5.0 Mustang & Super Fords
1999 Mustang Cobra Drag Test
Takin' The Snake To The Track
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We first introduced you to the '99 Cobra in our May issue ("Independent Thinking," p.36). That first meeting took place with special pre-production units that SVT had invited us to sample for your reviewing pleasure. Of course, with a limited touring course already laid out for us, a stop at the local digs was out of the question. So, while our initial opinions of the Cobra were good, we never had a chance to wring one out on the quarter-mile. Reports from testing done on prototype cars were promising, with 13.70 e.t.'s at over 100 mph. But prototype and production are worlds apart, and with the road race-inspired independent rear suspension (IRS) tossed in, we weren't sure what would happen. Unlike our first story about the '99 Cobra, this report will not deal with the overall aspects of the car, but rather focus on only those attributes, good or bad, that affect the Cobra while racing on a dragstrip. Straight-line freaks, this one's for you!
Getting the Car
Since the Ford press fleet was dragging its feet on getting a Cobra for us to test, the first hurdle we had to get over was finding an SVT dealer brave enough to allow us to borrow one. Fortunately for us, the same enthusiast attitude that makes cars like this possible is alive and well at the dealerships that sell them. Two people were key in getting this story to our readers: Paul Faessler of Paul's Automotive Engineering (Cincinnati, Ohio), and Jerry Rosenwald, the sales manager for Bob Williams Ford in Cincinnati. Paul runs one of the most well-prepared Mustang shops in the country with over 15 years of experience in restoring Cobras and Shelbys, cars that individually can be valued at more than a million dollars. Today, you're as likely to stumble across a blown '98 Cobra as you are a vintage Shelby within the confines of Paul's 20,000-square-foot facility. Jerry is a long-time friend of Paul's who instantly realized the value of letting us thrash the latest flagship Mustang that Ford (and his dealership) has to offer. With the SVT dealership title starting to lose its exclusivity, Bob Williams Ford is also making a statement about how they relate to the true enthusiast in all of us.
We've seen near-stock '98 Cobras go 13.40s under the best possible conditions. With a bump in both horsepower and torque to 320 and 315 respectively (thanks to new heads and intake), hopes were high that the '99 Cobra could better those numbers. The question of how, and if, the newly designed IRS could take the demands of drag racing was on everyone's mind. Add in the option of turning on the Traction Control with the more compliant IRS, and we had a lot of testing to do. Paul and yours truly met with Jerry at Bob Williams Ford on a Thursday night in early May to pick up the new Cobra. Low and behold, our Cobra was bright red, a very popular color with our editor. We traveled about three miles to Paul's Automotive Engineering and got down to business on Paul's chassis dyno.
The Chassis Dyno Test
Unlike most drag tests that you read about, we wanted to take a look at how the new 4.6 motor made power before we went to the track. The strategy was to use what was learned on the dyno to enhance on-track performance numbers. Plus, we thought our readers might like to know what a 13-mile-old Cobra makes on the chassis dyno. As you will see, we learned some valuable information about how these motors work and where they like to operate to make the big power.
With our fingers crossed, we blasted the Cobra to 7,000 rpm and started collecting data. The first pull was less than spectacular, to say the least--238.9 hp and 252.3 lb-ft of torque. Everyone was a little concerned that this thing did not make the power that we had hoped for (we had heard rumors of 270 hp at the rear wheels), but with the low amount of break-in miles, our test Cobra was as tight as they come. It could be reasoned that the more we ran this thing the more power we would get as the motor broke in and the tranny got loose. We continued on with a second pull in as-delivered condition. This time the Cobra sang out to 248.2 hp and 261.2 lb-ft of torque, suggesting that the first pull was just a warmup.
For the third pull, we removed the intake air silencer and the result was 247.2 hp and 261.2 lb-ft. For pull number four, we yanked the air filter and air filter housing and left the mass air sensor just hanging there. (With the controlled environment of the chassis dyno, we could keep engine compartment temperatures lower than they would be during normal street driving). We also let the Cobra sit for15 minutes. The chilled 4.6 picked up to the tune of 256.8 hp and 268.1 lb-ft.
We went to extremes for the next pull, icing the motor and mass air for almost an hour. We waited until the intake, valve covers, and heads were cold to the touch. A note here: Unlike 4.6 Cobras from '96-'98 which were equipped with a heat shield on top of the intake, the new '99 intake is very receptive to icing, just like the 5.0s of yore. The fifth pull resulted in a rewarding 266.6 hp with a thumping 285 lb-ft of torque. Bottom line: Ice the hell out of a '99 Cobra, and you will get an increase of at least 10 hp and close to 20 lb-ft of torque. An immediate back-up run cost us 2 hp and 3 lb-ft of torque as the engine started to regain some temperature.
As for the power band, we already knew that these motors are rev-happy freight trains that don't really come to life until 4,000 rpm. We would later realize that this point, where the torque and power band come alive, is right where you want to be when you launch this sled on the starting line.
The Drag Test
Our drag test was a pressure cooker, because we had only one weekend to figure out how to drive it to get the best numbers. With yours truly squeezing the trigger on the camera, Paul was chosen as our best bet to immortalize the '99 Cobra. As we soon found out, this car is extremely finicky with the launch, and it takes a real understanding of what is going on with the entire package to get the best e.t.'s out of it.
Paul and his head mechanic Mike Wilson loaded up the Cobra, and we were off to Tri-State Dragway in Cincinnati for a Saturday afternoon test and tune. The weather was surprisingly conducive to building horsepower, with a relatively low level of humidity, 65-degree temperature, and slightly overcast skies. While a few raindrops would slow the opening of the track, the only thing that hampered our testing was a 15-mph headwind throughout most of the day. Before we even unloaded the Cobra (complete with the new-car window sticker), it caused a stir with the locals, especially among those hip to the pedigree of the car.
Tire pressure was set at 50 psi for the front BFGoodrich Comp TA radials, and 30 psi for the rears. We allowed Paul to take a few practice runs to get accustomed to the tight chassis and high-revving motor of the Cobra, while the traction compound was worked into the starting line concrete by the big-tired cars. Right from the start, we knew it was going to be a long day. Despite Paul's best efforts, the Cobra was having a hard time handling massive applications of power while trying to dig in and accelerate.
The first official pass was a spinning 14.864 e.t. at 95.52 mph, with a terrible 2.51-second short time. Hot lapping the Cobra, Paul was quickly learning how to launch this thing as the Cobra ran a 14.528 e.t. at 95.72 mph, with a 2.28-second short time. A third pass under the same conditions netted a 14.46 e.t. at 95.79 mph, with a better 2.25 short time.
Two things bothered us immediately. First, the mph sucked! Only 95 mph from a 320hp car? Come on. Sure the motor and trans were brand-new, but we simply weren't seeing the power that Ford promised. Second, to launch a '99 Cobra, you have to be incredibly patient. There are several reasons why this car doesn't want to work on a dragstrip. The biggest is that the suspension is designed to keep the car in a neutral position at all times. This is great for road racing, but it's the kiss of death for a drag car. Paul was launching at 2,800 rpm while slipping the clutch to get it moving. There simply isn't enough gear or torque once the clutch hits to keep the car rolling. On the other hand, get too aggressive with the clutch and the tires go up in smoke as the IRS rocks the nose back to an even position, unloading the tires.
While there was little we could do about the tire spin other than continue to experiment, Mike got down to business trying to get this thing some power. Out came the entire air filter assembly just as it had on the dyno. Mke also plopped bags of ice all over the motor and started hosing off the radiator and anything else that was hot. Meanwhile, Paul stripped the trunk of the spare tire, jack, insulation, and anything else living back there. This thing was going to go faster, or we weren't going home.
A brief cool down, coupled with the freer-breathing intake did the trick. This time, Paul launched at 2,300 rpm, shifted at 6,500 rpm, and crossed the finish line in 14.21 seconds traveling 98.83 mph. The short time remained a sluggish 2.28 seconds. Another pass netted a 14.11 e.t. at 98.65 mph, with a best-yet 2.17 short time, followed by a 14.17 at 98.18 mph. The better starts came from a 3,500-rpm launch and 6,500-rpm shifts. We had hit the wall, and time was running out. The Cobra had run slower for the first time all day, so we knew it was time to get inventive. We had used up all of the tricks that we had learned on the dyno, so we had to reevaluate.
Since we knew that the Cobra liked it cold, we figured that it had better be real cold for the next pass. We spent an entire hour hosing down the motor and radiator with freezing cold water while cycling the 4.6 every once in a while. Ice went on the valve covers, intake, and mass air. Meanwhile, Paul was in the truck, doing some sort of voodoo Zen ceremony, trying to summon the concentration necessary to drive this thing out of the hole.
It must have worked. As he had done all day, Paul gave the big Comp T/As a quick spin to clean them, then he staged as quickly as possible to keep the motor cold. Slipping the clutch at 3,800 rpm and shifting at 6,500, the short time dropped to 2.16 seconds, and the Cobra romped to a 13.79 e.t. at 100.84 mph! We were psyched. The Cobra was finally living up to its press clippings. Paul went right back to the pits, and the cooling ritual started all over again. There would be time for one more pass, but we didn't have time to get the thing stone cold. It showed, as the e.t. dropped back to a 14.015 at 99.51 mph, with another 2.16-second short time. The day was over, and we went home with a single 13-second timeslip.
We put 20 miles--six dyno pulls and 10 quarter-mile passes--on our production '99 Cobra before it went back into public circulation. Could it go faster than 13.70s in stock condition? Probably. This car was devoid of a proper break-in period, so it should go faster after a few thousand miles. All in all, we walked away from this drag test a little bit frustrated since the vast majority of the Cobra's potential is lost in the first 60 feet. If only we had had some dry ice and a set of slicks.