts: 66
Joined: Sun May 11, 2014 6:36 pm

Re: LS1 Boost OS - Development

Postby Highlander » Sun Jul 03, 2022 11:12 am

bubba2533 wrote:So....I changed things again...

I've changed how I am doing desired air/fuel ratio. I replaced power enrichment with 2 new "Desired Air/Fuel Ratio" 3D tables based on MAP and RPM. I added 2 of them to allow for different Air/Fuel ratios between E0 and E80 (Flex Fuel Enabled).

I've stopped working on V3 and I'm going to start doing testing in my truck. I would like to get this out there for other people to play with as I think it's a huge upgrade from V2. There are significant changes so there will be no easy way to upgrade from V2 -> V3. But I'm hopeful that all the changes I've made will allow for relatively easy upgrades in the future.

Also......I've started work on V4 that will allow for some big changes for the MAF guys....lots more work to do, but it's looking pretty easy to increase the MAF frequency and g/sec capacity. If you are interested or have an opinion on the table size/limit for an update MAF calibration let me know what you think it should look like.

P59 MAF curve is 1500-12,000 Hz with 125 Hz resolution and a maximum airflow value of 511.99 grams/second
E37 & E92 MAF curve is 0-15,000 Hz with 150 Hz resolution and a maximum airflow value of 4,000 grams/second

You can increase the MAF Hz super easy on these. the g/s is going to be more dependent on the scaling that you use throughout. By changing inj constant you actually scale the maf directly in these.
E92 has ability to edit the labels. While its not needed (always liked the 150hz scaling) it is sometimes beneficial on cam'd cars.

Posts: 66
Joined: Sun May 11, 2014 6:36 pm

Re: LS1 Boost OS - Development

Postby Highlander » Sun Jul 03, 2022 11:21 am

Phoenix wrote:Please forgive me if this has been discussed before, but would it be possible to extend the Injector Flow Rate table to boost areas? I know that up to know people have been compensating by either adding more fuel or using a boost referenced regulator, but I think it would be pretty neat to give the PCM accurate injector data while in boost. I don;t think one would need to increase the table size, just change the values that are referenced. Please take a look at the attached injector data, I took this from the ID725 spreadsheet. The top table is what the P59 currently has and the bottom table is what I'm talking about changing it into. I'm not sure what OS or ECM uses the lower table.

0 kPa is atmospheric pressure, positive kPa is vacuum and negative kPa is boost. The lower table would max out around 12 psi in boost. Maybe the two halves can be scaled differently so the boost side could include more columns than the vacuum side?

I was always interested in doing thsi mod, but in reality, it is sort of useless as most of the time people have vac referenced pressure regulators as it natively increases the injector range of airflow it can fuel.

better mod would be to add fuel pressure sensor and adjust by it


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