Track brakes
#203
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Deer Hunter
After hard days at Statotech (the go cart track) my rotors look similar to the bottom pic, my brakes (94+ and XP10) work flawlessly there. I have yet to have fade, pedal loss, or bubbles bleeding after an event. I use the Prestone 5.1 fluid from CTC. It's cheap and will be upgraded this winter, when I turn up the power. For comparison to your times, I run 70 second laps, I am NA. If you know Grant with the white Mustang or Adelbert with the black GTR, we run quite close, they certainly out power me on the straights.
I think we have openings on the 22 Sept if you want more track time. 8am till noon
After hard days at Statotech (the go cart track) my rotors look similar to the bottom pic, my brakes (94+ and XP10) work flawlessly there. I have yet to have fade, pedal loss, or bubbles bleeding after an event. I use the Prestone 5.1 fluid from CTC. It's cheap and will be upgraded this winter, when I turn up the power. For comparison to your times, I run 70 second laps, I am NA. If you know Grant with the white Mustang or Adelbert with the black GTR, we run quite close, they certainly out power me on the straights.
I think we have openings on the 22 Sept if you want more track time. 8am till noon
Not to mention the speeds at the indy track are much higher then stratotech.
#204
Are there any alternatives to these Alcon temp strips or has anyone here used them with success? Has anyone taken caliper temps for reference?
I remember reading a post stating getting them up to temp and it was barely at the minimum indicator, not much resolution. I am interested in taking temperatures pre and post ducting to see how effective I make it so I have a measurement of improvement.
My IR temp gauge maxes out as is, but it only goes up to 230-250 or so. I can get readings in the rear, but fronts it just says "HOT!"
If the Alcons would read one bar from 250F to 340F, I don't think that's much resolution (I don't think my 1.6 brakes are getting above 340F front, but staying below 230F in the rear.
Kit Consists of 14 Temp Indicator Strips with a temperature range of 250F to 536F
Recommended Brake Caliper Temps:
Up to 340ºF - Too Cool
350ºF-400ºF - Ideal
400ºF-450ºF - OK
475ºF plus - Too Hot
Tempature Indicator Strips - Alcon Brake Caliper Kit
I remember reading a post stating getting them up to temp and it was barely at the minimum indicator, not much resolution. I am interested in taking temperatures pre and post ducting to see how effective I make it so I have a measurement of improvement.
My IR temp gauge maxes out as is, but it only goes up to 230-250 or so. I can get readings in the rear, but fronts it just says "HOT!"
If the Alcons would read one bar from 250F to 340F, I don't think that's much resolution (I don't think my 1.6 brakes are getting above 340F front, but staying below 230F in the rear.
Kit Consists of 14 Temp Indicator Strips with a temperature range of 250F to 536F
Recommended Brake Caliper Temps:
Up to 340ºF - Too Cool
350ºF-400ºF - Ideal
400ºF-450ºF - OK
475ºF plus - Too Hot
Tempature Indicator Strips - Alcon Brake Caliper Kit
#205
My infrared gun goes to 1500f. It isn't as accurate as test strips since everything cools some while I am coming off track instead of showing a 'high water' mark. Mainly, I look for temperature differentials front to back and side to side. I keep it in the door pocket of the truck and shoot the trailer's wheel bearings at least once during each long tow. Again, 3 bearings at +/- two degrees of each other and the 4th bearing 40 degrees hotter is all I need to know that trouble is on the horizon.
#206
My infrared gun goes to 1500f. It isn't as accurate as test strips since everything cools some while I am coming off track instead of showing a 'high water' mark. Mainly, I look for temperature differentials front to back and side to side. I keep it in the door pocket of the truck and shoot the trailer's wheel bearings at least once during each long tow. Again, 3 bearings at +/- two degrees of each other and the 4th bearing 40 degrees hotter is all I need to know that trouble is on the horizon.
the hotter corner is exactly what i found the night before a track day. i have a small IR meter, which is probably why it's limited to 230-250*. One corner was 50 degree hotter (pax front)-- piston seized i think as i found a hole in the boot. Luckily I had a spare with a good piston boot. It got me to the track the next morning, but was having brake issues all day (on top of heat cycled tires, 80A durometer, but that's another thread). The freshly lubed slider pin probably led to this:
same tires i ran 8 months ago, when it was running 4 seconds faster (in 48-61 gnd temps). when the brakes locked up, the tires were quiet about it until i saw smoke. i think this shot was in the first few laps. i had to ease off the brakes the rest of the day with 90-125F ground temps.
#207
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My IR gun from Harbor Freight was $29 and goes up to 500+ I think. It shows enough info to be useful, including trans and diff temps. Temp strips would be useful for showing peaks as stated.
#208
Measuring rotor temp is best done with paint on the edge.
E.g. https://www.pegasusautoracing.com/gr...upID=TEMPPAINT
E.g. https://www.pegasusautoracing.com/gr...upID=TEMPPAINT
#209
mr_hyde, do you think an infrared gun would be better instead of a "high water" mark for what I'm looking for? (keeping 1.6L brakes for as long as i can for weight... 1.6L power, on all seasons until I am sure my driving is up to sniff). p.s. all seasons still overheat Hawk HP+
--Ian
#210
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Strongly disagree. It's approximately the same amount of kinetic energy being converted to heat, but the conversion happens in a far more compacted amount of time with race tires, resulting in higher peak temperatures.
#212
The energy needed to accelerate is roughly the same that the brakes need to convert to heat during braking (minus some wind/rolling/transmission resistance). On the stickier tires, the overall speed around the track is higher, which actually leaves less time to build up energy between corners, which the brakes then need to deal with. On the other hand, you can start accelerating earlier out of the corners, which comes more into play on a high speed track with soft curves.
Now, the real issue is the time needed for the heat to move from the brake rotors to the air cooling them. On stickier tires there is simply less time between braking, so the heat will build up faster and generally sit at a higher level than on street tires.
- Tom
Now, the real issue is the time needed for the heat to move from the brake rotors to the air cooling them. On stickier tires there is simply less time between braking, so the heat will build up faster and generally sit at a higher level than on street tires.
- Tom
#213
Higher delta T means a faster heat rejection rate will occur and less distance on the brakes in the braking zone means more percentage of time off the brakes to reject heat and less percentage of the time generating it.
Bob
#214
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In any case, you also need to look at the force applied - since you're producing (essentially) the same amount of heat, but doing it in a shorter period of time, the force required to make that heat is higher, and this is going to wear on the brakes.
At the end of the day, the difference in heat rejection vs. heat production times is probably negligible, but the race-tire car is going to have brakes that are pushed harder and operated at higher tempeatures than the street car. That's going to cause additional wear.
#215
Of course, but "higher" is a relative term. Say a street tire car corners 10mph slower than a race tire car. The race tire car will exit the corner 10mph faster, however all cars accelerate faster at lower speeds. Therefore at the end of the straight the race tire car will only be going slightly faster than the street tire car, say 3mph faster.
10mph > 3mph
Of course this all depends on the track. The longer the straight the more pronounced the effect, and whether or not this effect is greater than the other effects you mentioned is beyond anyone's guesstimating ability.
A simple way to think about it would be a track in which the car reaches its top speed on every straight (something like Indy's oval with an under geared car). Obviously in that scenario race tires would always be easier on your brakes.
10mph > 3mph
Of course this all depends on the track. The longer the straight the more pronounced the effect, and whether or not this effect is greater than the other effects you mentioned is beyond anyone's guesstimating ability.
A simple way to think about it would be a track in which the car reaches its top speed on every straight (something like Indy's oval with an under geared car). Obviously in that scenario race tires would always be easier on your brakes.
#216
I was planning on staying with 1.6L brakes for weight, have 1.8L brackets ready and waiting, and I know they'll have better heat capacity overall, but whether I need it yet or not is TBD on pad and tire (currently Hawk HP+ which have lasted pretty long that I started dailying them). I planned on doing some ducts before slapping the 1.8L rotors on, mainly so I can gauge how effective the ducts are. I know the cooler the brakes are the longer pads will last etc, but so far with all seasons and HP+, it hasn't been an issue. I sure would like some Wilwoods for many reasons but it's just not in the cards. Please let me know if I'm going about this all wrong and that I should toss the 1.8s on ASAP regardless of if I've ducted the brakes yet or not.
#217
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Of course, but "higher" is a relative term. Say a street tire car corners 10mph slower than a race tire car. The race tire car will exit the corner 10mph faster, however all cars accelerate faster at lower speeds. Therefore at the end of the straight the race tire car will only be going slightly faster than the street tire car, say 3mph faster.
In the end, cars do accelerate slower at higher speeds, but it's not nearly that large of a difference.
#218
Joined the manly brakes club last night after ending Hallett with a slight taper up front on Hawk Blues. Holy **** does the car stop. Need to tweak bias valve a bit, the rear blues don't stand a chance against DTCs on a 11.75" rotor.
Big thanks to Andrew, had a tracking number not an hour after ordering. Getting threads started on the front line coupler was the hardest part of the entire install.
Anybody want to sell their rear 1.8 brackets?
Big thanks to Andrew, had a tracking number not an hour after ordering. Getting threads started on the front line coupler was the hardest part of the entire install.
Anybody want to sell their rear 1.8 brackets?
#219
I recently did a track day weekend at CMP with freshly rebuilt Na 1.8 on XP10/XP8 pads and noticed slight taper on the front pads, nothing like earlier pictures in this thread. I was not expecting this on factory power. The rotors looked like the snotty picture on post #197. I started with fresh rotors and after the first session I had the snotty rotor surface again.
What causes the snotty surface? Does it cause you to use more pedal pressure and greater force on the pad that then flexes the stock caliper more and result in the pad taper?
The funds for the awesome 11.75" BBK will not be avaliable any time soon, so that isn't really an option at this time.
How long do the XP10/8 pads last on NA power levels? Looks like I will only get 5 track days out of the ones I am running.
What causes the snotty surface? Does it cause you to use more pedal pressure and greater force on the pad that then flexes the stock caliper more and result in the pad taper?
The funds for the awesome 11.75" BBK will not be avaliable any time soon, so that isn't really an option at this time.
How long do the XP10/8 pads last on NA power levels? Looks like I will only get 5 track days out of the ones I am running.