I agree apex96 lots of testing. The reason I asked this is because its been an on going argument on here. I just want to know what formula they use to get on their ratio. You can go to a track one person may run good on 18 driver other may run good on a 17. I think its more about the kart set up, tire prep, and drivers ability more than a ratio is ratio. Its more about testing and what works for you.
Sprockets
- Thread starter Circle track maniac
- Start date
I dont have a dog in this fight and I am a beginner so I am most likely thinking wrong...but...would the advantage of a lighter weight driver gear be the same as the advantage of a lighter weight flywheel? ARC 4.05lbs flywheel vs ARC 3.5lbs flywheel... 3.5lbs accelerates more efficiently, right? 4.05lbs will hold high RPM more efficiently, right?
So, small driver gear on short tracks where you need to get off the corner quickly and a larger gear for a momentum track? Given like ratios.
I know a few teeth on a driver gear will not equal .5lbs, but its a race of 1/10's of a second.
Again, I am a beginner... I am probably confused.
So, small driver gear on short tracks where you need to get off the corner quickly and a larger gear for a momentum track? Given like ratios.
I know a few teeth on a driver gear will not equal .5lbs, but its a race of 1/10's of a second.
Again, I am a beginner... I am probably confused.
I'm pretty sure you have to add 3-4 to the rear. Weight gain/loss negated. I see no advantage either way. We ran a 1-2 tooth smaller driver this passed weekend than the others. We were just as fast. I see no advantage at all.
Adding or removing weight from the rotating mass of the engine might be a more correct descriptor versus weight gain/loss of the drive train as a whole.
Do all the "Ratio is Ratio" racers also not care about the weight of their flywheel?
Like most it seems, I don't know if its advantageous or not.
I am trying to learn on here, just discussion topics. This site is great!
-Shaky60
alvin l nunley
Site Supporter
How much difference can these small changes make when compared to the total amount of the kart & driver mass you now have. It's all in percentages and the rate of acceleration compared to the beginning percentages and rates. A calculation of a change in acceleration is very dependent on the rate of acceleration. The rate of acceleration of a kart is nothing compared to the rate of acceleration of AA fuel dragster. The weight reduction of the smaller sprockets and chain is extremely small, percentage wise, compared to the total weight of the kart & driver. The rate of acceleration of the car & driver is also very small, (compared to a fuel dragster) thus making the reduction in weight even less significant.
I hope that makes some sense.
From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
I hope that makes some sense.
From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
spotteddawg
New member
And I just took a look at the vega page since I'd never once seen or heard of the white being used. There's a good reason it's not been used in the big races, it's a control tire or spec race tire if you may, and i doubt it has anywhere near the performance potential of the reds or yellows.[/QUOTE]
Whites really started getting used here about 56 weeks ago when we were told by not one but TWO suppliers that the yellow was out of stock and no longer being produced. Both offered the whites as a substitute ( thankfully, I still had new yellows ); many folks bought them...and found that they work pretty well, particularly later in the feature. My understanding is that the white is softer than a red but harder than a yellow. BTW...once a goodly number of whites were sold, the yellows reappearred as if by magic
Whites really started getting used here about 56 weeks ago when we were told by not one but TWO suppliers that the yellow was out of stock and no longer being produced. Both offered the whites as a substitute ( thankfully, I still had new yellows ); many folks bought them...and found that they work pretty well, particularly later in the feature. My understanding is that the white is softer than a red but harder than a yellow. BTW...once a goodly number of whites were sold, the yellows reappearred as if by magic
MikeleoneCT
Member
We only run whites on the right side (on asphalt). They are a bit harder than the yellows and have some big differences in the way they cycle. I think they have much MORE speed potential on asphalt then the yellows, but you have to have everything else working right. The yellows seem to "handle" better but are not as fast for us. The hotter and greasier the track the more the whites beat yellows.
Remember there are thin and regular yellows and they run much differently.
I have heard the new series yellows are not as good as last years MBS's. I have not tried them.
I couldn't get the reds to work at all, but I don't use prep.
But what does this have to do with gear ratios ??
Remember there are thin and regular yellows and they run much differently.
I have heard the new series yellows are not as good as last years MBS's. I have not tried them.
I couldn't get the reds to work at all, but I don't use prep.
But what does this have to do with gear ratios ??
I personally think you can have a flywheel to light for a piticular application in circle track racing. I have no way to prove this.
I understand what your thinking about rotating weight. Seems we think alike but like Al I think the percentages are insignificant in the end when looked on as a big picture. Why not just take the tape off the motor?....You'll push more air in turn kinda doing the something as adding weight. It's a thought, lol!
My hang up in talking with people about this is they say "Ill lap you in 4 laps". You might because my kart setup isn't right, my tires are off, my motor is short on horsepower, my driver isn't getting the job done, or a combination of all these factors. I don't think it will be because of the gear ratio when we run the same final.
Nothing, but well worth reading
When an engine builder builds your engine, do you expect him to use the lightest valve train possible? To use the longest rod possible? Lightest rod possible? The least you could do is run the smallest (lightest) driver gear that will still produce the desired ratio.
All probably insignificant on their own.. But together make a difference. We are racers, we chase 1/10th of a second on every lap. We chase that extra 1/10 of a HP in every engine. The difference between champions and the rest of the field is the amount of "insignificant" advantages in his program (given equal driving ability).
Driver gear selection alone will not produce a feature win, but if your close.......
All probably insignificant on their own.. But together make a difference. We are racers, we chase 1/10th of a second on every lap. We chase that extra 1/10 of a HP in every engine. The difference between champions and the rest of the field is the amount of "insignificant" advantages in his program (given equal driving ability).
Driver gear selection alone will not produce a feature win, but if your close.......
Someone ...
Member
Dang, I promised myself that I'd quit these gear ratio arguments but here I go again.
My experience comes from years of testing. Don't get caught up in the gear ratio calculation because it is deceptively simple - it does not take into account real problems that your engine faces (such as loading caused by track conditions, total vehicle weight, and driving style) as well as how it produces power.
Gasoline fueled engines have a relatively small "sweet spot" power band where they produce their best power. Most people measure this power band via a tachometer, so they only see r.p.m. instead of the torque that truly drives the load. But fortunately r.p.m. and torque are related directly enough to be workable, especially when there are so many other variables muddying up the waters too.
You want the driver / driven gear ratio that best takes advantage of the power your engine can produce. Particularly in "stock" classes engines cannot turn a lot of r.p.m. and they cannot change r.p.m. really quickly, but they are pretty good at producing torque. So if you've got torque and can't achieve fantastic r.p.m. you may as well gear for it by using a larger driver. That's a starting point. Will a larger gear create a heavier rotating mass on the engine? Certainly. But weigh your drivers and you'll probably not see much difference. Even though that difference is approximately squared as far as its effect on the engine, it is not a huge number and is easily swamped by other variables - including track conditions that you cannot change.
While you are turning laps you can check for bogging (usually coming out of corners) or "running out of gear" on the straights (feel the engine quit accelerating, usually near the end). Most likely your gear selection will be a compromise between bogging and running out of gear.
Because there are so many other variables in play what works best for me is not necessarily what works best for you. But we might be close. Add in changing track conditions, engine and clutch wear, or even changing engines and the "best" ratio can change again. Experience and results will teach you the best thing to do. You've got to experiment, and write down the results. If you rely upon basic calculations or memory you might forfeit an advantage to somebody else.
My experience comes from years of testing. Don't get caught up in the gear ratio calculation because it is deceptively simple - it does not take into account real problems that your engine faces (such as loading caused by track conditions, total vehicle weight, and driving style) as well as how it produces power.
Gasoline fueled engines have a relatively small "sweet spot" power band where they produce their best power. Most people measure this power band via a tachometer, so they only see r.p.m. instead of the torque that truly drives the load. But fortunately r.p.m. and torque are related directly enough to be workable, especially when there are so many other variables muddying up the waters too.
You want the driver / driven gear ratio that best takes advantage of the power your engine can produce. Particularly in "stock" classes engines cannot turn a lot of r.p.m. and they cannot change r.p.m. really quickly, but they are pretty good at producing torque. So if you've got torque and can't achieve fantastic r.p.m. you may as well gear for it by using a larger driver. That's a starting point. Will a larger gear create a heavier rotating mass on the engine? Certainly. But weigh your drivers and you'll probably not see much difference. Even though that difference is approximately squared as far as its effect on the engine, it is not a huge number and is easily swamped by other variables - including track conditions that you cannot change.
While you are turning laps you can check for bogging (usually coming out of corners) or "running out of gear" on the straights (feel the engine quit accelerating, usually near the end). Most likely your gear selection will be a compromise between bogging and running out of gear.
Because there are so many other variables in play what works best for me is not necessarily what works best for you. But we might be close. Add in changing track conditions, engine and clutch wear, or even changing engines and the "best" ratio can change again. Experience and results will teach you the best thing to do. You've got to experiment, and write down the results. If you rely upon basic calculations or memory you might forfeit an advantage to somebody else.