Shelby GT500 Project Vapor Trail Upgrade

Ah, the slippery slope. It happens with every project Mustang we've ever owned. You start with a few mild bolt-ons, and before you know it you are piling on the parts to the point that your formerly street worthy 'Stang is a bleeding-edge monster that's more at home on the track than on the street. With Project Vapor Trail I never made the mistake of saying I wouldn't modify the car, but I did promise myself that I wouldn't push it over the edge.

Fortunately, today's modern Mustangs are suited to respond to just the right package of bolt-ons to bolster their power, while preserving their driveability. I've always loved the challenge of packing big power into a streetable package, and these days it seems easier than ever. This perfectly demonstrated by the expandability offered by Shelby GT500s like PVT. Picking up where the Terminator left off, these cars easily gain horsepower with just a few bolt-ons.

The last time we visited PVT's engine compartment for gain ("The Invisible," Nov. '08 p. 98), we demonstrated that with a 66hp and 74-lb-ft addition thanks to VMP Tuning's stock-look 2.65-inch blower pulley and some of VMP main man Justin Starkey's tuning artistry. This time around, we head back to VMP to add some boost, supplement the fuel flow, and open up the exhaust to pump out more power-without taking away from the car's fun factor.

On the upgrade roster this time is a selection of gear from the new FR500CJ drag car, including the 10-percent overdriven crank damper from Innovators West, the 123mm mass air housing, and the 80-lb/hr fuel injectors. Sadly the throttle body wasn't quite ready in time for our test, so we opted for VMP Tuning's even bigger twin 67mm throttle body. A set of E85-friendly Fore Precision fuel rails from our friends at Lethal Performance and a complete manifolds-back, 3-inch exhaust from Bassani rounded out the mods. Of course, Justin Starkey worked his custom-tuning magic using our SCT XCal 3 tuner to make our mix of parts work in unison.

You'll have to check out the captions and the sidebars for the explicit details, but the ultimate result left PVT with both more bark and more bite, but maintained a level of driveability suitable for my advancing years.