When we showed up at Brian Lorenz's home in rural Ohio to shoot his 9-second Regal Turbo T, we expected to find it the focal point of a shop dedicated to building a wicked-quick street/strip Buick. We were half-right. Along with the go-fast accoutrements in a separate shop building on his property, there was also a tightly packed, extended garage attached to his family's house that contained several more hair-dried Bufords—including an ultra-rare Light Sage Metallic and a D84-code two-tone light brown/dark Turbo Regal Limited. Both of them are among 1,035 Turbo Limited's produced in '87. There was also an '89 Turbo Trans Am in the garage. Clearly, we were dealing with a serious turbo Buick enthusiast. Case in point: the quick turbo car featured here is one of only a handful Turbo T models built in 1987 that were painted Light Brown Metallic. It's only got 17,000 miles on the clock, too. He's owned it for about nine years.
"I've always loved these cars—there's just something about their formal design matched with amazing power that's intoxicating," says Lorenz, an enthusiast ingrained in the scene for years—and a member of Turbobuick.com since the inception of its new board back in 2001. "And even after all these years, people are still finding ways to make them go faster and faster."
Our feature car is a prime example. It's gone as quick as 9.54 at 143 mph, but still has remarkably good street driving manners. And it sure doesn't look the part of a 9-second race car. Apart from a few performance-related accessories inside and out, the car remains very close to the factory-delivered condition. There are no racing seats in a tin-covered cabin and there are no radical chassis or suspension mods.
In fact, Lorenz is quick to point out the sheetmetal on his light brown metallic Turbo T is original and unaltered. Apart from a replacement Dakota digital instrument cluster and a handful of additional digital dials affixed to the side of the gauge binnacle, the cabin looks as staid as anything your grandpa might have driven to Bob Evans for the early-bird special.
"Just about all of these cars have had the quarter panel lips cut or modified, but I wasn't going to do that to a car this rare and original," he says. "This cars still has the original R-12 refrigerant in the air conditioning system that blows cold and it still drives through the factory 200-4R four-speed overdrive transmission and factory 3.42 gears, too."
Well, the trans and rear end are technically original, but they've definitely been upgraded. The same goes for the original LC2-code 3.8-liter engine. Lorenz sent it to renowned Buick engine builder Dan Strezo, at Wheatfield, Indiana's DLS Engine Development. He started with the stock block and added a 3.625-inch stroker crankshaft in place of the stock 3.400-inch-stroke crank, taking displacement to 249 cubic inches (4.1 liters). It was secured with new billet-steel main caps that replaced the original iron caps that are a known weakness in the LC2. The stock caps—the center ones in particular—are prone to cracking in higher-power buildups.
Attached to the block is a pair of Champion GN1 aluminum heads that have been completely worked over by DLS Engine Development to provide even greater airflow. They also lop a few crucial pounds off the front of the nose-heavy G-body. The Champion heads have been popular with Buick builders for about a decade, with features that include valves moved closer to the cylinder bore centerline to un-shroud them for greater flow, spark plug locations moved closer to the bore center for improved combustion, and large 1.9-inch intake and 1.6-inch exhaust valves. The 46cc combustion chambers are shaped differently than stock, too, for greater combustion efficiency.
"They work really well, helping the engine breathe much better," says Lorenz. "With the extra displacement, this combination moves a lot of air very efficiently."
To feed the extra displacement, the original turbocharger was replaced with a Precision HPQ71 billet turbo—so named for its 71mm inducer compressor wheel. It is capable of up to about 40 pounds of boost, but Lorenz pushes "only" about 30 pounds through a ported stock intake manifold and down into those Champion heads to help the 249-inch six-banger crank out right around 700 horsepower at the wheels—or about 840 at the crankshaft.
That's a power-to-displacement ratio of 3.37—or 3.37 horsepower for every cubic inch of displacement. That's very impressive and to put it in perspective, the Corvette ZR1's supercharged 376-cubic-inch LS9 is rated at 638, for a power-to-displacement ratio of a mere 1.68. Heck, a $165,000 Porsche 911 Turbo's 232-cube flat six makes 530 horsepower, for a very admirable 2.28 ratio, but it's got nothing on this modified 26-year-old Buick. And the million-dollar Bugatti Veyron 16.4 Super Sport can't touch Lorenz's Turbo T, either. It's 490-cube, quad-turbocharged W-16 engine—basically two V-8s joined at the crankshaft—produces 1,183 horsepower, but that's only a power-to-displacement ratio of 2.41. Feel free to use those trivia tidbits at your next dinner party.
With such impressive output, it's no wonder this car is in the mid-9s, but getting there was a journey. When Lorenz bought the car, it already had a few bolt-on performance goodies and with a bit more tweaking on his part he had it running 10.30s with a stock-displacement combination.
"We did the stroker motor and after a season of trying, it ran 9.90s—but we didn't have the HPQ71 turbo yet," he says. "I got one from Buschur Racing as soon as it was released and the car immediately went into the 9.70s. A few small changes and a different converter is what it took to get us into the 9.50s."
Until the last few seasons, Lorenz did all his own tuning, but now runs an XFI controller, dialed in by Cal Hartline of Hartline Performance in Melbourne, Florida.
"It was running those 9.70 e.t.'s at 138 mph with just the factory-stock GM mass airflow sensor and Red's computer chip with the stock ECM," says Lorenz. "It worked just great, but I switched to the XFI fuel management system to ensure the engine's safety at the power level we were achieving. It has the built-in correction elements and makes the changes in the tune on the fly—things that quarter-century-old ECM just can't do."