Alternative Tire pyrometers....

[Steve J.]

Does anyone know of any others then Longacre?

Maybe some smaller companies that do karting stuff or something else?

Just curious, as its strange the only ones I can find are longacre.

[B.Watts]

Others I've seen:

Rebco (I think it was a rebadged Longacre)
AccuTech

Longacre is definitely the best on the market.

There are some smaller companies that make them, but I don't believe any of them have memory, thus you'll need someone following you around the car with a pen to record the temps.

[Steve J.]

Well, there won't really be a need to record temps. I'm just going to need one to see the temp ranges across the tire, so i can get the tire pressure just right.

Well considering it looks like the longacre is the cheapest at $90, I guess I'll get that one.

[B.Watts]

Yeah, but can you remember 12 temperatures? It's a lot easier to record them and then have them all on the screen in front of you to see what the ranges are.

How would you use temps across the thread to determine optimum pressure anyway? Camber settings I can understand, but pressure?

We tried it without a memory pyrometer for a while, and I'll never do it again. It also gives you the ability to go back and right them into your track or session log/notes.

[Steve J.]

I'll use pen and paper It takes 30 seconds take temps and write them down.

[B.Watts]

I found that the time it took to put the pyrometer down and record each temp was enough time for the temps to begin to even out across the tread. Those extra 30 seconds can make your results tough to use.

[Steve J.]

I think I'll be ok... unless you feel so strongly you want to buy me the $400 deluxe model with the $400 printer so I can save even more time, instead of writing them down, haha.

They got some cool stuff, but from the data acq I did on our fsae car so far, i did fine with just paper/pen, and those are smaller tires....

[B.Watts]

I'm not buying you crap, just sharing my experience. I need that $400 to get my own set of tools if I end up getting a Spec Miata and trailer here soon!

Remember that the tires are more accessible on a FSAE car and you have a shorter distance to run/walk around the car to get to each tire.

Lots of times, I'll go back around the car after taking the initial readings just to see how much they've changed. The average temp over the tire surface usually hasn't changed much, but the individual readings (inside, middle, outside) have all moved closer to the mean.

[Steve J.]

Well for my needs that deviation will be fine.

I merely made the post to see what other ones were on the market.

I know the $500 top of the line, super duper tire pyrometer is whats best, but we all can't drop half a grand on something like this.

[B.Watts]

The Accutech runs around $130.

http://www.rebcoperformance.com/cata...id=237&catid=7

[Steve J.]

That is not a full recording, that does not help much.

I'm just going to get the "economy" model. Thanks for the info though.

[B.Watts]

Yeah, I know it doesn't record. I was just pointing you to some of the other "cheaper" options I know of.

[cpt97M3]

Originally posted by BMWRacerITS

How would you use temps across the thread to determine optimum pressure anyway? Camber settings I can understand, but pressure?

If the middle temp is higher than the average of the inner and outer temp, then lower the pressure. If it's lower, raise the pressure. YMMV.

[B.Watts]

Well, I understand that...but I would think that would really only apply if you have a seriously overinflated or underinflated tire. I wouldn't think a pyrometer is going to help you really narrow down to the most optimum pressure at which the tires create the most grip (within a 8 pound range or so)...you'll need a G-sensor, data acquisition, and some testing time (preferably on a controlled skid pad) to determine that...or better yet, just talk to the tire engineers who support the tires and find out what they recommend as a starting point!

For instance, I bet I could run our BMW tires with 40 pounds and 30 pounds and not see any appreciable difference in the relation of the temperatures to each other across the tire tread (assuming the same camber alignment), but a very appreciable difference in the amount of grip the tires are generating.

[jayhudson]

Originally posted by BMWRacerITS
Well, I understand that...but I would think that would really only apply if you have a seriously overinflated or underinflated tire. I wouldn't think a pyrometer is going to help you really narrow down to the most optimum pressure at which the tires create the most grip (within a 8 pound range or so)...you'll need a G-sensor, data acquisition, and some testing time (preferably on a controlled skid pad) to determine that...or better yet, just talk to the tire engineers who support the tires and find out what they recommend as a starting point!

For instance, I bet I could run our BMW tires with 40 pounds and 30 pounds and not see any appreciable difference in the relation of the temperatures to each other across the tire tread (assuming the same camber alignment), but a very appreciable difference in the amount of grip the tires are generating.

I'm surprised at your position Bryan. From my personal experience, checking tire temps across the tread shows differences in temps, between center and inner/outer, with as little as a 2 pound difference in pressures. Fred Phun, in his book "How to Make Your Car Handle", specifically tells how to adjust tire pressures based on temp readings.

Sway and camber settings should only affect the inner and outer temps, relative to each other.

Of course, different tire/wheel combos will be affected more or less by pressures

Jay

[B.Watts]

Maybe it simply has to do with the tires I'm running? I've only run on slicks (either on the BMW or the Formula Mazda) for about 3 years now. It's been a long time since I played with DOT tires. As compared to DOT tires, we run quite a bit less tire pressure, and thus the sweet spot is much smaller...we're talking starting pressures in the teens on my FM.

I have never really noticed a trend between pressure and center of the tire temps, and none of the engineers I've dealt with have ever recommended using a pyrometer to check anything but camber settings.

I'm heading down to Roebling this weekend to co-drive and crew for my dad in a CCA club race. We'll be dialing in camber settings on Friday afternoon, so I'll take a look at the temps, play with air pressure a bit, and see what sort of changes I notice now that I'm actually looking for it!

[Steve J.]

Can you give me these "engineer's" contact information, I am very interested to see what thier opinions are on these topics. Thanks

[B.Watts]

Goodyear guy - I don't know him by name. He would occasionally show up at events as support and give us some feedback on the tires, temps, pressures, etc for the Formula Mazda's.

Dunlop Guy - Not sure who to point you too. I've talked to 2-3 in the paddocks of ALMS events because we run take-offs from the ALMS Porsches and BMWs on our BMW Club car.

My buddy at Michelin/BFG - If memory serves me correctly, he's currently in Europe conducting winter tire testing. I don't give out friends numbers to people I've never met anyway.

Team Engineer for Velocity Motorsports - Not with the team, has taken another position and I don't have his new contact info.

Sorry I can't help you out.

[Steve J.]

Haha how convienent that noone is available and/or you don't know thier names

[B.Watts]

I knew the exact game you were playing, and I refused to play along. I don't need to prove anything to you, or need for you to start calling my contacts and bothering them.

[Steve J.]

As Liam Lynch would say, "then this kid bry came up and was like, "hey" and was like, " yea...WHATEVER!" That song is hilarious!

[1BADM3]

Originally posted by BMWRacerITS
I bet I could run our BMW tires with 40 pounds and 30 pounds and not see any appreciable difference in the relation of the temperatures to each other across the tire tread (assuming the same camber alignment), but a very appreciable difference in the amount of grip the tires are generating.

Bryan, I'll take you up on this bet. Maybe on your slicks it will be less. I know it makes a difference on my Hoosiers and of course it would also show up in tire wear.

Bob

[B.Watts]

I'm going to do a little testing this weekend. We'll see what the results are. I'm interested to see...always new things to learn, no matter how long I've been at this. I've honestly never used temps to determine pressure...I'm sure I've read it in various books and passed over it because it's simply something I've never done before.

It does make sense, I would just expect it to be useful for narrowing down to a range of say 5-6 pounds and not for getting down to a specific number. It's hard for me to believe that 1-2 extra pounds of air will contirbute significantly to how much hotter the middle of the tire will get.

Tire wear has never been a problem because we've always adjusted camber to the point that the inside of the tire runs about 15 degrees warmer than the outside, and at the pressure we run, the middle temp has always been right between the two and the tires have worn perfectly. Once we have the camber dialed in this weekend at our base pressure, I'll start playing with the pressures to see what sort of changes I see in the relation of the middle temp to the outer temps.

[Steve J.]

Just make sure you don't have 10 variables going on at once, because you are just wasting your time, and any conclusion you think you arecoming to, will be unjustifiable.

Temperatures, if used properly, should be able to get withing 1/2 a degree of the "proper" temperature.

[B.Watts]

Yeah, yeah, yeah...I HAVE actually run testing before. Heck, my team spent 4 hours on a skidpad making nothing but rake changes.