Reply to "GP4 front spoiler options"

A front spoiler is necessary if you're going to go fast. As Julian mentioned, speeds over 100 mph will generate enough front end lift to make steering progressively more vague as mph increases. At around 150 mph just as with the GT-40, front end lift will be a real concern for your driver; this was the subject of an early wind tunnel evaluation by Ford. At around 175 mph, rear lift will cause oversteer and even traction problems, calling for some sort of NASCAR-like rear blade spoiler or small wing.
One authority mentioned the fiberglas Revson mini-spoiler not only cured front-end lift (up to around 150), it channeled enough extra air thru the radiator to drop engine temps by about 5 degrees F. There are two versions, one developed by Peter Revson (a Pantera dealer and racer before his death): the second iteration done after Peter's passing has a built-in splitter while the original does not. Neither reduces ground clearance, and neither causes front brake overheating on-track as unvented air dams sometimes do.