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Old 07-24-2007, 12:11 PM   #16
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One thing to consider when temp gun shopping.....Over the years I've either lost or had 2 temp guns grow legs and walk off my pit table. I prefer to think it was just some stupid ass who grabbed it and forgot to return it rather than someone who set out to snag one from some overly trusting soul leaving their space unattended. In addition, I've gone through several more due to them being dropped, soaked with fuel, etc,etc. The last one I replaced because I forget it and it sat in direct sunlight all day, turning the LCD black.

I bought my first cheapie because I couldn't afford an exergen, I bought the rest of my cheapies because I didn't want to spend $250+ only to have it come up missing or broken.

It's easy to get distracted or caught up in a frenzy on race day, and temp guns have not been the only casualty of my addiction.
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Old 07-24-2007, 12:57 PM   #17
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Ya, thats true, I'll have to factor that in...

But, an Exergen-specific question: how far down the head do you shove that cone thing?

Thx.
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Old 07-24-2007, 01:50 PM   #18
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Okay so here goes..
First off I am sorry to ramble but this post just brings me to a question of Why? I guess basically I just cant understand why you should want or need a tool of such nature. ( I understand the need to temp,, ) but when does it become so critical to know that my tool ( an exergen standard $70 jobby ) is less accurate by 7 * than said other temp gun at 2 inches?


I guess I will skip to the bottom line.. This hobby is expensive enough why make it more when you dont need it. If you have a need for such tools buy them ( ie this is not the only place you will use it, and in that place you need that accuracy! ) by all means get and growl!!....
But we dont tune to temp atleast you shouldn't.. so if your motor is happy and your gun says its within a good heat range ( ive had motors run anywhere from 220 to 270 depending on motor) then why would you need an exact temp when your only temping mainly for your own peace of mind..?
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Old 07-24-2007, 05:06 PM   #19
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Quote:
Originally Posted by rregl0612 View Post

I guess I will skip to the bottom line.. This hobby is expensive enough why make it more when you dont need it. If you have a need for such tools buy them ( ie this is not the only place you will use it, and in that place you need that accuracy! ) by all means get and growl!!....
But we dont tune to temp atleast you shouldn't.. so if your motor is happy and your gun says its within a good heat range ( ive had motors run anywhere from 220 to 270 depending on motor) then why would you need an exact temp when your only temping mainly for your own peace of mind..?

I was waiting for someone to say that. The way you are supposed to use a temp gun makes the accuracy invalid. Example, I know my cheap $25 jobby is about 20* cold. My .12 runs great right in the 190-210 range (or 210-230 on an "expensive" unit). Now that's fine by me. The reason I even take the temp is simply to keep an eye on how my engine is doing. When it came off the track at 240 the other day I knew something was wrong and I found the pressure line had fallen off. So whether or not my temps jumped from 190 up to 240 or from 210 to 260, it's all the same.
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Old 07-24-2007, 05:51 PM   #20
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This is sad, you guys are talking about $600-1200 temp guns. Damn folks come on, unless your job requires you to have very accurate tempurature readings for whatever reason you dont need one of these. Hell i have an HPI temp gun that cost me $40 and i thought that was pricey. Secondly your not aiming to make your motor run at a certain temperature. You are trying to make the most power that you can put down on the track without getting your motors overly hot. I aim to keep my motor on my savage between 220 and 260. What the hell is the difference if the $400 snap on gun says its 246 and my HPI gun says its 242? None at all trust me either way i wouldnt touch my adjustment needles. I swear you guys with your raytek laser guns think it makes you a better racer? Its like he who carries the biggest condom in there wallet has the biggest schlong. Hate to tell you guys any jackass out there can go out and buy a Magnum and say hes Ron Jeremy.
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Old 07-25-2007, 01:10 AM   #21
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Well, of course I'm not only going to be using it for RC car temp measuring... there are plenty of other occasions on which I require high precision temp readings.

Can someone just tell me how far you can/should get the cone down the engine's head?
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Old 07-25-2007, 04:27 AM   #22
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Well, of course I'm not only going to be using it for RC car temp measuring... there are plenty of other occasions on which I require high precision temp readings.

Can someone just tell me how far you can/should get the cone down the engine's head?
Depends on the engine head itself. Some engine heads have larger openings then others. As long as the sensor is pointed at the glow plug your temp. readings will be pretty close. Find one that fits your needs and budget.
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Old 07-25-2007, 05:47 AM   #23
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All non contact temp guns read in a cone shaped pattern. Some are tighter than others but the bottom line is, the closer you get the tip to the item you are wanting to read (in this case the glo plug), the more accurate your reading will be.

Oh and BTW, it's only been in recent years that cheap temp guns have been worth having. The exergen is a holdover from the days when even the cheapest non contact temp probes ran in the thousands of dollars and were for industrial applications where size and pinpoint accuracy were not critical. If I'm not mistaken it was Ron Paris who contacted exergen and asked them to build him an r/c specific non contact temp probe, so it was the first (and still most accurate) unit made specifically for use with our toy cars.

Any way you cut it, a good temp probe is still a valuable tool for folks playing with toy cars. It's invaluable for the new folks who have yet to develop an ear (and eye) for a nitro engine in proper tune on the track, but it's still by far the best (and still most accurate) way to get a proper balance between your high and low speed needles, and trust me, as many engines are ruined by an overly lean low speed needle as are done in by overly lean high speed needle. The only reason for a low speed needle is to put enough fuel into the engine to cool it down when there is no air flow over the head. If you've ever owned an engine with a single needle carb you know what a PITA it is to deal with. Once you have it set where it runs good up top, the engine quickly overheats at idle. The 2 needle carb fixes this problem, but only if both needles are in proper balance and that's not something you can do accurately without a temp probe. You can get it close with the pinch test, but to get it just right requires a good temp probe.

Regards the "what's the point of a high zoot temp gun?" thing, it's really all about personal preference and what you can afford. The exergen is tank tough and will still be working when all the $30~$40 guns are propping open doors or holding down papers on your desk. It can also be calibrated and repaired if it gets damaged. There is also the on road crowd who pay MUCH more for their engines than us folks who play in the dirt. They also run them at the very edge of burning up so a temp gun accurate to within a degree or two is vital to these racers.

As far as I can see, the biggest problem with owning an exergen is everyone who owns a $30~$40 temp gun wanting to borrow it.
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Old 07-25-2007, 09:34 AM   #24
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Originally Posted by fhm555 View Post
All non contact temp guns read in a cone shaped pattern. Some are tighter than others but the bottom line is, the closer you get the tip to the item you are wanting to read (in this case the glo plug), the more accurate your reading will be.

Oh and BTW, it's only been in recent years that cheap temp guns have been worth having. The exergen is a holdover from the days when even the cheapest non contact temp probes ran in the thousands of dollars and were for industrial applications where size and pinpoint accuracy were not critical. If I'm not mistaken it was Ron Paris who contacted exergen and asked them to build him an r/c specific non contact temp probe, so it was the first (and still most accurate) unit made specifically for use with our toy cars.

Any way you cut it, a good temp probe is still a valuable tool for folks playing with toy cars. It's invaluable for the new folks who have yet to develop an ear (and eye) for a nitro engine in proper tune on the track, but it's still by far the best (and still most accurate) way to get a proper balance between your high and low speed needles, and trust me, as many engines are ruined by an overly lean low speed needle as are done in by overly lean high speed needle. The only reason for a low speed needle is to put enough fuel into the engine to cool it down when there is no air flow over the head. If you've ever owned an engine with a single needle carb you know what a PITA it is to deal with. Once you have it set where it runs good up top, the engine quickly overheats at idle. The 2 needle carb fixes this problem, but only if both needles are in proper balance and that's not something you can do accurately without a temp probe. You can get it close with the pinch test, but to get it just right requires a good temp probe.

Regards the "what's the point of a high zoot temp gun?" thing, it's really all about personal preference and what you can afford. The exergen is tank tough and will still be working when all the $30~$40 guns are propping open doors or holding down papers on your desk. It can also be calibrated and repaired if it gets damaged. There is also the on road crowd who pay MUCH more for their engines than us folks who play in the dirt. They also run them at the very edge of burning up so a temp gun accurate to within a degree or two is vital to these racers.

As far as I can see, the biggest problem with owning an exergen is everyone who owns a $30~$40 temp gun wanting to borrow it.
Thanks for the post. Can you tell me how you tune the LSN with the thermometer please?
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Old 07-25-2007, 09:55 AM   #25
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The biggest problems of temp guns is people being told they need to stay at a specific temp. And when they do learn how to tune they are afraid to put away the temp gun. How many guys do you see asking others to temp there engines for them since their gun is back in the pits. If you don't use the same gun everytime knowing the temp is useless. Best way to tune is on the track until it's running how you want it to.
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Old 07-25-2007, 10:10 AM   #26
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I temp my motors after a heat just to know.. when I set out in the mornings to practice and tune folr the day.. I tune by ear.. and trigger feel.. I still temp at the ends of those runs but it is really to only confirm that my ear and trigger finger are correct!....

The exergen gun is great probly the best accuracy per dollar! spent..
truthfully it is up to you hat your willing to spend and can afford!

Whenever you temp with anything you want to get it as close to the glow plug as possible..

Good luck to you all .. and watch out for the first corner!!!!
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Old 07-25-2007, 12:15 PM   #27
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Once you get everything (carb wise) close and have your HSN set correctly, run a few hot laps to insure everything is fully warmed up including the chassis being fully heat soaked. Bring it in and shoot the head temp, then let the car idle for the count of 10 and shoot the head temp a second time. You are looking for a drop of around 6~8 degrees. More than that and it's too rich on the bottom, less than that, or the temp going up, indicates an over lean LSN. Once you have the LSN where you want it you may have to reset your idle, as many times an over rich LSN will be keeping the engine running at idle rather than a properly set slide/barrel gap.

In order for this to work it's vital for the whole car to be throughly warmed up or you will not get a true read on what the engine temp is doing during the 10 count.
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