Sponsored

Factory alignment

luc

Well-Known Member
Joined
Mar 25, 2018
Threads
16
Messages
2,214
Reaction score
2,528
Location
CA
Vehicle(s)
2017 GT with PP
That's true.

What people seem to have missed so far is that the extra weight of your supercharger will lower the front ride height a little.

And just like lowering with lowering springs, camber will go slightly further negative. I'm guessing that for most MacStrut suspensions this effect runs about half a degree of "extra" negative camber per inch of lowering.

There's more . . . in front-steer cars (steering rack or linkage located ahead of the front axle line), adding negative camber normally moves toe in the outward direction.


Norm
That's true.

What people seem to have missed so far is that the extra weight of your supercharger will lower the front ride height a little.

And just like lowering with lowering springs, camber will go slightly further negative. I'm guessing that for most MacStrut suspensions this effect runs about half a degree of "extra" negative camber per inch of lowering.

There's more . . . in front-steer cars (steering rack or linkage located ahead of the front axle line), adding negative camber normally moves toe in the outward direction.


Norm
Norm, if I’m not mistaking, it’s the opposite
When the ties rods are below the axle line, increase negative camber increase the distance between the bottom of both wheels and therefore with front of axle line ties rods, you get toe in
Sponsored

 

Norm Peterson

corner barstool sitter
Joined
Jul 22, 2013
Threads
11
Messages
8,852
Reaction score
4,652
Location
On a corner barstool not too far from I-95
First Name
Norm
Vehicle(s)
'08 GT #85, '19 WRX
Norm, if I’m not mistaking, it’s the opposite
When the ties rods are below the axle line, increase negative camber increase the distance between the bottom of both wheels and therefore with front of axle line ties rods, you get toe in
Nope. Camber rotation happens about the ball joint rather than at the ground. The laterally fixed position of the ball joint determines this, so while the bottom of the tire does move outward with increasing amounts of negative camber, the tierod position only moves a little laterally, and being located slightly above the ball joint's center of rotation decreases the necessary tierod length. Meaning toe migrates in the toe-out direction until the tierods are shortened.

Tierod locations, lengths, and inclinations are designed to intersect the suspension's front view instant center at or close to static ride height, and this is for minimal bumpsteer. Tierod inclination will be close to lower control arm inclination, but not exactly equal to it.


Norm
 
Last edited:
OP
OP
Redfuzzbutt

Redfuzzbutt

Well-Known Member
Joined
Feb 10, 2021
Threads
10
Messages
187
Reaction score
380
Location
Northern AZ
First Name
John
Vehicle(s)
'17 Mustang GT
I’ve had a speed shop with deep racing experience do all my suspension and steering work and was asked several questions before they did my alignment so they could set the car up correctly. I would never bring my Mustang to the average shop for an alignment. A correct alignment to any modified car is a necessity and the tech needs to have experience with how to set the car up and not go by “book” spec settings.
Solid perspective and agreeable with what you said. I live in a smaller area with limited options, went to the place with the most experience and best reputation. But as you stated, if vehicle is modified, there is a high likelihood that the common daily driver vehicle doesn't correlate with the one with mods.

My car is 99% a dd, haven't tracked it (though that does sound like a blast) and would like to try a HPDE in the future, but recognize that it's basically a stock non-PP car with cute little brakes. So the alignment is now very bland/generic with the focus of tire life longevity.

In the future, my priorities and desired function of the car will probably change but for now
Nope. Camber rotation happens about the ball joint rather than at the ground. The laterally fixed position of the ball joint determines this, so while the bottom of the tire does move outward with increasing amounts of negative camber, the tierod position only moves a little laterally, and being located slightly above the ball joint's center of rotation decreases the necessary tierod length. Meaning toe migrates in the toe-out direction until the tierods are shortened.

Tierod locations, lengths, and inclinations are designed to intersect the suspension's front view instant center at or close to static ride height, and this is for minimal bumpsteer. Tierod inclination will be close to lower control arm inclination, but not exactly equal to it.


Norm
And this totally, 100% convinces me that I don't know jack about suspension.

Car update: new front tires, alignment shop installed camber bolts, .5 degree of neg camber, 1/16" toe in.
Basically, set up for basic daily driving as I don't track it. Not exciting but as this stage, serviceable.
 

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
121
Messages
13,455
Reaction score
12,262
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
Wow that is way out.
Factory street specs are -1.5 to -2.0 camber and 0 to 0.01 degrees toe.

If it is 1/16th total toe that is 0.14

I'd suspect you will still wear out the inside edge

I have - 1.7 camber and .01 toe in and have even tire wear.
 

Norm Peterson

corner barstool sitter
Joined
Jul 22, 2013
Threads
11
Messages
8,852
Reaction score
4,652
Location
On a corner barstool not too far from I-95
First Name
Norm
Vehicle(s)
'08 GT #85, '19 WRX
Car update: new front tires, alignment shop installed camber bolts, .5 degree of neg camber, 1/16" toe in.
Basically, set up for basic daily driving as I don't track it. Not exciting but as this stage, serviceable.
I'm pretty sure that Ford's preferred camber setting for a base car is closer to -0.7° front camber. There's a tolerance of 0.75° either side of that that'll still put the alignment readout "in the green", but for mostly straight-ahead driving and not too much in the way of enthusiastic cornering I'd shoot for -0.75° up to maybe -1.0°.

A little toe in is fine and may improve straight-ahead directional stability a bit. Ford's max toe in spec is +0.2° against a (somewhat questionable) preferred value of 0.0°.


Norm
 

Sponsored

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
121
Messages
13,455
Reaction score
12,262
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
Maybe I'm looking at the Shelby specs but that is the green on my 2017 gt printout.
 

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
121
Messages
13,455
Reaction score
12,262
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
Maybe my alignment shop changed the red ink to green?

Anyway I have even tire wear. I rotate each oil change and do like to corner at .5 g and above when it is safe to do so.
 

GTP

Deutsche Pony
Joined
May 27, 2015
Threads
260
Messages
5,973
Reaction score
3,847
Location
Indy
Website
www.BambergAudio.com
First Name
Philip
Vehicle(s)
2019 GT PP1 A10 Outrageous Orange HPDE mods
I’ve had a speed shop with deep racing experience do all my suspension and steering work and was asked several questions before they did my alignment so they could set the car up correctly. I would never bring my Mustang to the average shop for an alignment. A correct alignment to any modified car is a necessity and the tech needs to have experience with how to set the car up and not go by “book” spec settings.
What's a fair price for a speed shop alignment?
 

Pittpa

Well-Known Member
Joined
Jul 26, 2019
Threads
12
Messages
320
Reaction score
200
Location
Pittsburgh PA 'Burbs
First Name
Dave
Vehicle(s)
2019 GT 6MT
I'm annoyed that I'm just finding this out, nobody else's fault other than my own. Had my 2017 GT non PP for approx 5k miles.
During oil change, saw that inner front tires being very worn down, scheduled alignment. Tech said that there is 1.5% camber on both front wheels and isn't able to make any adjustments without camber bolt/kit. When questioned if it was due to worn out parts or anything else (car had 24k miles), he said no, that it's typical of the mustangs to come from the factory with that much. That may or may not be true, you all can chime in on that, but here is the part that concerns me:
The suspension is stock, does have 285/30R20 tires with the added weight of the Whipple SC. Does that sound like a recipe for the inner tires to be worn down that quickly? Guessing the tires have a little over 5k on them as they appeared to have a lot of tread when I purchased the car.

I have not tracked the car nor really hit up any twisties to account for additional uneven wear. Other measurement when attempting alignment was that toe out was at 1/16" on each front tire.
My local shop told me my tires needed replaced and I needed an alignment due to front inner tread wear on my GT at about 15k miles. I took it to a busier, recommended shop with an older alignment tech. He told me that this wear is normal and it is usually worse than mine by 15,000 miles and my alignment was in spec. He advised the camber setting from the factory wears tires this way. He recommended that the toe be adjusted to help minimize this type of wear. I agreed. I don't know the numbers involved, as I was ignorant of the problem until I spoke to him.
 

Sponsored

Doug T

Well-Known Member
Joined
Jul 13, 2021
Threads
9
Messages
76
Reaction score
34
Location
Pa
First Name
Doug
Vehicle(s)
2020 Mustang GT PP1
Norm is that rear toe in or out?
 

Norm Peterson

corner barstool sitter
Joined
Jul 22, 2013
Threads
11
Messages
8,852
Reaction score
4,652
Location
On a corner barstool not too far from I-95
First Name
Norm
Vehicle(s)
'08 GT #85, '19 WRX
Rear toe should always be 'in'.



The only exception I can even think of would be for a heavily understeering FWD car, where you might experiment with a little rear toe-out in order to trick the car into rotating.


Norm
 

Pnygrl61

Active Member
Joined
Jun 13, 2021
Threads
2
Messages
30
Reaction score
23
Location
Florida
First Name
Danae
Vehicle(s)
2015 Mustang GT Convertable
Hi,

I'm going to throw this out here and hope someone responds, I've got a 50th anniversary GT and it's all stock suspension. I took it to the dealer a couple of years ago for an alignment after I put new tires on it. They gave it back to and as I was leaving I noticed the steering wheel cockeyed. I returned and said what the hell, you let me leave with this? They took it back and straightened the wheel. I left again and the car was pulling horribly. I didn't noticed it before bc the steering wheel was so WAK. So I went back again, and said "I have no idea what's going on, y'all have monkeys for techs today? I can't keep it in the lines?!" They took it back, service mgr came out and said "we can't align it". "I'm like uh... What are you talking about?" He said "we can't align them, they're set up for the track. I'll give you your money back, you can go try another shop."
I did that. They couldn't do it either. They didn't charge me, have me a printout and a pat on the head. That was Goodyear, I think. 2 PLACES?
I'm gonna be putting another set of tires on it soon, it hydroplanes like a boat here in Florida, so anyway, tell me who's full of shyte here, and WHY, and where I should go, because Ford doesn't know how to align these cars and it's starting to pull bad to the left. I read through the comments, I can't get a string and try to calculate this. I know nothing about this, which is probably why I left both places with the same BS.
 

K4fxd

Well-Known Member
Joined
Apr 2, 2020
Threads
121
Messages
13,455
Reaction score
12,262
Location
NKY
First Name
Dan
Vehicle(s)
2017 gt, 2002 FXDWG, 2008 C6,
Call Steeda and set up an appointment for an alignment. It will be worth the drive.
 
 








Top