Alignment specs - 68 Camaro. What I can do without GS mod

[Chad-1stGen]

Hey All,

I have all my suspension parts installed now and when I get my T56 back from the rebuilder I plan on getting an alignment. I've been reading this site for the past few hours and while there is lots of good advice on specs and a lot of it consistent (good sign for me) I'm not clear on what specs are acheivable with stock arms? As I have my eyes on the AFX spindles as a future upgrade I don't realy wan't to do the GS mod for now.

Currently: Stock subframe, stock A-Arms, Hotckis front and rear springs (2" drop), Hotckis revalved Bilstiens, Hotckis 1 1/8" anti-sway bar.

Intended use of the car is 90% street and some track days once all the bugs are worked out of the car. Plenty of street driving on the freeway so high speed stability is a concern.

I've also read of some poeple having to supply their own shims? Is that normal?


Ok so I stole the following specs from a chicane post:

As per Global west:

Driver side / Passenger side
Caster 2 degree’s positive / Caster 2 ½ degree’s positive
Camber ½ to ¾ degree negative / Camber ½ to ¾ degree negative
Set toe to toe-in (3/32 total) / Set toe to toe-in (3/32 total)


As per DSE:

Driver side / Passenger side
Caster 5 degree's positive / Caster 5 degree's positive
Camber ½ degree negative / Camber ½ degree negative
Set toe to toe-in (1/16 total) / Set toe to toe-in (1/16 total) 1/8 overall


As per Guldstrand:

Driver side / Passenger side
Caster 3 degree's positive / Caster 3 ½ degree's positive
Camber 3/4 to 1 degree negative / Camber 3/4 to 1 degree negative
Set toe to toe-in (1/16 total) / Set toe to toe-in (1/16 total) 1/8 overall

Also per David Pozzi's page:

Guldstrand recommends the following specs for a "touring car":

• Caster: 3 - 4 degrees positive (+) PS = more, manual steer less.
• Camber: 1/4 to 1/2 degrees negative (-)
• With upper a-arm relocation Camber: 0 degrees
• Toe-in: 0 - 1/8 inch

Guldstrand recomends for racing:

(assumes "Guldstrand mod" is done)

• Caster 3 to 4 1/8 deg pos
• Camber 1.5 to 2 deg neg
• Toe in 1/8" out to 1/8" in (I would try 1/8" out first) more neg camber = more toe out.

Herb Adams recomends these alignment specs for the street:

• 1 degree positive caster ( I would use 3.5 degrees if PS)
• 1 degree negative camber.
• 1/16" toe in

Stock factory alignment specs:

• Caster +1/2 deg
• Camber + 1/4 to 1/2 deg
• Toe-in 1/8" to 1/4" (Radial tires need less toe-in, use 1/8" or less for them)

David has recommend his specs before but I wanted to make sure I got the right ones lol.

I'm thinking from reading other posts that if I can get 3* positive caster out of the unmodded geomtry I'm doing good? Is there a limitation on the ability to get a full 1* negative camber? Finally 1/16 toe in sounds like the way to go?

Thanks to the suspension experts for helping answer yet another alignment question.

[baz67]

Nice job on the research. Alright. Get as much caster as your stock uppers can give you. It should be between +3-4* depending on production tolarances. You will not get too much with your stock arms and location. I would do -.75 to -1* camber and 1/16 toe in. You should not have any issues getting that camber number with the drop springs you have.

[chicane67]

I'm not clear on what specs are acheivable with stock arms?

Intended use of the car is 90% street and some track days once all the bugs are worked out of the car. Plenty of street driving on the freeway so high speed stability is a concern.

I'm thinking from reading other posts that if I can get 3* positive caster out of the unmodded geomtry I'm doing good? Is there a limitation on the ability to get a full 1* negative camber? Finally 1/16 toe in sounds like the way to go?

Honestly... depending on the wheel and tire package... will really tell you which way to go. +3 to +3.5 caster with -1 3/4 camber and zero to 1/16 toe OUT works killer. 1/16 toe in will induce a fair amount of understeer.

I ran the above set-up for ever... and with hard street driving, the tire wear wasnt even an issue.... they were flat and true with 32psi front and 28psi rear.

[Chad-1stGen]

Honestly... depending on the wheel and tire package... will really tell you which way to go. +3 to +3.5 caster with -1 3/4 camber and zero to 1/16 toe OUT works killer. 1/16 toe in will induce a fair amount of understeer.

I ran the above set-up for ever... and with hard street driving, the tire wear wasnt even an issue.... they were flat and true with 32psi front and 28psi rear.

Wheels are TT2's 16 inch, tires are BFG's. Don't recall the exact model or spec atm.

I thought toe out made the steering slightly twitchy?

Finally, any advice for preparing before I go to the alignment shop? IE do I need to bring my own shims or modify some shims first? Any advice about questions to ask the shop to ensure they know what they are doing?

Thanks again.

[Marcus SC&C]

Any of those sets of specs would be a huge improvement over stock. There`s just one problem. With stock arms,stock cross shafts and Hotchkis lowering springs you probably won`t even get close,especially if it has any nose down rake (static + caster loss). I`ve done 1st gens where even with offset shafts I couldn`t get more than -1/2* camber and +3* caster with a 7/8" shim pack on the rear bolts. You may be able to get pretty good specs on one side but not the other so you`ll have to dumb one side down to match. You`re going to have to compromise but get as much - camber and + caster out of it as you can up to those specs. Almost anything`s a big improvement over stock though. I`d go with 1/16" toe in. Mark SC&C

[chicane67]

No, toe out doesnt make it twitchy... but improves the hell out of turn in !!

In an all stock configuration with my 16x8 w/245-50-16 on all four... I was able to get -1 3/4 camber with +3.25 and +3.5 caster, with ease. Call me lucky, I guess !?!!

The problem with this is going to be in the toe. If you run toe in, 1/16" in would be a max recommendation (it is going to have a safe amount of understeer with that setting)... but the good thing is... its easy to adjust so you can play with it all you want after the initial adjustment.

If the guy doing your alignment is using a magnetic mount, bubble camber caster guage... and he says lazer systems suck... he's your man.

[David Pozzi]

I agree when running a lot of neg camber the toe needs to be minimal or try toe out. When neg camber is used, the tires develop camber thrust that needs toe out to compensate.
I believe the Millikan and Millikan book says to use .1 deg toe out per 1 deg of neg camber per wheel. For a 26" tall tire, that's about 3/32" per wheel per degree of neg camber. So, for 1 deg neg on each side increase toe out to 5/32 over the "normal" toe in, normal radial tire toe in is 1/8" to 1/16" total, let's use 1/16". So a setting of 3/32" toe out is "proper" for a car with 1 deg neg camber and would drive the same as a car with zero camber and 1/16". This is not a result of my testing, just a quote from memory from a book. However use of toe out is very common when high neg camber settings are used. I have used a little toe out on my race car and more on my 67 Camaro but it was autocross only use when I did it.

Remember, original alignment specs were for bias ply tires, radials use less. Original camber was + 1/2 deg creating some camber thrust in the toe-out direction. That's why stock specs for toe in is between 1/8" to 1/4!

Generally with stock arms and no Guldstrand mod, shoot for +2.5 deg positive caster or as much as you can get, and 1 deg neg camber with 3/32" toe out if you want to try it. Use minimal toe in if you don't want to try the toe out.
David

[Marcus SC&C]

Chicane67, that`s the "fun" thing about working on cars from the `60-`70 when really sloppy chassis tolerances were still grooovy man! You car is the one the guy at the alignment shop would have hated in 1974 because he couldn`t take enough shims out to get the crappy factory recomended alignment specs. Now it`s a huge bonus! Mark SC&C

[Chad-1stGen]

Well I got the car aligned yesterday. Had to go to several places before someone would even be willing to try and align it to my specs. Guy ended up using the laser system and I was getting desperate to just get it done.

He was able to get 4* postive caster on both sides very easily and probably could of gone to 5*+

Final specs I ended up with are:
4* positive caster
1* negative camber
1/16" toe out

So far I've only driven it on the freeway so I can't comment on handeling in the twisties yet. But it sure looks better now that the wheels don't have huge positive camber from no shims at all.

Also got my t56 back from t56 rebuilds.com and installed it on Saturday. Man I love having a 6 speed in my car.