Final Assembly and Tuning on Project Solstice LS7

Last month we presented part one of our buildup of the World's Baddest Magazine Project Car, the HOT ROD Solstice. Doing the modern equivalent of the V-8 swap, we decided to stick a big engine in the four-cylinder Pontiac Solstice to make it a hot rod in the purest sense. No common V-8 would suffice, of course. GM's recent horsepower bonanza known as the LS7, the 505hp monster powering the spectacular Z06 Corvette, is now available as a crate engine, so when deciding which engine to stuff in the little Pontiac, we eschewed more commonplace choices and went straight for the jackpot. And to up the ante even more, we added a Hot cam from GM Performance Parts (GMPP) and tri-Y headers to allow the engine to blast out roughly 600 hp. The car will weigh less than 3,000 pounds when it is completed and ready to run, so it'll be fast.

Last month we ended with the car as a rolling chassis in need of bodywork, final paint, final assembly, and, of course, final testing. This month's installment will go into all of those finishing details, but were saving the full-on track thrash for next month. We have a few performance bogies we're going after, and the full-court press is on to make the car perform beyond expectations.

Now a word about that body; the stock Solstice is plenty sexy, so visually there really weren't any major changes to the basic shape or size. But our number-one goal was brutal speed, which meant that anywhere we could shave weight, we would. The drivetrain swap, rollcage, and other stuff we did to the car added about 700 pounds to it, so we went looking for ways to take weight out in other areas. That led to the decision to go all out and create a complete carbon-fiber body, and while we were at it, we did custom front and rear fasciae to give it a more aggressive appearance. The rear view turned out especially spectacular!

Yes, a complete carbon-fiber body is beyond what most people would do, but the real story here is in the details. The engine fits pretty well, and most of the parts used have GM part numbers on 'em. We leaned heavily on the expertise of GM Performance Division's engineering staff to make it all work at a ten-tenths level, but a V-8 Solstice is truly something a capable hot rodder could do at home.

Check out part two and start taking notes on how to build a V-8 Solstice of your own. And make sure to tune in next month when we give you all the nitty gritty performance numbers.

GM Performance Tune-up

When the car was completely assembled, it was shipped to General Motors' Proving Grounds to be run hard, hung up wet, and tuned up to top capability by the GM Performance Division in preparation for HOT ROD to thrash on it. If there was one thing we enjoyed watching, it was the GMPD team setting up the car to handle on a road course, street driving, and a dragstrip.

The engineers in this group are excellent drivers and ran the HOT ROD Solstice brutally hard to get everything working properly. As far as getting to an optimal chassis setup on a car that has no tuning in it, John Heinricy, director, GM Performance Division, said it best. "The best process for tuning the suspension is to set the shocks at full soft, drive the vehicle in both slow- and high-speed situations, then set the shocks at full stiff and drive it again. This way you'll know if there is enough adjustment in the shocks to attain optimal handling in all conditions. Then you can go back to the soft shock settings and add just a little damping to make sure the springs, sway bars, ride heights, tire pressures, etc, are 'right' to achieve a good balance. Adjust these before working the shock adjustments to attain the final tuning," Heinricy said.

Roll Your Own

Last month, we showed you a lot of the details around the exact GM part numbers you'll need to know to build your own HOT ROD V-8 Solstice. This month, we'll add just a few part numbers to that list.