as I spend my time reading and developing my plans for my chassis tuning abilities. Is Ackerman something that is commonly adjusted in the karting world? My old chassis didn’t have but one choice. But my new one has three adjustments.
Just trying to spark some conversation before I drop more suspension tuning questions so I can educate myself
It’s an atomica. Which is parolin based
We don’t mess with Ackermann on a tuning level, but some drivers prefer the feel of more or less Ackermann, as it speeds up or slows down the steering. But it’s not really a thing we use to adjust the actual handling of the kart on a regular basis.
I have used ackermann plenty of times over the years, and have found it can serve the following purposes:
A) Can help add/reduce grip, with an emphasis on front-end grip, in situations where the track conditions deviate significantly from “baseline”. Example: during early-season test days where the track may have very little grip, I will generally run one position down from standard on the steering column (towards the blue circle on the image below).
B) Can help to aid in driver comfort by reducing the weight of the steering. Generally a good tool for when the grip levels are high, and/or the driver’s arm strength may be an issue. Example: in situations where grip levels are high, and the steering is becoming quite heavy, I may run one position up (towards the red circle on the image below).
Ackermann be adjusted in a number of ways:
- Adjusting up or down on the steering column, as referenced earlier.
- Adjusting the tie rod mounting point on the spindles (pictured below).
- Changing steering columns to a model that has mounting points either closer together, or farther apart.
I find that generally I leave the spindle mounting points on the outside holes if multiple points are available (not always the case). If I make a change it will usually be the first option that I referenced, adjusting up or down on the steering shaft, though this is something that I would say I do occasionally at most. Even less frequently will I elect to use option #3, though I have done it in recent years.
I’d say most of the time you’re likely to have or find your baseline and stick to that, prioritizing other front-end changes to adjust handling characteristics of the chassis.
First port of call would be Steve Rickman (who I’m guessing you bought the kart from?). He probably set it as standard which will be fine until you’re about 3-5 tenths off the pace. More then that is likely driver or something really wrong that someone will recognise (like the engine not running right or the chassis being bent).
So I drove the Atomica at the last few rounds of the ICP Cup. Now I was in Tag Heavy so both heavier, more power and stickier tires then I think you’ll be running (based on a photo in another post it was LO206 right?). I increased the Ackermann to increase mid corner front grip and, as a consequence, keep the rear wheel unloaded for longer. On the Atomica that was the lowest holes in the steering column and inner most (towards the center of the chassis) holes on the stub axle.
But I would encourage you to get close to the pace before playing too much with the setup.
Oh absolutely. I’m just trying to gain knowledge so that as I gain confidence and feel I can translate that to adjustments. I have been chatting with Steve already. And it looks like I’ll be trying the new chassis out a race earlier than I initially expected. So looking forward to that.
I’m a person who just likes to get all the info I can so that I can use it when I need to instead of scrambling to find it when I need it.
I’m also just looking at how to translate to my race car as so many more things come into play with suspension being involved. Easier for my brain to translate when I have something to compare it to
I started in karts and went to cars, and have come back. Set up concept is completely backwards in many areas. Stiffening the front of kart makes it easier to lift inside rear wheel, improving turn in. Softening the front of car adds traction to front and takes from rear improving turn in.
So far that’s what I have learned in most instances. What would I do to my car? Do the opposite to a kart
The holes on the steering shaft that are closer or further away from the shaft mainly adjust steering “rate”, not ackermann. The holes on the spindle will more greatly affect ackermann. More ackermann will generally make the wheel feel lighter, help the Kart turn in, and rotate more.
The holes on the steering shaft affect rate. If the driver is too twitchy on the wheel you can take rate out by moving the mounting position closer to the shaft.