Suspension Yet another clarification
Thread Starter
|
6th Gear
Joined: Jan 2003
Posts: 3,301
Likes: 1
Yet another clarification
As I go thru some of my old threads and replys, I'm finding that my quick responses have lead to some fuzzy information. I corrected one thread about the CofG.
Here's another; when changing tire width or wheel offset, scrub changes. I wrote that it is possible to gain back stock SAI by adding more neg camber. That is wrong. It is possible to gain back (some or all) scrub, but the SAI angle is forever changed.
Here's another; when changing tire width or wheel offset, scrub changes. I wrote that it is possible to gain back stock SAI by adding more neg camber. That is wrong. It is possible to gain back (some or all) scrub, but the SAI angle is forever changed.
2nd Gear
Joined: Oct 2006
Posts: 84
Likes: 0
From: near Mankato, MN
If you don't know what you are doing then you cant be doing it wrong
If you know what you are doing then you will be aware that you are doing it wrong and regret it till the end of your days
so just do it and don't look back
If you know what you are doing then you will be aware that you are doing it wrong and regret it till the end of your days
so just do it and don't look back
6th Gear
Joined: Jan 2006
Posts: 1,705
Likes: 3
From: Chattanooga, TN
6th Gear
Joined: Jan 2006
Posts: 1,808
Likes: 3
what's tire scrub and SAI?
Trending Topics
Thread Starter
|
6th Gear
Joined: Jan 2003
Posts: 3,301
Likes: 1
To the first replys, funny, real funny guys Kenchan, where been? Your humor is still spot on!
SAI (Steering Axis of Inlcination) or Kingpin axis is the angle depeicted by a line the runs from the top and center of the strut tower thru the center of the lower ball joint. This line is typically extended to the ground where is usually(always?) falls under the contact patch. The distance from this point to the center line of the tire is one way of describing scrub. This line may fall inside, outside or at the center of the center line. Basically, this point defines the fulcrum about which the wheel turns. SAI si also responsible for lifting the vehicle's front end as the wheels are turned. Gravity essentially pulls the vehicle back down and it is this force that creates a self centering and return to center feel in the steering.
Center point steering - SAI meets the tire's center line at ground.
Positive scrub - SAI falls outside the tire's centerline
Neg scrub - SAI falls inside the tire's center line
Neg scrub is typically found on very sporty rear wheel drive cars. The leverage point has a closer relationship to the tire's actual contact patch.
Mini has positive scrub
Kenchan, where been? Your humor is still spot on!SAI (Steering Axis of Inlcination) or Kingpin axis is the angle depeicted by a line the runs from the top and center of the strut tower thru the center of the lower ball joint. This line is typically extended to the ground where is usually(always?) falls under the contact patch. The distance from this point to the center line of the tire is one way of describing scrub. This line may fall inside, outside or at the center of the center line. Basically, this point defines the fulcrum about which the wheel turns. SAI si also responsible for lifting the vehicle's front end as the wheels are turned. Gravity essentially pulls the vehicle back down and it is this force that creates a self centering and return to center feel in the steering.
Center point steering - SAI meets the tire's center line at ground.
Positive scrub - SAI falls outside the tire's centerline
Neg scrub - SAI falls inside the tire's center line
Neg scrub is typically found on very sporty rear wheel drive cars. The leverage point has a closer relationship to the tire's actual contact patch.
Mini has positive scrub
Thread
Thread Starter
Forum
Replies
Last Post
bamatt
5th Annual MINIs on the Dragon (May 3-6, 2007)
192
May 17, 2007 05:29 PM