I have -1º camber on all four, 1/8" toe-out front, 1/8" toe-in rear. Didn't touch the castor.
Impressions? It REALLY likes to corner. But straight-line stability is reduced quite a lot. The car will wander a little more from road-surfacing, and steering feels REALLT twitchy. Once the car gets into the corner, it feels rock-stable, though.
Streetable? Yep. I just wouldn't try and WOT runs in 5th gear
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11:17 AM
The Aura Member
Posts: 2290 From: Winnipeg, Manitoba, Canada Registered: Nov 2001
Maxing the Front Castor increases steering effort a lot but helps transfer weight for better cornering and transitions.
Actually, it helps caster induced camber gain in tight corners. The front toe out is responsible for rapid transitions. I prefer somewhat less caster to get a better feel for what the front contact patches are doing. Try it both ways (buying a lifetime alignment is a good idea) and see which one you like.
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01:03 PM
Formula88 Member
Posts: 53788 From: Raleigh NC Registered: Jan 2001
I take it the front toe OUT is what causes the on-center twitchy-ness? In that case, for a high-performance street setting how about:
Front Camber: -1 Front Caster: +5 Front Toe: 1/16-1/8" toe-IN
Rear Camber: -1 to -1.5 Rear Toe: 1/8" toe-in
How's that sound? I do a lot of highway driving, so the twitchiness would get aggrivating after a while. I want to get the best handling I can, but maintain decent tire life, and not have the car twitchy.
Also, any "track-only" settings are welcome, too. Please mention if you use your settings on the street or track, and if you've noticed driveability or tire life changes.
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01:23 PM
Mach10 Member
Posts: 7375 From: Winnipeg, Manitoba, Canada Registered: Jan 2001
I'm not so sure about toe'ing in the front... On the corners, the toe-in would make the front end slip a little easier... If anything, I'd leave it neutral.
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02:12 PM
Formula88 Member
Posts: 53788 From: Raleigh NC Registered: Jan 2001
ok. Well, I'd be looking for good high-speed stability as well as good cornering, so it may be a bit of a trade-off. For sure, it's going to be close to 0, I would guess. Probably 1/16" either toe-in or toe-out. Just not sure which would be better.
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02:19 PM
Fredrik Member
Posts: 25 From: Trelleborg, Sweden Registered: May 2003
I have -1º camber on all four, 1/8" toe-out front, 1/8" toe-in rear. Didn't touch the castor.
Impressions? It REALLY likes to corner. But straight-line stability is reduced quite a lot. The car will wander a little more from road-surfacing, and steering feels REALLT twitchy. Once the car gets into the corner, it feels rock-stable, though.
Streetable? Yep. I just wouldn't try and WOT runs in 5th gear
First of all I respect your many posts Mach10... Shark is the authority and following his advice I have a streetable track car that handles, and corners awesome and is stable and tracks dead on even above 120 mph. A small amount of increased steering effort is nothing compared to the advantages of 5 or so positive caster. 1)Hi speed stability 2)Lower speed hard cornering is improved because the tire is held more square to the road...more patch contact. etc. Read 8shark web pages on set-up and do it...he's right on.
Mach10, try changing your caster setting only to +5 and tell us what you feel.
I've run at Willow Springs racetrack with my daily settings with fantastic results and absolutly even wear...inside & out...side to side. here it is; Front -1 camber, +5 to +6 caster, 0-1/16 inch toe out...not more for street or road racing...up to 1/8 toe out for autocross. Rear -1.5 camber, toe in not less than 1/16 up to 1/8
JD
[This message has been edited by vse1fiero@cox.net (edited 06-17-2003).]
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08:35 PM
PFF
System Bot
vse1fiero@cox.net Member
Posts: 278 From: Carmel Valley, CA Registered: Sep 2002
ok. Well, I'd be looking for good high-speed stability as well as good cornering, so it may be a bit of a trade-off. For sure, it's going to be close to 0, I would guess. Probably 1/16" either toe-in or toe-out. Just not sure which would be better.
Its not new news that toe-in in front can be dangerous (twitchy) for fieros. Just like not having enough rear -camber or being toed-out in the rear is very dangerous...unless you like merry-go-rounds. I think it important to say as other times when this topic appears that if you have'nt gotten new suspension parts ie ball joints, ty-rods, A-arm bushings and springs your not ready to much benefit from this info because your car won't hold settings well anyway and won't be safe to push hard. JD
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08:54 PM
Will Member
Posts: 14216 From: Where you least expect me Registered: Jun 2000
You want more toe IN in the rear than in the front to help tame the Fiero's infamous lift-off reaction.
Toe in would increases slip angle and traction in the front (increasing oversteer). Toe in in the rear increases rear slip angle and traction in the rear, reducing oversteer.
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09:06 PM
vse1fiero@cox.net Member
Posts: 278 From: Carmel Valley, CA Registered: Sep 2002
You want more toe IN in the rear than in the front to help tame the Fiero's infamous lift-off reaction.
.
Again, you don't want ANY toe-in in front. 0- 1/16 out. Some go with more to make up for the instability of worn suspension parts. But wear(scrub) increases with more. JD
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09:20 PM
Will Member
Posts: 14216 From: Where you least expect me Registered: Jun 2000
I said more toe IN at the rear. That means that the rear should be toed in further than the front whether that's neutral at the rear with excessive toe out in front or whatever, the balance is what's more important, as verhicles are EXTREMELY sensitive to rear slip angle.
If you have more adjustment range, front camber can be set as high as 2-1/2 degrees negative, especially if you are using oem rubber bushings. Ditto on the rear. That much would start to affect tire wear a lot though.
If you are experiencing "twichiness", you may have worn out rubber bushings in the rear a-arms, or some other worn suspension part. A Fiero with toe-out on the front and toe-in on the rear should be fairly stable under most conditions, although it "could" do that on a rough road, if you have quite a lot of toe.
Actually, toe varying from zero will probably cause more tire wear than aggressive camber and caster settings. Large amounts of toe "drag" the tire sideways down every straight, but camber and caster correct the tires during hard cornering, actually reducing tire wear from what you would otherwise get.
Most aggressive drivers get more even tire wear with added camber and caster, instead of wearing out the outside edge of the tread first.
The toe settings are to reduce "dartiness" on the front from steering inputs, and to help reduce trailing throttle oversteer on the rear. If you are concerned with tire wear, set those both closer to zero, the camber and caster will improve handling (cornering speed) more anyway.