Wheel Translator Board

If you have ideas for a new board, for new features for existing boards, or want to suggest new applications for the I/O Extender, this is the place to post.
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dwizle
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Wheel Translator Board

Post by dwizle » Thu Jun 06, 2019 12:02 pm

Jean would you consider re-releasing the Wheel Translator Board for MS2/3
I know they have Tri-Tach but Tri-Tach doesn't address a certain family of engines
specifical the early 944/951 engines which use dual wheel VR sensors but not Cam sensor
I've tried the 36-1 on the front of the crank but I keep running into issues because it is so close the the
Alt and the wires run close to the spark plug plus I would like it to be plug n play into the stock harness
I live in California an had to do a bi-annual smog check if not a re-release a schematic so I could build my own?

jbelanger
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Re: Wheel Translator Board

Post by jbelanger » Thu Jun 06, 2019 1:04 pm

The wheel translator would likely not be of any help because of the number of teeth on your setup. You need a divider that will result in a number of teeth between about 30 to 60 teeth but you also need that resulting number to meet the MS2 requirements for the number of teeth. That is a number that is an integer number of tenths of a degree and a multiple of the number of cylinders/2.

If you're not sure, post the number of teeth in your setup and I'll explain.

And you cannot build one from a schematic because it requires a small microcontroller programmed by me with my proprietary code.

Jean
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dwizle
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Re: Wheel Translator Board

Post by dwizle » Sat Jun 08, 2019 2:44 pm

So I am building on a 944 NA
The 944 has 130 teeth and is used for speed sensing, additionally, the flywheel has a pin that is used for reference position, the pin tells the DME when the engine is at TDC #1

MS3 now has tri-tach that can handle that teeth count but requires 3 inputs a 944 and 951(944turbo) don't have a cam sensor only the twin cam 944 S2 has a cam sensor

dwizle
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Re: Wheel Translator Board

Post by dwizle » Sat Jun 08, 2019 2:52 pm

5.3.40 Specific ignitions: Flywheel tri-tach
Known applications include:
• Early 1980s Porsche 911
• Porsche 944 Turbo (951)
• 1986 and earlier BMW 325e
• E30 chassis BMW M3 with S14 motor
• Many 1980s and early 1990s Audis
This application uses a VR sensor that counts flywheel teeth, with a second flywheel sensor that
reads a single post and, in most implementations, a cam sensor. Note that the number of teeth is
hardcoded for a specific number of cylinders. With a cam sensor, this will support full sequential.
Current ones available include:
Number of teeth Number of cylinders
135 5
135 6
136 8
132 4
130 4
This mode is also considered experimental at this point.

jbelanger
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Re: Wheel Translator Board

Post by jbelanger » Sat Jun 08, 2019 4:07 pm

135 works for 5 and 6 cylinders because you can divide by 5 and get a virtual 45-1. This works for a 5 cylinder with 18 teeth between ignition events (but you do need a cam signal) and it works for a 6 cylinder with 15 teeth between ignition events (and it can either be with or without a cam signal). And it works out to 8.0 degrees per virtual tooth. You then use the generic missing tooth mode with either MS2 or MS3.

You cannot do the same for any of the other setup using a simple divider like is used with the wheel translator board (the MS3 uses a dedicated mode which is not available on the MS2). 132 teeth can be divided by 3 or 4 but it gives 33 or 44 virtual teeth which will not give an integer number of tenth degrees and 33 is not a multiple of 2 (number of cylinder divide by 2). 130 teeth can be divided by 5 to give 26 virtual teeth which again does not give an integer number of tenth of degrees.

And trying to implement the MS3 code inside the small processor on the translator CPU is not possible or practical due to limited resources and the effort needed to create the code. It would also not be accurate enough to use for ignition timing (the current code uses the real teeth and simple code so there is no issue with resources and accuracy).

So you will need to rely on the MS3 code and the will of their developer to add what you need.

Jean
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dwizle
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Re: Wheel Translator Board

Post by dwizle » Mon Jun 10, 2019 1:52 pm

I have a MS3 board with the expansion board, the current firmware supports Tri-tach which the say support early 911, 944, 951 which all used dual sensors reading off the flywheel but no cam sensor.
I am trying to figure out how to get the dual sensor single wheel 130 +1 setup to work in MS3

So my question is how many teeth could your board read and what vehicle was it intended to be used on?

jbelanger
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Re: Wheel Translator Board

Post by jbelanger » Mon Jun 10, 2019 2:08 pm

dwizle wrote:
Mon Jun 10, 2019 1:52 pm
So my question is how many teeth could your board read and what vehicle was it intended to be used on?
jbelanger wrote:
Sat Jun 08, 2019 4:07 pm
135 works for 5 and 6 cylinders because you can divide by 5 and get a virtual 45-1. This works for a 5 cylinder with 18 teeth between ignition events (but you do need a cam signal) and it works for a 6 cylinder with 15 teeth between ignition events (and it can either be with or without a cam signal). And it works out to 8.0 degrees per virtual tooth. You then use the generic missing tooth mode with either MS2 or MS3.
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dwizle
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Re: Wheel Translator Board

Post by dwizle » Mon Jun 10, 2019 2:13 pm

:| :| Thanks for your time
so to get this to work I would have to figure out the code on the chip in the DME and somehow transfer it to the MS3 firmware?

jbelanger
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Re: Wheel Translator Board

Post by jbelanger » Mon Jun 10, 2019 2:23 pm

You don't need to figure out some code from somewhere else. You 'just' need to get the MS3 developers to modify their existing code to allow it to be used without a cam signal. That code modification should be quite simple but I haven't seen the latest MS3 code so that's only speculation.

Trying to add to the MS3 code is a problem because the code is not simple and the only source available is from the last generation (1.4.x instead of 1.5.x). So if you do need a recent code version, you can only rely on the MS3 developers.

So you need to post on the msextra forum and hope for a positive response.

Jean
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dwizle
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Re: Wheel Translator Board

Post by dwizle » Mon Jun 10, 2019 2:44 pm

I did post to MS forums and emailed him at his website 2 weeks ago no response to either message

http://www.msextra.com/forums/viewtopic ... 4&start=40

jsmcortina wrote:
Currently the code does not support operation without a cam sensor - hence "TRI" tach. But in a future release I may be able to make it so it allows just the hi-res flywheel and reset pin only.

James

dwizle
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Re: Wheel Translator Board

Post by dwizle » Mon Jun 10, 2019 2:46 pm

I think you would have a market if you could make a board to accommodate the early Porsche water cooled set up.

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