Opinions on gear / driver selection on dry slick

[H1Motorsport]

Experienced opinions please on driver gear selections on very dry slick trick. 13/65 vs 14/70. This ratio giving me right rpm range.

[racing promotor]

What Motor and class ?

[H1Motorsport]

Medium/ clone

[flattop1]

Experienced opinions please on driver gear selections on very dry slick trick. 13/65 vs 14/70. This ratio giving me right rpm range.

You may get a lot of experienced opinions .
RP - will get you a straight answer .

[racing promotor]

Medium/ clone

Well for sure not a 14/70 don't even bother taking anything bigger than a 68 along, In general Track size and amount of momentum it creates dictates front driver size, the bigger the track the better it grips up ( creates momentum ) the bigger the front driver all while keeping the rear around a 66 to hit your target RPM, a 13/65 would fit about an 1/8th Mile track that is NOT flatfoot with drops around 1000 to 1200, or a little bigger track with tight turns, with NO grip and loosing more momentum a 12/62 might be a consideration, Try the 13/65 if you feel your lacking off the turns only then try the 12 front driver.
Do you know the track size ? and is it tight turn out of the throttle ? or just the NO grip has you out of the throttle ? Do you know your lap times ?

[SoCo Tire Treatments]

Dont go larger than a 64 with a clone, lots of the Pros wont even go above a 62-63. These motors dont like a big rear gear.

[racing promotor]

Dont go larger than a 64 with a clone, lots of the Pros wont even go above a 62-63. These motors dont like a big rear gear.

I'm surprised to see that as ALWAYS, here that holds true to smaller than a 1/5th mile less momentum, tighter turns lower grip, but the 1/5 th miles better grip and faster like Selinsgrove not so much the Pros are 66 ish , especially since we started cranking them 7000 RPM plus.

[racing promotor]

Another question I would have is how did you come up with the 13/65 to compare ? Is that on track tested ?

[H1Motorsport]

Yes RP, that 13/65 ratio is track tested. Our racing buddy runs 14/70 and believes its a better combo, tho the race results are very close between he and us. But this is a dry slick track private club track, where momentum is a challenge. You experienced veterans have shared and explained what I have thought, but much more in detail. I appreciate all the imput. While track size is the major factor, momentum vs throttle dancing comes into play on clutch driver choice also.

[racing promotor]

Yes RP, that 13/65 ratio is track tested. Our racing buddy runs 14/70 and believes its a better combo, tho the race results are very close between he and us. But this is a dry slick track private club track, where momentum is a challenge. You experienced veterans have shared and explained what I have thought, but much more in detail. I appreciate all the imput. While track size is the major factor, momentum vs throttle dancing comes into play on clutch driver choice also.

Try a 12/61 ,62 sometime, you might get surprised !!

Good Luck !!

[H1Motorsport]

Already was thinking on that,,, probably will try that. My son( 27 years old) is an awesome driver, hustles the kart. But if theres an area to work on , it's the starts and restarts. That 12 driver may be an idea.

[racing promotor]

If he's keeping close pace with 14/70 provided his motor is legal, you are letting speed on the table with tires and prep.

[CarlsonMotorsports]

Just go by your stop watch.
A stop watch never lies.

If it's faster on the clock, it's faster on the track.
* At least for qualifying.
Now, being able to pull out and pass traffic during a race might be a different reason to add a tooth or two on a small track.

Also monitor corner exit rpm - that's an indicator to me on scrub, gearing, set-up, tires, etc if the kart is indeed fast or not.
No two motors (karts & drivers as well) are alike...some like to turn a couple hundred rpm more than others, so comparing peak numbers is a shot in the dark at best.

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Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
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29 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com