[Zoom This]

Several years ago a group of us got together for a chassis dyno day using a Dastek Eddy current chassis dyno. Two of us had SPF cars with similar motor builds. My car with a 418W pulled 478 HP at the wheels. The other car 468 HP at the wheels. His motor had a known flywheel HP of 550. Using a modest 15% gear and other parasitic losses on my pull would give you around 564 HP at the flywheel. I think a 20% loss with a an SPF car using an IRS rear axel, stock sidepipes etc. is a little too much as this would give a 590HP at the flywheel for my car, As mentioned earlier 15-17% loss seems reasonable.