Sodi seating situation


(Lee Swindell) #1

Hi crew.

Im in a crew racing The Sodi World Series and we’ve been using a rubber insert to keep from flogging around in the gigantic hire kart seat. This moves the driver up and forward by over an inch relative to where he / she would sit without it. Can someone tell me please ewhat the change in COG does to the handling?

It’s effect is surely microscopic - but a microscopic change multiplied by a couple of hundred laps is probably worth thinking about.

We’ve discussed buying our own seat insert and cutting the bottom out of it in order to bring the COG down to where Sodi designed it to be, even if we’re still forward of what’s ideal.

How big a deal is this?

Thanks team.

Lee


(TJ Koyen) #2

Seat position is a big factor in how a kart will handle.

Basically on a setup like you’ve got, moving the driver forward will increase front grip, moving back will increase rear grip.

If a driver needs to be moved forward because they aren’t as tall, having them sit up higher will help too, so I’m not sure you really need to cut the bottom out of your insert.


(Lee Swindell) #3

Thanks for that TJ.

So a slightly higher COG is actually ok if we’re sitting slightly forward of the optimum COG?

I assume that’s a function of the stiffness of the chassis? Might also help with levering the inside rear tire.

Please correct me if I’m wrong.

Thanks TJ.


(Chris Burke) #4

Are you able to scale the kart with the driver and insert? Can you move ballast around to compensate? A smaller driver will typically sit higher to get a better weight transfer effect to free up the kart to rotate, like you said when you referenced levering the inside rear tire.


(Lee Swindell) #5

Interesting idea Chris. I in fact do have a set of corner weight scales. If the track owner is willing to let me use them I’ll get back to you with the result.

Cheers.


(Dom Callan) #6

Col? did a very cool video a few years back that talks about this in a roundabout way. Moving weight around. There was an odd conclusion that he arrived at that was somewhat counter intuitive. I’ll see if I can find it.

Jump to 2:30ish


(TJ Koyen) #7

Col’s the man, he always has interesting perspectives on stuff. Gotta watch his theory on “twisting” vs. “sliding” tires now.


(Lee Swindell) #8

I found Col randomly and started raving about him thinking the word should be spread. Great to see he’s a well established legend at KP.

All hail King Col.


(Lee Swindell) #9

Gold.
I’d never thought of a sliding tire in terms of wasting the potential of the other tires. Brilliant.

Thanks for sharing Dom.


(Lee Swindell) #10

And what the hell does ‘bimodal rocket’ mean?


(Dom Callan) #11

Welcome! His stuff is very interesting.


(Dom Callan) #12

It’s my Xbox gamertag. It was auto generated and I like how it sounds. I’m not sure what a bimodalrocket rocket does but it does more than one thing!


(Lee Swindell) #13

I get it. identity confusion is part of the deal these days.


(Warren Chamberlain) #14

Well, if it’s ‘bimodal’, then I assume mode 1 is the rocket goes up, and mode 2 is the rocket comes back down. :grin:


(Dom Callan) #15

I sure hope so. Otherwise I’d end up like voyager and I hear theres no karting in interstellar space.


(Dom Callan) #16

What do you expect from a dog wearing a helmet? Pretty confused dog.