Another gearing question

Outlaw28

New member
We run on a slightly banked 1/7 mile momentum track in a green plate winged kart with treaded tires (RR 36.5”) 52 on the duro (35.5” 45 duro on the lr). We are getting killed by .4-.6 tenths a lap and been all over the 15 driver gear chart. Last week we ran a 15-73 and turned 5800 and was way behind the leaders. Thought about trying a 14 driver this week. Anyone got ideas on where to start?
 

racing promotor

Moderator
Sorry it is a qrc outlaw kart
I know nothing about these frames other than I"m sure they won't roll and make momentum like a standard kart chassis, BUT even with that being said I can't imaging it taking a 15/73 to turn only 5800 rpm on a 1/7th mile momentum track.
As an example that motor on a Jr Sportsman champ chassis on slicks the gearing would be close to a 16/62 ish to turn 5800.
I'd start pulling rear teeth 3 at a time and monitor RPMs I'd say your gear bound now and pulling 3 rpms might not change, If that happens keep pulling rear teeth, I highly doubt a 14 driver is your answer.
With all that being said I'd also add pretty sure you have other issues going on hindering momentum, like set up, tires, and is your driver flat footing it for sure and has enough seat time to build momentum, racing up in the groove, making passes without hesitation ?
 

Outlaw28

New member
Drops are 800 ish so kart maybe a little on the tight side as the micros lay a bunch of rubber down. Kid is wide open and definitely not afraid to pass and runs a solid line. His lap times are usually very close lap after lap. Any other track we go to he is usually winning or fighting for the lead.
 

racing promotor

Moderator
Drops are 800 ish so kart maybe a little on the tight side as the micros lay a bunch of rubber down. Kid is wide open and definitely not afraid to pass and runs a solid line. His lap times are usually very close lap after lap. Any other track we go to he is usually winning or fighting for the lead.
Have you tried less teeth on the rear with the 15 driver
 

racing promotor

Moderator
I have tried a 67 and it turned 5300 a couple of weeks ago..
So you added 6 teeth and gained 500 RPM, not real far off, You gotta have something holding back momentum drops on that size track with everything pretty close should not be over 500 for sure. Even the 15/67 should be to much gear.
Are you having any handling issues that you can see ?
 

Outlaw28

New member
Not that I can see. But I haven’t played with cross. I usually have the LR scooted all the way out to help free it up.
 

racing promotor

Moderator
Not that I can see. But I haven’t played with cross. I usually have the LR scooted all the way out to help free it up.
That's not good only masking another issue, Don't worry about cross for now that's a minor tweak for speed you got bigger issues, Do you have set up numbers for that kart ? Have you scaled it ?
 

Outlaw28

New member
LF-58lbs 6x5.5 Hoosier D10 duro 25 RF-58lbs 6x6.5 D30 duro 35
LR-86lbs 6x6.5 D30 duro 45 RR-73lbs 6x11.5x8 D50 duro 52
Total-275lbs
Rf camber -2 degree block
Rf caster 12 degrees
LF camber 0 degree
LF caster 10 degrees
Toe rf straight lf- 1/8 out
Front- 42%
Left-52%
Cross-52%
 

racing promotor

Moderator
LF-58lbs 6x5.5 Hoosier D10 duro 25 RF-58lbs 6x6.5 D30 duro 35
LR-86lbs 6x6.5 D30 duro 45 RR-73lbs 6x11.5x8 D50 duro 52
Total-275lbs
Rf camber -2 degree block
Rf caster 12 degrees
LF camber 0 degree
LF caster 10 degrees
Toe rf straight lf- 1/8 out
Front- 42%
Left-52%
Cross-52%
I have no clue how that kart compares to standard kart chassis, BUT it sounds like it has tight written all over it.
Hopefully someone with experience with the outlaw karts can chime in.
 

Outlaw28

New member
It maybe we went to a track with low grip and the kart was freaking rails so your probably right. Say it was a flat kart where would you say it was right at?
 

racing promotor

Moderator
LF-58lbs 6x5.5 Hoosier D10 duro 25 RF-58lbs 6x6.5 D30 duro 35
LR-86lbs 6x6.5 D30 duro 45 RR-73lbs 6x11.5x8 D50 duro 52
Total-275lbs
Rf camber -2 degree block
Rf caster 12 degrees
LF camber 0 degree
LF caster 10 degrees
Toe rf straight lf- 1/8 out
Front- 42%
Left-52%
Cross-52%
That can vary based on year but, A standard chassis would be more like 46 % nose, 56 % left , 58 % cross, 8 & 12 caster, .5 LF pos camber, 2.5 RF neg camber , 1/8 toe out is ok.
 

Outlaw28

New member
Have you walked to a corner and listened to this big rpm drop? Are you sure he is wide open and the kart is bogging down that much?
Yes coming out of two it sounds flat and off tone of the leaders. Go pro is pointed at him and his right foot never leaves the floor. This past weekend I took teeth off and rpm’s stayed the same and so did the stop watch. I’m going to give racing promoters gear a go this weekend.
 

racing promotor

Moderator
Yes coming out of two it sounds flat and off tone of the leaders. Go pro is pointed at him and his right foot never leaves the floor. This past weekend I took teeth off and rpm’s stayed the same and so did the stop watch. I’m going to give racing promoters gear a go this weekend.
If you pulled teeth and RPMs stayed the same, your still gear bound keep pulling teeth till your RPMs drop.
How many did you pull ? and where did that put you on gearing ?
 
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