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Hi folks,

just curious as to what (EPTS) temps folks are seeing on the cluster for their 6000 sleds? I just got through my first winter with mine but never thought to have a look at the EPTS readings (borderline snow conditions had me focused on the coolant temps to avoid overheating). I am familiar with the acceptable temperature range for an EGT probe mounted in the collector but have no clue as to what the readings would/should be further "downwind" at the EPTS. I will be toying with some TPI adjustable airbox vents next winter and want to have a reference for the temps I should b e shooting for.

thanks in advance :)
 

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I agree with Greg B. (and Hooper), here's why- 2 years ago on day 4 of an 8-day back packing trip my wife's 2015 zr6000 threw a code (believe it was P0546) for exhaust pipe temp sensor. I asked her how the sled was running. She said "fine". No limp mode or any noticeable difference but if you toggled to the temp sensor mode on the gauge it was maxed. Hmmmm... we were about 500 miles from base camp so we just continued to ride. We swapped sleds on a long railroad grade that was hard-packed and flat & smooth. So she had my '19 ZR8000 and we raced several times from 30 mph. It was on one of those pulls I saw 95mph on the dream-o-meter. She said she saw 104 mph on the 800 during that run and she was slowly walking away from me. So it was pretty accurate. The moral of the story is that failed pipe temp sensor had no affect on the sled what-so-ever. When we got home I bought a new sensor and that the code went away and now the gauge works in that mode. Once again, NO difference. As far as I'm concerned that temp sensor is useless.
 

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EGT as used by most manufacturers is definitely important. It helps monitor the ideal temp to be maintained to help the engine operate at the designed pipe temp and corresponding rpm. It also provides a warning in case the engine starts running too lean for some reason. In the case of Polaris engines, the desired temp at WOT is 1000-1200 degrees F. Part throttle can be much lower.
 

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EGT as used by most manufacturers is definitely important. It helps monitor the ideal temp to be maintained to help the engine operate at the designed pipe temp and corresponding rpm. It also provides a warning in case the engine starts running too lean for some reason. In the case of Polaris engines, the desired temp at WOT is 1000-1200 degrees F. Part throttle can be much lower.
Your "computer" is reading that. Your not going to change anything, So,,,,,
Well let's see who to believe, I'll take John Hooper seeing as how he's inducted in the Snowmobile Hall of Fame
John Hooper | Snowmobile Hall of Fame

Heres his engine building business website, you want one of his racing engines you better get out your checkbook it will easily go over $10 Grand. Give him a call, tell him he's all wrong.
2120625

Hooper Race Engines -
 

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EGT as used by most manufacturers is definitely important. It helps monitor the ideal temp to be maintained to help the engine operate at the designed pipe temp and corresponding rpm. It also provides a warning in case the engine starts running too lean for some reason. In the case of Polaris engines, the desired temp at WOT is 1000-1200 degrees F. Part throttle can be much lower.
You are right on that. But what I think is displayed on cats gauge is 2 different things. Mine is never below 1400 degrees.
 

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You are right on that. But what I think is displayed on cats gauge is 2 different things. Mine is never below 1400 degrees.
Interesting. I've done lots of EGT testing in the field and on the dyno. This includes emissions testing. Some of these tests included wideband O2 sensors as well as EGT probes in each of 8 exhaust pipes in a 355 CID SBC race engine.
Air/fuel ratios from 10:1 to over 16:1. Any EGT temp over 14-1500 Deg F indicates a lot of afterburning in the exhaust pipe. Actual combustion temps inside the chamber can reach 2500 + deg F.

Any engine builder knows that EGT temp is important as an indicator of wasted energy that isn't being applied to the piston. One of the interesting things about EGTs is that they can be misleading, as a temp that is seen as too low can be due to being either too rich or too lean. Unless you know the temp cause, you don't see the potential problem.
This is sometimes why certain engine builders don't want to focus on EGT as a true indicator. O2 sensors can be equally misleading as they only read the AFR in the exhaust, not in the combustion chamber. The best indicator of ideal combustion is a pressure probe installed inside the combustion chamber. This shows how fast and how high the pressure builds without detonation/preignition.
Mazda is using exactly that in their latest engine that switches from spark ignition (normal combustion) to diesel operation (Detonation) on GASOLINE.


 

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Interesting. I've done lots of EGT testing in the field and on the dyno. This includes emissions testing. Some of these tests included wideband O2 sensors as well as EGT probes in each of 8 exhaust pipes in a 355 CID SBC race engine.
Air/fuel ratios from 10:1 to over 16:1. Any EGT temp over 14-1500 Deg F indicates a lot of afterburning in the exhaust pipe. Actual combustion temps inside the chamber can reach 2500 + deg F.

Any engine builder knows that EGT temp is important as an indicator of wasted energy that isn't being applied to the piston. One of the interesting things about EGTs is that they can be misleading, as a temp that is seen as too low can be due to being either too rich or too lean. Unless you know the temp cause, you don't see the potential problem.
This is sometimes why certain engine builders don't want to focus on EGT as a true indicator. O2 sensors can be equally misleading as they only read the AFR in the exhaust, not in the combustion chamber. The best indicator of ideal combustion is a pressure probe installed inside the combustion chamber. This shows how fast and how high the pressure builds without detonation/preignition.
Mazda is using exactly that in their latest engine that switches from spark ignition (normal combustion) to diesel operation (Detonation) on GASOLINE.


could be why some of that cats are known to shoot flames out the exhaust pipe. Mine isn’t a flame thrower. I have also noticed my cat runs a good 10-15 degrees higher water temp than my axys in the same conditions
 

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Interesting. I've done lots of EGT testing in the field and on the dyno. This includes emissions testing. Some of these tests included wideband O2 sensors as well as EGT probes in each of 8 exhaust pipes in a 355 CID SBC race engine.
Interesting so your putting your tests on an 8 cylinder small block Chevy (which all the major professional race series Nascar, Imsa, TransAm no longer use for years) and your basing that against the preeminent two stroke engine builder in the country, probably one of the best in the country, and your telling John Hooper he's all wet?

I'm all ears, tell me how you know more than him. I think saying A/F ratio would be the better point but let's hear it! Tell me how a guy your up against, a guy that's in the Snowmobile Hall of Fame, doesn't know as much as you do about exhaust temp and tuning a two stroke engine using exhaust temp?

And again, what are you going to do about what your reading? Write your own software?
 

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Egts are not for tuning they are for monitoring.
 

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Interesting so your putting your tests on an 8 cylinder small block Chevy (which all the major professional race series Nascar, Imsa, TransAm no longer use for years) and your basing that against the preeminent two stroke engine builder in the country, probably one of the best in the country, and your telling John Hooper he's all wet?

I'm all ears, tell me how you know more than him. I think saying A/F ratio would be the better point but let's hear it! Tell me how a guy your up against, a guy that's in the Snowmobile Hall of Fame, doesn't know as much as you do about exhaust temp and tuning a two stroke engine using exhaust temp?

And again, what are you going to do about what your reading? Write your own software?
You obviously want to pick a fight, however, if you really want to read into Hooper’s statement the argument should remain isolated to performance. The mass production engine builder is obviously seeing an opportunity to add a layer of protection or they would elect for the cost savings of removing an additional sensor and production process to the pipe.
 

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You obviously want to pick a fight,
No not at all, I want him to justify what he said, Hooper the Two stroke engine builder of race engines against what this guy said. How many World championship engines again did he build? Who again do we thank for set screw clutch weights? Just looking at the long list of accomplishments of John Hoopers history and if someone want to trash it all, I want his qualifications and accomplishment list as well so we can compare. So, lets start with the Snowmobile Hall of Fame, so what has patrioticinnovations done again? Has he built and dynoed any world championship engines?
 

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You obviously want to pick a fight, however, if you really want to read into Hooper’s statement the argument should remain isolated to performance. The mass production engine builder is obviously seeing an opportunity to add a layer of protection or they would elect for the cost savings of removing an additional sensor and production process to the pipe.
now to the Op's original post he wanted to know

"I am familiar with the acceptable temperature range for an EGT probe mounted in the collector but have no clue as to what the readings would/should be further "downwind" at the EPTS. I will be toying with some TPI adjustable airbox vents next winter and want to have a reference for the temps I should b e shooting for."

Not what your stating, the op wanted to know what temps to look for, the answer is "none", don't pay any attention to it, you can't do anything about it anyway. Your looking to solve a problem that doesn't exist. The computer in your sled, car, bike , boat takes care of that for you and you can't do anything about it anyway, so keep riding.
 

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now to the Op's original post he wanted to know

"I am familiar with the acceptable temperature range for an EGT probe mounted in the collector but have no clue as to what the readings would/should be further "downwind" at the EPTS. I will be toying with some TPI adjustable airbox vents next winter and want to have a reference for the temps I should b e shooting for."

Not what your stating, the op wanted to know what temps to look for, the answer is "none", don't pay any attention to it, you can't do anything about it anyway. Your looking to solve a problem that doesn't exist. The computer in your sled, car, bike , boat takes care of that for you and you can't do anything about it anyway, so keep riding.
the reason I keep saying it is irrelevant is the cat will dump fuel when it hits above 130 degrees water temp. This is why my sled runs super high egt on the gauge. What patriotinvoations has said is exactly what is happening with my sled. If you were trying to tune by that thing you would be going the wrong way
 

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Interesting so your putting your tests on an 8 cylinder small block Chevy (which all the major professional race series Nascar, Imsa, TransAm no longer use for years) and your basing that against the preeminent two stroke engine builder in the country, probably one of the best in the country, and your telling John Hooper he's all wet?

I'm all ears, tell me how you know more than him. I think saying A/F ratio would be the better point but let's hear it! Tell me how a guy your up against, a guy that's in the Snowmobile Hall of Fame, doesn't know as much as you do about exhaust temp and tuning a two stroke engine using exhaust temp?

And again, what are you going to do about what your reading? Write your own software?
You sound like a left winger. Making things up. Your knowledge of EGT is way wrong. And, you are misreading why Hooper says to don't use them. How about another world respected guy named Olaf Aaen. He uses them and even sells the gauges. Way back when New England Dyno used to run 2-stroke dyno tests, they recommended them along with other ways to read A/F mixtures. I use EGT to monitor every turbocharged 2-stroke I ever build. I've watched EGT climb to 1300 deg F and seize a piston. Why do you think that small gasoline powered aircraft use pyrometers to allow the pilot to adjust the fuel mixture for power for takeoff and fuel economy while in motion? Diesels also use them for monitoring EGT so it doesn't get too high.

Many things affect what is a recommended EGT temp for a given engine. For example, high compression lowers safe EGT because it creates less wasted fuel that burns in the pipe rather than the combustion chamber. Cylinder head design also affects EGT as does ignition timing. Rate of fuel burn also affects EGT. These are among the many reasons engine tuners might not want someone to try to zero in on a particular EGT reading. BTW, the Arctic Cat race manual provides a EGT probe location and a safe temp for most of their production engines.

Here's some info for your enlightenment:
 

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No not at all, I want him to justify what he said, Hooper the Two stroke engine builder of race engines against what this guy said. How many World championship engines again did he build? Who again do we thank for set screw clutch weights? Just looking at the long list of accomplishments of John Hoopers history and if someone want to trash it all, I want his qualifications and accomplishment list as well so we can compare. So, lets start with the Snowmobile Hall of Fame, so what has patrioticinnovations done again? Has he built and dynoed any world championship engines?
Actually, I'm the guy who built the world's first turbocharged 2-stroke 92 Vmax 4 as well as the first 93 Storm and 93 Thundercat turbo sleds. I also helped develop computerized engine hot and cold test stands for the auto industry. What's your claim to fame?
 

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You sound like a left winger. Making things up. Your knowledge of EGT is way wrong. And, you are misreading why Hooper says to don't use them.
Number 1 , my political views are irrelevant, But I'm no left winger.
You really need to turn it back a notch bud
Number 2, my "knowledge of EGT is way wrong"? How so? where did I say "my knowledge" I'm quoting what John Hooper says in his website just the same as Greg did. you want to attack me go ahead and attack other as well, tack836 said something else. All I said was you wouldn't do anything about it anyway outside of shutting it off. It's a stock sled, the OP is asking about temps, we all pointed to a direction to look and a few of us quoted Hooper. You have a beef with it CALL JOHN HOOPER! No matter what turbocharged engines you built I would think you have a ways to get to his list bud.
Making things up?
As I said (and what I DID say)
End of story, forget what those reading say. And thats coming from Hooper. Who built who knows how many Eagle River World Championship winning engines!
So no-where was I making anything up, I quoted a website, take it up with them
 
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