Wheel Alignment: Specs and Theories

[VTECMACHINE]

10kg front
5kg rear ( both with matched shocks)

Does your car understeer alot?

I know it's down to driver preference etc etc and different shocks/springs etc etc. But I have never heard of a Honda running 10F, 5R before. I've run 12F 8R, and the 12K 10R were heaps faster with a bigger rear sway.
I think you should give it some more toe out on the front aswell. Not saying this will work for you, or i'm right - that's just what i'd do.

Whilst this thread it informative and answer heaps of questions and is interesting to know what people run - it's sort of hard to comment on what the perfect W/A is. Trial and error I guess, plus testing.

[touge crx]

Also, degrees are broken down into 60minutes and every minute is further broken down to 60seconds. So did you mean that "2 degrees and 80 mins" should be "3 degrees and 20 minutes"?

Fixed!

Does your car understeer alot?

I know it's down to driver preference etc etc and different shocks/springs etc etc. But I have never heard of a Honda running 10F, 5R before. I've run 12F 8R, and the 12K 10R were heaps faster with a bigger rear sway.
I think you should give it some more toe out on the front aswell. Not saying this will work for you, or i'm right - that's just what i'd do.

Whilst this thread it informative and answer heaps of questions and is interesting to know what people run - it's sort of hard to comment on what the perfect W/A is. Trial and error I guess, plus testing.

Funnily enough it doesnt understeer at all, however i see a loss of traction as the car trying to tell you that you are doing something wrong so if it starts to go i tone it down a notch.
12k 10k sounds interesting im guessing it was on an integra. Ive been debating getting an adjustable sway bar but they are 3 times the size of the standard item and i have no idea the affect of such a large swaybar will be. So my question to you and anyone else is from personal experience how swaybar adjustments affect the car?

when your wheel moves up in your guard that is call bound or compression and when it drops out of your guard it is called droop or decompression, the reason i ask about your droop is if you do not have enough droop when your car is mid corner and your weight starts to transition and unload the inside wheel if you do not have enough droop you will start to lift your inside wheel off the ground and in a fwd

A: this will cause loss of traction
B: this will cause loss of handling
C: this will over heat your out side tire and cause your rubber to go off quicker the normal

the reason i ask about your damper bound and rebound setting which is the damper setting in your shocks is if your rebound values are to high you will cause unwanted effects while driving which can be loss of mid corner turning power and braking issues if there is any bumps in the road.

now i am sure some one here is going to say " if you buy top quality coil overs then you wont get that problem " and who ever that is going to be you are incorrect, Bilstien, Tien, Cusco, BC, and just about all over damp them from factory.

you can have all your numbers right and if your dampening is wrong your car will still turn like shit, your dampening is is one of the most critical parts of your suspension and you must fond out what your dampening rates are and have the set acordingly to the rest of your suspension.

to test your suspension properly you really need 2 people with you at the track to do everything while you sit in the car because by the time you get out of the car and start checking things they are all ready cold and the info is useless.

Droop is an interesting concept ill measure it when i have some time, but a rough guestimation is about 15 to 20cm.
I tried finding the damping ratio of my coilovers but no luck. I have set the shocks on +10 (0 being soft and 36 hard), im not to sure if that helps.

Also sorry if im spaming the thread this stuff is realy interesting.

[brett]

Thanks for the responses. Both of you have raised some very good points that realy got me thinking about how i actualy drive the car rather than how i should be driving it through corners. I have recently overhauled the suspension system to camber adjusters and coilovers also using wider tyres. The car is totaly different to drive when compared to the old setup so i think some old habits need some changing before blaming the car.

Specs for the hell of it.
springs:
10kg front
5kg rear ( both with matched shocks)
spring pre tention: 10mm front and rear

W/A specs
Front:
castor 3 deg (stock)
camber -2 deg
toe 1.5mm out

Rear:
camber -1 deg
toe 1mm in

my fwd alignments are exactly the same almost, i know with my car its all about accelerating out of the corner and making use of the lsd, slow in getting the line right then punching it out.... only driven a rear wheel drive once around a track and it was completely different from memory

[marvis]

Front
Camber: -3 degrees
Toe : 4mm out total
Caster : 6.5 - 7 degrees

Rear
Camber: -5 (80's IRS)
Toe: 2mm total toe in

For drifting. Toe is slightly less for grip/daily

[mrpham]

So I have a dilemma.... getting re-aligned tomorrow so they will sort it out, but I'm interested in the theory behind it.

Car isn't crazy lowered or have massive camber/toe, I think it's a pretty modest setup.

My rear wheels aren't centered in the arch, they sit further back which causes scrubbing on rear of the arch. As I understand it, by shortening my adjustable traction rods it will pull the wheel forward and center it within the arch. No more scrubbing! But if I shorten the rear traction rods then I will have a lot of dynamic toe (bumpsteer?).

I would like to keep the same camber, toe settings and ride height. But I also want the rear wheels to be more centered within the arch so that I don't scrub.

[mrpham]

yea look this is a common problem in nearly everything you will do in suspension, you adjust 1 thing and it affects another.

this is why measuring everything is so critical and allot of the time you will either have to come to a compromise or start re fabricating component's i would be assuming that it is either very low wheel to guard clearance or the wheels / offset are to big for the car for this to be a issue though? do you have a picture.

This is probably the best photo I have showing the wheel gap: http://omgpham.com/mystuff/06.jpg

Is it possible that the previous owner who installed the arms set the traction rods too long, and the other arms were adjusted to suit the traction arm length?

Hopefully will get to the bottom of this tomorrow at the aligner's =)

[Cazal 856]

This is probably the best photo I have showing the wheel gap: http://omgpham.com/mystuff/06.jpg

Is it possible that the previous owner who installed the arms set the traction rods too long, and the other arms were adjusted to suit the traction arm length?

Hopefully will get to the bottom of this tomorrow at the aligner's =)

I guess that could be it?!? Alignment shop should be able to work it out man.

I'll be honest, I've never seen anyone have that issue, so keep us updated.

[mrpham]

So I posted in this thread too:
http://zilvia.net/f/tech-talk/296725...ml#post3725369

They recon traction rod length of 8.5" seems to be sweet spot:

[mrpham]

So I have a dilemma.... getting re-aligned tomorrow so they will sort it out, but I'm interested in the theory behind it.

Car isn't crazy lowered or have massive camber/toe, I think it's a pretty modest setup.

My rear wheels aren't centered in the arch, they sit further back which causes scrubbing on rear of the arch. As I understand it, by shortening my adjustable traction rods it will pull the wheel forward and center it within the arch. No more scrubbing! But if I shorten the rear traction rods then I will have a lot of dynamic toe (bumpsteer?).

I would like to keep the same camber, toe settings and ride height. But I also want the rear wheels to be more centered within the arch so that I don't scrub.

An update regarding this...

Just got back from the alignment shop and turns out my traction rods were adjusted really long... the previous owner/aligner must have messed up.

My traction rods have been shortened and now measure 220mm (8.7"), this has centered my wheels in the arch, and all other arms were adjusted accordingly to match the old camber and toe settings.

Car is feeling even better now! Couldn't be happier

[mrpham]

Don't know if it's placebo or what.... but driving through bumpy corners is much smoother and controlled now!

[fatboyz39]

I've owned both FWD and AWD, yes both alignment are different.

This is what i run on the BYP Civic FWD
Wakefield setup

Front

Camber : -4 degree
Castor : +10
Toe Out: 1.5mm

Rear

Camber: -2 degree
Toe : 0mm

As for Fish hook traction, we have over 250 fwkw and we don't experience much wheel spin at all. Keeping in mind we run 225/50/15 tyres. Traction is key at wakefield to achieving good lap times.

[1I1]

every degree of toe you give a car is a 20bhp loss in a strait line.

Is this a guess or actually proven? I can see how having Toe in or out can affect straight line speed but to be specifically 20hp? (not trying to be smart arse - just curious)

[Cazal 856]

na it is proven, i dont have a article or anything but the race engineer that i have been learning from was telling me that with all the data logging that he has done on all the race teams it has averaged out around 15 - 20 hp strait line power per degree of toe.

I'm guessing theres a lot more weighing into this than just toe. Whilst I wouldn't say that it is proven as such, toe out would definitely have the ability to affect straight-line speed and acceleration. I'm also guessing it's a sliding scale, much like driveline losses. I can't see a car with 100hp losing 20% of it's outright power due to running toe out.

[Cazal 856]

um look most cars would be different but the way which he does all his data logging through all the V Box with the sat nav gear onbaord he said from full rally cars which he worked on a few of the big wrc teams in europe and dideicated circuit car teams all over the world he said that it boils down to 15-20 hp per degree and the maths came to that answer in every car he worked on.

i dont know the maths formlue or how they come to it but that is what it is i guess, i spose that would be why most serious track cars dont run much toe.

While thats all well and good that he has told you each degree is worth 15-20hp, if I have a car that only makes 20hp, it's still going to drive with a degree of toe out on the front of it.

You get where I'm going yet?

[Cazal 856]

yes i do get where your going, i would be asuming the calculations are done on the time loss over a lap per degree of toe and to regain that time you would need the equivilant of 15-20hp more.

so if you had 20hp and you ran 1 degree of toe you would need and extra 15-20 to be as fast as you where if you ran zero deg of toe providing the rest of the car was set up properly to be able to run 0 deg

So based on exactly what you said, you believe that a car with 40hp, running 1 degree toe out, will be as fast as a car with 20hp, neutral toe. Right?