Track Tac

LF / RF - Caster and Position

J

jscholt

Member
I have done a lot of research on these forums and seems there is no "set way" in relation to the position of the blocks on the right and left other than run them in the back position or LF back and RF Forward.

My son races a '17 Triton Jr, we've historically always followed the PRC Setup sheet and ran with RF Forward and LF Back... standard Caster setting 7/10. However, we started running a very flat indoor, very small no grip track this winter...very sandy and they keep it soft, so requires a really soft duro tire. Think 11 clutch and really large real gear, huge drops.

I'm curious, is there any advantage to putting the LF in the forward block and moving the RF to the rear? How will that change the handling and steering for a small bullring track like the one we are racing on? Is there any advantage in increasing/decreasing caster settings and getting them closer together like a 6/8 or a 10/12?

For those that like to know settings:
Left - 58%
Cross - 60%
Rear - 52.5-53%
JR 3 class
Front stagger 1.5
Rear stagger 1.75
RF Cam - 2.25
LF Cam - +5 - +75

Any help or advice would be appreciated.
Thank you!
 
I've always used more caster on a track with less grip and less caster with a track the has more grip in it. I've been told I'm wrong about this before and I have been ( my wife will tell you I'm wrong all the time lol). But the more caster you add the more camber gain you have when having wheel input. I run a 2 degree split pretty much every where. I belive that's more of a feeling on what you like as a driver.

Now, pulling the RF back puts it closer to the CG. Which means it loads the RF harder and generally faster.

Like @"J'-remy was saying what track is it.
 
Dougherty#39 said:
I've always used more caster on a track with less grip and less caster with a track the has more grip in it. I've been told I'm wrong about this before and I have been ( my wife will tell you I'm wrong all the time lol). But the more caster you add the more camber gain you have when having wheel input. I run a 2 degree split pretty much every where. I belive that's more of a feeling on what you like as a driver.

Now, pulling the RF back puts it closer to the CG. Which means it loads the RF harder and generally faster.

Like @"J'-remy was saying what track is it.
Click to expand...
i don't think that's right put your kart on four scales and turn the wheel left and watch what happens to the numbers. right front unloads weight more caster does it faster .

caster in a road car returns the wheels to driving straight if you let go of the steerin. wheel with split caster the kart wants to steer left instead of correcting straight. i would decrease camber on slower tracks with less grip and leave caster alone
 
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For those asking about Track, Doe Run Indoor in Palmyra MO. I can load a picture of it, if i can figure it out if that'll help on my curiosity with LF/RF block placement and Caster settings.
 
J'-remy said:
i don't think that's right put your kart on four scales and turn the wheel left and watch what happens to the numbers. right front unloads weight more caster does it faster .

caster in a road car returns the wheels to driving straight if you let go of the steerin. wheel with split caster the kart wants to steer left instead of correcting straight. i would decrease camber on slower tracks with less grip and leave caster alone
Click to expand...
When increasing caster you increase transfer yes. But you also Increase amount of camber gained as the wheel is turned.
Turning the steering wheel on a static go-kart will not give you the same results as a go kart at speed. You have no weight transfer factored in at that point.
But yes you are correct when sitting on the scales and turning the wheel it does unload the RF because it's gaining camber. And when gaining camber you lose cross.
Normally i would lower camber in those situations as well. But his question wasn't about changing camber.
 
jscholt said:
For those asking about Track, Doe Run Indoor in Palmyra MO. I can load a picture of it, if i can figure it out if that'll help on my curiosity with LF/RF block placement and Caster settings.
Click to expand...
Moving the RF back will move it closer to the Center of Gravity. Which will put in on the RF sooner and generally harder. More caster will speed up transfer as well. But it also can make the wheel heavier. What issues are you having?
 
Didn't read through all responses yet to confirm someone hasn't mentioned it, But just changing Caster numbers and keeping the same split is more just a preference in how the steering feels , lower numbers more like driving on ice " Free " feeling , Higher numbers Feeling more Gripped up , Changing the amount of split is where you'll notice slight difference the MORE Split the more Kart will naturally pull towards the lower number , which when only turning Left racing just helps Rotation , Closing up the split of course just the opposite effect .
 
Dougherty#39 said:
Moving the RF back will move it closer to the Center of Gravity. Which will put in on the RF sooner and generally harder. More caster will speed up transfer as well. But it also can make the wheel heavier. What issues are you having?
Click to expand...

Not necessarily having any issues, my question was more on the generic side of the equation in the sense of if I moved the blocks and upped the caster, what would the net impact be for my driver.
 
racing promotor said:
Didn't read through all responses yet to confirm someone hasn't mentioned it, But just changing Caster numbers and keeping the same split is more just a preference in how the steering feels , lower numbers more like driving on ice " Free " feeling , Higher numbers Feeling more Gripped up , Changing the amount of split is where you'll notice slight difference the MORE Split the more Kart will naturally pull towards the lower number , which when only turning Left racing just helps Rotation , Closing up the split of course just the opposite effect .
Click to expand...

Thank you for the insight @racing promotor
 
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