1/10 Dirt Oval Gear Setup

KochRacing

Member
This seems to be a common question here but here it goes. I'm working on the gearing for my 8 year old kid.

Ultramax Badmax Chassis
100% OTB Stock Predator 212 Hemi including governor
Weight 308LB him and the kart combined
RPM around 5400 on stand
Tires Burris 33A
Tire Pressure 3lb right, 2lb left
1" of stagger from side to side
Clutch Noram Stinger
Current Gears 15/64

Track - Riverside Kartway Ulysses, KY 1/10 Dirt Steep Banks

if any more info is needed please ask.

I've been messing with gears trying to get him around the track faster, with the current setup he ends up around 1/4 to 1/2 track behind at the end of the race. he is holding the throttle down the entire race and cranking around 5100 RPM. i did have him on a 13/61 and he was cranking 5300 but going slower than he is now. What would be a suggestion for changes?

Also his class don't do a rolling start, he is getting left at the starting line and spends the whole race trying to catch up. When i had him on a 13/64 he would beat everyone out of the hole but would be passed before the 1st lap was completed.

Videos of him racing can be seen on my youtube... www.youtube.com/danielkoch87
 

Pops90

Member
Sounds like very low air pressure for Burris tires and a Jr. Driver. You want to try to run as much as you can without sacrificing handling.

I would target about 5,000 rpm with the predator as long as he is pretty consistent.

Your track looks much bigger than 1/10th of a mile to me.

Do you have the Crossweight, Noseweight and Left Side Weight numbers?
 

KochRacing

Member
I was running him on 4.5 left and 5.5 right. I dropped the air because of recommendation from other racers.. im new so I don't know what I'm doing lol
 

KochRacing

Member
Sounds like very low air pressure for Burris tires and a Jr. Driver. You want to try to run as much as you can without sacrificing handling.

I would target about 5,000 rpm with the predator as long as he is pretty consistent.

Your track looks much bigger than 1/10th of a mile to me.

Do you have the Crossweight, Noseweight and Left Side Weight numbers?
Never had it scaled other than the track checking the total weight. As far as track size thats what the owner advertise it as
 

Kj26

Member
You have to get it scaled, not being scaled is not helping the situation to start.
You can get away with bathroom scales and using an app like iRaceWeigh.
A kid will only run in the back so long until they give up and quit, help him out !!
 
This seems to be a common question here but here it goes. I'm working on the gearing for my 8 year old kid.

Ultramax Badmax Chassis
100% OTB Stock Predator 212 Hemi including governor
Weight 308LB him and the kart combined
RPM around 5400 on stand
Tires Burris 33A
Tire Pressure 3lb right, 2lb left
1" of stagger from side to side
Clutch Noram Stinger
Current Gears 15/64

Track - Riverside Kartway Ulysses, KY 1/10 Dirt Steep Banks

if any more info is needed please ask.

I've been messing with gears trying to get him around the track faster, with the current setup he ends up around 1/4 to 1/2 track behind at the end of the race. he is holding the throttle down the entire race and cranking around 5100 RPM. i did have him on a 13/61 and he was cranking 5300 but going slower than he is now. What would be a suggestion for changes?

Also his class don't do a rolling start, he is getting left at the starting line and spends the whole race trying to catch up. When i had him on a 13/64 he would beat everyone out of the hole but would be passed before the 1st lap was completed.

Videos of him racing can be seen on my youtube... www.youtube.com/danielkoch87
For 8 yr old and there is NO plate required ? If so what color plate ?
 
This seems to be a common question here but here it goes. I'm working on the gearing for my 8 year old kid.

Ultramax Badmax Chassis
100% OTB Stock Predator 212 Hemi including governor
Weight 308LB him and the kart combined
RPM around 5400 on stand
Tires Burris 33A
Tire Pressure 3lb right, 2lb left
1" of stagger from side to side
Clutch Noram Stinger
Current Gears 15/64

Track - Riverside Kartway Ulysses, KY 1/10 Dirt Steep Banks

if any more info is needed please ask.

I've been messing with gears trying to get him around the track faster, with the current setup he ends up around 1/4 to 1/2 track behind at the end of the race. he is holding the throttle down the entire race and cranking around 5100 RPM. i did have him on a 13/61 and he was cranking 5300 but going slower than he is now. What would be a suggestion for changes?

Also his class don't do a rolling start, he is getting left at the starting line and spends the whole race trying to catch up. When i had him on a 13/64 he would beat everyone out of the hole but would be passed before the 1st lap was completed.

Videos of him racing can be seen on my youtube... www.youtube.com/danielkoch87
Your turning to many RPM even with the 15 driver, You were WAY off with the 13, Way to low on air especially for a predator class, not enough rear stagger at 1" if it's a 1/10 th mile, As just posted you need to get it scaled out ASAP !!
 

alvin l nunley

Premium User
This might help you. Observed that with a 15 driver to start, one tooth on the driver is worth 4 teeth on the axle, approximately. As the driver gets smaller, that 4 tooth difference goes up as the driver gets smaller.
10_53 7 15 3030.jpg
 

Pops90

Member
I was running him on 4.5 left and 5.5 right. I dropped the air because of recommendation from other racers.. im new so I don't know what I'm doing lol
Until you get the kart scaled, it is hard to know if you should go up or down on air pressure because you don't know how much grip you need for the track conditions. With that being said, 2/3 psi on a Burris is very very low. I would be shocked if the kart isn't bottoming out especially with the bumps. That will hurt your speed also. Even if you don't have time to scale it before the next time you race, I would go back to your original air pressure.

It will help you a ton to get the kart scaled.
 

KochRacing

Member
Until you get the kart scaled, it is hard to know if you should go up or down on air pressure because you don't know how much grip you need for the track conditions. With that being said, 2/3 psi on a Burris is very very low. I would be shocked if the kart isn't bottoming out especially with the bumps. That will hurt your speed also. Even if you don't have time to scale it before the next time you race, I would go back to your original air pressure.

It will help you a ton to get the kart scaled.
this weekend I will run the air pressure back up and see how he does.
 

KochRacing

Member
Thanks for all the input guys! I'm going to try to have it scaled this weekend before he races. What kind of percentages should i be looking for when scaling the kart? is the only way to make changes is by adding more weight, or can I move stuff? The tack weight for his class is 250 and he probably already weights 30-45 pound more than the other kids in his class his kart currently has no added weight.
 

KochRacing

Member
Your turning to many RPM even with the 15 driver, You were WAY off with the 13, Way to low on air especially for a predator class, not enough rear stagger at 1" if it's a 1/10 th mile, As just posted you need to get it scaled out ASAP !!
How much stagger should he need? also how can i add more stagger other than Air Pressure?
 
Thanks for all the input guys! I'm going to try to have it scaled this weekend before he races. What kind of percentages should i be looking for when scaling the kart? is the only way to make changes is by adding more weight, or can I move stuff? The tack weight for his class is 250 and he probably already weights 30-45 pound more than the other kids in his class his kart currently has no added weight.
You can move weight around when you have weight, move seat if needed and even motor, 56% left, 46 % nose, 58 % cross, 2.5 RF neg camber, .5 LF pos camber.
 

alvin l nunley

Premium User
Racing promoter is probably close, but if you want to figure out yourself this is what you need. Everything in red needs to be filled in. This is just a picture, don't go by it.
40 foot track.jpg
 
What do I do to make them bigger? Or the left side smaller?
Smaller pull valve core out heat good with little bottle hand held torch and place in a freezer for an hour, Bigger air them up 1 1/4" bigger than what you need set them in the sun for an hour and check, once you get them right as soon as your done racing purge left sides of air put 12 lb in rights and store until needed again.
 
Top