5.0 Mustang & Super FordsFeatured Vehicles
2005 Ford Mustang Roush Convertible - Top Down, Boost Up
Fastlane Prototypes A Drag Twin-Turbo Kit On This '05 Roush Convertible
Horse Sense: Mike's desire to get back on the strip with a hot car coincided with Fastlane's desire to build a prototype turbo for maximum horsepower. The prototype Saleen developed its street twin-turbo kit; the Roush could do the same for a race twin-turbo kit. They wouldn't be the small turbos.
Mike Rhame loved the looks of his new Roush convertible, especially after he installed the 20-inch black Bling-Z chrome rims for the street. It probably felt plenty fast, too. But as with most things, speed is relative. Until you experience something faster, you don't know what you're missing. Such was the case with this Roush. It felt great, until Mike took a ride in one of Fastlane's Mustangs equipped with the twin-turbo kit. The kit adds 190 hp, increasing the stock 280 rwhp to 470. After feeling that, discontent set in. Mike figured he would build his Roush into a slightly hotter street car to make it "a bit faster."
What kind of fun can you have with this ride? "It was a blast," Mike says. "On the freeway, I beat a new Z06 Corvette that had nitrous on it." But Mike wasn't through modifying by a long shot. He wanted a shot at the strip.
Nick Field, part-owner of Fastlane [(713) 600-8600] in Houston, Texas, was one of Mike's drag racing buddies in the glory days. The two were partners in speed. "Ten years ago, we raced Fun Ford stuff," Nick says. "He went his way and I went mine. Then, we met again after all these years. When he showed up, he had just bought this Roush Mustang. He saw what we had been doing in the last few years with the twin-turbo program. I guess he had a lot of confidence in me, because he said, 'Just do it. Put the turbos in it to make it go fast.'"
To achieve the required power output and keep the rotating masses in one piece, Fastlane built the bottom end to handle the power so they could "turn up the boost," according to Nick.
"We built adaptors for the motor mounts so we could put it in the new car. We did the standard 20 overbore and hone." The result was a classic 289 ci, but in a new configuration. Fastlane retained the Three-Valve heads, which dictated the company's retrofit to older-style plugs in place of the nonadjustable, platinum tips. High boost levels necessitate more and hotter spark so an ignition system was also required, even with the retrofit plugs. Unfortunately, this isn't as simple on an install as it is on pre-'04 Mustangs. A total of six different MSD boxes comprise the ignition system. Two DIS-4 boxes and four tach adapters were installed in the trunk. In addition to amplifying the spark, this also allowed the use of a two-step rev-limiter.
As the project proceeded, the Roush buildup became the prototype Mustang for Fastlane's twin-turbo race kit. Horsepower and torque settled around 750 and 620, peaking at 6,000 and 4,500 rpm, respectively.
Going fast on the track dictated a more consistent shifting three-speed C4 automatic by TransKing to replace the six-speed. The lightbar had to go in favor of a rollcage, courtesy of NHRA safety rules. Those Bling-Z wheels were also casualties. The plain Bogart Racing Wheels for drag racing are lighter in the front and bigger and fatter in the back. The openings in the rear valance that once housed exhaust tips are now empty and unstylish. Side exhausts route the spent gases from the headers. Once e.t.'s become a priority, form must follow function throughout.
As we arrived in Houston to photograph this twin-turbo Roush, the joint Rhame/Fastlane assault was on to achieve the high nines. The Roush is a fairly heavy Mustang at 3,900 pounds, a key statistic in the speed equation. Nick figures they need 650 hp at the tires to crack the 10-second barrier. So far, their fastest time is 6.40 in the eighth-mile, which computes to 10.00-10.20 in the quarter-mile.
What was once a sharp and aesthetically pleasing street Roush Mustang now has a racer edge. As Mike related the drag-race modifications, he couldn't help but inject his intentions to put the sharp rims back on, cut out the rollcage for another Mustang, reinstall the six-speed manual transmission, and put the beautiful Roush convertible back on the street-albeit with the "big turbos." Once Mike cracks the nines, as he surely will, the Roush will be configured for the street with 750 hp-the same as the dragstrip version. Then, it will have all the looks and all the horsepower.