Engine monitoring - Gauges/sensors - time to get serious!
 

After dealing with a few ongoing manifold, spooling, MS2 earth and various other issues last season I thought I had finally gotten the car to be all set for the beginning of the new season.....

Meeting 1 of the season, 4 laps in practice/qualifying, engine lost power and blew white smoke EVERYWHERE.

Suspected burst radiator hose but turns out the engine suffered massive detonation, lost all 4 forged Wiseco pistons, the ported head and maybe even the block. The holes in the head to the water jacket mean the detonation most likely came first and pressurised the water system.....

Cause of detonation to be discussed seperately.....have a few theories, don't believe tune was involved.

I may not have saved the pistons etc but at least with Oil temp, Oil pressure, water temp and Water pressure warning lights I might have saved something...this was all discussed in a previous thread where Emilio and other racers listed their monitoring preferences (that i now can't find).

I have a Rev built MS2 enhanced and own (but hadn't fitted yet) an AIM MXL Dash.

However this is on a slightly different tack...

I would like to add the sensors listed above to the Megasquirt and hopefully canbus the readings AND warnings etc to the AIM dash.

Can any one please suggest the correct Oil temp and Water Pressure sensors i can/should use?

and any other suggestions on gauges, monitoring, sensors etc that might be helpful....

With the AIM dash you can set warnings for everything you mentioned. I would also suggest an overboost warning (suspected cause of detonation?) alarm. The I would love to find a way to add a Large Master Alarm light once one of the small LED's are triggered. It's still easy to overlook those small alarm lights.

Your MS2 has adjustable warnings for coolant temp (high/very high), knock, oil pressure (low/high), oil temperature (high) through a single output (the CEL output). So that only leaves the water pressure, which can be connected to the AiM.

Thanks Rev, k24...can the CEL output go to a big ass warning light or does that just activate the dash CEL?

Also, I forgot to add the knock sensor to my list (After that detonation you would think it would be first on my list!! :loser: )

What is the best sensor and where to get it from that will work in the MS?

I have a sensor from a previous FM Link that i will look up the part number of...

okay, that is a Bosch part with these numbers...0 261 231 006...mean anything to anyone?

Any knock sensor will work. The MS2 can activate any warning light if you connect the light to the CEL output wire, but take care not to install a light that draws more than ~400mA (or just use a high brightness LED that draws 50mA and call it a day).

This thread has some good info on gauges.

https://www.miataturbo.net/race-prep...s-79373/page6/

with 400mA you can make an array of up to 20 of he 20ma LEDs and that should get your attention. Or use the CEL wire to trigger you door open buzzer or something.

I presume it could trigger a relay to utilise an after market shift light etc?


I run the EBC unit that Rev organised with the MS and was watching the boost gauge, could it still overboost? ( I was so focused on boost and AFR I forgot to check oil pressure and water temp!)


Okay, I have the sensor for the following.

- Knock Sensor
- Oil pressure

but need guidance on what possible sensor will suit the MS for,

- water pressure
- oil temp..

Can anyone suggest part numbers, links to parts etc?

Pressure transducer will usually have a 0-5V output signal so makes sure you have a free analog input available on the MS. Find a transducer with the right psi working range. They will have an equation to convert the voltage to Psi so it will require some conversion code in MS or post processing in matlab or excel or whatever you use. You work backwards and find what voltage is your max or min psi and set a CEL output trigger that way.

here is an example of a sensor (AEM 30-2131-15G AEM Sensors, Connectors & Accessories - Free Shipping on All Orders @ JEGS)


Most temp sensor are variable resistors (like the GM IAT you probably use). Your MS has a ciruit to convert the resistance of the sensor to a voltage then converts that to a temp using an equation (when you put in the calibration points). I think the MS has a few drop down sensor option for temp so if you can find one of those that is compatible with oil and had the correct operating temperature range. Also make sure your MS has an open temp sensor port available.

example temp sensor (http://www.jegs.com/i/AEM/017/30-201...ydNRoChlXw_wcB)

Cyotani, thanks for your help.

I am setting up a purchase on the Jegs site for those sensors you linked and wonder if you have a moment to look up the code for the correct GM IAT sensor. My one has never worked (it always reads 21 deg Celsius). I figure that a new one will prove either a wiring or sensor fault....and be a spare if it is a wiring issue.