Click here to make us your homepage

ATTENTION SPONSORS ADVERTISE WITH US CLICK HERE FOR DETAILS

V6FBody Online's - Techbase:

2nd Generation FAQ: Suspension, Tires, Brakes

How can I improve handling?
How can I improve steering response?
What changes came with the RTS (Radial Tuned Suspension) in 1974?
What tires were available for the Camaro's?
What is the largest tire I can use?
When were rear disc brakes first offered on the Firebird?
What do I need to convert my rear drums to disc brakes?

How can I improve handling?

A key in cornering ability is the possibility to have small or even negative camber alignments. But less camber means more shims on the upper A-arm. It often turns out that too many shims are required to get a desired alignment. The solution has been to buy an expensive tubular A-arm that is shorter than stock.

Well, TRW had a brain-storm and released a custom offset upper A-arm shaft. This shaft is cheap, and can be installed two ways: One that gives you stock alignment, and the other gives approximately 1 degree less camber. Ideal for most street driven cars that want better handling. The shaft comes complete with nuts, brackets, and bushings. This is actually a Moog part (K6146) which sells for around $50. Call the TRW help line (1-800-237-9090) for more information.

Here are some low-buck suggestions for the Camaro. Some of them can be used on the Firebird:

If it's not a Z28, install Z28 front springs. If you want a real hard suspension on a smallblock car, get big-block springs and cut them to get your desired ride height.
Add an additional leaf to the rear springs. This additional leaf may be used to lower the rear of the car somewhat. Or replace the rear leaf springs with fiberglass leafs.
Get a 1.25" front sway bar and a 13/16", 7/8" or 1" rear bar from late a '70s Trans Am. Also get the bushings and brackets for the front bar. These bars bolt on without frame modifications.
Replace the subframe to body bushings with polyurethane or aluminum to reduce the deflection of the subframe under load in corners. But keep in mind that the lack of rubber bushings results in a much harsher ride.
Install good gas charged shocks.
Use polyurethane or similar control arm bushings.

Set front end alignment to:

 
                      Min     Max
                     -----   -----
             Camber  -3/4      0    dgr
             Caster   +3      +5    dgr
             Toe in    0      3/32  inch

On the rear the stock 7" rims will accept upto 245mm wide tires (they might rub some on the shocks however). With aftermarket rims with positive offset wider tires are possible. The front will also accept up to 245 wide tires. Some minor rubbing is possible.
Try 16 or 17 inch wheels with the biggest tires which will fit.

How can I improve steering response?

The 12:1 steering box from a 3rd gen car (IROC/TA/GTA) can be used on the 2nd gen cars for very fast response. These can be found on the following models: 85-87 Camaro's with 16" wheels, 88-92 Camaro's with the FE2 or F41 option, 84-86 Firebirds with 16" wheels, 87 Firebirds with 16" wheels and the heavy duty suspension, and 88-92 Firebirds with the FE2 option.

For installation, you need a hybrid coupler to attach the new box to the steering column and metric fittings so you can use your current compression fitting hoses. Your stock Pitman arm can be used. As for the pump, you can swap flow control assemblies because the late model pump usually has the wrong brackets.

Another option would be to have your steering box rebuilt with the guts from a 3rd gen box which has a better ratio. The original box mounting can be used and no major modifications are necessary. Whaling Gear Company does such a conversion at the standard rebuild price of $179 (818-899-5090).

What changes came with the RTS (Radial Tuned Suspension) in 1974?

It included the following:

GR-70-15 radial tires
Front anti-roll bar diameter shrank on the Trans Am from 1.25" and grew on the base model from 1" both to 1.125".
Rear anti-roll bar diameter also shrank on the T/A from .875" and grew on the base model from .625" to .75".
Stiffer springs - 330in/lb fronts and 125in/lb rears up from 300/100
Heavy-duty, revalved shocks
Altered bushing durometers

What tires were available for the Camaro's?

The following are standard tire measurements:

 
    1970 1/2
       Base - E78-14 (~205/78-14)
       Z28  - F60-15 (~215/60-15)
 
    1971
       Base - E78-14 (~205/78-14)
       Z28  - F60-15 (~215/60-15)
 
    1972
       Base - E78-14 (~205/78-14)
       Z28  - F60-15 (~215/60-15)
 
    1973
       Base - E78-14 (~205/78-14)
       Z28  - F60-15 (~215/60-15)
 
    1974
       Base - E78-14 (~205/78-14)
       Z28  - F60-15 (~215/60-15)
 
    1975
       Base - FR78-14 (~205/78-14)
 
    1976
       Base - FR78-14 (~205/78-14)
 
    1977
       Base - FR78-14 (~205/78-14)
 
    1978
       Base - FR78-14 (~205/78-14)
       Z28  - 215/60-15
 
    1979
       Base - FR78-14 (~205/78-14)
       Z28  - 225/70-15
 
    1980
       Base - FR78-14 (~205/78-14)
       Z28  - 225/70-15
Back To Top

 
What is the largest tire I can use?

Without any modifications, 15" x 8.5" wheels (front and back) with 4.5" backspacing and P245/60R15 tires will fit. For 16" x 10" (front) and 16" x 10.5" (rear) with 5.375" backspacing and P255/50R16 tires, the inner lip of the fenders will have to folded under. Also the control arm (near the upper ball joint) may have to be grinded up front and shock mount clearance should be checked in the rear. For 17" x 11" (front) and 17" x 12" (rear) with 6" backspacing and P275/40R17 (front) / P315/35R17 (rear), the same changes as above are required plus notching of the lower control arm up front may be required.

When were rear disc brakes first offered on the Firebird?

In 1979 as part of the WS6 Performance Package.

What do I need to convert my rear drums to disc brakes?

If you want to take the cheap route, late model (1979-1988) G-body (Grand Prix, Monte Carlo, Regal, Cutlass Supreme) front calipers will work on the rear of the 2nd gen cars. But, you won't have an emergency brake. Otherwise you can obtain the parts from stock equipped cars:

'79 - '81 caliper mounting bracket (10004494 LH / 10004495 RH)
'79 caliper (18005294 LH / 18008295 RH)
*** OR ***
'80 - '81 caliper (18006748 LH / 18006749 RH)
'79 - '81 proportioning valve (1257187)
'79 - '80 master cylinder (18005285)
*** OR ***
'81 turbo master cylinder (18008061)
*** OR ***
'81 master cylinder (18008060)
'79 - '81 emergency brake cable (10004675 LH / 10004676 RH)
'79 - '81 power brake booster (18004365)
'79 - '81 rear axle shaft (1263988)
'79 - '81 rotors (10005272)

Note that it's necessary to change the proportioning valve since a disc/drum valve meters only the amount of fluid going to the rear wheels while it maintains the same proportionate pressure differential between the front discs and rear drums. A 4-wheel disc valve varies both the amount and the pressure going to the rear. As the car brakes harder, this special valve decreases the rear brake pressure to prevent the rear discs from prematurely locking up the rear end.