DamonB

I've got Geez (www.extremegeez.com) up and running and plan to add a tire pyro to my toolbox as well this season. I know temps are all over the place for different tires and vehicles but am told that ideally you want to see the inside edge about 15-20 degrees hotter than the rest of the tire. (Speaking of which is that C or F? 15-20 degrees is a big difference between those two scales.)

Anyone actually used probe pyros to setup their camber and pressures? How small a change in camber can you notice on the pyro? How do temps change over the life of the tire?

bradrx7

Damon,

Good question. First, tire temps should ONLY be taken with a probe. you MUST get next to the cord for accurate temps. Those laser pyrometers are NOT for tire temps.

I use my memory pyrometer (Longacre) to check temps when I go to a new track or change settings. Remember, I run on full slicks. There are some key things to remember to do. Take the temps in a constant progression for exact comparisons and record all the data into a setup sheet. You must take these temps in pit lane (I try to get as close to pit in as possible) and have someone help so you can get the temps ASAP.

As for the data itself, temps are taken in F. I see about 10-15 degree differences across the face when my hot tire pressures are right. As for camber, those settings on my car are not changed for years as I have found the right setup and stay there. I only fine tune now with shock settings.

I use my cross averages to set my shocks. You can really see which tire is sliding more with these averages and make the adjustments. Look here for a super tip sheet for using a memory temp gauge... http://www.bakerprecision.com/longacr12b.htm

The info is aimed toward circle track racers, but is applicable to road racing cars. If you are going to run at TWS, send me a private e-mail and I'd be glad to take temps for you and help you evaluate the findings. Just let me know.

DamonB

What exactly are you doing with the shocks if a tire is running hot for instance? Is it merely a damping setting or are you adjusting the spring perch and changing crossweight?

bradrx7

I was talking about average cross temps. The side that is cooler can be adjusted with less rebound to help generate some heat/pressure. I use the double adjustables to fine tune. Honest, my car is set up very good with spring rates and sway bars. I haven't needed to change in years. The shocks give me plenty of adjustment to fine tune at this point. Using shocks for suspension adjustment should always be a fine tune. In other words, don't mess with them until everything else is right with the shocks in medium position.

Damon, this is too much for a small message. The bottom line is to replicate the settings on a car that is fast, then drive and see how you like it. Make big changes to see what happens and go from there. When making changes, don't drive more than three lapas before making your assessment. Humans can adapt quickly and you'll find you are driving around a change. Top teams know this and you'll often see them make a change, go out for one lap and come in to talk about it.

i've found most guys will gladly share their setup in a DE environment. Find out what they run, then duplicate it. For instance, what I run will not help you unless you run huge Dunlop slicks and stiff springs. If you run Hoosiers and weigh XXXX, then find a guy who runs that and ask.

I hope that helps.

DamonB

Yeah, I'm pretty aware of the generalizations but realize the whole package comes down to what you can do with small changes. IMO the car feels very good and does what I want it to, but that doesn't necessarily mean I have it setup to optimum. Keep in mind I autox, so I don't run for entire sessions. I do agree with you though about changes on the car: You notice right away. I typically know after the first two corners if the change I made is better or worse and since the run is so short you don't really have to worry about developing a bad habit, you just change the car back.

As for replicating settings on a car that is fast, those are harder to come by in Solo2 People aren't rude but tend to be more secretive, and even then I may hate the way that guy likes his car. Couple that with the number of guys running FD's in SS now is approximately zero. My car is good and I am happy with it but I'm trying to verify if it's as good as it can be with what I have to deal with. That's why I decided to install Geez and am going to back that up with tire temps to see what they are doing and then adjust setup from there. It's definitely in the ballpark, but I want to see what's left and as you know that line starts getting finer and finer as the setup progresses.

I know plenty of you guys have more first hand experience with this stuff than me and it's easier to learn from someone else than to try it all yourself for the first time Essentially I want to be certain of what tire temps really tell me given that I race on different surfaces and in many different kinds of weather with some runs short, some long, some with minutes between them and some with hours.

bradrx7

Yeah, I forgot you doing AX. Wow, tire temps would be problematic at many venues. you really need help to get them, plus a lof of that depended on course direction (LH v RH dominance). Also forgot you are competing. i've been instructing too long... LOL.

Maybe, doing some tests on your own in a parking lot could get you some data. Maybe you can find a place to skidpad and do temp tests? you Definitely need a probe style pyro, though. Don't get swapped into a laser.

DamonB

That's the only thing I am sure of so far Hoping for a Longacre with memory. If I have to write down twelve temps as I take them I figure that alone will skew my findings. I know the Longacre to be quick to acquire readings.

Bern

Brad:
Question... what series do you run in? Also what tracks do you run at, during the season? Just curious as to the no need for much adjustments on your car. It seems you have it pretty hooked up.

Thanks,

-Bern

bradrx7

Bern, I don't run a series. I do a lot of instruction and this is my open track car that I run in the instructor group. I run with a group of guys from all over who have similar third gens. Last year we went to Mosport, Mont Tremblant, Watkins Glen, VIR, Barber Motorsports Park and my local track, Texas World Speedway.

The car is hooked up really well, I've been working on the setup for many years and have figured it out to my liking. Full cage, no interior, stiff suspension (1000/700 spings), manual brakes, 265/650x18 slicks all around, etc. Slowest thing on the car is the driver. <G>

in2twins

Question for you Brad, since we are primarily looking at relative temperatures, ie differences across the tread and from tire to tire, why is a probe so much better than IR? I would imagine that the disadvantage of IR is that the surface temps on the tires both change quickly, and are effected by pavement heat or cold to a greater degree. however, it seems to me though that since all four tires are under the same influences, this is easily accounted for, additionally, if you have an assistant, the temps can be taken with enough speed to mitigate the cooling, and or you could observe the speed of change on a tire(for future reference), and adjust accordingly. Not saying the probe is not better, but in my own experience the IR works well in all but the coldest/and or wet conditions. What are your thoughts? Thanks, Carl

Bern

Thanks Brad! Continued success with the car! I'd love to get that group of FD's over to Cali for a trak event.. what do you say to Laguna?

-Bern

bradrx7

We'll plan a West coast trip sometime, maybe 2005. Laguna's noise restrictions are a pain. They had those at Mont Tremblant and the only reason we passed was by whining. LOL...
We'd all like to run Sears, Laguna and T-hill. Todd Serota and Mark Dadgar keep begging me to come out and run with them, so it may happen.

RenoCYM

Damon; I too autox and find that by the time I get back to the grid, fish out my pyrometer and get my fat fanny out of the car and start checking temps, everything has either cooled on the shady side of the car, or stayed hot on the sunny side. Also, I seem to be the only one at the event who is even trying to check temps, but everyone is checking pressures.

bradrx7

Yeah, you need an assistant and need to check them ASAP. You cannot do it yourself.

adam c

iTrader: (2)

I always understood that even tire temps across the tire was optimal, although nearly impossible to achieve. Testing on a circle track won't give the same kind of readings because the tires are not being "pushed" in both directions.

For autocrossing, the tires are barely hot by the time you exit the course. I would thing that a surface reading would be better than deep probe (for auto-x).

Carl Byck

I typically see ~130* across the treads on RA1s in my FC, no more than 5-7* difference inside to outside. Maybe 10* cooler on one side of the car if the course is heavy to one direction. That is on a 40 second course at ~80* ambient. Also, I agree with your statement Adam. Carl
W/IR

xfeastonarsex

iTrader: (5)

we took temps on the tires at the auto-x after each run with the miata. I used an infrared thermo.

DamonB

That's not been my findings. We certainly heat the tires but since we have less time to do it our static pressures are usually higher than for roadcourse work. When I take the same tires to go roadracing I start out with my cold pressures about 6 pounds lower; my hot pressures end up the same.

I understand the need to get to the tires quickly for temps and that can easily be arranged.

DamonB

I constantly check pressures and have to bleed them slightly before nearly every run as the day and tires warm up. The pyro is going to be used more for setup work and will not be used all the time, though probably for much of this season so I can see what the temps do on different surfaces. I race often on concrete and different kinds of asphalt from the coolness of March to the 110 degrees of August I want to see what all this does to the tire temp along with setup and pressure changes. Call it a learning experience

GT3_racer

Hey,
I am a local,in your area, gt3 racer, I use tire temps to set up preasures and camber in the front end only.
I purchased a simple pyrometer at smilyies in Balch Springs.
I would be happy to show you my data sheets from previous races, including last week at College Station.
E mail me back to arrange meeting.
I will be at MSR next week testing if you want to see how it works.

DamonB

Thanks GT3_racer. Emailed you!