Alpha Powersport built the ultimate Polaris Slingshot. The factory Slingshot comes with a inline-four and only three wheels. This particular version has been upgraded with a 6.2 L LS376/525 which produces 525 horsepower and a four wheel conversion. Alpha sells the four wheel conversion for $10K and the V8 conversion about $30K-$35K. This modified Slingshot went 11.0 sec quarter-mile.
You can understand why some clients are choosing to have the four wheel conversion. The factory three-wheel Slingshot has a very hard time putting a fraction of the LS3’s 405 horsepower to a single rear wheel.
Source: Alpha Powersport