Daox's 2004 Toyota Prius Build Thread

[bwilson4web]

When I didn't have any information on transaxle oil temperature, I built my own:


I used this for warm-up studies:


Now the Graham scanner can read out inverter temperatures but they are rare. I've got a second one that I rent out. My recommendation is use the scanner to build a better instrument and use the scanner to check calibration or other special studies.

Bob Wilson

[Daox]

Yeah, thats kind of what I was thinkin. Thanks Bob.

[orange4boy]

Nice block Daox, I'm fixing to do mine soon too. Although the aesthetics inspector will probably want it on the inside. I may be able to get away with a plexi one though.

You might look at hacking a temperature reading from the inverter coolant loop. The first little radiator in front of the vehicle radiator is the inverter coolant loop.

Where is the OAT sensor located on my 2003? When I return the Graham scanner, I would like to do that hack.

[koihoshi]

Originally Posted by bwilson4web

When I didn't have any information on transaxle oil temperature, I built my own:


I used this for warm-up studies:


Now the Graham scanner can read out inverter temperatures but they are rare. I've got a second one that I rent out. My recommendation is use the scanner to build a better instrument and use the scanner to check calibration or other special studies.

Bob Wilson

That is very cool! Do you have your own set of gauges that you set for using these or does it go to electronic diagnostics? I'm assuming you're pulling it electronically with the given above graph?

[bwilson4web]

Originally Posted by koihoshi

That is very cool! Do you have your own set of gauges that you set for using these or does it go to electronic diagnostics? I'm assuming you're pulling it electronically with the given above graph?

For my studies, I needed the data for analysis, not 'real time.' So I calibrated my thermistor in a batch of ice water, 0 C, and live steam, 100 C. Once I had two points on the thermistor curve, I spot checked with ordinary tap water and a kitchen thermometer.

For my study, I simply measured the thermistor values on a pad and later entered them into a spreadsheet, which gave me the time and temperature values. Piece of cake.

Once we understand the dT of transaxle and transaxle warm-up, it is easy enough to use this information in driving benchmarks. So my rule of thumb is no benchmark driving until at least 30 minutes of travel in the speed range to be tested. Then have fun.

Some of the NHW11 drivers have no doubt noticed that 90% of the warm-up happens in the first 15-20 minutes. But if they look at those bar graphs long enough, they will probably notice it really is closer to 30 minutes before 'random' variations predominate. Having measure the transaxle warm-up, I know why. <grins>

Bob Wilson

[koihoshi]

Very cool info indeed. That's awesome, Bob!

[Daox]

Got a pic of the grill block in sunlight. The other pic is pretty dark. I also fixed the right side by sliding some wooden spacers in behind the right side screws. It looks much better.

[Daox]

I put the snow tires on the Prius today. Thankfully, the wheels off the Matrix fit on the Prius, same OD too. However, I do believe I'll be taking an mpg hit (unsure of how large it'll be). The Matrix steel wheels are not only 16" vs the 15" lightweight alloy wheels, but the tires are also wider 205s instead of the 185s that come on the Prius. It'll be interesting to see how this effects things.

[bwilson4web]

Originally Posted by Daox

. . I also fixed the right side by sliding some wooden spacers in behind the right side screws. . . .

I missed the part about how the bolts were installed. Just a hole through the verticals, thread the bolt through? Do you fix the bolt in the hole with an adhesive?

Thanks,
Bob Wilson

[Daox]

I just have a fender washer under the head of the thumb screw on the outside of the grill block. On the backside of the grill, I have another larger fender washer with a wing nut holding it on. I screw it down until it starts bending the coroplast a little so it puts some load on the nut to avoid backing off.