That's so funny!

 

I put the bike inside my house for a few days to get a more exact reading than before

House @ 65*f
Bike @ 249*f

That should create a total difference of 184*f

 

You guys are assuming that these differences are constant, right? Are you sure that's how it works? How do you know it's not proportional?

I'm not saying you're wrong, but just throwing it out as food for thought.

In other words, you guys are assuming the gauges are off by a constant 170 (or 184, whatev) but are you sure it doesn't change proportionally.... so that the higher the temp goes, the farther off it gets. And if that is the case, how is stacking resistors going to affect that? Is it going to bring it the reading down to some ratio of what the temp unit is sending (how I would expect it to work; this is how an inaccurate speedo behaves) or reducing the temp readout by a constant temperature.

This just seems like something you'd want some precision on... I mean 20 degrees can be the difference between your fan kicking on at the right time or your bike overheating. (I know the fan doesn't kick on from this sensor, just illustrating the jump 20 degrees represents)

I dunno... just throwing it out there.. hope it contributes to the discussion.

 

well i can tell you 3 reasons on why i want to at least attempt this
1) it will be interesting to find out the questions your asking about proportionality, and fun
2) it will give me a better reading than 270* blinking
3) the annoying temp light will go off and stop annoying me on the highway

hell even if its 50*off it would still be better progress, no?

 

Yeah as long as I can get it under the 270 mark. Maybe I can get pretty close to accurate around the proper operating temp. I don't care if it shows 50 degrees and it's 50 degrees outside. So our window of accuracy can be pretty small (+/-30 degrees.)

 

i bought some rheostats at radio shack today
ill let you know about the outcome tomorrow

 

Awesome

 

Well, it appears chuck here had the right idea. After my testing I ended up with the following results.

F3 Thermistor:
115 deg - 184 ohms
140 deg - 128 ohms

Ohm readings that were required to get proper reading on F4i gauge:
115 deg - 6490 ohms
145 deg - 4030 ohms

So, obviously it is proportional and simple resistors won't do the trick. When I would set the gauge to the water temp with the rheostat, I could take the sensor out of the water and it would only change like 1 or 2 degrees.

I am out of ideas.

Josh

 

i guess no variable resistor?
hell i might as well just cut it off then, at least then i wouldn't have to worry about it nagging me anymore

 

I'm going to still work on this. I was looking at a digital resistor. It allows you to set specific resistance at certain temps. And you can set up to 100 different "taps". This way you can get extremely accurate if you want.

rothjl749 do you know the correction needed at around the 200 deg mark? I just need some more correction points to dial in. if not I can check. Thanks!