The subsequent journey to Silver Dollars quarter mile proved much more successful. After the previous fiasco, everyone associated with the project was looking for the Camaro to make a good showing, not only with respectable ET and mile per hour numbers, but also with respect to whatever type of vehicle was in the adjacent lane. But Murphy and his Lawyers appeared to be at work once again. As the Hard Rock Camaro rolled into the water box, a nasty sounding Mustang pulled up along side. Here we were with a mild Tuned Port engine running through a complete exhaust system, including catalytic converters, and the car in the next lane rumbles up with open exhaust, an obvious over-abundance of camshaft duration and a probable over-abundance of horsepower. Evidently, the Camaro would be humbled once again.
But as the lights flicked green and the Mickey Thompson ET Drag slicks bit into Silver Dollars concrete surface, the Mustang appeared to be traveling backwards and was thereafter visible only in the rear view mirror. Thankfully, the time slip proved it was definitely not an illusion. The Camaro had tripped the win light with a 12.997-second elapsed time at a speed of 105.54 miles per hour while the Mustangs full gallop managed only a 13.223 ET at 103.97 miles per hour. A second pass proved the first one wasnt a fluke as the Hard Rock Camaro tripped the timers at 12.950 and 105.96 miles per hour.
That was more like it. All the preparation, blood, sweat, tears and expletives (lots of expletives) had paid off. With an appropriate baseline established, additional tuning and fiddling would certainly result in even more impressive performance. According to a number of computer modeling programs, (Quarter Jr and Drag Strip Analyzer) the Camaro was capable of clicking off ETs in the 12.40-12.50 range, so the next step was to get it headed in that direction.
Like most late model vehicles, Third Generation Camaros retain a lot of underhood heat which ultimately has a negative affect on horsepower. To cool things off, the stock thermostat was replaced with a Hypertech 160-degree model and the Manifold Air Temperature (MAT) sensor was relocated. In Tuned Port systems, the original mounting position for the MAT sensor is in the bottom of the plenum. Since the entire plenum/runner/manifold assembly acts like a giant heat sink, MAT sensor output is typically biased so it sees a higher temperature than that of the incoming air. To rectify the situation, Howell Engine Developments, a respected manufacturer of custom wiring harnesses for fuel injected engines, offers a remote MAT sensor kit which includes a thermistor-type sensor and harness. Approximately six feet long, the harness has the correct connectors on both ends, so one end plugs into the supplied sensor and the other into the vehicle harness. Installation is so simple, even a magazine editor can do it.
Remote mounting of the sensor was of particular importance because we had just installed a Random Technology ram air system. Consisting of two lengths of 4 flexible ducting and two flanges which, in essence, allow the insertion of a round peg into a square hole, the Random Tech system brings cold outside air from behind the fog lights directly to the air cleaner elements. Installation of the system requires removal of the air cleaner trays bottom section and modification of the hard plastic ducts just behind the fog lights.
During initial check-out, the modifications effectiveness was immediately apparent. Using Diacom software to monitor ECM operation, it was readily apparent that heat soak was much less of a problem. Rather than climbing 30 or 40 degrees after the engine was turned off, manifold air temperature rose only 10 or 15 degrees. And after just a few minutes of normal driving, manifold air temp dropped sufficiently to be virtually identical to ambient air temperature. At the track, the effect was even more dramatic as the on-rush of air instigated by a throttle body gaping wide open brought MAT readings down to ambient within seconds.
There was never any doubt that horsepower varies in direct relationship to air temperature and testing with the Random Technology ram air system proved it once again. Cooler air and more accurate temperature measurement, combined with the ram effect at higher speeds, dropped elapsed time to 12.665 at 107.90 miles per hour-- in spite of a 20-degree increase in ambient air temperature compared to the last test session.
Another aspect of vehicle operation that called for updating was transmission shift point. If left in Drive during a quarter-mile run, shift points are determined by a mechanically perverse device known as a governor. As with most pre-electronic GM automatics, the 700R-4 governor employs a pair of springs in combination with counterweights to control shift points. When tuned properly, the spring/weight combination moves a plunger, which alters a hydraulic circuit which causes the transmission to shift at the desired engine speed. But having cut my driving teeth in vehicles with three pedals and a shift lever, Ive never felt comfortable having my destiny controlled by refined crude oil.
Manually shifting a transmission puts the driver back in control, but the original equipment shifter is bereft of the detents that allow gear changes to be authoritatively commanded during the heat of competition. Conversely, the appropriate Hurst Quarter Stick shifter (part no.3160082) not only puts precise gear control at hand, it also fits in the original console. Installation requires a small slot to be cut in the console (to accommodate a reverse lock-out lever) and a hole to be cut in the floor pan (for the shift cable) but is otherwise accomplished with standard hand tools. (With this particular car, the wires for the neutral safety switch also had to be lengthened.)
To make sure the driver knew precisely when to demonstrate unerring hand/eye control, an Auto Meter Shift Light (part no. 5340) was installed on the dash. Rather than relying on a tachometer needle, which requires some amount of thought processing, a shift light requires nothing more than a Pavlovian response (see light, move lever) which implies that even a canine can be taught to drive a race car.
Another aspect of quarter-mile performance is tire preparation prior to leaving the starting line. For slicks to bite properly, they must be warmed to the point that oils in the tread rubber come to the surface. Hence the necessity of a properly executed burnout. Aside from generating an abundance of smoke and increasing tire sales, burnouts with true street tires (as opposed to DOT race tires) are useless because the tread compound doesnt contain the oils that increase a slicks stickiness. (With street tires, only a light burnout on dry pavement-- just enough to clean the tread-- affords the best traction.)
Considering the effect on rear brake life, its not particularly efficient to hold a car in the water box using the brake pedal, so a device that was once known as a line lock (but cant be called that any more because its a registered trademark) is commonly used. Installation of such a device used to be relatively simple, but late model Camaros are blessed with brake lines having metric bubble flares, rather than conventional inverted flares.
The TCI Roll Stop that was plumbed into the Hard Rock Camaros front brake system required a hydraulic line with a metric bubble flare on one end and a standard inverted flare on the other. This may be accomplished by purchasing a brake line with bubble flares from an auto parts store, cutting it to length, and flaring the opposite end.
Once the hydraulic lines are connected and the brakes bled, a Roll Stop or other generic front brake locking device requires only two electrical connections to complete the installation. A wire caring 12-volts must be connected to one of the actuating switchs leads and another wire must be run from the other switch lead to the appropriate one on the Roll Stop solenoid. A third wire, from the solenoid to ground provides the necessary current path when the switch button is depressed.
The Roll Stop does exactly what its name implies, so when the Hard Rock Camaro is driven into the water box and the Roll Stop button is depressed while the brakes are locked, it prevents the front brakes from releasing. As a result, when throttle is applied, the rear tires are free to spin rubber into smoke, growing hot and sticky at the same time. While such burnouts do wonders for traction, they can prove as deadly as a well-placed grenade to a rear end.
According to Jerry Francis of Mickey Thompson Performance Tires, the correct procedure is to begin a water burn-out in first gear, shift to second and stay on the throttle for two to three seconds (this will vary with vehicle and tire size). As the brakes are released, the drivers foot should be off the throttle so that the car rolls, rather than drives out of the water box. Staying on the throttle too long (allowing spinning slicks to bite into drive pavement) can lead to a loud thump, and pieces of metal being deposited on the track surface. (This is an especially important consideration in vehicles equipped with a 7-1/2 10-bolt rear end.) Francis also notes that once a burnout is completed, a set of tires is at its stickiest. The tires therefore give their all the next time theyre asked to grab a piece of pavement. Doing a dry hop simply decreases the traction available at the starting line.
Another trick that pays improved performance dividends is locking up the mechanical clutch inside the torque converter. Under normal circumstances, Torque Converter Clutch (TCC) lockup is controlled by a vehicles ECM which does not apply it at wide open throttle. But by rewiring the TCC circuit, so that its under the control of a manual switch, (easily accomplished using TCIs Universal Lockup Kit, part no.376600) a torque converter clutch can be locked in 2nd, 3rd or 4th gear, irrespective of throttle setting. (Internal circuitry prevents TCC lock-up in 1st gear.)
Testing has routinely demonstrated that locking the converter is worth a tenth and one mile per hour in quarter-mile times. If a vehicle is still in possession of its original wiring, the torque converter can be forced to lock by simply installing a jumper wire between terminals A (top row far right) and F (top row far left) on the ALDL. Although this works perfectly most of the time, the jumper can fall out so in the Hard Rock Camaro, the switch that formerly controlled the fog lights was rewired to control TCC lock-up through the TCI Universal Lockup kit. After a burnout is completed, the switch is flicked on and the converter locks as soon as the transmission is shifted into 2nd gear.
The aforementioned modifications proved useful not only in lowering elapsed times, but also in improving launch consistency. The Hard Rock Camaro now recorded 60-foot times ranging from 1.735 to 1.746 while quarter-mile elapsed times dropped to 12.484 seconds while trap speed bumped up to 108.30 miles per hour. We still have a few more tricks in store, before the Hard Rock Camaro goes under the knife for some constructive surgery, but thats a story for the next feature.
Auto Meter Products Howell Engine Developments Hurst Performance Hypertech Inc. K&N Engineering Mickey Thompson Tires Performance Trends Racing Systems Analysis P.O. Box 7676 Random Technology Rinda Technologies Silver Dollar Raceway TCI Automotive
413 West Elm Street
Sycamore, IL 60178
6201 Industrial Way
Marine City, MI 48039
8700 Brookpark Road
Cleveland, OH 44129
1910 Thomas Road
Memphis, TN 38134
561 Iowa Ave.
Riverside, CA 92502
4670 Allen Road
Stow, OH 44224
P.O. Box 573
Dearborn Heights, MI 48127
(Drag Strip Analyzer program)
Phoenix, AZ 85011
(Quarter jr. program)
1313 Temple Johnson Road
Loganville, GA 30052
5112 N. Elston Ave.
Chicago, IL 60630
P.O. Box 512
Reynolds, GA 31976
One Equion Drive
Ashland, MS 38603
Howell Engine Developments
Mickey Thompson Tires
Racing Systems Analysis P.O. Box 7676
Silver Dollar Raceway