The one problem we have seen with the 5500 rpm rule and I’m talking about motors sealed that you have to purchase from the track it you set it to turn 5500 rpm max during the day and it’s checked on the stand at 12 that night all the conditions have changed and your in a heap of trouble if you have a good engine an example of this is we won a money race and they told everyone that they was doing the 5500 rpm check for the top 3 karts I set mine at 5300 and when the top 3 was checked ours was 5480 the next 7 karts was over 5500 and all of them swear they set theirs at 5500 before hot laps started and 1 I know was it was one of my buddies that race with us I even tried to get him to set it lower and explain why to him never the less he set it on 5500 and finished 2nd and got tossed 6 karts in a row got tossed karts 8 and 9th got the 2and3rd place finish but the tech man used his tach what a bad night for the track owners should be a 100 rpm give or take especially going from 90 degrees when set to 60 degrees when checked oh and the humidity change ever wonder why we keep a weather station in our kart trailer?
5500 rpm stock motor
- Thread starter C Wetzel
- Start date
racing promotor
Moderator
This was all after the race on stand in tech with his tach ?
racing promotor
Moderator
I've never seen them change based on conditions, if I knew where I set mine I would of been demanding he try a different tach proving his correct.
Did none of those karts have a tach on during the race that he could compare to in tech with his tach ?
racing promotor
Moderator
I've only ever witnessed a few but have witnessed them set at 5450 on the stand and after the race in tech 4 hrs later they were 5450. You say sealed but are they still stock out of the box before sealed ?
racing promotor
Moderator
I'm no engine guy to explain it, I have also witnessed the tech guy help set one and suggest allowing a little cushion but no where near 200, now I'm curious to see the builders and tech guys response to your post. And if this is the normal I cant believe it's not been pointed out yet.
We do several dyno pulls almost every day several meaning 20 or more not in controlled environment pull up the garage door and do the testing we use performance trends 4.2 and check corrections on every pull oh and inertia dyno and we pull from mid day sometimes to midnight and we see changes unlike dyno’ing in a controlled environment which we have tried
Not sure why a 'maximum' number would ever need a cushion.
If the rule needs to read 5550, publish that number.
Same as scale after races. If you do not make weight, you did not make weight for the whole race.
As long as it is perceived as an advantage, some will always push that maximum, or minimum.
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It gives the honest racer that just bought a new motor from the track that is sealed where you cannot make any changes to it a chance to win without it being taken from them you probably would not like it taken from you some of these are young kids that spent their $100 they made from mowing yards or weed eating taking a smile from them leaving them with a frown your answer had 0 merit to it
Reallity is, if allowing 100 rpm cushion, engines will be set pushing that limit, expecting more cushion if slightly over.
The rule already has the cushion built in. The line has already been drawn.
Max is max.
No matter who it is, the rule should be enforced as written.
What will be learned if you let even 1 go being over the limit?
Penalize the 1 breaking the rule, not the rest of the field, who followed the rule.
How much merit should that have?
The rule already has the cushion built in. The line has already been drawn.
Max is max.
No matter who it is, the rule should be enforced as written.
What will be learned if you let even 1 go being over the limit?
Penalize the 1 breaking the rule, not the rest of the field, who followed the rule.
How much merit should that have?
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alvin l nunley
Site Supporter
On the humidity; even if the actual water vapor in the air stays exactly the same, when the temperature goes from 90 to 60, the relative humidity number will go way up. That's just how they're calculated.
For an example, if the relative humidity is 40% at 90°, and the temperature goes down to 60°, and the water vapor in the air doesn't change, the relative humidity might read 70%. Not actual numbers, just an example to show how it works.
In this particular situation, if there had been any air density reads, I'm sure you would get a different perspective. I'm not sure how an increase in air density could affect the settings on the maximum RPM. The device that controls the RPM, I think, has nothing to do with the horsepower the engines putting out.
For an example, if the relative humidity is 40% at 90°, and the temperature goes down to 60°, and the water vapor in the air doesn't change, the relative humidity might read 70%. Not actual numbers, just an example to show how it works.
In this particular situation, if there had been any air density reads, I'm sure you would get a different perspective. I'm not sure how an increase in air density could affect the settings on the maximum RPM. The device that controls the RPM, I think, has nothing to do with the horsepower the engines putting out.
The governor is connected to the throttle blade. It closes the throttle blade to control RPM.
I think that has a lot to do with the horsepower the engine is putting out.
Lightning3
Member
It sounds like the general consensus is there is no performance advantage to turn more RPM's. Is the rule in place for safety reasons?
I can only speak from observation. Everyone I've seen tossed for violating the RPM rule has been at the front of the pack.
I can only speak from observation. Everyone I've seen tossed for violating the RPM rule has been at the front of the pack.
If you don't modify the engine, there is no reason to turn them above 5,000 rpm on the track. The theory is that if you have one that turns over a certain RPM, you've done something to it. The engine can't breathe enough to make power above ~5,000 without modifications.
In reality, that isn't necessarily correct though. Our limit is 5,850 around here and I've got one that I have to put 10.8 lb springs in sometime soon to keep it from going over, only modifications are a weenie pipe and governor removed. I still target about 5,000 rpm at the end of the straightaways.
It really doesn't matter if you beleive it makes any difference on performance. The rule is there. Either enforce it, or remove it so everyone has the same opportunity.
If you make a mistake and go over it, by any amount, it would be no different than being 1 pound light at the scales. Or a no-go gauge slipping into the restrictor plate. That's the reason for the gauge or the scales. Rule is in black and white. No need for judgement calls.
If you make a mistake and go over it, by any amount, it would be no different than being 1 pound light at the scales. Or a no-go gauge slipping into the restrictor plate. That's the reason for the gauge or the scales. Rule is in black and white. No need for judgement calls.
Then why when we dyno put in the correction factors for that dyno pull if it made no difference then why put it in or use auto correction heck they are none even turning them close to 5500 on the track I have even made several (over 20 ) pulls with the governor set at 56 to 5800 and most at 4800 drop drastically in hp and yes humidity and temperatures has a big difference in hp and torque if not get on your dyno and do some testing for the public like some on here do
flattop1
Dawg 89
I must say I agrre with 95 Shaw . If the rule is 5500 rpm then thats it .
The clone had a plus this rule , that did not work out real well .
It understand the day night thing were it may change . You also have the ability to check and change as the event progresses .
Would i cry about getting tossed for 100 rpm , honestly I am sure some one would ask if i wanted cheese with that whine or do you need a tissue
The clone had a plus this rule , that did not work out real well .
It understand the day night thing were it may change . You also have the ability to check and change as the event progresses .
Would i cry about getting tossed for 100 rpm , honestly I am sure some one would ask if i wanted cheese with that whine or do you need a tissue