Clone Gear torque range.

Krtrcr47

Member
Ok if you use roll out calculator 15 59 should give you more mph. Me judging by sound and strain on motor when rpms dropped the 16 63 chugged through it better. I had a mock qualifying run 4 laps came in washed tires changed gears went right back out for mock qualifying again. Did this 2 weeks in a row even raced the 15 combo to see if it drafted better it did not it was 2 tenths slower period. I was signed up for senior over 35 and clone heavy. That is why I was able to get out in same track condition so fast. I know what I'm doing from now on.
 

alvin l nunley

Site Supporter
What I find interesting is; I've never heard of anybody finding these 2 tenths on a dyno. I can't help but think; if you're getting more HP to the axle (I'm pretty sure that's what you'd have to do to go faster) why does that not show up on a dyno?
 
This has been an interesting thread. A successful racer in my area, runs the smaller gears while we run the bigger gears (15/60 vs 16/64). We tried it last year and had findings similar to Krtrcr47. We are going to try it again with a different engine combo.

I'm still trying to wrap my head around power vs rpm. That's how I rationalize in my mind why one gear set may be faster than the other even though ratio is the same or close. I go back and forth which is "better". My driver seems to perform better with RPM's (both on clone & predator) rather than staying in the power curve. We can run AKRA or NKA. We do better on NKA which is against the grain with most other drivers and even with the engine builder. I justify it in my head that RPM's = wheel speed.

I'm open to learning more on this. Please be nice with your comments. Lol
 

Pete_Muller

Moderator
Al,

The dyno will not always equal what's happening on the track.

When you were racing enduro karts, did you ever have a chassis crack somewhere near where the engine is attached? If not, I can tell you what happens: it feels like the engine just fell on its face. What do you think the dyno would say if you bolted that same engine back on the dyno and checked it?

The LTO guys are testing and feeling subtleties that may not show up on a dyno where the engine is bolted on the same way every time, (and may use the same gearing/chain every time).

My "guess" is that inertia in the drivetrain (which slightly changes when sprocket sizes are changed), and maybe the difference in force vector amount and position of the chain, along with a lot of other things that are not "mathematically" understood.... are what is being not only felt, but seen on the stopwatch -- and in race results!

PM
 

1fasttiller

Member
What I find interesting is; I've never heard of anybody finding these 2 tenths on a dyno. I can't help but think; if you're getting more HP to the axle (I'm pretty sure that's what you'd have to do to go faster) why does that not show up on a dyno?
Al that is because on a dyno a gear ratio is a gear ratio, It will not show a gain but that is certainly not the case on the track! On a momentum track a 16/63 will outperform a 15/59 every time. I've tried it multiple times just to prove it to myself. Why, I can't say.
 

alvin l nunley

Site Supporter
Al that is because on a dyno a gear ratio is a gear ratio, It will not show a gain but that is certainly not the case on the track! On a momentum track a 16/63 will outperform a 15/59 every time. I've tried it multiple times just to prove it to myself. Why, I can't say.
I can't figure it out either. Do you have a dyno? Maybe a friend with one?
 
Al that is because on a dyno a gear ratio is a gear ratio, It will not show a gain but that is certainly not the case on the track! On a momentum track a 16/63 will outperform a 15/59 every time. I've tried it multiple times just to prove it to myself. Why, I can't say.

From our testing when we would say go from the 16/63 to the 15/59 mathematically we end up needing to drop down a extra tooth on the rear and vice vs. when you are adding a tooth to the driver..... food for thought
 

alvin l nunley

Site Supporter
From our testing when we would say go from the 16/63 to the 15/59 mathematically we end up needing to drop down a extra tooth on the rear and vice vs. when you are adding a tooth to the driver..... food for thought
Can you explain the reason for having to change at one tooth down. Did it turn more RPM before you took the tooth off? What happened?
 

racing promotor

Moderator
Your still not comparing apples to apples 100% with different on track runs even if only 15 min apart, don't matter if it is the same set of tires, same number of laps, there are a lot of contributing details that come into play that can show 2 th difference either way that has nothing to do with the different gearing combo's being tested. But hey confidence is probably worth 2 th as well !!
 

paulkish

old fart
"What I find interesting is; I've never heard of anybody finding these 2 tenths on a dyno. I can't help but think; if you're getting more HP to the axle (I'm pretty sure that's what you'd have to do to go faster) why does that not show up on a dyno?"

It's because your stuck in your obsolete little world of only being able to comprehend going faster, when the rest of the world has past you bye learning how to keep from going slower.

When on the better edge of the oval game is not about acceleration because with today's prepped tires everyone can accelerate at different rates to the limit of grip the track has to offer. It then becomes a game of who is best able to maintain momentum not slowing down when speed drops below below the limit of grip. That Al happens in the turns and also on straights if excessive grip has been put into their tires.

That is until things change when at any time or place around the track grip can be exceeded because of abundant available hp.
 
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Krtrcr47

Member
I'm not trying to convince anyone at all. I'm just sharing what I found. I was convinced 15 59 was going to be faster. Week before I lead the race on 16 63 thought for sure with someone pushing 15 59 was going to hold the lead. Nope switched 2 tenths it was more like 5 min scramble to get back on track to see if my experiment was correct. I seen results thought same thing promoter thought. But now I have enough info that I'm not going to 15 again. I have someone in clone mediums doing the same thing with me. He laughed cause last race in 15 driver he finished back of the pack. This race 16 driver he was swapping with leaders contending to win.

I'll let everyone know if I figure something new out.
This is just interesting to me.
 

Krtrcr47

Member
Also 2 tenths change not one lap 2 tenths. Mylaps are consistent. That is what I meant 2 tenths every lap. Not 2 tenths on my best lap. I went from front runner to back of the pack.
 

racing promotor

Moderator
I'm not trying to convince anyone at all. I'm just sharing what I found. I was convinced 15 59 was going to be faster. Week before I lead the race on 16 63 thought for sure with someone pushing 15 59 was going to hold the lead. Nope switched 2 tenths it was more like 5 min scramble to get back on track to see if my experiment was correct. I seen results thought same thing promoter thought. But now I have enough info that I'm not going to 15 again. I have someone in clone mediums doing the same thing with me. He laughed cause last race in 15 driver he finished back of the pack. This race 16 driver he was swapping with leaders contending to win.

I'll let everyone know if I figure something new out.
This is just interesting to me.
It's interesting to me as well, I'm still curious as to 100 % details of timing between your test, I see week before you lead on a 16, then i see 5 min scrambled to prove, still doesn't paint the picture of exact details full account, also 100 % details on tires for all the runs.
 

paulkish

old fart
Also 2 tenths change not one lap 2 tenths. Mylaps are consistent. That is what I meant 2 tenths every lap. Not 2 tenths on my best lap. I went from front runner to back of the pack.

What if you put it on the scales after the change?
Does relocating the engine cause any note worthy difference?
 

alvin l nunley

Site Supporter
Your still not comparing apples to apples 100% with different on track runs even if only 15 min apart, don't matter if it is the same set of tires, same number of laps, there are a lot of contributing details that come into play that can show 2 th difference either way that has nothing to do with the different gearing combo's being tested. But hey confidence is probably worth 2 th as well !!
I agree with you 100%, and that's my point.
 

Krtrcr47

Member
I have 3 chains quick change to keep motor in same place. The entire reason I started the discussion is because I knew what was better with my flathead and animals the clone is new to me. I'll maybe share some mychron5 info when I get it on the pc. I'll tell all what I learn through the year.
 
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