Renntech takes the supercharged 5.5-liter V8 that resides in every SLR and adds some of its magic. This time it's a simple application of one of the company's upgraded intercoolers and a new intercooler pump. These revised units have twice the capacity of the stock coolers and reduce temperatures by a full 50 degrees. The result is horsepower that now hits the magic 722 mark. No price is listed for the conversion, but it sounds like it could be a real winner with the few customers lucky enough to have a 722 parked in their garage. We could do without the aftermarket wheels though.