The first thing that became clear in taking down the Bmw M6 was bore and stroke. It was just sort of begging for stroke. It require a bit of bore too. So, Dinan stroked it to 83 mm and bored it to 93 mm. Boring the V10 from the stock 5.0 liters to 5.7 was tricky, since the cylinder walls were lined with silicon-saturated aluminum alloy.
Dinan's CNC bore equipment were equal to the task. The silicon's impregnated deep enough into the block that you can bore out into the aluminum and still have the silicon.
We had actually perfected all this technique on the racing engine. The racing motor is the one Dinan placed into the Grand-Am vehicles, one of which won this year at Laguna Seca, near the company's headquarters in Morgan Hill, California.
To contain the extra power and torque, he added his own forged crank and lightweight forged pistons and con rods, balanced and blueprinted the whole thing and dealt with it with corresponding electronics and software. Although the $39,995 ( €32,000 ) price tag is far from cheap, it provided the car with an extra 65 horsepower.
Another 55 hp is provided by high-flow intake assemblies, throttle bodies, rear mufflers, middle exhaust and 13 percent underdrive pulleys.
Maximum power generation is 628 hp and 480 lb-ft of torque, in contrast to stock yield of 500 hp and 383 lb-ft. And we are just talking only about the engine. Dinan has also been famous in its 30 years of business for suspension enhancements.
Once more, these came from the taking down of the car. Bmw wanted to leave room for the convertible, which compromised the amount of shock travel, Dinan discovered.
He designed new upper-shock mounts and bump stops at all four corners, improving shock travel and ride compliance. Caster and wider front tires get rid of a little of the stock understeer. The result is fully enhanced grip and steering feel: It feels more like a 3-series than a 5-series.