MS1/extra firmware differences?

[elaw]

Can someone answer a noob question about MS1/extra? I'm pretty experienced with MS2 and MS3 but almost totally ignorant of MS1.

On the downloads page, I see 3 different versions of the firmware:

MS1x.PNG

What's the difference between them?

I remember reading somewhere that the hi-res code has higher resolution (go figure) on spark or fuel or both, but I don't think the page I read said whether there were any tradeoffs for that... othewise why would anyone *not* use the hi-res code? And in the list, I see both "hi-res" and "hr" firmware - are those both the hi-res code?

So if someone could unconfuse me on this I'd really appreciate it! I've searched here and on Google but couldn't find anything definitive.

[racingmini_mtl]

I know almost nothing about MS1/Extra but i do know that the high res version loses PWM for the injectors so you can't use low Z injectors directly.

Jean

[jsmcortina]

Bin the MS1 and upgrade to MS2 instead.

James

[elaw]

Believe me I would if I could... but right now my budget for this project is no more than the $0 this MS1 box is costing me...

[Matt Cramer]

The high-res code has higher injector pulse width resolution, but no PWM current limiting. In theory it's something like 100 times more resolution, but in practice, the 8 bit calculations give you about 3 times the resolution.

[Six_Shooter]

Is the injector control the only difference?

I have two MS1 ECUs here, one has the HR_11d firmware loaded, the other has 0289y4a firmware loaded to it. I have a third MS1 CPU as well, but I've never powered it up to see what is on it...

Anyway, in Tunerstudio the 029y4a firmware seems to have more options and better layout (using TS v2.6.19, haven't upgraded my desktop TS install yet). Is my quick look accurate in that 029y4a has more refining in options and setup?

A complete list of differences would be great, since it would help others choose the best firmware for their uses as well.

I'm using an MS2 currently on one project car, but I'm going to need that for a different project and in the future I will be installing a Crower mechanical injection intake that has had electronic injectors installed (just need to finish the rail mounts and a couple other details) and originally had planned to add both IAC and MAP manifolds to the intake (because original plan was to use a Delco '7730 ECM), but since I have a couple MS1 ECUs, I thought I might try MS1 using Alpha-N so that I don't need to drill and tap any more holes into the intake than I absolutely have to, and keep the possibility for leaks to a minimum.

[Matt Cramer]

There was a menu layout copied from MS2 and MS3 that was put together for the 029y4 code that was not brought over (to the best of my knowledge) for the HR code, but the options are the same. Just arranged differently.

[dontz125]

There is *something* between 10g and 11d that didn't survive the upgrade experience unscathed. There were several threads a few years back about people complaining about this particular aspect - might have been baro correction - that didn't work properly in 11d, and the cure was to roll back to 10g.