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Hey Everyone,
I just wanted to share some "behind the scenes" work being done at MotorvateDIY Garage.
I have often wanted to know how hot does the manual transmission oil get... AND how hot does the differential oil get..
Well...Now I can monitor manual transmission oil temperature AND differential oil temp AND data log them with the current time to a SD card.
Rear Differential Oil Temperature Sensor:
Manual Transmission Oil Temperature Sensor:
Motorvate Designed & Built (Arduino Uno based) differential and manual transmission oil temperature display with max temp and data logging to SD card. (oTemp is outside temperature)
Why bother doing this?
Well, I wanted to see how much these oil temperatures increase during:
• A long highway drive
• Driving in traffic
• Drag racing
• A few pulls on the dyno
• A track day (HPDE)
ALSO...
Will the temperatures change when I put in fresh RedLine 75W90? The differential currently has 3 year old non-synthetic Nissan 80W90 differential oil.
Drag racing is scheduled for next week. The HPDE is booked for October.
You will find that even with milder ambient temperature of October, only your first HPDE session will see the 7AT perform as expected. Assuming you use manual mode, in subsequent sessions, the trans will make uncommanded up-shifts at about 6k rpm and will often ignore a downshift command though it will change down if you request it again. I would short-shift in an attempt to keep the trans happy enough to obey my first down-shift command. Quite irritating. I installed Z1's trans cooler, to no obvious benefit. This was the real impetus for me to have my Miata converted to an HPDE toy.
Last edited by slartibartfast; Sep 7, 2019 at 01:04 AM.
Exciting!! I was honestly planning on doing something similar, but it’s just thoughts in my head right now...
what sensors were used? Or should I wait to hear in a video...?
The temperature sensor is an engine coolant sensor from a 03 Sentra. They are cheap (from the scrap yard) and have a water tight connector.
You will find that even with milder ambient temperature of October, only your first HPDE session will see the 7AT perform as expected. Assuming you use manual mode, in subsequent sessions, the trans will make uncommanded up-shifts at about 6k rpm and will often ignore a downshift command though it will change down if you request it again. I would short-shift in an attempt to keep the trans happy enough to obey my first down-shift command. Quite irritating. I installed Z1's trans cooler, to no obvious benefit. This was the real impetus for me to have my Miata converted to an HPDE toy.
Hey slartibartfast.... Umm, this trans temp sensor is on a 6 speed manual transmission.
What have you been logging so far?
What sensors did you use?
I used coolant sensors from an 03 Sentra. They are water tight, cheap ($8!) and readily available at the scrap yard.
I don't have a lot of data yet, but so far in mixed city and highway (easy driving with mild acceleration), the diff oil temp is typically 80-90C and the manual transmission is 60-80C with an outside temp of 25-28C.
Drag racing and a track event are planned over the next few weeks. I want to see how hot it gets under full engine power
