4th gen setup questions. . . don't be stingy!

[Supercharged111]

If I were to guess, I'd say too much roll is when you exceed the usable range of the suspension and can't maintain even tire temps across the face?

[Suck fumes]

Bingo! Have to try various rates though to know what is too soft. Have to have someone take temps right when you come into the pits to get accurate readings.

[Supercharged111]

I think I have a grasp on this, just haven't had a real logical way to get there in my mind. I've read my ass off on suspension so when somebody talks, I'll understand. It's just a little intimidating to put it to work for yourself.

I just measure my scrub. I ran a string across the 2 ball joints all the way to the floor. Then I put a straight edge against my brake rotor where the wheel mates with it. The distance between those 2 points on the ground was 2". Subtract 54mm (the offset of a Z06 wheel) and I have -4mm scrub. I'm going to measure again, but right now it looks like all of my scrub comes from spacers. I wonder if sliding the lower control arms back in some and using wider bolt on spacers up front wouldn't change it for the better?

EDIT: I just calculated wheel rate, strictly with respect to springs. I'm not entirely sure how to treat the sway bar as both wheels share it. A 950# spring has an effective rate of 489# with a 1/2" spacer and 482# with a 3/4" spacer so IMO that change in the car's behavior was in no way attributed to the effective change in spring rate. Now it may still want softer springs to be better than it was, but it seems that's only part of the story.

[Suck fumes]

Work on springs and bars first. Spacers aren't a consistent fix

[Supercharged111]

Yeah, spacers are all I had though so my goal is really to extrapolate what the spacer change actually did to make an informed decision on my next move. I snuck an edit in up there too.

[GlennCMC70]

Like I said above - The sway bars are fixed variable for the most part since 4th gens only have 2 real options for front and rear. Most all guys I know run the biggest you can. Then make the car work w/ spring changes.
Use the smaller bars to tune the balance from track to track or from old tires vs new tires.

Keep in mind.....
Big spring rates, small bars. Small spring rates, big bars. Caster is a fine tuning tool here.
Stiff set-up, less camber. Soft set-up, more camber. Again, caster is a fine tuning tool here.

Caster give you the camber you need in the corner, but don't want to run under straight line braking.

Lots of camber, less caster. Little camber, lots of caster.



Something I always tell myself and when it was told to me the light bulb started to come on.......
The end of the car w/ the least amount of grip will let go first.
If the car pushes, the rear has more grip. If it overstears, the front has more grip. Don't confuse that w/ one end or the other at max possible grip, but the grip level relative to one end vs the other.

For 4th gens, it is far easier to make at the track changes on the rear of the car.
Gotta find the balance for everything together. They all play off one another.

[Supercharged111]

Yeah, haven't forgotten a thing anyone's said. I just have to wonder though, just because everyone's doing something 1 way does that mean it's the best way? There is more than 1 way to skin a cat. I know I can reduce rear grip to balance the car, but then in my mind I'd just have both ends sucking. I'd really prefer to increase grip up front. I'm currently looking at how much money I have to see if I can't slice off some for a tire pyrometer with probe. This far into a season is usually pretty thin for me.

[GlennCMC70]

Your right, more than one way to get there. But the range of "getting there" is not unlimited.

The car will not work w/ 900lb roll rate sway bars and 100lb springs. Get my point?

I like to use Nick Steel as an example. 2006 Nats. I ended up behind him in the Champ race. We had a great battle for most of the race. I was only slightly faster than him, but only after 10-15 minutes of racing. At the start, he was faster. He was known for running 1200lb rates on the front. I noticed as I got closer, he was making more and more mistakes. I finally figured out his tires were going away. This was a 45 minute Champ race. I sat back and just stayed on his ass showing my nose any chance I got. He ended up driving off at T1 at Mid O.
So like Aaron said, stiff still may be fast, but for how long? Is stiff for you? Your style will dictate if that works. Stiff will also not work well off line. Not many passes take place w/ the overtaking car on line.

If you do some testing on non-race weekends, see if someone will allow you to use the springs they have to test with.

[Supercharged111]

Well you confirm what I've experienced with the car. I also found an old video of someone beating him at Sonoma. Off like a rocket at the start, then a few laps in he gets passed and is never heard from again.

How hard is it to change driving style? I have to believe that my style is currently developed around how the car acts. I know I tend to cheat corners at times with an early initiation/late apex simply because the car won't tolerate a sudden, large input to bomb down toward the apex so that's the only way to force it down to the apex. It's subtle, but because my trajectory is slightly off at the apex I feel I've been sacrificing mid corner speed. I saw it work against me at Hallett T1. There's that dip right where you need to turn in. When I tried to turn in from that dip, the car snapped loose and I'd miss the apex so I cheated the corner and lost a bit of speed. As I chased Dave Francis, I watched his car wallow through, hook, and turn up the hill nailing both curbs along the way. He carried more speed through T1 and that's likely part of why he was able to pass me back in the bus stop 1/2 lap after I passed him.

[Rob Liebbe]

Supercharged111 - remember that Mustangs and Camaros are different animals. While the generalizations may cover both vehicles, the details are vehicle specific.