payneracing714
Member
is the 58-62 rear gear still apply for the plate engines also?
Thanks
Thanks
Clone Gear torque range.
- Thread starter Krtrcr47
- Start date
racing promotor
Moderator
By saying nobody said much about the driver, I assume you mean front sprocket, not the person holding the steering wheel. If so the fact of saying use whichever front driver matches to keep your rear between a 58 & 62 and hits your target RPM, pretty much says it all, you say VERY small I'd start with a 13 / 62 If your RPM is right there for practice you know as track gets faster you'll go lower or rear so you'll leave the 13 driver on, IF your RPMs are real low you'll need to drop driver to a 12, IF your RPM are to high you'll need to go up to a 14 driver.
alvin l nunley
Site Supporter
With the 14, 15 or 16 driver, increasing the axle sprocket size by 1 – 4 teeth, for one tooth on the driver is fine, but if you get much smaller on the driver, or much bigger on the driver, 4 teeth on the driven will not be enough .
racing promotor
Moderator
We just debated this some last week or so in a different thread and pointed out to you it doesn't work out that way actual racing on DIRT oval racing, and I thought you pretty much agreed !! but anyway what works out much closer average is for front sprocket change in size by 1 = 3 teeth. Before you post it YES we know that won't make ratio's match on your chart.
alvin l nunley
Site Supporter
Are you saying my charts are wrong? If you're not, and I don't see how you could, then I'm left totally confused. My charts have no mysteries, they're just math, plain and simple.
racing promotor
Moderator
NO I'm saying no one races on paper, and pointing out what works out closer on track.
1fasttiller
Member
Great post, I'm playing with this now on my sons Jr2 kart at our local 1/4 mile very large kart track... We started him off about 2 years ago on a 14/55. He was very fast and ran up front alot UNTIL some fast kids showed up... We then went to a 16/63 (still 3.93) and were able to run with them and even win several races not changing much else. Now this year the track has some new clay and we're on a much newer Eleanor Chassis. The 16/63 just didn't seem to be doing it so I tried a 15/59 (3.93) this past weekend and we were still off. All the other karts in his class seemed like the RPM's were screaming as they came down the straights, much more than we were (average 5800-6000) I'm even told some of the big dogs are running 17 drivers now so I'm debating that for our next run... this is a BIG track especially for a restrictor plate kart.
I've always been old school and with my ME background, a ratio IS a Ratio but in karting its not and it drives me nuts!
I've always been old school and with my ME background, a ratio IS a Ratio but in karting its not and it drives me nuts!
racing promotor
Moderator
What color plate ? Big pipe or small ?
1fasttiller
Member
Its still our Purple plate (.500) and small pipe.
I think you were the one last year that pushed me to use the 16/63 and even though it was the exact same ratio we had with the 14, we went faster!
racing promotor
Moderator
Yes as long as you know tires are right and your driver is maximizing momentum I'd stick closer the front driver that fits the 62 or in your case the 63, If you test just gearing drop to the 15/59 or 60, I'd point out 5800 to 6000 I think you can turn it little more, and I'd say the difference you saw was more tires than gearing, because of the new clay your tire choice just didn't match as good as last year.Its still our Purple plate (.500) and small pipe.
I think you were the one last year that pushed me to use the 16/63 and even though it was the exact same ratio we had with the 14, we went faster!
Ok everyone I want to wake this up. So I have now had a couple races to give a real opinion what I see. The 16 63 driver is way faster. I talked myself into putting a 15 59 on with a 34 inch rr tire. I lost 3 tenths. I have gone back and forth. Everytime the taller driver gear is faster. The math shows 15 should be but the load on the motor is too much. It is a 2 tenths difference with no change to track or tires or setup. It is consistent. I'm not sure for jr classes. I just know now what I will do for sure always taller driver gear that gets me around the 62 rear gear or 63. Basically I'm not affraid of the tall rear gears I've seen it now for sure. I can hear the load on the motor.
racing promotor
Moderator
Certainly stick with what works for you and what you have most confidence in, but If your willing to share I'd be curious to here all the precise details between runs of switching back and forth, full details of tires, timing between runs, which gearing combo when ?
alvin l nunley
Site Supporter
Is it he same for a Predator?First I'm no engine builder and not sure on proper verbiage to best describe what range your keeping it in, But what I'm hearing and seeing now is for normal racing on tracks with 600 + rpm drop keep rear from 58 to 62 some builders will say even little lower, Of course you need to hit your target RPM, I used to not follow this lower rear logic and a few years ago would of said 62 to 66 but have been testing the waters more and right now what seems to be best for people I'm helping, is stick to as posted above unless the track gets real good and rpm drops are close 300 or less only then go into the 62 to 66 range, AND ONLY with a driver that maximizes momentum close to 100 %.
Also this question is pretty easy to verify for yourself even if all lips are sealed, as long as you venture out to some bigger races, just go to the grid and look at rear gears of all the hot shoes you can easily tell which size range there in
racing promotor
Moderator
Yes you could apply this same logic to the predator
alvin l nunley
Site Supporter
In Sprint racing, with the McCullough's, all we ever used was the bushing drum. One exception, Atwater CA, big long track. People used 10 , 11 and 12's. In the 101 class I ran a 5.3 ratio and won.
I'd say that points to a bushy not being that bad.
I'd also like to see some results running smaller gear sets. After seeing one person doing it, and winning, it got me to wondering. If I can run a 10/53@11,000 RPM on a McCullough, why can't we do that on a 6000 RPM Briggs & Stratton. Just wondering. 12/48....... 11/44........... what's so bad about that? I think it's worth a try. Of course we would have to make a different axle sprocket holder. Not an impossible task! Duck soup with todays CNC's! Who will be the first to try it?
I'd say that points to a bushy not being that bad.
I'd also like to see some results running smaller gear sets. After seeing one person doing it, and winning, it got me to wondering. If I can run a 10/53@11,000 RPM on a McCullough, why can't we do that on a 6000 RPM Briggs & Stratton. Just wondering. 12/48....... 11/44........... what's so bad about that? I think it's worth a try. Of course we would have to make a different axle sprocket holder. Not an impossible task! Duck soup with todays CNC's! Who will be the first to try it?
