diy infrared brake temp sensor

[ihasnostang]

i ordered the sensor today, 145 shipped. funny i was interested in those stickers for my calipers last year but when i tried ordering some from OMEGA they wanted $20 for 10 stickers and 20 for shipping. feel free to send any partially used rotor paint or stickers for a comparison

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[ihasnostang]

off to road America tomorrow. Last update. bracket was made out of 1/8" aluminum, added a doubler plate. Coding and harness is complete, but i haven't tried fitting up the completed harness yet. Ran some modal FEA on the bracket itself, and then spent a couple hours modeling the dust shield, only to get incomplete results.

 

[ihasnostang]

final install ( was zip tied in 2 places), full session, hotlap. First time i've seen my rotors change color. Getting even 1 lap which happen to be the last of the session to sync up with my gopro and data from the accessport took hours because all 3 were started at different times. I only sampled at 2 Hz from the sensor as i wasn't sure exactly what rate my accessport would log at. I did a couple cooldown laps before starting a flyer due to CHT/oil. Not sure what happened to the readings mid way through.

Overall, i think the results are plausible. Open to criticism.

 

[Optimum Performance]

final install ( was zip tied in 2 places), full session, hotlap. First time i've seen my rotors change color. Getting even 1 lap which happen to be the last of the session to sync up with my gopro and data from the accessport took hours because all 3 were started at different times. I only sampled at 2 Hz from the sensor as i wasn't sure exactly what rate my accessport would log at. I did a couple cooldown laps before starting a flyer due to CHT/oil. Not sure what happened to the readings mid way through.

Overall, i think the results are plausible. Open to criticism.

Mark,

The system you designed seemed to work pretty well.

Rotor temps stayed pretty low for your pace. What pad are you running? Those temps are pretty high for an OEM pad.

Again. Nice job being able to test it our. It looks like you really need a big oil cooler.

 

[ihasnostang]

Thanks, i was using the vorshlog brake deflectors with the PP belly pan that has the air channels in them too. Pads are powerstop Z26 "xtreme street performance". yeah with 255's all around and a ~$200/ea street tire i am only going to be able to slow down so fast. i set 280F be the temp when i need to back off, but at least that is with 5w-50. i am trying to avoid putting another heat exchanger infront of the race intercooler and rad

 

[boB]

A nice project and looks like it was well done.

 

[TeeLew]

Thanks, i was using the vorshlog brake deflectors with the PP belly pan that has the air channels in them too. Pads are powerstop Z26 "xtreme street performance". yeah with 255's all around and a ~$200/ea street tire i am only going to be able to slow down so fast. i set 280F be the temp when i need to back off, but at least that is with 5w-50. i am trying to avoid putting another heat exchanger in front of the race intercooler and rad

If oil is at 280*F, then water is going to be through the roof as well. You're going to need at least 1 more heat exchanger, but probably 2. Time to get a Shelby or Mach 1 nose so you have functional side air intakes. Stacking coolers quickly becomes futile.

The brake temps look great. In practice, you'd have one on each corner and then adjust the cooling to make sure the pre-application temperature difference across the axle is minimized (to avoid pulling). Front to rear temperature you'll likely want to favor the front by ~30*F.

Iron brakes really aren't that sensitive to temps; Mu is very consistent through the range for any pad we want to be driving. Because of this, we really just need to know if we're abusing the discs with excessively high temperatures. This is where the paint comes in. Green/Orange/Red on the disc. You want to be able to light off the orange during a run. If you're getting into the red, it's too high and disc life will suffer. If that's where you have to run, just have a good disc budget. If you're only into the green, then you're not running enough blanking, which gives away downforce and usually a little initial brake performance.

You have to be careful at places like Road America. It has big brake zones, so the peak temp on paint might show very hot, but, especially in low HP cars, the straights are long enough that the brakes can get quite cool in between. This can cause very serious disc cracking due to the big temperature swings more than the actual high temperatures. This is where sensors like you've made come in. Running the discs what appears to be artificially hot on paint can increase life and performance at times by reducing the thermal stresses due to temperature swings. We can often change pre-application temperature by quite a bit without massively influencing the peak.

Great project and very well done! You should probably look into getting an AiM data system or something, because there's all sorts of fun rabbit holes you can run down. Obviously, you can do it all as you are, but having an actual data system with a GUI is nice. You can export the data and play with it if you start to feel MatLabby.

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