5.0 Mustang & Super FordsProject Vehicles
2005 Ford Mustang GT - Automatic Weapon
One Of Our Readers Gave Us A 2005 Mustang To Play With-Guess What's Going To Happen Next
Longtime readers of 5.0 Mustang & Super Fords magazine and fans of heads-up Mustang drag racing in general will be quite familiar with Kenny "The Stud Field Mouse" Moss and his series of hot Mustangs. Kenny and his Baby Blue LX hatchback first slammed onto the scene in 1998 when he shattered the Outlaw world record with a jaw-dropping 8.35-second e.t. on 28x10.5-inch tires. That came with a wild ASSC Vortech-supercharged combination and a stock TRZ Racecars suspension. The legend of Baby Blue was followed by a Sonic Blue '03 Cobra that graced our cover on the July '04 issue as a ProCharger test mule. Since then, Kenny, like the rest of the free world, has become entranced by the possibilities presented by the newest Mustang. Retro styling; a solid, fresh chassis; and a raging 4.6 Three-Valve Modular V-8 that just begs to be modified-the new Mustang has something for everyone.
But months before Kenny took delivery of his car, there was a great deal of angst over which option boxes to check. It had to be blue (of course), and Ken told Ford it could keep the wing. He also checked the base interior option to save the weight, although the Pimp Red interior was inviting. But the one decision that really kept our boy Kenny up late at night was which transmission to go with. He called us for weeks, then right before good buddy Bruce Hemminger, new-car sales manager at Van Drunen Ford, placed the order, Ken decided to go with the five-speed automatic.
Intrigued by the possibilities of throwing around a brand-new Mustang with its equally fresh automatic transmission, we convinced Ken that he should just hand us the keys. (Hey, he got a couple of 5.0 Mustang & Super Fords magazine license plates out of the deal!) A tentative plan for modifications was laid out, and our friends at Paul's Automotive Engineering agreed to do all the modifications. Thus was born our newest project car: Automatic Weapon.
The obvious angle we'll be playing up with this car is answering all the questions regarding the new 5R55S five-speed automatic transmission. How much power can the transmission take? What modifications work with this transmission? What special tuning does the transmission require? Does the drive-by-wire programming really mess with the car? How much power will the stock Three-Valve take before eating itself?
Hopefully, before Kenny gets his car back, we'll have poked and prodded every aspect of the transmission while building up one fast street car. Sure, we fully expect to have spilled tranny guts on the floor, but not before we put some serious beans to it. In the end, we're looking to have a lot of fun with this car, and that's what this hobby is all about.
As delivered, the automatic GT Mustang is an amazingly capable performance car. Forget everything you think you know about Ford's lazy transmission from AOD days gone by. This car is for real, and it will keep right up with and sometimes beat its five-speed manual brothers (depending on who's doing the driving). The car comes equipped with a 3.31:1 final drive gear, and the 5R55S transmission features a wonderfully low 3.22:1 First-gear ratio that immediately gets the action going.
As you can see by the accompanying chart, the 5R55S transmission has gear on top of gear, especially when compared with the First gear (2.84) of the venerable 4R70W automatic in the '04 Mustang V-8 it replaces. This is most noticeable in part-throttle applications around 20-40 mph. Stand on the gas, and this Mustang instantly moves out. In the old days, AOD owners had to endure a long wait for the right gear to be chosen, then an insufferably long period of time for acceleration between gears. With a tight gear ratio, four usable gears, and Overdrive, this is a fun car to drive.
As stated, we've turned over this entire project to the capable hands of Paul Faessler, owner of Paul's Automotive Engineering, a Mustang super center in Cincinnati. Paul has been maximizing Mustangs for more than 20 years, and the members of his staff of Ford technicians were eagerly awaiting the arrival of Kenny's car so they could get to work on it. Having already done several blower installations, engine builds, race suspension installs, as well as most of the basic bolt-ons for the S197 Mustang, Paul had a leg up on most tuning shops.
We began our evaluation of the car with a trip to the in-house chassis dyno. Shop Manager Tom Honsaker and Head Technician Big Mike Wilson strapped down the Sonic Blue beauty on the rollers and we snapped the pictures. The automatic GT spit out 242.9 hp and 257.6 lb-ft at the rear wheels, which, given a 22 percent drivetrain loss, comes out to around 297 hp at the crank. We also encountered a 120-mph speed limiter built into the stock Ford programming due to-we are told-the car coming through with the HR speed rated tires.
One hot topic (that got a few Ford people fired if the stories are true) is the weight of these new Mustangs. Ours weighed in at 3,540 pounds, with 1,900 pounds on the front tires and 1,640 pounds on the rear. That's about 100 pounds heavier than a comparably equipped stick car, 200 pounds heavier than an '04 GT, and probably 600 pounds heavier than an '88 5.0 LX notchback. We're interested in seeing how that weight affects the car's performance and the longevity of the automatic transmission.
While at Paul's Automotive Engineering, Big Mike worked with C&L's Lee Bender to develop a new program on the Predator tuner for Lee's new "Race" cold-air intake for the '05 Mustang. The C&L cold-air system performed well in our 11-way comparison ("Cold Score," Dec. '05, p. 84), and this new system looks to further improve the C&L line. On the PAE chassis dyno, the C&L race kit was good for a 23hp and 10-lb-ft pop, and Mike was able to bypass the speed limiter as well as monitor inlet temperature with the Predator.
Before we headed to the dragstrip, we wanted to address another concern with our baseline testing: traction. Because of the low gearing on this car (and testing it on the streets), we knew it would give us some serious grunt off the line. We gave Jonathan Ozeretny of Nitto Tire a call to see what he had available for the new Mustangs. He quickly sent a pair of P245/45R17 NT555R drag radials. We mounted them on a set of take-off rims supplied to us by Sutton High Performance-a great source for all sorts of special '05 Mustang gear. Now, you may think these tires are on the small side, but we were looking for a slightly shorter tire to pick up some gear (shorter tire equals increase in numerical rear gearing). We also didn't plan to do much testing in near-stock trim, so plans for a full-on drag slick are in this car's future.
The Nitto drag radials are well known for dramatically improving traction while also having a respectable wear rating. In other words, you can drive these on the street without going through a set of tires every 1,000 miles, as with some other drag radials. If you're planning to put a set of Nitto drag radials on your Mustang and leave them there, we suggest you try Nitto's 275/40-17s-that way, you'll have the best of both worlds.
Ford Mustangs have always been built to be driven-and driven hard. So, off to the local dragstrip we went with a 1,300-mile '05 Mustang. We had read stories of mid-13s in showroom stock condition, and we didn't expect anything less. It didn't surprise us when the first pass on the car was a 13.815 at 99.21 mph (2.107-second short time), but what did surprise us was how easy it was to do that. Remember, this is with the car in completely stock trim-we hadn't tuned it, added the cold-air, or put sticky tires on it yet. Pull through the burnout box, heat the tires enough to clean them off, power-brake the car against the tight 1,800-rpm stock converter, drop the brake and mash the gas on green, leave the thing in Drive, and pick up your 13-second timeslip. It was too easy! We swapped drivers; we ran it hot; we ran it cool; we tried big burnouts and no burnouts; and the worst the car ran was a 14.093 e.t. at 96.76 mph. The best we got was a rewarding 13.726-second e.t. at 99.87 mph-completely stock and still tight. With a car that had some more miles on it, we believe the 13.30-13.40s that some people are reporting might truly be possible.
The cool part about driving this car at the dragstrip is that the transmission really goes to work for you. The first three gears are pounded out so fast right to the factory redline of 6,000 rpm that you feel as though you're just getting sucked along for the ride. Bang, bang, bang-and High gear hits a little after mid-track with the Three-Valve screaming for all its worth. You'll really appreciate this car if you ever owned something like an '89 GT with the AOD transmission and the stock 2.73 gearing. You have the same torque in the new Mustang, but the factory has finally given you the hardware to make it work for you without having to rebuild a transmission and dump money into a rear-gear change.
It also becomes more apparent at the dragstrip just how tough these new Mustangs are. Whack the thing off the line, and it just goes. There are no interior pieces rubbing together, no body twist, and no shifter trim panel popping off the tunnel. The weight we see on the scales pays off in a solid chassis that should see a long and healthy life.
Once we established a solid baseline on the car, we were eager to start the modification process. As mentioned earlier, we began by installing a set of Nitto drag radials mounted on Sutton Performance take-off factory rims and the new C&L cold-air intake with companion Predator tuner featuring a custom, Paul's Automotive Engineering tune. The car responded with a stout 13.543-second e.t. at 100.79 mph. So, we picked up a couple of mph while dropping two tenths. Our short times (the time it takes the car to cover the first 60 feet of the dragstrip and a direct indicator of available traction) dropped from the low-2-second range into the high-1.90 range. That's not as dramatic a reduction as we thought we'd see, and it gives us good reason to start the serious modifications with a performance torque converter.
Still, a good cold-air system, a performance tune, and sticky tires are easy modifications you can do at the track to your own '05 Mustang that will result in a faster, more consistent car. Speaking of consistency, you can't help but realize what an outstanding bracket car the new Mustang is when equipped with the automatic transmission. With a good set of tires out back, you should be able to split your dial-in down to the thousandths of a second. And, with that low gearing, you can get a great launch, which should translate into confidence for good reaction times.
We have quite a lineup of stories about this car coming for you. We already have a performance torque converter installed, we're looking at creative ways to drop weight from one of these cars, CNC-ported Three-Valve heads and performance camshafts are sitting here, and we're going to put on some sort of power adder. By the time Kenny gets back his car, he might have to update his NHRA Competition driver's license!
Our ultimate goal is to dig into this car and see what happens, and-hopefully-we'll all learn a lot about the new Mustang in the process. If you have any questions or a specific direction you'd like to see us take, please send an e-mail. We'll do our best to show you the right way to build one of these amazing new Mustangs.