20mm drop-SPC front and rear parts.

[OTB]

Hi all, new guy around here just got my first 86 car and it is of course getting rubber, springs, and alignment (via SPC front camber bolts/rear LCA). The rear LCA comes with an offset toe link bushing.

This will be the ever-so-popular ~20mm suspension drop via RCE Tarmac. I'll be putting it together in my garage and just driving a little prior to alignment shop. do you guys know:

1. Do I automatically start with the front SPC bolt tab pointed inboard?

2. Do I automatically want the SPC rear toe bushing offset to the inboard or outboard, or does that depend on each vehicle?

I'd also appreciate any input on my alignment plans. Fortunately I have canyon road options every day, and I'll only do a track day here and there. So "performance street" alignment if you will.

My target plan:
Front toe 0 deg
Front camber -2 deg
Rear toe .05-.1 deg (toe in)
Rear camber -1.5 deg

thanks techies!

[churchx]

1. SPC camberbolts have included instruction, where position of tab is illustrated. In short, to which direction it points, that will be max position of skewing wheel side. Of course that position is opposite depending if it's upper or lower hole bolt.
2. I'd probably skip installing SPC rear toe bushings.
As for target,
- for just DD, i'd probably reduce rear camber to -1, so that it's less then front's,
- if for track, then i'd get as much camber as i can front (if camberbolts in both upper and lower hole and with lowering, i guess it will be -2.5 to -2.6 front), and again, by around 0.5dg less camber in rear then in front, to dial out stock-ish understeer bias.
- planned rear toe-in seems way too much. Suggest not going for more then 0.1 to 0.2 total toe (each wheel half of total of course). Toe (both out or in) is what affects tire extra wear much more then camber. And that much toe as 0.5 will make rear very unwilling to rotate. Think of toe as presteered wheels (to inside or outside), so even going in straight line wheels will drag a bit all the time due being at angle at travel direction. Be more modest with toe.

[finch1750]

You shouldn't need the rear toe bushing. Though I hope you mean .05 and not .5

And you'll want to flip the camber numbers at the very least, maybe go a bit more negative on both. What tires and in what spec?

[OTB]

Thanks you two.

Fixed that to .05-1 deg toe in. Fixed the other targets as well.

Car is on the "performance pack" wheels (17x7.5) with 225/45R17 Pilot Super Sport.

By the way, don't bother with the PSS tires. Yes they do have pretty nice corner grip for higher treadwear tires, but I have no idea why there's all the reviews about quiet ride and street comfort, etc. They sound like basketballs just like a lot of tires, so I wish I had just gone for R1R, 615K, Star Spec, etc.

[churchx]

fix it again to .05-0.1 degree toe in
As for quietness .. it doesn't matter for me on this car. It's full of rattles and road noise is passed in with close to no sound insulation at all, i just accept it as given. And after driving with studded tires at highway speeds and with lowered rear seats no tires will be too loud for me .
As for grip, PSS, or even more so PS4S, which enhances wear & wet grip on top of what PSS were, they hit my sweet spot for dual use car, so i'll keep buying them

[Takumi788]

Originally Posted by churchx

fix it again to .05-0.1 degree toe in

Then fix it again to .06 inches bc that is how alignment machines work.

[strat61caster]

Originally Posted by Takumi788

Then fix it again to .06 inches bc that is how alignment machines work.

No they don't, measuring inches/mm of toe is based on measuring at the front and rear of the tire center (so across the tire diameter, for an 86 ~25"). A laser alignment rack isn't measuring two points 25" apart aligned to the wheel, it's hitting a few alignment targets attached to the wheel, calculating distances, converting that into degrees of toe & camber, then, in the case of that specific alignment rack, converting the toe to inches.

Degrees of toe should be universal across any method of gathering alignment data, provided that method is accurate.

http://rayjurgen.com/alignments-whee...nment-systems/

[Takumi788]

Originally Posted by strat61caster

No they don't, measuring inches/mm of toe is based on measuring at the front and rear of the tire center (so across the tire diameter, for an 86 ~25"). A laser alignment rack isn't measuring two points 25" apart aligned to the wheel, it's hitting a few alignment targets attached to the wheel, calculating distances, converting that into degrees of toe & camber, then, in the case of that specific alignment rack, converting the toe to inches.

Degrees of toe should be universal across any method of gathering alignment data, provided that method is accurate.

http://rayjurgen.com/alignments-whee...nment-systems/

Alright point taken....I mis-spoke. I should have said "then change it to 0.06 inches because that is the unit system the alignment tech adjusts toe with. "

[churchx]

I also recall that it was selectable in rig's user interface, if you want in inches/mm, or degrees&minutes on rigs i've been at, so i guess, most can be set to display alignment this or other way, whichever as per tech/user preferences. If alignment techs are not completely clueless, they'll now to what extent they need to dial if one specifies in degrees.

[Takumi788]

Originally Posted by churchx

I also recall that it was selectable in rig's user interface, if you want in inches/mm, or degrees&minutes on rigs i've been at, so i guess, most can be set to display alignment this or other way, whichever as per tech/user preferences. If alignment techs are not completely clueless, they'll now to what extent they need to dial if one specifies in degrees.

I have always specified and adjusted toe in inches. But I could see the units being interchangeable per the tech's preference.

[wparsons]

Whatever you do, make sure you take it to a shop that gives a proper performance alignment and not just a shop that'll get toe within spec and send you on your way.


I don't think you'll get -2* up front with just one set of bolts. Assuming you bought the SPC bolts for the lower hole, you can replace the upper bolt with the stock lower bolts for more adjustment, or you can live with what you get from just the bolts in the lower holes. If it is the lobed bolts for the lower holes, you want the tab (and arrow on the bolt) pointed outwards. I just installed mine the other day, so it's fresh in my mind.



Like it was already mentioned, don't bother with the toe bushings, you'll have plenty of adjustment range on the stock rear toe adjuster to get to your specs.