:NERD ALERT: Braking data
Aug 12, 2009, 09:53 AM
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:NERD ALERT: Braking data
Some stuff I posted in the suspension/brake area sticky.... This is just data from the testing of the instrumentation. Looking to get some stock rotor vs 2 piece rotor data in the near future. Pretty much nerd-bombing sort of stuff related to brake pad temps, thermal equilibrium of the braking system etc.
My car has recorded steady state 1.25 G's of traction in corners, pretty sure I've got at least 1.15 available in braking... so far I'm only using about 1 G, and not in every braking zone - so there's lots of stopping power still available.
Here is the track map, with the braking zones in RED. This is just fun stuff to look at for us nerd types. The data itself isn't that impressive because I'm still a tenderfoot behind the wheel.
1. Braking zone. Entry speed is roughly 135 mph, corner entry is 60 mph. Typical G's in braking are about .75g, with a quick blip up to .96g. The pavement is bumpy and it gets sketchy laying on the brakes at the limit through the rough sections. There's lots of room for improvement on my end.
2. Braking zone, this is down hill into the tighest corners on the track. Entry speed to braking is the top of 4th about 115 mph, corner entry speed is 40 mph. This zone sees a good 1.0g stab of braking and then trails them into the corner.
3. This is up-hill just to scrub some speed for turn -in. Speed is 115 mph, light on the brakes at .5g's and then a little stab to .75 g's and turn-in at 60 mph.
4. Last real braking zone, this is just a quick stab entry speed is around 85-90 for braking and corner is taken at about 55 mph. This lap showed .75g's, and it varies bewteen that and 1.0g's depending on how much speed I carry up the hill.
Here is a temperature plot of the ST43 pads, after the outlap (going slow) they are up to temp after 3 hot laps. And based on my setup, this track, and ambient of 80-90 they stay in the neighborhood of 700-800F.
My car has recorded steady state 1.25 G's of traction in corners, pretty sure I've got at least 1.15 available in braking... so far I'm only using about 1 G, and not in every braking zone - so there's lots of stopping power still available.
Here is the track map, with the braking zones in RED. This is just fun stuff to look at for us nerd types. The data itself isn't that impressive because I'm still a tenderfoot behind the wheel.
1. Braking zone. Entry speed is roughly 135 mph, corner entry is 60 mph. Typical G's in braking are about .75g, with a quick blip up to .96g. The pavement is bumpy and it gets sketchy laying on the brakes at the limit through the rough sections. There's lots of room for improvement on my end.
2. Braking zone, this is down hill into the tighest corners on the track. Entry speed to braking is the top of 4th about 115 mph, corner entry speed is 40 mph. This zone sees a good 1.0g stab of braking and then trails them into the corner.
3. This is up-hill just to scrub some speed for turn -in. Speed is 115 mph, light on the brakes at .5g's and then a little stab to .75 g's and turn-in at 60 mph.
4. Last real braking zone, this is just a quick stab entry speed is around 85-90 for braking and corner is taken at about 55 mph. This lap showed .75g's, and it varies bewteen that and 1.0g's depending on how much speed I carry up the hill.
Here is a temperature plot of the ST43 pads, after the outlap (going slow) they are up to temp after 3 hot laps. And based on my setup, this track, and ambient of 80-90 they stay in the neighborhood of 700-800F.
Last edited by jid2; Aug 12, 2009 at 10:34 AM.
Aug 12, 2009, 11:41 AM
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The brake temps are pulled in with a separate Thermocouple datalogger, my glove box gets full of computers and loggers.
Yes, there is a lack of full-throttle. I've been granny shifting like crazy and there are a few areas (that long sweeping black area coming into braking zone 1) where I'm just a whoose and afraid of the speed though those sections. I've been going through the kinks on the front "straight" at about 135 mph. To do that you shift into 5th and give it a little throttle and then just coast - if I pinned it I think I'd be at 145-150 through that section. Also in the back section coming up the hill if you pin it you'll crest the hill and have too much speed to make the corner - but you can't brake or you'll get loose, so you just coast with uber light throttle over the crest.
Last edited by jid2; Aug 12, 2009 at 11:44 AM.
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Aug 12, 2009, 12:39 PM
#8
Do you have data from both the inner and outer pads?
On my car, I only had the factory brake cooling guides. I was getting double the wear on the outer pad compared to the inner pad, on both sides of the car. I can only hypothesize that it was due to the cooling on inner pad and not the outer.
Also, what did you use for the thermal imagining?
On my car, I only had the factory brake cooling guides. I was getting double the wear on the outer pad compared to the inner pad, on both sides of the car. I can only hypothesize that it was due to the cooling on inner pad and not the outer.
Also, what did you use for the thermal imagining?
Aug 12, 2009, 12:46 PM
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These must be very mild pads - stock? Your brembos are still way too red.
After 2 weekends, my brembos turned blackbos using stock lines, calipers & rotors, DTC-60 pads & Motul brake fluid with just NT01's in 245 size. I have 2" brake ducts as well.
My pad wear is not even: the inners would wear faster than outer pad. This actually got a little improved after I switched from stock springs to swift spec-r. My theory was correct that while trail braking when the car was bending in weird ways had affected the pads. Also, the top of pad would get used much more than bottom part despite the smaller top piston.
My dust boots are obviously fried.
My rotors will be pretty much done after the next event (getting close min thickness) so I will want to replace it with a 2-piece rotor....question is, what will hold up to my driving style and not bankrupt me?
After 2 weekends, my brembos turned blackbos using stock lines, calipers & rotors, DTC-60 pads & Motul brake fluid with just NT01's in 245 size. I have 2" brake ducts as well.
My pad wear is not even: the inners would wear faster than outer pad. This actually got a little improved after I switched from stock springs to swift spec-r. My theory was correct that while trail braking when the car was bending in weird ways had affected the pads. Also, the top of pad would get used much more than bottom part despite the smaller top piston.
My dust boots are obviously fried.
My rotors will be pretty much done after the next event (getting close min thickness) so I will want to replace it with a 2-piece rotor....question is, what will hold up to my driving style and not bankrupt me?
Last edited by xtnct; Aug 12, 2009 at 12:53 PM.
Aug 12, 2009, 01:29 PM
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I only have the thermocouple on the inside pad. I may try and get a picture of both pads with the camera next time out. So far the wear is pretty even on my setup.
The thermal images came from an expensive camera we use at work. We use it for gathering thermal data on electronics devices.
Pads are Raybestos ST43's, they are a track only pad - and rule. My car has never been tracked without cooling ducts and for whatever reason they are not brown. The paint is flaking off like crazy though. They are maybe a few shades darker now then in that install picture but still red for sure.
All 2 piece rotors are expensive, that's the reality. It took me 5 years of EVO owning to finally buy them. The Girodisc parts are very nice, and have a strong track proven record with most of the serious track guys on here. They've got a "local" presence here on the forum and are great to talk to and deal with - that's why i chose them over Performance Friction.
The thermal images came from an expensive camera we use at work. We use it for gathering thermal data on electronics devices.
Pads are Raybestos ST43's, they are a track only pad - and rule. My car has never been tracked without cooling ducts and for whatever reason they are not brown. The paint is flaking off like crazy though. They are maybe a few shades darker now then in that install picture but still red for sure.
All 2 piece rotors are expensive, that's the reality. It took me 5 years of EVO owning to finally buy them. The Girodisc parts are very nice, and have a strong track proven record with most of the serious track guys on here. They've got a "local" presence here on the forum and are great to talk to and deal with - that's why i chose them over Performance Friction.
Aug 12, 2009, 02:30 PM
#11
Some stuff I posted in the suspension/brake area sticky.... This is just data from the testing of the instrumentation. Looking to get some stock rotor vs 2 piece rotor data in the near future. Pretty much nerd-bombing sort of stuff related to brake pad temps, thermal equilibrium of the braking system etc.
My car has recorded steady state 1.25 G's of traction in corners, pretty sure I've got at least 1.15 available in braking... so far I'm only using about 1 G, and not in every braking zone - so there's lots of stopping power still available.
Here is the track map, with the braking zones in RED. This is just fun stuff to look at for us nerd types. The data itself isn't that impressive because I'm still a tenderfoot behind the wheel.
My car has recorded steady state 1.25 G's of traction in corners, pretty sure I've got at least 1.15 available in braking... so far I'm only using about 1 G, and not in every braking zone - so there's lots of stopping power still available.
Here is the track map, with the braking zones in RED. This is just fun stuff to look at for us nerd types. The data itself isn't that impressive because I'm still a tenderfoot behind the wheel.
Looks like others pointed this out already and perhaps it's track conditions - ie too high of speeds! I know your car has a lot more power than mine.
As for braking force, I hit right around 1g peak in my braking zones. Sometimes I tend to jab the brakes and don't get a nice 'bell curve' so I'm working on that.
Here's my fast lap from Blackhawk this past weekend. The short bits of black (buried in the green) are usually my shift points.
Last edited by boomn29; Aug 12, 2009 at 02:41 PM.
Aug 12, 2009, 05:49 PM
#15
Originally Posted by boomn29
I run a traqmate too. The first thing I see what I look at your brake and turn zones map above is all the black. Green = go; Red = Stop; Black = coasting. You want to either be on one pedal or the other; and braking less is obviously faster.
Looks like others pointed this out already and perhaps it's track conditions - ie too high of speeds! I know your car has a lot more power than mine.
As for braking force, I hit right around 1g peak in my braking zones. Sometimes I tend to jab the brakes and don't get a nice 'bell curve' so I'm working on that.
Here's my fast lap from Blackhawk this past weekend. The short bits of black (buried in the green) are usually my shift points.
Looks like others pointed this out already and perhaps it's track conditions - ie too high of speeds! I know your car has a lot more power than mine.
As for braking force, I hit right around 1g peak in my braking zones. Sometimes I tend to jab the brakes and don't get a nice 'bell curve' so I'm working on that.
Here's my fast lap from Blackhawk this past weekend. The short bits of black (buried in the green) are usually my shift points.
Great advice.
If you do not need to be braking you should be on the gas, if you are not on the gas you should be braking.
There is no reason to be coasting in a race car except small periods mid corner.
Try to eliminate the time spent between braking and accelerating and you will go much faster!
Sam