[Rennmeister]

Originally Posted by chris82

Why should you increase the stiffness of your sway bar as you increase your spring rates? Not seeing any logical reason for this in the articles you mentioned. If you have a car that corners flat, why increase the sway bar stiffness? All it will do is lift up the inside wheel

EDIT: I know you that cheat sheet doesn't apply to all situations

Author of the article in question here.

You increase the sway bar thickness because the rate generated by the sway bar is relative to the amount of suspension travel. The sway bar will generate less moment / roll resistance with a harder spring because of the spring's additive roll resistance.

As far as lifting the wheel is concerned. That has more to do with maintaining a healthy spring:sway rate ratio, avoiding jacking / excessive rebound, and maintaining the travel arc of the suspension. It's not always the sway bar that is the cause of the pee'ing dog stance. Even polyurethane bushings can cause a slow return to droop due to their resistance.

The article is meant to be directional ... it would be 10-times that length if I had to explain diameters / motion ratios and all of that in relation to dynamics / statics and roll resistance strategy.

Perhaps it warrants further explanation ... ?

[Rennmeister]

Originally Posted by Cloud9blue

Yeah, it is also weird it states why sway bar thickness should decrease when tire traction is increase. Wouldn't you want less lateral load transfer with thicker bar when you run stickier tires???

Stickier tires = higher G's = more suspension travel

This is a soft recommendation based on my experience / preference. There is a benefit to running a less effective bar and letting the springs themselves handle all the major lifting and that is the car is MUCH more stable over curbs / street roads surfaces.

Also, tire traction increases linearly with tire load until a certain point where it becomes digressive. A stickier tire compound simply raises the amount of mechanical key'ing (read: friction) the tire generates. The tire can still have a poor laden behavior which is what you are trying to mitigate with variances in your springs (sways being a "3rd Spring" on an axle).

As people have said, it's a directional guide ... not a definitive "do this." There's a ton of variables in these things.

[Rennmeister]

[QUOTE=Kgolf31;19467480]

Originally Posted by Ginger_Extract

I don't care about the wear. 38 PSI isn't fast.

26 PSI is.

I'm competing for Nationals, I'll go through tires that's fine with me

How much caster, ackerman, etc. does the 1-Series have?

Naturally you've jacked around with toe?

[Rennmeister]

Originally Posted by Ginger_Extract

That said, in terms of balance, a front bar will add a touch of mid-corner understeer, but it helps the front end transition more quickly, so it's able to be driven around.

I would recommend tinkering with the toe angle. I've noticed on a McStrut they like a touch of toe-in on the front, it really improves that mid slip angle frontal grip.

Likewise if the toe is zero'd and the car suffers from bump steer issues it will want to do that steady state push and respond poorly to unloading the front.

[Kgolf31]

[QUOTE=Rennmeister;19492805]

Originally Posted by Kgolf31

How much caster, ackerman, etc. does the 1-Series have?

Naturally you've jacked around with toe?

I have about 8* of caster. I don't know anything about ackerman.

I run with 0 toe up front.

Also, poor plug, but I'm trying to sell my Eibach 28mm bar.

http://www.e90post.com/forums/showth...3#post19493743

[justpete]

Originally Posted by Rennmeister

Perhaps it warrants further explanation ... ?

Um, yes. TIA

[chris82]

Originally Posted by Rennmeister

Author of the article in question here.

You increase the sway bar thickness because the rate generated by the sway bar is relative to the amount of suspension travel. The sway bar will generate less moment / roll resistance with a harder spring because of the spring's additive roll resistance.

As far as lifting the wheel is concerned. That has more to do with maintaining a healthy spring:sway rate ratio, avoiding jacking / excessive rebound, and maintaining the travel arc of the suspension. It's not always the sway bar that is the cause of the pee'ing dog stance. Even polyurethane bushings can cause a slow return to droop due to their resistance.

That makes a lot of sense now, thank you for clarification