In last month's issue, we introduced the '79 Trans Am that was the subject of our suspension upgrades and the parts included in the build. This month, we wrap up the installation and compare the results of before and after testing.

Our partner in this build was Pro-Touring F-Body (PTFB). "Whether your Second- Gen is a driver or destined to compete in a myriad of road racing venues, our line of suspension kits and chassis components can assist," says PTFB's owner Dave Masello. "PTFB was born from my obsession to make my Second-Gen Trans Am handle on par with the best Pro-Touring setups on the market, but at a budget price. The ability to engineer parts that raise the bar for the platform and still provide individual customer service sets us apart."

Hang on as we finish up the installation and test the combination. Will the Bandit-era Trans Am eat up the road without eating up our project budget? Read on and let's find out.

The results

For a conservative investment in the suspension and the right combination of wheels and tires, the Second-Generation Trans Am can easily surpass the best stock Fourth-Generation Trans Am and push upwards of 0.90 g's.

During baseline testing, it became painfully obvious to us that the Trans Am's BF Goodrich Radial T/A tires on 15x8-inch factory wheels were very close to being maxed out on lateral grip. Swapping the wheels to 17-inch replacements and wrapping them in BFGoodrich Comp-2 tires increased the lateral g's by 0.06.

The biggest handling deficiency turned out to be the original body and core-support bushings. According to Dave: "Enthusiasts usually overlook a suspension in their quest for performance, but much like the results with the smaller wheels and tires, increasing power without the hardware to turn it into forward motion is not dollars well spent. For the vast majority of enthusiasts, simply changing to a solid body bushing will not result in a stiff, jarring ride if done in conjunction with our subframe connectors. Build a solid foundation and then put the power to it."

Although higher average g's would have looked better, our testing did not have the luxury of a professionally groomed race track. After seeing results lower than expected, we brought out a new Cadillac CTS-V to establish an objective baseline, and it averaged 0.79 lateral g's. (Motor Trend recorded a 0.91 g average with the same car.) Knowing that we were up against test-surface deficiencies, we focused on measureable gains, not the overall g's. The gains from the larger tire section width and stiffer sidewall were well noted in the baseline test (from 0.76 to 0.82), but an additional 0.05 g's were attributable to the suspension changes.

When all was said and done, the Trans Am not only looked the part of a well-handling street machine, but turned in numbers that bested stock Fourth-Gen WS6 handling results. The investment in the suspension increases the owner's driving experience and sets the foundation to effectively use future power increases.

Ride Height Before and After
Ride Height (in inches) Stock PTFB
Front Left 25.25 24.875
Front Right 25.25 25.25
Rear Left 25.25 25.25
Rear Right 25.00 25.50
Note: All measurements were made from the bottom edge of the wheel to the bottom edge of the fender. The new Pro-Touring F-Body suspension could potentially settle more.

Stock-Radial T/A Modified-Radial T/A
Slalom MPH 55 60
*Lateral g's (avg.) 0.76 0.77
Stock YO/Comp2 Modified YO/Comp2
Slalom MPH 62 65
*Lateral g's (avg.) 0.82 0.87
T/A-Testing Tire Pressure RF/LF Tire Pressure RR/LR
Stock Radial TA 38.0/38.0 38.0/38.0
Modified Radial TA 38.0/38.0 38.0/38.0
Stock BFG Comp2 35.5/35.5 35.5/35.5
Modified BFG Comp2 30.5/30.5 34.0/33.5
All pressures noted are optimal pressures achieved during best runs.

Test Parameters

Testing was conducted on a 600-foot slalom course and 200-foot skidpad. Both courses were concrete rather than asphalt, and had incongruities inherent in them that would affect the results compared to dedicated testing facilities run on asphalt that were perfectly flat and concentric. In order to determine if the slalom and skidpad were skewing the results, we utilized a '13 Cadillac CTS-V wagon to benchmark against published tests and then adjusted the skidpad numbers to be reflective of a standard course. No adjustments were made to the slalom numbers.

Benchmarks
'13 Cadillac CTS-V Wagon
Slalom mph 67
Slalom mph N/A
Lateral g's (avg.) 0.79 (unadjusted)
Lateral g's (avg.) 0.91
*Adjustment Factor 1.422
'76 Trans Am
Slalom mph 54.9
Lateral g's 0.785
'00 Trans Am WS6
Slalom mph 64.6
Lateral g's 0.84

Tools and Supplies
Prybar Cut-off wheel Penetrating oil Metric socket set Metric wrenches Torque wrench Drill and drill bits Pole jack Floor jack

Torque Specifications
Fastener Torque (ft-lb)
Bolt: shock-absorber lower retaining 10
Bolt: shock absorber, upper retaining 20
Bolt: spring and shock absorber anchor plate 40

Wheels and Tires

SOURCE
Year One
PO Box 129
Tucker
GA  30085
800-932-7663
770-496-1949
http://www.yearone.com
Whiteside Customs
2421 E. University Drive
Building 2112
McKinney
TX  75069
972-542-0255
http://whitesidecustoms.com/
Pro-Touring F-Body
847-594-9021
http://www.pro-touringf-body.com
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