jermdm

At the dealership I work at, we have a hunter alignment machine that uses cameras and targets to align the car. Pretty cool machine since you only have to roll the car back and forth about 2 feet to get your measurements besides the caster sweep you have to do to get that measurement. I looked at the specs for my iroc and this is what I got from the machine. Front toe 0.00, caster 4.80, and camber .30. The specified range is, toe -0.10 to 0.10, caster 4.3 to 5.3 and camber -0.2 to 0.8. With these specs, what changes would any of you guys make? My car is not modded in any way and is pretty much a weekend driver unless my daily driver brakes down.

Reid Fleming

iTrader: (2)

sofakingdom

iTrader: (1)

Reid's are pretty typical for a good "hot street" alignment.

Quite a bit different from autocross or even oval-track setups; but, right for the street.

Ignore the factory specs. While I usually give the factory engineers credit for doing something right for some situation or other, or some constraints that they have to live within (EPA, NTHSA, liability insurance, the "storied history of GM", whatevz....) I am forced to concede that in the case of alignment specs, they merely had their head stuck up their anus. There is NO POSSIBLE UNIVERSE THAT CAN BE CONCEIVED OF in which those specs are "right".

jermdm

Thanks guys for the input. Not forsure what to think about the total toe since its displayed in inches and the others are in degrees. The rest is no problem. Is there a degree measurement for toe or total toe or do I just set it at the 0.00 degrees and toe in or toe out 3/32? Don't know if the machine is able to display inches or switch it to inches.

johndinu

The 3/32 value is toe out?
Also, the different caster values left to right are to account for the driver's weight?
I plan to put some weights to account for my bodyweight, then could I just set em equal?
Thanks
Sorry for the newbie questions
PS:jermdm, u could calculate the angle knowing the rim size for the toe "in" value tan(angle)=3/64/8 I get 1.02e-4...
my trig skills r beyond rusty tho sorry if I'm off by the proverbial mile

Alice89

iTrader: (6)

The 3/32 is toe in. The caster split is due to road crown. (Slope in the road for water drainage)

hellz_wings

iTrader: (2)

Agree with Reid and Sofakingdom.. I put mine to -1 camber, +4.8 caster (0.5 less on driver's side), 3/32 toe in and it drove much much better compared to stock wobbly drive-all-over-the-road-like-im-drunk crap specs.

jermdm

Thanks for the replies. I will be using the street spec when I get around to replacing the inner and outer tie rods ends with new adjusting sleeves and the strut mounts. Figured I'd wait to do the alignment till then.

572_Rat

These are alignment specs I found on the board which I used before and had no problems with tire wear or steering. This is a copy of the post


The best way to align these cars, for street use, is to about 4°/4.5°positive caster, -1°/-1.5° camber (those are given as L/R), and about1/32" toe-in. The factory "specs" have positive camber, whichGUARANTEES to chew off the outside edge in a few hundred miles.

johndinu

positive camber seem to be a thing of the past. yes maybe the front loads up from the aero forces but maybe at higher speeds (100mph?) yet u're left with the stability drawback at lower speeds.
I'll go today to have it alligned for the "hard street use";-)

IROCZTWENTYGR8

iTrader: (1)

Was that a consensus or just an opinion? Seems like a mix of the first 3 on that chart. I wonder what kind of difference it would make over stock.

sofakingdom

iTrader: (1)

That's close to my "opinion"; for that matter, all of the "street" specs listed up there are. Close enough to work with at least.

Like so many other things, alignment is easy to change, if you do it in small measured reversible increments. Like, get it aligned to x specs; drive it, see what it does; add ¼" more caster (measured at the strut towers) and see what it does; put it back; adjust the toe in ¼ turn on each adjuster, see what it does; put it back; and so on. If you like what something does, do some more, until it gets worse. Keep doing it as long as it keeps getting better, and until ANYTHING that you do, makes it worse.

It's not rocket science after all. It's just a car. There's like a BILLION of em in the world, and EVERY ONE was built by mere humans. Can't be that tough to figure out, even if you're nothing but a human yourself.

Cudascious

I was having outside right tire scrub issues on my 89 formula using roughly the factory specs. The final specs were

+0.5 camber (L) -0.1 camber (R)
4.2 caster (L) 4.3 caster (R)
0.15 total toe in

So I re-aligned it myself and threw it on the Hunter at local tire shop for free (because I bought my Cooper RSC's there) to see what I had done. I was at max negative camber on the left, and max positive caster on the right but specs came out to

-0.3 camber (L) -0.3 camber (R)
4.4 caster (L) 4.6 caster (R)
0.05 total toe with 0.0 steer ahead

And that's as good as it gets with the stock strut retainer (camber/caster adjustment) on my car anyway. Hoping that might help lessen the outside scrub.

1989 formula with stock wheels (16x8 with the correct 16mm offset for the rear) and stock size 245/50/16

Only 1 alignment shop in the area said they could set the camber and caster but 100 bucks. I did it for free with my eyeballs, some string, Jack stands, and a tape measure and a little help from my 18 year old daughter. No special tools required. Two eyeballs and a few test drives were the most important. Lol

I'm hoping the car likes this. Drives better now. So time will tell.

skinny z

Thanks for that Mr Fleming. I was looking for that chart.
New BFG Sport Comp 2s waiting to be installed and I don't want them burned up on the outside edges like the last set of tires.
I brought modified specs to the last alignment shop however its obvious they didn't pay attention. I'll see if I can't get better service this time around.