Logging Boost on a Gen 2 or 3 Coyote

[xr4x4ti]

This seems so easy that I don't quite understand how this is not common place. I searched the web and I have not found anybody else doing this, but maybe I am just looking in the wrong places.

So, what did I do?

I wanted to be able to log boost on my Supercharged 2017 GT. The Mustang G2 and G3 Coyote's do not have a MAP sensor, the intake manifold pressure is calculated based on the MAF and engine load using the VE model in the ECU. I am currently using HP tuners to tune and log the car and I wanted to be able to log actual boost, not calculated boost. Of course the simple solution is to add a MAP sensor. But how do you get that information into the computer? The HP Tuners MPVI3 does have two extra Analog inputs for this very purpose, but then you have to run wires into the car and plug them into the MPVI3 every time you want to log. This may not be a big deal but I wanted a more elegant solution.

I knew that the Roush tunes used the IMRC inputs to hookup a MAP sensor to the stock ECU. All of the positive displacement superchargers (Whipple, VMP, Roush) of course do not use the IMRC since they don't use the stock intake manifold. EACH IMRC flap (there are two) has a position sensor which is a simple potentiometer fed by a 5 volt reference voltage that feeds into an analog ECU input. So why not wire a map sensor into that input and simply log the IMRC voltage and use a Math Channel in HP Tuners to read boost?

That is what I did and it totally works. You can have the IMRC's disabled in the tune but still have the sensor active and read the voltage.

I ordered this Bosch TMAP sensor and cable from Amazon for the experiment.

https://www.amazon.com/dp/B00BL75RX6?ref=ppx_yo2ov_dt_b_fed_asin_title

https://www.amazon.com/dp/B07TNJB9SJ?ref=ppx_yo2ov_dt_b_fed_asin_title

Now the trick is to get the connector that plugs into the IMRC connector on the engine harness. In the case of the GEN 2, I could not find just the connector so I bought this complete cable set.

https://www.ebay.com/itm/384947067105

This is a VERY low quality kit.

I should have bought the VMP harness. I had to cut the keying feature off of the cheep kit as they were wrong. But I wasn't sure this was going to work and I didn't want to cut up an expensive harness just for the experiment. If I did it again I would buy the VMP harness.

https://www.vmpperformance.com/VMP-...s-for-2018-GT-intake-manifold-on-2015-2017-GT

Here was the result.

I then went into HP tuners and setup the channel.

I have not driven the car much for other reason, but on my short test run it seemed to work great.

I will keep people posted if there are any issues with this setup.

I can detail out the wiring if people are interested.

Tim

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[robvas]

Sick. Smart idea, seems so obvious after you read it.

 

[mejohn50]

Good find. I’ll be bookmarking this for future reference.

 

[xr4x4ti]

I will post a wiring diagram when I have some time. But I will add that there are of course two inputs for the IMRC and you can record any 5V signal. I may mess around with logging fuel pressure (gen 2 don't have a factory sensor) and/or absolute pressure after the throttle but before the supercharger to see if the throttle is a restriction.

 

[Kryptickzz]

Can you compare the accuracy of the map sensor vs the calculated boost number in the maf? I have the Ecoboost boost gauge which uses that number and I'm curious about the accuracy

 

[engineermike]

Can you compare the accuracy of the map sensor vs the calculated boost number in the maf? I have the Ecoboost boost gauge which uses that number and I'm curious about the accuracy

Depends completely on the tune.

 

[Zrussian13]

Can you compare the accuracy of the map sensor vs the calculated boost number in the maf? I have the Ecoboost boost gauge which uses that number and I'm curious about the accuracy

My car is lund tuned and it's with in a pound pretty consistently. I can log and use load to get an accurate number too. Both are on par with my eboost2.

 

[robvas]

Wondering if anyone has done this on a gen 1? Would love to log boost with my SCT

 

[tdstuart]

This is exactly what I want to do, I also have no idea why no one else seems to be doing this. Everyone wants to use the ac pressure sensor but for long term use it sucks to not have ac and they don't produce the connector you need as a standalone thing as its just meant for sensors (for sensor specific connectors often only the male/female is available for the harness and the mating side is supplied to sensor manufactures and not produced separately to mate to a harness)

As far as the info on the connector for the imrc you are looking for a molex MX-150 connector. It is a pretty popular and inexpensive connector with widely available information. There are multiple key types. I do not remember off the top of my head which one is used here.

I plan on doing the exact same thing so I can log MAP and fuel pressure when tuning my car.

 

[tdstuart]

Going to purchase this exact mapt. Info about connectors and mapt voltage below.

Just for reference for those wanting to make their own harnesses/connectors. The bosch sensor OP references is PN#0261230283. This uses the Bosch Kompakt (Compact) 4-Way Connector. I believe it is code-1 (The code is the slot/grove pattern that is used to allow/prevent the same connector from connecting to different codes). Chief enterprises is a bosch sensor/connector dealer I have used before and they could probably get you more info on the connector.

As I already mentioned IMRC is a 3-pin Molex MX150. It is keying option B. Molex website has lots of info on the connector and you can find all the part #s for pins etc.

If you are diy-ing this I highly recommend getting pre-assembled connectors as every connector pin uses a different crimp tool and the proper tools are expensive. Also when assembling use crimps (brass u ones) and don't soldier.

Attached is the official Bosch info for voltage to pressure and temperature conversion so you can get the values.

 

[tdstuart]

Got it wired and working. Not my best wiring work but I didn’t have a wire shrink sleeve that was big enough so I had to improvise.

Pro tip, download a barometric pressure reading app on your phone. All (newer) iPhones have barometric pressure sensors. I was wondering why the map sensor was off from what the weather app said my local barometric pressure was, downloaded an app to pull the phones reading and it was spot on with my new map sensor.

Photos of the wiring and sensor install.

 

[diambo4life]

I see you have HPT. Any particular reason you didn't use ProLink? That's how I log it in my Gen 1.

 

[tdstuart]

I see you have HPT. Any particular reason you didn't use ProLink? That's how I log it in my Gen 1.

Extra stuff to purchase and setup, also not every device supports prolink. I just have an rtd I use to log with hptuners if I want.

Also this method will let it work with pcmtec if you want to use that. PCMTec has the values defined but the description is wrong, I contacted them to update it.

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