Muscle Mustangs & Fast FordsEvents
Five Cobras, 10 corners, one straightaway-- how suspension affects auto crossing and drag racing.
Over the past decade, autocrossing and open track road racing has grown in popularity among Mustang owners. Controlling your car in the tight confines of an autocross, or at high speed on one of America's race circuits, is more fun than one should be allowed to have on four wheels.
And while many Mustang owners look at this as something they can't do, all it takes is some time and effort and you can be cutting corners with the best of them. Naturally, tossing your pride and joy around at high speed takes a balance of driver skill and a well-prepared car, but rising to the challenge can be made a reality--even I can do it. And with organizations like the SCCA, and schools like Track Time Driving School to help racers along, learning to carve corners is easier than you may think.
As readers of MM&FF know, straight-line acceleration ranks up there pretty high with us, but our demented staff also like Mustangs that can turn quickly and produce serious lateral g-forces (even when you're not running from the cops). In the past few years we've arranged shootouts that pit man and machine against our tight but very quick autocross, then we test the vehicles on the strip to see just how many Camaros they can bash in the stoplight grand prix. This allows us to evaluate virtually all aspects of how you build your cars.
For this exercise we grabbed our cones, helmets and timing gear and then we gathered five distinctly different SVT Cobras for a day at the track. Dave Spear of the NESCOA (Northeast SVT Cobra Owners Association) offered to line up a group of capable Cobras, all with mostly stock engines but different suspension modifications. According to Spear, "The NESCOA is currently the largest organized group of Cobra owners in the northeast. Our organization is involved in all forms of racing (open track, drag and autocross) as well as car shows, dyno days and cruise nights and some spirited bench racing." We set a date and told Mr. Spear to bring 'em on.
On a fine day at the end of May we met with Dave Spear and his posse of Stang Bangers at Old Bridge Township's Raceway Park. Next we set up the autocross course, which incorporated 10 turns and a fairly long straightaway and let the owners wring out the bugs. The tight design of our track enabled us to sample the acceleration, braking, and of course, each vehicle's level of grip. This particular track also featured (though not by design) a few dips in the pavement, some rough spots in the road, and some broken asphalt. Ironically, this allowed us to drive over various road surfaces and get a feel for the compliance (or tire grip) of each vehicle.
Spear did a fine job assembling the stable of Cobras that included a variety of stock, modified and all-out Stangs. Before the day was done we tested the latest Kuhmo V700 tires (size P275/40ZR17), which proved to have unbelievable grip. Amazingly, the Kuhmos knocked as much as three seconds off some lap times.
OK, enough talk, let's get to the results. But wait, there's one last thing: if you'd like to get your Stang, or other funky Fox flyer, in a MM&FF shootout, get out your camera and send us some information regarding you and your car. We're looking to do a comprehensive autocross/drag strip/highway shootout. We'll accept between 5-8 Fox or Fox-4 body cars (1979-present), and they must be street legal and capable of handling a day at the strip and a day on the autocross. Each car must also be clean, because we will be shooting color film. Interested parties can contact MM&FF Ultimate Shootout, 299 Market St., Saddle Brook, NJ 07663.
Comments: The combination of softer springs and the independent rear suspension made Mike Carr's '99 Cobra very easy to drive on the autocross course. With IRS, the rear tires follow the road independently, so they have improved adhesion in turns, especially over rough portions of our course. Additionally, I feel the independent rear kept the back of the car flatter in the tight turns, which allowed me to get after the throttle sooner than I could in the live axle stock suspension Cobras.
Recently, I drove a stock 2001 Cobra convertible, and I was amazed by how loose it felt compared to Carr's Cobra. What a difference the addition of subframe connectors and the 4-point roll bar makes. I highly recommend both of these in any convertible that will see track or hard street duty.
With just the chassis stiffening, the Cobra convertible was stable and responsive. Overall ride quality is excellent, yet the car can hold its own on the autocross. The balance of the stocker leans more towards understeer, but there is sufficient power to throttle oversteer if necessary. I must also mention that the '99 had some brake dive, but even so, the stock brakes hauled the car dow handily. After lapping the car on the stock tires, Carr swapped on a set of Kuhmo 275/40ZR17-inch tires mounted on Cobra R wheels and that's when the real fun began. I was floored at the level of grip, or, should I say, the lack of slip with the Kuhmo tires. My lap times dropped by almost two seconds and that is quite a bit on a short course.
Carr told us his Cobra is a "race ready package" that he can race on the weekends and drive to work during the week. He competes in SCCA ESP (Solo II) and has run his car at Watkins Glen, Lime Rock Park and New Hampshire International Speedway. In addition to the Cobra, he's previously owned a '99 Contour SVT and a 1979 Mustang Pace Car.
Comments: Due to mechanical problems with the cooling system, I only accumulated a handful of laps in Clancy's Cobra. His snake was the raciest of the bunch and we would have loved a fair shot at the autocross, but we could only rip off two laps before the engine temperature went through the roof (read: past 240*). A check under the hood revealed that the upper radiator hose was cool to the touch, so we assumed the thermostat was stuck closed.
Letting the car sit for a while got the temperature back down to a normal reading, but it shot back up within minutes of running the engine so we decided to park it rather than risk a blown head gasket, or worse.
Nevertheless, we did sample the hopped up Cobra, if only for a moment. In our short evaluation, we noticed that the car's handling was neutral thanks to a Griggs Torque Arm, 350-lb. front springs and the Koni struts and shocks, which meany the car didn't favor either understeer or oversteer. The torque arm drastically reduced nose dive under hard braking, which, in turn, kept the car flat. This, combined with the Cobra R Brembo brakes, helped to get the car set up when exiting the turns and allowed me to get in the gas much quicker, thus reducing lap time.
While we offered to let Clancy's Cobra sit out the drag strip portion of the test, the owner decided to let the engine cool w-a-y down and then he flipped us the keys. Despite a 45-minute cool down, the engine heated up quickly and our only shot at the strip was a modest 13.58 at 104 mph.
"I liked the technology in the 4.6 Cobra," says Clancy. "I read about them in magazines and one day I said what the heck, and traded in my rice burner for a '96 Cobra. I went out to Bridgehampton with only 600 miles on the odometer and I was hooked. The car stayed in stock trim for two years and after a few open track events I made most of the modifications. Eventually I entered the Silver State Classic and set the car up in full race mode. Now I run in the Grand Sport class with an average speed between 145-150 mph. So far I've run two events and have finished fifth and sixth."
According to Clancy, future plans include more power and a move to the Unlimited class where he will make a run for the 200-mph barrier.
Comments: When I first met Chris Connacher he had a big smile on his face. He exclaimed, "I think you're going to like the way this car handles. It has 1000-lb. front springs, 350-lb. rear springs Koni shocks and struts, and it really turns."
Ummm, 1000-lb. front springs. So that's why he was grinning. But wait, it gets better. Connacher's '97 model is Rio Red and the interior features super-rare cloth Cobra seats. Neat, right? The driver is held in place with a M&R 5-way harness that's secured by a harness cross brace and inside you'll also find Auto Meter gauges, a Hurst shifter and aftermarket pedal pads on the clutch and brake.
The engine is stock, however there is a custom ram air, a K&N filter and two-stage, 150-horsepower nitrous kit from NOS on board, but we resisted the temptation to hit the juice during our testing.
When it comes to the handling of his machine, Connacher did not lie. His Cobra cuts into the turns like a go-kart with no body roll to speak of. Turn the wheel and this car turns in instantly. The Kuhmo V700 tires did a great job gripping the track, though the car proved to be set up a bit stiff for our tightly laid out autocross, and at the limit it wanted to understeer. From past experience we know this suspension combination is much better suited to a smooth open road course where you can build lots of speed and take the turns with high velocity. It seemed that our slightly rough parking lot test track tried to upset the stiffly sprung car, hampering the ability for the Kuhmos to maintain constant grip.What I really liked was the quick steering response, especially because I was driving the car on an autocross track. Having the ability to turn in quickly allowed me to run hard at each corner before squeezing hard on the brake and getting the car rotated around the cones. The Cobra brakes did a fine job, and with PRB pads in the front and Hawk Blue pads in the rear, I experienced no brake fade.
"I like the Cobra because it has it all--power, handling and braking," says Connacher. "I first attacked the suspension, lowering the car with Ford Racing C springs; however, I found the C springs to be too weak so I upgraded to Griggs 1000-lb. springs in the front and 350-lb. springs in the rear. I had to dampen the springs properly, so I installed Koni DA Yellow springs and struts. I also installed polyurethane bushings to tighten things up."
Not one to just beat up cones, Connacher races with the COM (Corvettes Of Massachusetts) car club. With the current modifications, the Cobra runs in the ST-1 where Connacher has recorded a best lap time of 1:03.03 seconds at Lime Rock Park in Connecticut. Connacher competes against Porsche 911s, BMW M3s and Nissan 300ZXs.
His hard work paid off because the 1.03.03 time placed him first during a recent event at Lime Rock time trial event. He also won recently at Summit Point in West Virginia and he is leading the points in ST-1.
"I set up the car to be mostly neutral, but so it will oversteer at the limit," Connacher told us. "My other goals for the car are to run 11.50s in the quarter and to win a championship in my racing class."
Comments: Vincent Recca loves his Cobra. So much in fact, that it's his only car and he drives it everyday. The Chrome Yellow Snake is also raced on the weekends and kept out in front of Recca's house. It's no garage puppy.
Like Mike Carr's convertible '99, Recca's model is almost 100 percent stock. Okay, it features a Ford Racing billet flywheel, Apex Motorsports kevlar clutch, K&N filter and Crane 8.8mm wires, but otherwise it is stock as a rock. But being stock isn't so bad--if you're a Cobra Mustang.
The model Recca wheels is more softly sprung than the other cars we tested and this allowed the yellow car to absorb the bumps and bruises in the autocross, thus keeping the tires planted on the road. I found the stock suspension easy to drive, mainly because the car was predictable. I could drive the car at the limit of the brakes and the suspension without losing it.
We made quite a few laps on the autocross, all the while trying to compare this car to the stock convertible with IRS. Being a hardcore drag racer, I love the solid rear axle, but I have to admit, the IRS was better at slicing turns. It clearly showed its stuff by keeping the back of the car more flat and in sync with the pavement.
Additionally, the higher ride height in Recca's '98 (compared to the lowered cars) produced more nosedive than we would have liked during hard braking. When the nose drops under braking, the sprung weight is transferred to the front and the rear tires lose grip. With this, the car had a tendency to oversteer or fishtail. This isn't a problem in everyday driving, but it's not the best for autocross or open track racing.
Unfortunately, when we headed over to the drag strip, the yellow Cobra developed an engine miss. Recca tried to solve the problem, but he couldn't get the 4.6 to rev smoothly and all I could muster from the bright car was a rather slow 14.34 at 98 mph.
Future plans for this '98 include a full Griggs suspension and then perhaps more horsepower.