Wheel Alignment: Specs and Theories

[VTECMACHINE]

Really? What makes you say that?

Disclaimer: This following comment, is based purely on MY own learning, and from what I have played with and experienced.
This thread is good btw, I dig.
Obviously i'm new to AWD cars and all. but the concept of camber is the same. I personally wouldn't run more than say 1.5-1.8 -ve on the rear. The front seems sweet as, but from what i've played with too much grip on the rear leads to a crap load of understeer on corner entry and mid corner. After speaking to people that have been racing for many many years and getting times of 1.06's in AWD cars that hasn't much power or work done to it have all said the same thing. Especially with Evo's and STi's, they understeer alot out the factory, you want to use a stiffer rear sway or stiffer rear springs and reduce the camber on the rear. I'd also run at least 2mm toe out on the rear to make the rear run. When I had the DC2R (know it's different to the Evo, even though AWD is glorifed FWD) I got intrigued by wheel alignments when I all of a sudden understood the concepts of grip through a corner. It's amazing how much time the 'right' alignment for your OWN driving style chops down lap times. I shared my alignment with some that became slower and hated it cos they couldn't drive straight on the main straight or would spin every corner. Some loved it and became faster. So end of the day, it does all come down to personal preference.
But I suppose you've had your evo for ages, and you know more than me. Just wondering, who has set up your car? Or are you alignment settings speced by yourself? Also, curious as to why you chose those alignment settings? This has got my mind all working and shit. Alignment is all about sacrifices (ie: my agressive cornering alignment made me lose 8km/h down the main straight at wakefield), so just wondering what are the strong points about your alignment.

[Cazal 856]

Disclaimer: This following comment, is based purely on MY own learning, and from what I have played with and experienced.
This thread is good btw, I dig.
Obviously i'm new to AWD cars and all. but the concept of camber is the same. I personally wouldn't run more than say 1.5-1.8 -ve on the rear. The front seems sweet as, but from what i've played with too much grip on the rear leads to a crap load of understeer on corner entry and mid corner. After speaking to people that have been racing for many many years and getting times of 1.06's in AWD cars that hasn't much power or work done to it have all said the same thing. Especially with Evo's and STi's, they understeer alot out the factory, you want to use a stiffer rear sway or stiffer rear springs and reduce the camber on the rear. I'd also run at least 2mm toe out on the rear to make the rear run. When I had the DC2R (know it's different to the Evo, even though AWD is glorifed FWD) I got intrigued by wheel alignments when I all of a sudden understood the concepts of grip through a corner. It's amazing how much time the 'right' alignment for your OWN driving style chops down lap times. I shared my alignment with some that became slower and hated it cos they couldn't drive straight on the main straight or would spin every corner. Some loved it and became faster. So end of the day, it does all come down to personal preference.
But I suppose you've had your evo for ages, and you know more than me. Just wondering, who has set up your car? Or are you alignment settings speced by yourself? Also, curious as to why you chose those alignment settings? This has got my mind all working and shit. Alignment is all about sacrifices (ie: my agressive cornering alignment made me lose 8km/h down the main straight at wakefield), so just wondering what are the strong points about your alignment.

Just gonna throw it out there...

Any car with power going through the rear wheels, be it 4WD or RWD, will work better with either neutral rear toe, or slight toe in. If you run toe out on a driven wheel, as the outside wheel is the one with all the weight carried on it, it's going to get better traction than the inside wheel. That wheel will be fighting against the inside rear and will try to pull the back end of the car out of line. On a FWD car, this might be suitable to try and get some turn in, but i've never really driven or owned FWD cars, so I'm not sure.

As mentioned before, rear toe in will give you more rear stability under power. You might not need it depending on what you drive, but it's worth a try. I wouldnt say that it will induce understeer 100%, but I'm sure it has some kind of effect.

I think understeer is something that seems to be quite often misunderstood. The cars that I have loved driving most have normally had a small and very controllable amount of understeer to their handling when you really start to push them. Theres no such thing as a car that is entirely neutral in my opinion, and I think that 9 times out of 10, a car with slight understeer is going to be much faster than a car with slight oversteer.

[VTECMACHINE]

^^ You just confused the crap outta me.

So are you saying Tow out rear on a AWD/RWD car will have the effects of Oversteer - if so cool, this makes sense in my brain and it's what Heasmans and a few other AWD gurus have told me aswell. You said toe in at the rear stabilises the car, so I guess that is what you meant. If not, i'm lost.

I'd love to explain the shit that is going through my head right now regarding alignment, but it's impossible.

[3AM]

ive had quite a few scotcheseses(?) so this might not make sense but ....
im sorry but in my opinion, setting a car up so it toes out, and promotes oversteer whether its static toe or dynamic. is just reinforcing a bad driving habit. (same with tilting rear subframes backwards for "drift" setting)i'll admit im not the fastest round wakefield and killing my ackerman has fucked my lap times severely, but setting up the alignment to promote oversteer, just seems redundant. in rwd platform (and what limited awd, i have driven ) oversteer is so easily achievable, imo its better to set up the car for as much grip as possible, and whether its drift or circuit, in rwd and awd setups toe in promotes grip. and we should leave it at that.

[VTECMACHINE]

Valid point made above re driving style etc, although all i've heard from alignment shops and performance garages is the toe out rear for oversteer and this is what they use on their race cars.
I guess this is something that has made me hella curious now, and next outing to wakefield i'll have to give it a go. Regarding grip, awd's have too much grip with stock power - LOL, it was understeer heaven with 2mm out on the rear. Maybe i'm just going in too hard? Either way, i'm new to this AWD stuff and i'm digging this thread.

[Cazal 856]

^^ You just confused the crap outta me.

So are you saying Tow out rear on a AWD/RWD car will have the effects of Oversteer - if so cool, this makes sense in my brain and it's what Heasmans and a few other AWD gurus have told me aswell. You said toe in at the rear stabilises the car, so I guess that is what you meant. If not, i'm lost.

I'd love to explain the shit that is going through my head right now regarding alignment, but it's impossible.

This is exactly right.

[Cazal 856]

ive had quite a few scotcheseses(?) so this might not make sense but ....
im sorry but in my opinion, setting a car up so it toes out, and promotes oversteer whether its static toe or dynamic. is just reinforcing a bad driving habit. (same with tilting rear subframes backwards for "drift" setting)i'll admit im not the fastest round wakefield and killing my ackerman has fucked my lap times severely, but setting up the alignment to promote oversteer, just seems redundant. in rwd platform (and what limited awd, i have driven ) oversteer is so easily achievable, imo its better to set up the car for as much grip as possible, and whether its drift or circuit, in rwd and awd setups toe in promotes grip. and we should leave it at that.

I agree with all of this except the scotch.

[3AM]

yeah my roll center is fucked now too. its these damn stupid trends, i was happy monster truckin'

because ive reduced ackerman my inside wheel is going to toe in and drag on cornering, which would mean less grip and more prone to understeer?, but it makes it a hell of a lot more stable when im going sideways down a straight

[VTECMACHINE]

Enirkys ^^^ Thanks mate. Just reading up on stuff that you have mentioned there. Your point about finding grip and finding the problem instead of masking it is soooo true.

someone stickey this thread!

[J]

Also, i fund running front toe out has its true gain on fast corners, where as i don't find neutral toe to toe out making as much of a differece on slower corners... would toe in even be better on slow corners than toe out?



and is toe out also compensating for the loss of inner edge grip due to negative camber?


(and im only referring to front rack alignment, wouldn't the world be easy if we all owned live axles.)

[Cazal 856]

Also, i fund running front toe out has its true gain on fast corners, where as i don't find neutral toe to toe out making as much of a differece on slower corners... would toe in even be better on slow corners than toe out?



and is toe out also compensating for the loss of inner edge grip due to negative camber?


(and im only referring to front rack alignment, wouldn't the world be easy if we all owned live axles.)

If anything, I think I find the opposite with faster and more sweeping corners, but it probably depends on the amount of toe out you're running.

I've never really seen toe out as a compensation for negative camber though. Anyone else know much about the relationship between the two?

[Jays14]

I run pretty much the same as brett...

Front
Camber: -3 degrees
Toe : 4mm out total
Caster : 7 degrees

Rear
Camber: -1
Toe: 0mm toe

Any w/a settings around that seem to work for silvias..

There are so many differences in different makes and models, suspension types on different cars and verables in types of tyers on cars and condition of bushes that the same thing that works for one care may not work well on the same make and model....

You just got to get a w/a thats recomended for your cars make and model and ajust it other time till you get what works for you and your car (well at lest thats what i did)....

[BLISTC]

Agreed. The trick is to take your car to a workshop with proven experience. You also need to specify whether you want a more track oriented alignment, or something suitable for street use, as there is a large difference.

i also agree. it also helps that these 2 places mentioned above have the best wheel alignment machines in the country, which the operators always continually calibrate and check to ensure its giving the correct readings.

i would never ever go to *insert overmarketed tyre / luxury rim seller here* and get a wheel alignment, after a bad experience when i was desperate to get one done.

i hate he people who bitch moan and complain about paying a bit extra to get it done at the above mentioned places, then go to habib's down the road to get a $30 wheel alignment to 1. not receive a printout 2. find the car pulls to the left/right and 3. you have no idea wtf someone has just done to the suspension of your vehicle.

[mrpham]

So got the car back from the alignment place today, very happy with the results so far . Explained to them that I was getting a bit of understeer and the rear felt a bit weird mod-corner so they made some recommendations and we tried it out.

Rear
Camber : -1.7 degrees
Toe : 0mm total

Front
Castor : +7 degrees
Camber : -2.0 degrees
Toe : 2mm total toe out

Asked him about adjustments on the rear traction rods, and he said it does need adjustment depending on your camber, toe and ride height.

[VTECMACHINE]

How are you guys getting that much castor. Everyone run so much castor! I want more!