bump to the top...

 

Just checked my tires as I hit 25k miles today and my rears are perfect, maybe 60% left, but my fronts are BALD on the inner edges...

I just put 2 new tires on the front (OEM Dunlops) and got it aligned, results below...

BTW, off-topic, I was going to take my car into the dealer for the free less-dust brake pads, but my front brake pads look like NEW! I was shocked to see that as I am pretty hard on my car, especially braking before entering a corner... So anyway, I'm not going to change them for at least another 6 months as they seem to be wearing VERY evenly against my rotors...



Alignment results:

BEFORE:
FRONT
Left Front Camber: -0.8
Left Front Caster: 7.4
Left Front Toe: 0.16 (Out of Spec)
Right Front Camber: -0.7
Right Front Caster: 7.2 (Out of Spec)
Right Front Toe: -0.12 (Out of Spec)
Front Total Toe: 0.04
Steer Ahead: 0.14 (Out of Spec)

REAR
Left Rear Camber: -1.4
Left Rear Toe: -0.08 (Out of Spec)
Right Rear Camber: -1.5
Right Rear Toe: 0.05
Rear Total Toe: -0.03 (Out of Spec)
Thrust Angle: -0.06



AFTER:

FRONT
Left Front Camber: -0.8
Left Front Caster: 7.4
Left Front Toe: 0.04
Right Front Camber: -0.7
Right Front Caster: 7.2 (Out of Spec)
Right Front Toe: 0.04
Front Total Toe: 0.08
Steer Ahead: 0.00

REAR
Left Rear Camber: -1.4
Left Rear Toe: 0.12
Right Rear Camber: -1.5
Right Rear Toe: 0.10
Rear Total Toe: 0.22
Thrust Angle: 0.01


They put it in the computer as "Standard Suspension" instead of sport suspension but I looked at the sport specs and there doesn't seem to be any real difference except minor SAI which I didn't even see on the printout... Anyway, glad I got it aligned, all those potholes really did a number on my alignment...

 

Did they check and adjust your tire pressure before they did the alignment? If they didn't, that alone could cause the caster discrepancy. In any case, those specs are typical of a stock, severely understeering daily driver. A degree and a half negative in the rear with 0.8 in the front is just amazing. My Supra is -1.5 on all four corners. Thank goodness for adjustability!

 

I don't think they checked pressure, they just drove it up on the alignment machine and went to work... But I'm not too worried about the 7.2 caster... Probably just that way because of the pressure, or worst case, something got slightly bent when I hit a pothole... 0.2 is not big enough for me to worry... Or should it be?

Also, do you think the "before" numbers explain why my fronts were bald in the middle (toe and steer ahead)?

 

Caster is normally staggered a little to help the car counter road crown. 0.2 is no big deal at all and might make the car easier to drive.

Bald in the middle of the tread is overinflation. Nothing else can do that.

 

Argh, I didn't mean bald in the middle, I meant bald on the inner edges... My fronts were bald on the inner edges...

 

Edge wear (inner or outer) is from toe being wrong for the driving you do. Inside edge wear is usually too much toe out. Toe out helps the car turn in, so autocrossers have been known to run more toe out than would be prudent for a daily driver. Toe out can (but not always) make the car a little unstable at high speed (feel twitchy or dart into turns.)

 

I haven't really heard anyone mention SAI and Included Angle measurements. Are these measurements crucial to the alignment?

I did notice some of the alignment scans had these on there, but there was nothing listed or said N/A.

I got my alignment done at Sears today and they showed some measurements for these items, but they were a little out of spec. Oh well.

 

I have some inner tire wear with what I think is so slight feathering on the left inside. Dunlops 18k and some change in miles.
I'll scan my settings when my wife gets home to show me how to file up this crazy scanner.
35 psi fronts. I checked the air in the tires before I took it in. I generally run 35 in the front, 40 in the rear.

Left front
The only thing that was out of specs was the left front toe 0.23°
Specified range (-0.04° to 0.12°) They changed it to 0.04°
Camber -0.3°
Caster 8.1°
Toe 0.04°
SAI 10.1°
Included angle 9.8°


Right Front
Right toe was 0.08° , they changed it to 0.04°
Camber -0.5°
Caster 7.7°
Toe 0.04°
SAI 10.8°
Included angle 10.4°




Here is what the final settings:
Cross Camber 0.1° Before 0.1°
Cross Caster 0.4° Before 0.4°
Cross SAI -0.7° Before -0.7°
Total Toe 0.07° Before 0.31° (out of tolerance -0.08° 0.24°)


Drives different, drift to the right is more pronounced. Tire noise has Significantly increased !
I don't know whats up with that. I have some tread, but noise is so loud I will have to to replace soon cause its annoying. It must be the fronts making more noise. I should have not let the dealerships service manage talk me into the rack replacement.
Thanks.

 

Is dealership able to get alignment within spec when lowered on F-Sport or H&R? And is it better to get them as close to within spec, even if left and right don't match, or try to match them as much as possible/as close to spec?

 

i woulddnt let the dealer mess with the alignment. better take it to a shop that only does suspension work. plus i'd be surprised if the dealer will do any work on a car with modified suspension. my local dealer wont even install f-sport parts.

 

I haven't seen a "suspension only" shop in many years, and the last one I saw used equipment that looked 30 years old. I'm sure they did a good job, but I don't think I would take my cars to them now. I'm sure a decent Lexus dealership would have great equipment and a skilled technician that has more IS alignment experience than any other shop. The only reason why I might not take my IS to a dealer is due to the pricing.