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...
Despite using a thin-wall wrench to secure nuts on each manifold stud, Greg found it necessary to grind the tool down a bit (left) for better leverage and swing in the tight space.
Greg lowers the TFS Box R...
Greg lowers the TFS Box R upper plenum onto the lower intake manifold. Once the intake is bolted down and the throttle body, linkage, and vacuum connections are made, the Clevor-powered 'Stang is ready for the chassis dyno. Again, this swap process is as simple as they get.
While the Box R application...
While the Box R application calls for using the aforementioned 1-inch billet spacer, we must note that it increases the overall height of the manifold quite a bit and could warrant a hood swap (to at least a 4-inch cowl). With Greg's interest being to maintain a 3.25-inch cowl-hood profile, a beautifully machined 3/8-inch spacer is used in place of the 1-inch piece.
The Box R upper plenum certainly...
The Box R upper plenum certainly does away with the traditional Fox 5.0 appearance that the 408 Clevor had when we started this project, but we dig the no-nonsense, racier look.
You might recall that Greg...
You might recall that Greg installed a 3.25-inch cowl hood from Boss Inc, to accommodate the Trick Flow R Series upper.
With the Box R plenum being...
With the Box R plenum being a bit longer (front-to-back), a 5x5-inch (tall) opening was made at the back of the hood's lower panel, to accommodate that extra length, and 3/8-inch spacers are used on both hood hinges, to ensure there's enough height clearance.
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)...
Run 1 (11.14/124.63 mph) Drag radials @ 15.5 psi Two-step at 5,000 rpm (bog at launch) Shift light at 6,300 rpm Run 2 (11.06/124.51 mph) Drag radials at 15 psi Two-step at 5,200 rpm (left good) Shift light at 6,350 rpm Run 3 (11.02 124.72 mph) Drag radials 14.5 psi Two-step at 5,200 rpm (left good) Shift light at 6,400 rpm
Run 2 (11.06/124.51 mph)...
Run 2 (11.06/124.51 mph) Drag radials at 15 psi Two-step at 5,200 rpm (left good) Shift light at 6,350 rpm
Run 3 (11.02 124.72 mph)...
Run 3 (11.02 124.72 mph) Drag radials 14.5 psi Two-step at 5,200 rpm (left good) Shift light at 6,400 rpm