Does lowering change rear toe?

[mhuffman]

I have eibach prokit of my 1g FWD. im going to be getting used (but close to new) kyb agx (dont want to dish out for konis, though i'd like them). I noticed i dont have enough front camber for my driving style (im rolling onto the sidewalls at 40psi pressure) so im also getting the ingalls front camber kit.

Problem is the car feels a little swirly at higher speeds, like the toe is out or something. does lowering the car with prokit change rear camber/toe?

 

[eclipsh]

Yes.

Edit: well it does for the AWD model. I believe FWD cars use a solid rear axle so it shouldn't change the rear but it should change the front toe.

 

[Talesin]

From what I remember of my GS-T, it just had stub axles plus a crossmember brace arrangement on the rear, not a solid rear axle.

 

[eclipsh]

My bad, I should have just pulled my post when I realized he was FWD

 

[Talonracn50]

lowering it changes the camber and the toe.

The camber should help you, the toe will chew up your tires.

 

[mhuffman]

lowering it changes the camber and the toe.

The camber should help you, the toe will chew up your tires.

Sounds good. i ran my last FWD car at 1.5 neg camber front. is this a good amount for an aggressively street driven (daily driver) and autocross fwd DSM?

 

[Talesin]

Sounds like a little overmuch camber for a FWD, given the traction issues it'll cause. Can have all the camber you want without too badly stressing the tires... but bad toe will eat them in a week. I'd probably limit it to one degree for a FWD.. -1.5 front -0.75 rear is the 'generic' AWD DSM camber setup for autocross, but there's a lot less accelleration demand on the fronts on exit, with AWD. A FWD will probably break traction and be more prone to understeer with that much camber, when powering out of a turn. It'll also hurt your launching if you still intend to take this car to the dragstrip, with similar wheelspin problems.

If it were me, I'd probably invest in a good set of camber/caster plates, a thicker rear sway bar and get a GOOD alignment shop to get you as much caster as you can, especially if you still have your power steering (where steering effort will be less of a problem).

 

[mhuffman]

Sounds like a little overmuch camber for a FWD, given the traction issues it'll cause. Can have all the camber you want without too badly stressing the tires... but bad toe will eat them in a week. I'd probably limit it to one degree for a FWD.. -1.5 front -0.75 rear is the 'generic' AWD DSM camber setup for autocross, but there's a lot less accelleration demand on the fronts on exit, with AWD. A FWD will probably break traction and be more prone to understeer with that much camber, when powering out of a turn. It'll also hurt your launching if you still intend to take this car to the dragstrip, with similar wheelspin problems.

If it were me, I'd probably invest in a good set of camber/caster plates, a thicker rear sway bar and get a GOOD alignment shop to get you as much caster as you can, especially if you still have your power steering (where steering effort will be less of a problem).

Why's the caster beneficial for FWD?

I know there will be tradeoffs, namely straight line acceleration traction, but i am rolling past the sidewall indicators. i need the camber. ive heard you can run up to four degrees with little affect on braking or acceleration traction. maybe this doesnt apply to DSM's.

 

[Talesin]

Additional caster is beneficial regardless of drive type, aside from contributing to mild high-speed twitchiness, potential tread squirm, and increased steering effort with a manual rack. Think of it as situation-specific camber, at least as far as I understand it. When the wheel is turned, it allows the wheel to lean into the turn, giving you a few extra degrees of camber only while you're turning, and reverting when you straighten out again.

If you're folding over the sidewalls, sounds like you need some extra tire pressure to help prevent that, and a better suspension setup to encourage the car to rotate as you need it. I'd suggest upgrading your rear sway bar ASAP.. it makes a HUGE difference, even with an otherwise stock suspension setup. Our cars seem to mostly need the rear end stiffened up a WHOLE lot, regardless of FWD or AWD.

You don't have an engine-bay shot in your profile, so I figure I'd better mention this as a just-in-case... if you're running a front strut tower bar, remove it. Extra frame rigidity is good, but only after you get the suspension set up as you like it, and then raise the stiffness equally front to back as needed. I can't count the number of FWD/AWD guys who have painful amounts of understeer, and can't figure it out... and are running a front STB. And can't answer why, when asked what it does. Namely, stiffening the front reduces oversteer and is handy for RWDs.. but only makes understeer worse. I can only guess that Honda kids saw them, and the fad caught on from there.

 

[mhuffman]

Additional caster is beneficial regardless of drive type, aside from contributing to mild high-speed twitchiness, potential tread squirm, and increased steering effort with a manual rack. Think of it as situation-specific camber, at least as far as I understand it. When the wheel is turned, it allows the wheel to lean into the turn, giving you a few extra degrees of camber only while you're turning, and reverting when you straighten out again.

If you're folding over the sidewalls, sounds like you need some extra tire pressure to help prevent that, and a better suspension setup to encourage the car to rotate as you need it. I'd suggest upgrading your rear sway bar ASAP.. it makes a HUGE difference, even with an otherwise stock suspension setup. Our cars seem to mostly need the rear end stiffened up a WHOLE lot, regardless of FWD or AWD.

You don't have an engine-bay shot in your profile, so I figure I'd better mention this as a just-in-case... if you're running a front strut tower bar, remove it. Extra frame rigidity is good, but only after you get the suspension set up as you like it, and then raise the stiffness equally front to back as needed. I can't count the number of FWD/AWD guys who have painful amounts of understeer, and can't figure it out... and are running a front STB. And can't answer why, when asked what it does. Namely, stiffening the front reduces oversteer and is handy for RWDs.. but only makes understeer worse. I can only guess that Honda kids saw them, and the fad caught on from there.

I'd like to add caster, but how hard is this?

I am running 40psi already!

I've had FWD cars with a RSB and they were really neutral/oversteer. i might go in that direction.

I have only a rear STB.

 

[asexton6969]

First off, please explain to me why you need to run 40 psi? When are cars are supposed to run 30-32 psi. If you lower a car, your changing your camber which in turn affects toe. Too much positive or negative camber will wear tires as well as toe will wear your tires. Please let me know what your reasoning is and tomorrow I'll grab my hunter specs book from work to see what the factory specs are.

 

[mhuffman]

First off, please explain to me why you need to run 40 psi? When are cars are supposed to run 30-32 psi. If you lower a car, your changing your camber which in turn affects toe. Too much positive or negative camber will wear tires as well as toe will wear your tires. Please let me know what your reasoning is and tomorrow I'll grab my hunter specs book from work to see what the factory specs are.

The higher the tire pressure, better the turn-in and steering response, and the effective sidewall stiffness increases. Also, rolling resistance decreases. Our cars are "supposed" to run whatever we feel right. My tires are rated to 51psi. i've found that 40psi makes for a flat, full contact patch with increased steering response and stability. Try it! Tire pressure changes in the rear can have a noticeable affect on the balance of the car as well.

When i add more negative camber, im going to have the toe aligned to factory specs.

 

[asexton6969]

Im not arguing or anything so dont take this the wrong way. I just see running 30-32 as the best tire wearing pressure. (Suggest by manufacturer) It would actually be decreased stability as the vehicle is that slight amount higher in the air and your running more on the center of the tire. The more air you put in a tire the more oval shaped it becomes. If you've ever seen tires that are overpressure. They are worn on the center with minimal wear to the outsides. Underpressure would create the exact opposite wearing the outsides of the tire and actually shoving the center up. 30-35 psi would create the most tire contact.

 

[Talesin]

Okay, first, how are you determining that your sidewall is folding over? Doing the shoe polish trick? Mine don't fold and I run at 35psi on 215/45/17s, under extremely aggressive cornering.

You can run as much camber as you want, and it will not SEVERELY impact your tire wear. It's non-zero toe that kills tires in nothing flat, NOT camber.

Adding caster requires the addition of caster plates.. essentially replacements for the strut tower mounts. Most setups that provide caster adjustments also provide camber adjustment as well... RRE sells sets of front camber/caster plates for the 1G, but they're not cheap. You'll also need to take it to a REAL alignment shop, not a tire joint that can rough-in the camber and toe good enough for a DD. You want to get the caster equalized across both sides, then increased as much as the shop thinks is feasible while still being a DD. You can also 'rough' adjust the caster to try and balance both sides by loosening the front subframe and using the bolt slop to shift it around a little bit, and at least get it arranged a little bit better, before starting in on the caster plate adjustments.

I'd honestly go for the upgraded rear sway bar first, try running a bit softer tire pressure on the front (32 front/37 rear), and give serious thought to upgrading your shocks, since you have enough spring, but the GR2s aren't really going to cut it for serious driving.
I'm using the Suspension Techniques rear sway bar from RRE (they're local, so I usually grab my parts from them), and as far as handling goes, it's the best $160 I've spent. Install was a bit of a PITA on the AWD (had to drop the rear subframe a bit to install it) but the FWD version should be a snap. I've also driven a Laser RS-T with the FWD version of the same rear swaybar, and it felt a hell of a lot more nimble and responsive than my GS-T.
Rear strut tower bar... well, the jury's still out on those, for our cars. Some say that they do no good given how the weight of the rear is supported by the frame, others just toss them on to have a good fastening point for harnesses. I have one, but haven't bothered to put it on yet, as I can't be arsed to cut holes for it in the rear plastic panels.


EDIT: And I'm incorrect, it seems.. RRE doesn't sell a set of camber/caster plates, they sell a set of camber adjustment plates (sized for 2.5" coilovers only) that have been cut to provide a large degree of additional caster. Which would still be a severe performance gain, though would obviously require swapping out to a set of coilovers, in addition to the rather steep cost of the plates themselves.
http://www.roadraceengineering.com/camberplate.htm

 

[eclipsh]

Ground control makes a very nice set of camber/caster plates. Pagosa DSM has a set and is very pleased with them. He and I also have a set of eccentric bushings for the front a-arms,which he found through an Australian company, that help add caster. He may not need his set of bushings since he upgraded to his coilover setup so you might ask him if he is interested in selling them to you.

Oh and FWIW, I run 38/33psi for AutoX based on recommendations from pros running tires my size (245/40/17).

 

[asexton6969]

.

You can run as much camber as you want, and it will not SEVERELY impact your tire wear. It's non-zero toe that kills tires in nothing flat, NOT camber.

You need to work for a tire company. Saying that camber does not cause tire wear. Really? How come every alignment machine I have ever worked on lists excessive shoulder wear could result from camber. Every person I have ever been taught by, has told me that camber causes wear. Now I would agree toe will wear your tires out alot faster, but you are wrong to say you can run as much camber as you want without tire wear. I would like you to come explain to every customer that I've ever had with camber wear. Don't post that for others to see, Camber does cause wear, dont spread misinformation Camber causes wear, toe causes wear. Caster does not cause wear. One other thing that does depend on how much camber you run is your tires.

To OP if you would like to run some agressive camber I have been running Continentals ExtremeContacts for over a year. Rear Camber is around -3.0 degrees. They have held up substantially, it is a harder rubber compound but if this is also your street car you want something that will last. I have found they stick very well for me and don't wear fast like my last set of tires I had(Kumho 711's)

 

[mhuffman]

Im not arguing or anything so dont take this the wrong way. I just see running 30-32 as the best tire wearing pressure. (Suggest by manufacturer) It would actually be decreased stability as the vehicle is that slight amount higher in the air and your running more on the center of the tire. The more air you put in a tire the more oval shaped it becomes. If you've ever seen tires that are overpressure. They are worn on the center with minimal wear to the outsides. Underpressure would create the exact opposite wearing the outsides of the tire and actually shoving the center up. 30-35 psi would create the most tire contact.

I actually get full contact patch at 40psi. and the change in the center of gravity is probably negligible compared to the increased tire stiffness and less squirm, helping stability. In the rear, 40psi will make the tires oval. in the front with more weight on them, i can do 40psi and still have a full, flat contact patch.

 

[mhuffman]

You need to work for a tire company. Saying that camber does not cause tire wear. Really? How come every alignment machine I have ever worked on lists excessive shoulder wear could result from camber. Every person I have ever been taught by, has told me that camber causes wear. Now I would agree toe will wear your tires out alot faster, but you are wrong to say you can run as much camber as you want without tire wear. I would like you to come explain to every customer that I've ever had with camber wear. Don't post that for others to see, Camber does cause wear, dont spread misinformation Camber causes wear, toe causes wear. Caster does not cause wear. One other thing that does depend on how much camber you run is your tires.

To OP if you would like to run some agressive camber I have been running Continentals ExtremeContacts for over a year. Rear Camber is around -3.0 degrees. They have held up substantially, it is a harder rubber compound but if this is also your street car you want something that will last. I have found they stick very well for me and don't wear fast like my last set of tires I had(Kumho 711's)

I had 711's as well, they were pretty decent.

When i had the 711's on my old car, 1.5 degrees camber in the front made them wear ALOT BETTER, because without the camber i was mostly taking rubber only off the outside shoulders. so, the proper amount of camber can help decrease tire destruction during aggressive frequent cornering.

 

[Talesin]

You need to work for a tire company. Saying that camber does not cause tire wear. Really? How come every alignment machine I have ever worked on lists excessive shoulder wear could result from camber. Every person I have ever been taught by, has told me that camber causes wear. Now I would agree toe will wear your tires out alot faster, but you are wrong to say you can run as much camber as you want without tire wear. I would like you to come explain to every customer that I've ever had with camber wear. Don't post that for others to see, Camber does cause wear, dont spread misinformation Camber causes wear, toe causes wear. Caster does not cause wear. One other thing that does depend on how much camber you run is your tires.

It's the (overblown example) difference between rolling a tire on its shoulder, and running a belt sander across the tire. Toe is the latter, as you roll down the road, dragging the tire slightly sideways across the asphalt. It is the number one tire killer. Camber WILL only make a bad-toe problem WORSE, concentrating the effect of that 'sanding' on a small patch of the tire, and eating through it damn quick.
Running two or even three degrees of negative camber will not dramatically decrease tire life, so long as toe is zeroed. Hell, my outside shoulderblocks are toast *way* before my insides.

Also note that I specifically said that it will not 'severely' impact your tire wear, in my original post. I never said that it would have NO effect. Just that its effect on tire wear is minimal as compared to bad toe.

 

[wret]

You need to work for a tire company. Saying that camber does not cause tire wear. Really? How come every alignment machine I have ever worked on lists excessive shoulder wear could result from camber. Every person I have ever been taught by, has told me that camber causes wear. Now I would agree toe will wear your tires out alot faster, but you are wrong to say you can run as much camber as you want without tire wear. I would like you to come explain to every customer that I've ever had with camber wear. Don't post that for others to see, Camber does cause wear, dont spread misinformation Camber causes wear, toe causes wear. Caster does not cause wear. One other thing that does depend on how much camber you run is your tires. want something that will last. I have found they stick very well for me and don't wear fast like my last set of tires I had(Kumho 711's)

I don't belabor the point as the argument has been well presented by Talesin. But the camber/tire wear issue has been discussed over and over. Camber (with well adjusted toe) does not cause significantly increased tire wear. Negative camber shifts weight toward the inner part of the tread. Typically this would not be enough to pick up the outer edge but there is obviously more weight riding on the inner half of the tread. If this causes you to wear out the inside tread first then you should elimate the negative camber or do more turning.

mhuffman has the right idea about tire pressures. The "correct" pressure varies with the vehical and the driver. It can be diffiucult to measure the effect but tire pressure will not be overlooked or taken for granted by any serious racer. In general track pressure will be significantly higher than street pressure for the reasons mhuffman stated.

 

[mhuffman]

I don't belabor the point as the argument has been well presented by Talesin. But the camber/tire wear issue has been discussed over and over. Camber (with well adjusted toe) does not cause significantly increased tire wear. Negative camber shifts weight toward the inner part of the tread. Typically this would not be enough to pick up the outer edge but there is obviously more weight riding on the inner half of the tread. If this causes you to wear out the inside tread first then you should elimate the negative camber or do more turning.

mhuffman has the right idea about tire pressures. The "correct" pressure varies with the vehical and the driver. It can be diffiucult to measure the effect but tire pressure will not be overlooked or taken for granted by any serious racer. In general track pressure will be significantly higher than street pressure for the reasons mhuffman stated.

Word.