THSCC Forums

I've been shopping around for a probe type pyrometer. I've found these 3 that are in my price range. What do you think?

Tif Instruments

Longacre Economy

Accutech Deluxe

Graham

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http://www.greywinds.com

FWIW, I've got the Longacre and have been happy with it.

My biggest problem is not the equipment, it's the crew (or lack of it, in my case.) You probably already know this, but to get helpful numbers, you've got to come in to the hot pit lane off the track, and have a crew member measure the temps immediately. Trying to do it yourself, where you have half a cool-down lap at the end of a session, then drive to the paddock, get out of your car, grab the pyrometer, and measure -- just takes too long and the temps have already come close to equalizing across the tread.

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Marvin McBride
Spec Miata #62

Thanks Marvin. This is for autox. I figure as soon as I finish a run I can go straight to grid or pit somewhere quick and grab some readings. This is mainly a learning experience right now. I've been reading some books on suspensions and tuning. This seems to be the first tool you need along with air pressure gauge to get a reading on what is really happening. So I figure I'll give it a whirl and see if I learn something...

Graham

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http://www.greywinds.com

Our local guys seem to use the infrared thermometers for autocross - Aaron, et al. - care to comment?

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Marvin McBride
Spec Miata #62

I like my infrared one. The whole talk about measuring inside the rubber blah blah blah is for F1 cars. I've been using one of those $40 radio shack deals, I think I paid $30 on a group buy last year for it. It measures just fine.

-Tom

That's exactly why I looked at the probe style pyrometer. The 2 books I have on suspension tuning both say to use that instead of the laser because the surface temperature cools down too quick. Maybe I'll just get a decent laser one. At least those are good for more than tires...

Graham

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http://www.greywinds.com

I will sell you mine. They are worthless for autocross. I agree with Tom, you never built up enough heat in a tire to make a probe work, at least not in the DOT tires. The infrareds are good toy to impress your friends with.

Save your money and time.

Instead of jumping out of your car and tyring to read the temps, spend the minutes reviewing your run for what you did right and where you would like to improve on the next run.

The only neat thing I did with my infrared was when the power was out and the gas logs were the heat source. I shot the top corner of the room and a corner down by the fllor. There was a 20 degree difference, 60 at the floor and 80 at the ceiling.

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Jim Pastorius
2008 Silverado VortecMax
1992 Camaro CMC#92
2002 BMW R1150R

2009 3rd Place CMC Mid-Atlantic Championship
2009 CMC Hyperfest Winner

Ok so if follow what you are saying Jim, There is no value in using a pyrometer (probe or digital) because an autox run won't generate enough heat to tell me anything?

I figured in the warmer months those tires get plenty hot on a 60 sec course and I might learn something about the alignment, suspension, weight balance, etc.. Not that I can change much in stock class but I was hoping to learn something about the car setup.

Now I'm confused, again

Graham

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http://www.greywinds.com

Don't be confused. You have a ton of set up information for your Corvette. Probably a little too much. You probably have everything from alignment to what pressures to run. Use that information to set the car up to your liking.

You are more than welcome to use my infrared toy. Try it out.

It will probably save you a $100 or so

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Jim Pastorius
2008 Silverado VortecMax
1992 Camaro CMC#92
2002 BMW R1150R

2009 3rd Place CMC Mid-Atlantic Championship
2009 CMC Hyperfest Winner

Graham,

For what its worth I tend to agree with Jim's comments regarding using a pyrometer in Stock class, especially with the site conditions we have. For a Vette the proven setup and tire pressure ranges are probably well known so you won't need the pyrometer info to help set up the car. You probably also don't want to try to change the balance of the car with tire pressures. Set it to one of the "recommended standard setups and pressures" and then focus on getting the best times you can. I do not recommend trying to change tire pressures between competition runs based on pyrometer readings. Certainly in a test and tune if you are trying to find pressures you prefer, but only if you can be confident that all the other possible variables haven't changed. On our sites that is very difficult to do.

If the car pushes or oversteers too much for your taste in too many situations then use front bar, alignment, or shocks adjustments to tweak the balance. I would be surprised if minor tire pressure changes will effect the balance of a Vette much.

Note that what I've done for years (even though I have a pyrometer) is to use tire wear over numerous events to tell me what is "really" happening "on average". Wear patterns will show if the alignment and/or pressures are OK or as good as they can be given rules constraints. They will also show which end of the car is working the hardest (my rear tires always wear faster even though they are bigger and I only have 114 HP). I suspect that you will have a similar result.

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Dick Rasmussen

FS 50 2018 Mustang GT

Jim,

Sure I'd like to borrow the pyrometer sometime just out of curiosity. I understand your point about taking time to review the run while it's still fresh in your mind. And I know I could use it.

Jim, Dick,

Yeah there is plenty of info on suspension settings. I've played around with the alignment specs and have something that works pretty good with my street tires. It's a combination between some popular settings used for Advanced Street and baseline Autocross. The all out Autocross settings are probably too much for a daily driven car. I was hoping the pyrometer would help me see if I have camber and toe set where I get the most out of the tires. No doubt this is also affected by the way I drive the car and what feels good to me.

Someone told me to take the car to a big parking lot and make a really big circle and use it as a skid pad and then test tires temps. That would generate enough heat to show how the tires are working.

Graham

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http://www.greywinds.com

When you find a parking lot big enough to do that without getting dizzy(BTDT trying to heat cycle new tires), let Miles know where it is so he can check it out for an AX site. Seriously you'd need a very large piece of paving like the part of VMP behind the bleachers. 200' diameter min is what is used for skidpads+ runoff room. That's almost a football field square of clear space.

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SPIN or WIN!
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