Is the Pontiac Solstice a V8 swap away from perfection?

Summer Solstice

General Motors launched Pontiac’s Solstice in 2005 to great acclaim. Remember the advance-order hoopla spurred by “The Apprentice”? GM took orders for 1000 of the 2006-model-year cars in 41 minutes and put thousands more customers on a waiting list. Shortly thereafter, the Solstice was nominated for the North American Car of the Year Award and the Design of the Year Award. 

The automotive press seemed delighted with the Solstice, and GM was finally building a roadster that could compete with Mazda’s MX-5. With a base price of $20,000, sales ignited. Pontiac sold more than 21,000 examples in the car’s first year. 

The tiny Solstice featured a quirky new shape and promised open-air fun. GM’s 2.4-liter DOHC four-cylinder Ecotec engine provided 177 horsepower, which was routed through a five-speed manual or optional automatic transmission. 

The Solstice rode on GM’s Kappa platform, which it shared with the Saturn Sky, Opel GT and Daewoo G2X. The Pontiac roadster featured a 95.1-inch wheelbase but it weighed nearly 2900 pounds. With a zero-to-60 time of 7.2 seconds—and the ability to run the quarter mile in 15.8 seconds at 87 mph—it struck some testers as more cruiser than sports car. However, it handled and rode well enough for enthusiasts and got decent mileage to boot.

To keep costs down and reduce development time, Solstice engineers raided parts bins around the company. Cadillac’s CTS donated its rear axle, differential and automatic transmission. The steering column and other interior parts came from the Cobalt, and the back-up lights were borrowed from the Envoy. Engineers even put the touch on Hummer’s H3 for its five-speed manual transmission as well as its with heating, ventilation and air-conditioning modules. The Solstice shares a steering wheel with the Corvette and Malibu, among others. 

Somehow, all of these pieces worked well together. Solstice sales rose in 2007 as the car found a market niche with mostly young buyers. Answering demands for more punch, Pontiac introduced the GXP version, which was powered by a turbocharged 2.0-liter, 260-horsepower Ecotec engine. 

But as automakers have learned, timing is everything. As the nation’s economy tanked in 2008, so did Solstice sales. The introduction of a targa-top coupe in 2009 didn’t help matters. 

Winter Solstice

As every enthusiast knows, the last two years have not been good for the auto industry. Early in 2009, Uncle Sam and the taxpayers’ dime bailed out General Motors, which was reeling from plunging sales for all of its brands.

As the company teetered on the brink, it killed the 84-year-old Pontiac brand. Solstice production ended when the Wilmington, Delaware, assembly plant closed in July 2009. 

Pontiac built 65,724 Solstices over a four-year run. As the last of the Pontiacs, the car grabbed its place in automotive history. It was the final gasp of a once proud and exciting brand (well, if you ignore the Aztek).

Hit It With a Mallett

In the fall of 2005, Ohio-based Mallett Cars, a tuner shop known for building very quick Corvettes, decided to find out if a Chevy LS2 engine would fit in a Solstice. With a nip to the frame rail here and a tuck to the rack and pinion there—plus a dash of fabricated mounting hardware—the engine slipped right in. 

The Pontiac Solstice GXP was no slouch thanks to a turbocharged, 260-horsepower engine, but Mallett Cars wanted more. They shoehorned a Chevy LS2 V8 in the nose and ended up with lightning in a tiny two-seat bottle.

The shop selected a LuK Pro clutch to route power to the CTS rear end and the Solstice’s Aisin five-speed gearbox—those last two stock parts were deemed beefy enough to handle the torque. The exhaust system retained the OEM catalytic converters for 50-state emission compliance.

Next, Mallett installed a custom aluminum radiator, a special wiring harness, new plumbing and a reprogrammed engine computer. To beef up the suspension, they installed modified springs and shocks, added poly bushings, and made a few other suspension tweaks. Thus equipped, this potent Solstice weighed only about 200 pounds more than a stock example.

Let the fun begin! This prototype rocket worked so well that Mallett Cars declared they would build 1000 of them. Alas, they would not reach a quarter of that number. 

When 2.4 Liters Is Not Half Enough

Orlando-area car guy Bill Kroll bought his Solstice in late 2005. It’s an early-production 2006 model, No. 2970 in the original run of 10,000. 

While Bill bought it new, he’s technically the second owner of the loaded roadster. A friend had ordered the car but was no longer able to make the numbers work. When the dealer wanted to charge Bill $5000 over sticker to step into the transaction, his friend took delivery and the two made the deal on their own. 

Bill liked the little car well enough, but he’s a V8 guy at heart, having owned a number of Mopar muscle cars. So when he wanted to punch up the Solstice, he naturally started looking at a V8 conversion. He did a lot of research online and talked to a number of Mallett owners. Then he visited Mallett’s shop and talked to the principals. He liked what he saw.

In July 2008, he shipped the Solstice to Mallett’s shop. Six weeks later, they sent it back with twice as many cylinders, three times the rumble and quadruple the OMG factor. All of these extras didn’t come cheap, as the conversion tab was just over $26,000—the new LS2 ate up a good part of that tab.

Bill says he’s very pleased with the way the converted Solstice drives. “I love the power and the sound from the Corsa exhaust system,” he says. “The only thing I wish I’d done is change out the rear gears. The current gear is 3:91. You can get the limited-slip rear with 3:73 or 3:42 ratios, which would make it a little smoother in the lower gears.”

The V8 Mallett has an impressive power-to-weight ratio. In fact, if you give one a go at a stoplight, odds are good that you’ll end up reading the logo on the back of the car as it rockets away. 

With all of that power on tap, Bill wasn’t happy with the brakes. “They seemed a little soft to me,” he says. So he added more braking power with a kit from DDM Works, which included stainless lines, Hawk HPS pads, slotted rotors and high-temp fluid. He reports that the brakes now feel much more capable.

Only one problem has cropped up since: The engine harness wires were touching the exhaust manifold, which sent the engine into limp mode. A local Corvette shop, Corvette Masters in Maitland, Florida, solved the problem. 

Since the conversion maintains OEM parts, any shop can plug in the diagnostics for an LS2 Corvette and look for problems. And since the Mallett Solstice is basically a Corvette, there is plenty more performance on tap from any number of available LS2 mods.

Solstice Support

As it turns out, Pontiac and Solstice were not the only victims of the nation’s economic woes. Mallett Cars closed its doors without warning in mid-2009, leaving some owners scrambling to retrieve their vehicles. After a several-month shutdown, Mallett relocated to Concord, North Carolina, where the company is again providing tuner services as well as support for their conversions. 

Bill’s car is No. 18 of an estimated 200 Solstice conversions Mallett has completed to date. Online forums provide information and support for these enthusiastic owners, who realize their cars are now rarer than they ever expected. Examples show up for sale occasionally, generally with asking prices in the $40,000-to-$50,000 range. 

Bill thoroughly enjoys his stealthy Solstice and plans on keeping it. The peculiar reactions it provokes are part of its appeal, like the one Bill got when he pulled into a show for special-edition cars. The folks at registration, believing this was a mere regular Solstice, were going to deny him entry. After an exhaust sound check and a peek under the hood, however, they were delighted to let him in. 

And then there’s the possibility of that stoplight fun. Not that Bill would do that, of course.