We have all seen cars "laying frame" at local car shows and cruise nights, and at PHR we scratched our heads and tried to figure out the all-important question "why?" It wasn't that we didn't think the cars looked great slammed to the ground, or that we didn't see the benefits of being able to raise a car on demand in order to clear a speed bump or navigate a crappy road. What had us perplexed was why people would give up performance for what seemed to be a cosmetic example of form over function. Part of our preconceived thoughts on airbags came from how they were first used on hot rods. Back then, the only reason for using them was to control the ride height of the car and performance was not even part of the thought process. On our "to-do" list, the idea of putting on an airbag suspension was second-to-last only to sticking on a lowrider hydraulic deal.
Rumors had been circulating that our thinking might be a little out-of-date on this technology. It seems that Air Ride Technologies has been making great strides in bringing performance back into the equation of air-bagged rides and they were willing to put it on the track. Still skeptical, it wasn't until we were invited to an Air Ride Technologies track event that we began to see that maybe there was something to this besides the car show aspect. At the track, we got the chance to flog several cars equipped with Air Ride ShockWave performance air systems around Putnam Park Raceway with the likes of NASCAR drivers Steve Grissom, Mike McLaughlin, and Boris Said. Everyone came away with a new perception of how different today's air spring systems are from the show-bags of yesterday. Still, it was one thing to drive a car that has been extensively tweaked, but what we wanted was a direct comparison done with a car we had tons of baseline data on. It was then that Bret Voelkel, President of Air Ride Technologies, suggested installing one of their ShockWave systems on our g/28 project 1976 Chevrolet Camaro. The deal was made and a date was set to put their system to the test.
The plan was pretty simple. Air Ride would send out an install tech and g/28 would get the full Air Ride treatment, both front and rear. Air Ride Technologies had just released their Second-Gen Camaro system; we would be going with the 4-link Air Bar rear suspension and their StrongArm upper and lower control arm front suspension. Our window for getting this all done was very tight with only two days for the install and one day to test. The particular system we installed is "mostly" a bolt-in deal. The only welding required is the attachment of the upper-link gussets to the axle tubes and the only real cutting involved making room in the front coil spring pocket for shock clearance. These modifications are specific to our install and some Air Bar applications are true bolt-in deals. With the car on the lift, we supported the rear end and then removed the heavy leaf springs and shocks. The brackets for the links were then bolted to the underside of the car and the upper link brackets were welded to the rear end. Careful measurements need to be made at this stage to ensure that the pinion angle is kept correct and that the rear end is centered.
For the front install, the old A-arms were removed and a section of the coil spring pocket was cut away to allow for clearance of the wider front air springs. Nothing will kill an air spring shock faster than abrasion, so it's important to make sure that the bags do not rub at any point in the suspension travel. The rest of the front install is just like installing any coil-over system and is very straightforward. We also installed a new hollow Hotchkis front sway bar since this is what Air Ride offers as part of its package. The rest of the install involved running the wiring, air lines, and mounting up the equipment in the trunk. The 3-gallon air tank, compressor, and other parts do take up a fair amount of trunk space. If this was a Riddler show car or if we had more time, most of it could've been hidden, but we just wanted it to be functional and track day was fast approaching.
One other preconception many others, us included, had of air systems was that they're heavy and would add weight to the car. After all, you are adding a compressor, a tank, and a host of other equipment, how could it not weigh a ton? With this in mind we ran g/28 down to the local scale and got a baseline weight for the front, back, and whole car. The weighing was done without a driver and with the same tires and wheels in an effort to make it as fair as possible. Keep in mind that our baseline weight already included dearched leaf springs, lighter control arms, lowering springs, and high-performance shocks-so your weight may vary. The starting weight came in at 3,510-pounds with 2,010-pounds on the front axle and 1,490-pounds on the rear axle. After the install, we weighed the Camaro again and came up with a surprising result. The Air Ride system was not heavier, in fact, it knocked a lot of weight off the car. The results were 1,970-pounds on the front axle, 1,450 for the rear axle, and only 3,420 as a total for the whole car. The new exhaust system is a bit smaller, so of the 90-pounds saved, we figure 80-pounds of it was a direct result of the air bag suspension install. We wondered where the weight went until we thought about how heavy the rear leaf springs are and how light the front air spring shock is when compared to the stock shock and steel coil spring combination. We were surprised, but the scale doesn't lie.
With the system installed, the third day of the project proved to be a busy one. We had g/28 waiting at the alignment shop when it opened. The fact that we could easily raise the car's ride height sure made getting the usually low Camaro up on the rack easier. A fairly aggressive alignment was dialed in (about 1 degree negative camber- almost as much as in previous testing) and then we drove it over, open headers and all, to Lee at the Muffler Man in Placentia, California, for a little exhaust surgery. Being short on time, we decided to just shorten up the system and dump it before the axle. The four-link and associated parts do allow for an over-the-axle system, but it's a tight fit and, to be honest, the Camaro sounds better now anyway. With daylight burning, we hit the scale, then headed off to California Speedway in Fontana for our noontime track date.First up was a trip through the slalom cones. Technical Director Nick Licata set up the 420-ft slalom course and wired the test equipment so we could start getting a feel for the new suspension. The initial settings on the front double-adjustable shocks were set to "7" for rebound and "3" for compression. After that, the testing commenced. Six runs quickly netted us a best time of 46.41 mph and we were pretty happy with the overall feel of the car. Right out of the gate, g/28 had bettered its best-ever slalom speed (46.2 mph) with the previous performance-oriented suspension. But was there still more in it? To answer that, we then tightened the rear shocks, from the initial setting of "3" rebound and "1" compression, two clicks to make them a little firmer and once again launched g/28 though the cones. This got us a best speed of 46.13 mph, but the back of the car felt a bit stiff, so we backed the rear shocks down to a setting softer than the initial settings, with "5" rebound and "3" compression. After six runs, our best speed was a slower 45.51 mph, so we decided to go back to the initial settings for the balance of the day. Bret Voelkel of Air Ride Technologies wanted a little time behind the wheel so Hunkins handed over the keys. After a couple runs, Bret impressed us by knocking down the best speed of the day with a clean 46.48-mph run. While these runs look only marginally faster than our previous best, it should be noted that we got these numbers much easier this time, and the control of the car was vastly improved.
Next up was the skidpad test. The 200-foot skidpad is done both clockwise and counter-clockwise with the best times in each direction being averaged together. The best g-force counter-clockwise was .932g and the best time clockwise was a .948g. Average them together and you get an even .94g. Again, this number was dead-even with the best we were able to get out of g/28 with its previous set-up. Considering how little tuning was done with the ride height, corner weights, and shock valving, we'd have to say the Air Ride suspension is marginally better right out of the box. There is more performance lurking inside the suspension-we just haven't spent the time to unlock it.
Overall, we were very happy with how the system went together and performed. Even though some welding was required, the install was simple and not beyond any competent "car guy" to do. The ride quality of the car on the street was vastly improved and the performance of g/28 wasn't degraded in the least bit. The fact that we managed to shave 80-pounds off the car was just icing on the cake. Keep in mind that what we swapped out was not a stock suspension but an upgraded performance set-up that we had tweaked over the course of several track sessions. For detailed information on previous suspension installations and track test data, visit www.popularhotrodding.com. Given our time constraints, we were only able to do minimal tuning and didn't adjust tire pressure beyond a baseline setting of 35psi. In the hands of a competent tuner there will be some serious performance improvements.
The only fly in the ointment is that the complete ShockWave system is not a cheap date. Every install will typically involve three part numbers: a front system, a rear system, and a compressor system. The rear Air Bar 4-link system (part No. ABAR20500) has a suggested retail price of $1,995 and includes the air springs. The front Shockwave 1000-series system complete with StrongArm upper and lower front control arms (part No. 1037-LUCA) runs around $1,495 and the RidePro compressor kit (part No. ARC4000e) lists out at $1,099. That brings the total to $4,589 for the complete front and rear suspension. You can save about $650 if you forego the upper and lower control arms. For those who want the flexibility that Air Ride Technologies offers, at least they know that they will not have to sacrifice performance to enjoy a high-tech ride.
Driving Impressions
PHR has featured plenty of air-bag equipped cars over the years, sometimes to the detriment of the magazine's performance reputation. Bottom line: lots of guys will just ignore a car with air bags as "poseur." We admit to having the same personal bias. Nevertheless, after years of gentle persuasion by Air Ride's Brett Voelkel, we finally agreed to drive some Air Ride-equipped cars on a road course. But like that dude in Green Eggs And Ham, we weren't super happy about it. That all changed after the first lap at Putnam Park Raceway. Since then, we've been angling to get an Air Ride system on Project g/28. So here we are. We noticed from the first street mile how well-mannered the Air Ride system is. There is apparently a small enough volume in the air spring such that the ride is not harsh at all (the spring rate of an air spring is roughly proportional to its volume). We then wondered: would softer spring rates effectively take the edge off g/28? All we can say is that Air Ride must've done its homework, because the range of shock valving is complimentary to the spring rate, neither over-controlling the air spring nor being overcome by it. The companion Hotchkis sway bar likewise works well to flatten the front of the car in corners. We still have yet to need a rear sway bar (second-gen Camaros seem to work better without one).
In testing, we noticed right off how sharp the cornering response was, although that must be partly attributed to our new Flaming River steering box. The recommended shock settings are pretty well dialed-in too, with our best results coming with those. Changing those settings (at least for the rear) does invoke a noticeable change in how quickly the rear sets into a "bite" mode. To wit, longer slalom gates (equating to higher speed corners) would almost surely require softer settings and shorter gates (similar to slower, autocross-like corners) firmer settings. Our second-gen Camaro project car goes exactly where we point it, which is comforting.
The only remaining question is to determine what the effect of ride height (i.e. air spring volume) has on spring rate. In theory, a lower ride height equals less spring rate, which is exactly the opposite of what you get when you cut a steel coil spring. Added to the lower spring rate is also the effect of a lower center of gravity, which makes it impossible to completely divorce the effects of the two. So far, neither has been a detriment to the handling of g/28: it works as well on the track as it does on the street. --Johnny Hunkins
