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I have been running the systems that the OP and Paul have linked to for about 6 months and they are accurate to about .1 PSI in steady state. They update every 3 sec. They are clearly not to learn from but provide you with an under inflation warning way before your butt does.
Originally Posted by Paul Solk
In addition, especially as someone who is just trying to understand the art of tire management which is indeed a skill and an art unto itself it is nice to know when I am in the optimal window. Contrary, it's nice to know when I am over driving the tire with my inputs and need to back off. No you aren't going to learn what an ir system is telling you but you can still learn from these systems...
There's a ton to learn from them. I was really surprised to compare driver feel with pressures and IR Temps. What drivers feel and is fast doesn't always match what they were aiming for with pressures. Different tires also vary A LOT in how they come up to pressure and how they maintain heat/pressure. It's been eye opening.
I'll try and post some data later today. Now back to lawn mowing, pool maintenance, and little league games! Maybe Home Depot for some tile, but I'm not sure if we'll have enough time. Nice little Saturday.
Here's some data from the same car, same setup, same tires, different tracks. The optimum pressure (by evaluating most grip) varies by 3-4 pounds. Once you factor in asphalt surface, track temps, ambient, sun, etc., optimum pressures can change pretty quick.
Also, one of the great things about these systems is that most have temperature built in. Then you can calculate starting pressures instead of just guessing. The data you build on pressures, temps, and build can be a real advantage if used right.
How do you read that from these charts? Wouldn't you want to look at this information in one particular corner rather than over an entire lap/session?
You can look at what pressure produces the most lateral G, long G, or break it down further with grip factors.
You could certainly go by track corner, but I'm not sure they would all be the same. At some point you need to aggregate data, so I go by the lap or session. Overall grip is what I try to maximize.
That’s a great chart showing the four corners and the correlation between the measured g loadings versus measured tire pressure over several laps.
It’s worth pointing out that the variance in grip is very small, in relation to the total AND to the tire pressure delta, but it IS measurable.
I’d want to make sure the laps are within a very tight group to improve the consistency, predictibility and repeatability of this information. Plus, validate with other measure before I came to a concrete conclusion.
I think for this crowd, to calculate and visualize Jorge’s grip factors spreadsheet might be best reserved for post race analysis, but that’s the sort of validation you could use to augment these excellent scatter plots!
That’s a great chart showing the four corners and the correlation between the measured g loadings versus measured tire pressure over several laps.
It’s worth pointing out that the variance in grip is very small, in relation to the total AND to the tire pressure delta, but it IS measurable.
I’d want to make sure the laps are within a very tight group to improve the consistency, predictibility and repeatability of this information. Plus, validate with other measure before I came to a concrete conclusion.
I think for this crowd, to calculate and visualize Jorge’s grip factors spreadsheet might be best reserved for post race analysis, but that’s the sort of validation you could use to augment these are excellent scatter plots!
Thanks for sharing! Great stuff!
Agree on all points. These a set of laps that were tightly grouped. That's one of the hardest parts of doing this analysis. Traffic, driver consistency, setup changes, and more make lap selection tough.
This is certainly post event (or day) analysis. With that is the involved study of track temp correlation, temp build up speed, tire cooling, and more. These systems have taught me a ton and are still giving me more to dive into.
It's also lead to some study if tire design and rubber compounds. Those are very different across models and especially manufacturers and the results of the tire build have the largest affect on performance, heating, cooling, tire life, and more.
How do you read that from these charts? Wouldn't you want to look at this information in one particular corner rather than over an entire lap/session?
No. Looking at one corner might easily lead you to not only the wrong conclusions (based on topography and driver comfort in those corners), but miss the idea of optimizing the car throughout the whole lap, which is the prime directive of a proper setup.
The way Matt has arranged the info is superb in both the way and the speed which the driver/engineer can isolate the trends and the quantitative differences between pressure levels, on all four corners of the car, across a variety of best laps.
Many tracks benefit from asymmetric setups and this is not only a good measure of effect of other, more significant chassis changes, but also the direct, primary results of the most important end result, your connection with Mother Earth!
This thread in particular, among many other threads on RL in general, is a great example of how much you guys all contribute to helping share your experience and wisdom with others.
I, for one, really appreciate the time and effort you guys put into sharing.
Agree on all points. These a set of laps that were tightly grouped. That's one of the hardest parts of doing this analysis.
It's also lead to some study if tire design and rubber compounds. Those are very different across models and especially manufacturers and the results of the tire build have the largest affect on performance, heating, cooling, tire life, and more.
THIS!
It’s been a few years, but when I was heavy into SCCA Club Racing testing various constructions and compounds at Roebling Road and doing tire tests at Michelin’s Laurens Proving Grounds for Grassroots Motorsports and other magazines, there were very good communications and support from the tire companies, which drove development of carcass construction and tread compound.
The equipment, testing and engineering support, for both R-Comp and real, non-DOT slick tires was incredible! I was struck dumb by how comprehensive their testing was. For a magazine article, my only job was to do three 2-mile long, 100-mph average laps on their high-speed handling loop, in short bursts from stone cold to 250-260 degrees tread temp and not vary more than .15 seconds (one and a half tenths) to do it. From stone cold out-lap to greasy, over the top overheating in-lap. For forty sets of tires. Blind.
It was intimidating, retiring to the lab as they were correlating the data, but evidently my feedback and identification of the tires was good enough that they invited me back. Wish I’d had Matt’s setup on my test cars to look at this information this way...
Thanks, HelpMeHelpU. These discussions are as valuable for those of us contributing because they help us distill and define what’s really important, after accumulating substantial experience. What I like is Matt, myself and others have gotten LESS sure and MORE curious and OPEN to finding objective answers to subjective questions! Thanks again.
You can look at what pressure produces the most lateral G, long G, or break it down further with grip factors.
You could certainly go by track corner, but I'm not sure they would all be the same. At some point you need to aggregate data, so I go by the lap or session. Overall grip is what I try to maximize.
Thanks Matt! The corners won't obviously all be the same but some corners will be more important that others. If you are aggregating this data over a lap, why would you care about pressure variations during the lap? I am just trying to figure out whether this investment would be something I should look into.
Originally Posted by ProCoach
No. Looking at one corner might easily lead you to not only the wrong conclusions (based on topography and driver comfort in those corners), but miss the idea of optimizing the car throughout the whole lap, which is the prime directive of a proper setup.
The way Matt has arranged the info is superb in both the way and the speed which the driver/engineer can isolate the trends and the quantitative differences between pressure levels, on all four corners of the car, across a variety of best laps.
Many tracks benefit from asymmetric setups and this is not only a good measure of effect of other, more significant chassis changes, but also the direct, primary results of the most important end result, your connection with Mother Earth!
Agreed - but why would you not prioritize certain corners/sectors over others when it comes to set-up. For example T17 and T7 at Sebring, T1 and T7 at WGI and Hog Pen at VIR? I can always look at the grip interval over a particular lap but that doesn't help me optimize the car set-up for the fastest lap,, This is similar to % of full throttle during a lap. Those measures are not granular enough when it comes to fine tuning another 10th or two out of the car.
Frank, if you focus too much on the granules, you can miss the whole pile! <grin>
In my experience, for drivers up to IMSA Championship winners, one corner or complex does not make or break a lap, but a series of similar corners and the driver and car’s behavior through them may...
Like it or not, most Club level drivers, even the most accomplished and studied of them, like you, are driving to a particular comfort level (albeit high and with confidence).
THAT is the limiting factor and THAT often bleeds over into high variability in specific corners of a particular track, car performance impacted MORE by the driver than the car itself.
It is when THAT envelope is expanded, either through bolstering of the driver’s detailed knowledge or massaging the car setup to make the driver feel like he or she can go BEYOND what they believed the “limits” to be, that true and quantified improvement is made, in my opinion.
Great discussion, and not unexpected that you would use as examples two of the most difficult corners/complexes in North America! <very big grin>
No. Looking at one corner might easily lead you to not only the wrong conclusions (based on topography and driver comfort in those corners), but miss the idea of optimizing the car throughout the whole lap, which is the prime directive of a proper setup.
The way Matt has arranged the info is superb in both the way and the speed which the driver/engineer can isolate the trends and the quantitative differences between pressure levels, on all four corners of the car, across a variety of best laps.
Many tracks benefit from asymmetric setups and this is not only a good measure of effect of other, more significant chassis changes, but also the direct, primary results of the most important end result, your connection with Mother Earth!
Cheers and see you at VIR.
This conversation is phenomenal thank you... You first sentence is similar to what you have said about T1 at WGI if I am reading it correctly. If we focused on turn 1 and removed the inherent understeer in T1 by focusing on that corner alone we would end up with a car set up to oversteer the majority of the track. Am I reading that correctly?
Thank you again. I am amazed how squiggly lines become such useful information!
If we focused on turn 1 and removed the inherent understeer in T1 by focusing on that corner alone we would end up with a car set up to oversteer the majority of the track. Am I reading that correctly?
Yes, sort of!
The topographical challenge that IS T1 at WGI leads to an act of faith, where turn-in and apex-approach understeer, if the heading is right and the vMin is close to the area picking up the curb, is transformed into better mid-corner and exit grip (and ideally, under proactive power, a return to neutral balance that cancels out the understeer). You just need to KNOW it's coming!
To make a car better at the front turning in at a downhill entry as steep as the entry to T1 or T5 would make a car quite exciting in T6, T8, T9, T10-T11!
Of course, this depends on the car, but I do discourage "tuning for a particular corner" as opposed to "tuning for a particular TYPE of corner," one that is prevalent at a particular track.
__________________ -Peter Krause www.peterkrause.net www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
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This thread made my head hurt and I had to skip through most of the posts. Way over my head or needs.
OP, if you're looking for cheap TPMS to beat on at the track to monitor pressures, here's a great option: oewheelsllc.com. I've been using their TPMS for years on the track. Early sensors had some inconsistencies and sometimes would take a while to sync, but the recent ones work flawlessly. Great for keeping an eye on your tire pressures and knowing when to bleed, when you can start pushing, etc., etc., etc. I've been using them for years in instructor groups in ohh 4 separate sets of wheels (not all at the same time), and yes, I get my wheels plenty hot! No problemo whatsoever.
What the data guys are discussing is way above my pay grade, but if you just want to monitor tire pressures oewheels is a great option. No affiliation other than as a satisfied customer. Even bought them for street cars (multiple)!!
.... are driving to a particular comfort level (albeit high and with confidence).
THAT is the limiting factor and THAT often bleeds over into high variability in specific corners of a particular track, car performance impacted MORE by the driver than the car itself....QUOTE]
Completely agree. All this "stuff" we do with data is great, but the spacer between the seat and steering wheel is the ultimate variable. If we can tune them up to be comfortable being uncomfortable, they quickly progress. That is the challenge and why I think the mental game (and driver biometrics) is such a tool for performance advancement. It's done in all other sports at a very high level and is being done in driving at the highest levels now too.
Originally Posted by ProCoach
Of course, this depends on the car, but I do discourage "tuning for a particular corner" as opposed to "tuning for a particular TYPE of corner," one that is prevalent at a particular track.
Agree. There are very few places were 1 corner makes the track. It's often a sort of corner or direction (i.e. Lime Rock) that you can tune towards, but not a specific corner. This is where track metrics come into play for the people that really want to dig in.
06-09-2018, 11:10 AM
Way over my head or needs.