AltezzaLink - expansion connector digital input for frequency measurement

[zaihas.chan]

I'm planning to install Borg Warner Turbo Speed sensor and connect it to one of the digital input of the expansion connector (DI 9 OR DI 10). From what i understand, these 2 inputs are not capable of measuring frequency. Am i right?

If that is the case, then since i'm gonna disable the exhaust VVT (replace the exhaust pulley with static pulley), can i use DI 2 (originally was for the exhaust VVT position) for this purpose? Any impact on trigger? what i believe is the intake VVT sensor also used for piston synchronization. 

 

Thanks in advance.

[Adamw]

You are free to use DI2 if you dont want VVT on exhaust.  It is not needed for triggering.

Be aware though that the plugin DI's are limited to 500Hz, this will be too low for many turbo speed sensors.  You will need to find one that has a large divider built in to it.  I know some work since I have seen logs with realistic turbo speed in them but I dont know what brand they were.

[zaihas.chan]

Thanks Adam,

Good info. This sensor has by 8 divisor, which should be like almost ~3KHz at 1 bar (2 PR) with my 14 blade turbo. This will not work. any other DI i can use?

This is the link to the sensor - https://www.full-race.com/store/fabrication-materials-kit-builders/electronics/borgwarner-efr-turbo-speed-sensor-kit-2/

Edited September 15, 2017 by Zaihas Amri Fahdzan Hasfar

[cj]

You can build a frequency divider using a chip like this https://www.jaycar.com.au/4024-7-stage-ripple-carry-counter-divider-cmos-ic/p/ZC4024 which are available for a couple $ at most electronics shop. Depending on how you wire them they can divide square wave frequency by between 2 and 1024. Max input frequency is between 5 and 15Mhz depending on input voltage so should handle your turbo fine. You just need one of these, a pinboard to solder it to, a small (ideally waterproof) box to mount it in, a couple pullup resistors depending on your source sensor output, and a socket of some sort you can solder onto the board so you can join it into the wiring harness and have it look just like any other little black control computer. I've currently got one working to drop a high frequency 2007+ honda gearbox speedo output from 5-10KHz @100kph down to a hundred Hz or so @100kph to get it within acceptable range of a link input.

You can also buy pre-built boxes that do the same thing from dakota digital and a couple other manufacturers I cant remember right now.

[zaihas.chan]

@cj thank you for your input. I have the same idea where i'll be adding clock divider (divide by 8) to the output sensor output. just trying my luck to see if there is simpler solution. 

[Adamw]

Unfortunately there is no easier option unless you find some already built device.  The fastest DI's on your ECU are 500Hz.

[zaihas.chan]

Thanks! i'll go with that option then.