People occasionally ask about wheel alignment specs for the '88 Fieros. This is an attempt to answer that question once and for all. (Note that these specs apply to the '88 Fieros only. If you have an '84-'87 you'll have to look elsewhere.)

The original specs as published in the '88 GM/Helm Factory Service Manual were incomplete and contained several important typos. In January, 1988 GM released TSB (Technical Service Bulletin) #88-3-11 to address the issue. There have been references to TSB 88-3-11 in past threads on PFF, but they incorrectly reported one or more of the alignment parameters, and the TSB itself has never been posted. Here is a true copy of the original TSB:



Obviously, GM published this alignment information for a street driven Fiero with stock wheels, tires, and suspension. But even if your car has been modified, these specs are probably a good place to start.

FWIW, the data provided for the '88 Fiero by some alignment equipment manufacturers (e.g. Hunter) may be incorrect. You might want to make a copy of this TSB and take the specs with you to the alignment shop. I hope this helps '88 owners to get better alignment results in the future.

[This message has been edited by Marvin McInnis (edited 10-02-2009).]

The only trouble with the spec is that basically all 88 Fieros had manual steering. So, does that mean that GT's and Formulas should use the manual steering figures? When the spec was originally written, the plan was for GT's and Formulas to have power steering.

How you use this information is up to you. But think:

GT & Formula: w/ WS6 suspension option, 15 inch wheels

Base Coupe: w/o WS6 suspension option, 14 inch wheels

Probably the most significant component of the '88 WS6 suspension option was the addition of a rear anti-roll bar, and my opinion is that this was probably the main reason for the higher caster recommendation in the GT and Formula. Adding a rear anti-roll bar reduces understeer somewhat, and increasing front caster would probably help to maintain straight-line stability.

IMHO, all '88s would probably be OK with anything between 3 and 5 degrees of caster. Low cross-caster is probably more important than the absolute caster value.

[This message has been edited by Marvin McInnis (edited 10-02-2009).]

Maybe 'Manual Strng" should have read "Bse Cpe" and is a heretofore unrecognised important typo?

With manual steering, is it ok to have full positive caster? I know that it should improve responsiveness, but is it rough on your wrists?

quote Originally posted by Marvin McInnis: How you use this information is up to you. But think: GT & Formula: w/ WS6 suspension option Base Coupe: w/o WS6 suspension option IMHO, all '88s would probably be OK with anything between 3 and 5 degrees of caster. Low cross-caster is probably more important than the absolute caster value.

Also it should be noted that on the 1988 coupes they used the standard 14" aluminum wheels with the same size tire all around and on the GT and Formula that used the 15" wheels that had different offsets and different tire diameters from front to rear. This stagger of offsets and tire diameters also affects the alignment specs. If you change your wheels and tires to aftermarkets with the same offset and tire diameters all around on your 1988 GT or Formula, the alignment specs for the coupe should be utilized.

[This message has been edited by Oreif (edited 10-02-2009).]

Only if that offset is the SAME as that of the 14" wheels.

Really, there are no *definitive* alignment specs. Some people are going to like driving the car better when it's setup one way vs another. Six degrees of caster vs 3, more rear camber vs. less, etc.

Most 'factory' alignment specs are designed to have cars with a bit of understeer, as that is considered 'safer' than neutral or oversteer for most drivers. That's typically why you see positive camber on the front of most cars, and at least for most domestic cars, not a whole lot of caster. Lots of caster on a manual steering car makes for more effort to turn, but also makes the wheel want to return to center more. Most higher-end german cars seem to have more caster from the factory. It also tends to enhance high-speed stability and handling.

I tend to like my cars with as much caster as I can dial in, but equal side-to-side. On my Fiero, for the street, I usually like camber at about 0 degrees front, and 1.5 to 2 degrees in the rear, but again, equal from side to side. For autocross (or track use with both right and left turns), about as much negative camber as you can get: -2 front, -3 or -4 rear. Toe is a different beast, but in general, toe-out in the front leads to a 'darty' feel on the street, with a tendency to follow groves and such on the pavement. But slight toe-out on the track helps turn-in greatly.

In practice, I usually set my Fiero to as much caster as possible, and accept that it will make steering a little more of an effort in the parking lot. This seems to be an OK setup for mostly street/occasional autocross, at least for me:

Camber:

Front: 0 to -.5
Rear: -1 to -1.5

Toe ( I like to pre-load the front wheels, much like Mercedes suggested on some of their cars, with about 10-15 lbs of force on the front of the wheels )
Front: 0 to 1/16" toe-in
Rear: (preloaded, but in the rear), 0.

Most importantly, find an alignment shop that will work with you a bit. Factory alignments are designed for 'safe' handling first and foremost, for 'average' drivers. That's most people. If you change the tires and wheels from factory, you may want to tweak things to suit your driving style.

Thanks for posting this spec Marvin, I'm going to print it out, laminate it, and stick it in the glovebox of my '88s. However, I've got to take issue with this statement:

quote Originally posted by Marvin McInnis: Probably the most significant component of the '88 WS6 suspension option was the addition of a rear anti-roll bar.

Not even. Stick a rear anti-sway bar on a non-88 and tell me that you still think it's the most significant component. People wouldn't bother swapping in entire '88 rear cradles if that were true. The multilink suspension eliminates the bumpsteer problem inherent to all the non-88s and dramatically improves handling. Not to mention the larger brake rotors, aluminum calipers, and integrated parking brake.

quote IMHO, all '88s would probably be OK with anything between 3 and 5 degrees of caster. Low cross-caster is probably more important than the absolute caster value.

All Hunter alignment machines incorrectly list the 3 degree caster spec for all manual-steering 88s with no differentiation between 4 and 6-cyl cars. The power steering spec is correct for the Formulas and GTs with 5 degrees, but it can be difficult to try to explain that to alignment techs without some 3rd-party source to back it up.

[This message has been edited by crazyd (edited 10-02-2009).]

quote Originally posted by crazyd: Stick a rear anti-sway bar on a non-88 and tell me that you still think it's the most significant component. People wouldn't bother swapping in entire '88 rear cradles if that were true. The multilink suspension eliminates the bumpsteer problem inherent to all the non-88s and dramatically improves handling. Not to mention the larger brake rotors, aluminum calipers, and integrated parking brake.

I think you misread my post. I agree with you that the '88 suspension design was superior to previous years. But all of the '88s had the same cradle (except for transmission mount differences), the same basic upgraded front suspension design, the same multilink rear suspension design, and the same brakes. Only the GT and Formula included the WS6 suspension option, which according to the GM 22P manual comprised only five items: 1) a rear anti-roll bar, 2) different upper and lower front control arms, 3) different lower front control arm bushings, 4) different outer tie rod ends, and 5) one of the two steering rack mounting bushings was different. I have heard it suggested that the '88 WS6 option may have included a steering rack with a slightly faster ratio, but the parts detail in the 22P manual dispels that notion; both WS6 and non-WS6 rack shafts and both pinion shafts have identical part numbers in the '88s.

[This message has been edited by Marvin McInnis (edited 11-01-2009).]

Yes, I misunderstood your post. I'm with ya now, thanks for the clarification. As for the steering rack, I think that may be an urban legend that grew out of the power steering option, and the 'different lower control arm bushings' - maybe a harder durometer? They are still rubber. AC Delco lists the same part number for both. Or could that be referring instead to the poly endlink bushings on the lower control arm?

[This message has been edited by crazyd (edited 10-02-2009).]

quote Originally posted by Marvin McInnis: 2) different upper and lower front control arms

??? Never heard this before, does anyone have more info?

quote Originally posted by BluEyes: ... does anyone have more info?

Refer to the 22P parts manual. I was somewhat surprised myself, but the '88 WS6 and non-WS6 front control arms have different part numbers.

[This message has been edited by Marvin McInnis (edited 12-08-2009).]

quote Originally posted by Marvin McInnis: ..... the '88 WS6 and non-WS6 front control arms have different part numbers.

Probably because they come complete with bushings, which are different (i.e., harder durometer rubber).

Definitely possible.

Thanks for the info