When you think about our Clevor's original induction setup, it's easy to understand how the long runners of the engine's Trick Flow R Series upper manifold actually decrease intake-air's (drawn through Anderson Ford Motorsports' 4-inch Power Pipe, Abbaco's 97mm DBX mass air sensor and a 90mm throttle body) velocity and efficiency, before passing into and through the large openings in the heads.
Replacing the standard R-Series upper-intake manifold with Trick Flow's famed Box R topper (PN TFS-51500008; $395.99) is a move that we're excited about. It should increase air volume in the manifold and shorten the distance that it actually has to travel. We strongly believed it would take the Clevor's naturally aspirated performance to a level that's more in line with the horsepower and torque values we all optimistically forecasted at the outset of the project.
Like many of you, Greg's a more-than-capable do-it-yourselfer and has handled all of the bolt-on assignments for Project Leave It to Clevor since the effort really hit full stride in our Sep. '11 issue ("Turning Tricks"). So with that said, check out the photos and captions highlighting the upper manifold exchange, and the compelling data that is a result of hitting both the dyno and the dragstrip immediately after the operation was completed.
Despite using a thin-wall wrench to secure nuts on each manifold stud, Greg found it neces
Greg lowers the TFS Box R upper plenum onto the lower intake manifold. Once the intake is
While the Box R application calls for using the aforementioned 1-inch billet spacer, we mu
The Box R upper plenum certainly does away with the traditional Fox 5.0 appearance that th
You might recall that Greg installed a 3.25-inch cowl hood from Boss Inc, to accommodate t
With the Box R plenum being a bit longer (front-to-back), a 5x5-inch (tall) opening was ma
On The strip
Shortly after the dyno test, we took advantage of a private test session at Auto Club Dragway that featured several project cars and motorcycles from Source Interlink Media's SoCal-based performance mags. Despite 85 degree temperature, density altitude that reportedly was close to 4,000 feet, and a clutch that was not doing well at all (see Horse Sense), Project Leave It to Clevor put down solid low-11-second runs across the 1,320.
While Greg's run notes are included in the caption for each timeslip, we must add that the GT carried a full fuel tank and tipped the scales at 3,500 pounds with Greg in the seat. Perhaps if we had removed the spare tire, jack, and full nitrous bottle (which we weren't using), approximately 50 pounds would have been gone and "official" 10-second e.t.'s could be claimed.
Run 1 (11.14/124.63 mph)
Run 2 (11.06/124.51 mph)
Run 3 (11.02 124.72 mph)
Run 1 (11.14/124.63 mph) Drag radials @ 15.5 psi Two-step at 5,000 rpm (bog at launch) Sh
Run 2 (11.06/124.51 mph) Drag radials at 15 psi Two-step at 5,200 rpm (left good) Shift l
Run 3 (11.02 124.72 mph) Drag radials 14.5 psi Two-step at 5,200 rpm (left good) Shift li