![]() As far as the billet gears go, we knew we were going to be turning a lot of RPM with Cobra Jet manifold and this is another pace they fail. You can give up as much power as any modification can make by having bad ring seal, plus the F150 Coyote uses a lower quality 10.5:1 piston. We were working with an F150 that was in an unknown condition. One of our biggest questions on this build was in regards to the short-block rebuild and the billet gears. Once you change the pistons, rods, and camshafts, a F150 engine is essentially a Mustang GT 5.0. The quick hits: 11:1 short-block with a slight overbore, Comp Cams CR-Series Stage III camshafts, upgraded Comp valve springs, MSD coils, and Triangle Speed billet gears. If you want to read the complete story on the Coyote engine build, you can go here. Plus, it would be off-road only and currently we don’t see the level of aftermarket support to make it worthwhile.” We developed a 92 mm but the gain was so minimal that we have shelved it for now. With a cowl hood or lowered engine, the Cobra Jet manifold is worth some power but few customers are interested in going down that path. The GT350 manifold has proven so good that we tried to make a slightly modified Cobra Jet manifold that would package under the S550 hoodline but it wasn’t any better than the stock GT350 with the stock, round throttle body. The GT350 was able to hit its performance targets with a slightly larger 87 mm over the GT’s 80 mm. In regards to the throttle body redesign, Kershaw mentions, “Maintaining idle and emissions is critical and far easier with the round throttle body. If you could build a manifold that took the best of a short and long runner design, this is basically what Ford was trying to accomplish. Ford revisited the Intake Manifold Runner Control (IMRC), also called Charge Motion Control Plates, feature that manipulates the intake’s runner velocity. The newest manifold to the OEM manifold market comes from the GT350. By lifting off some restrictions we were able to maintain a preferable torque curve and pick up horsepower.” ![]() Of course testing always validates what we think we know so it’s still critical. When we asked Kershaw how Ford Performance was able to maintain a strong torque curve with the Cobra Jet while increasing peak horsepower, he responded, “Ford has proprietary modeling software and simulation that allows us to ‘get it right’ often with few iterations of design. The dual bore version is best suited for street cars to increase the available partial throttle tuning window. We ran the Ford Performance single blade Cobra Jet throttle body which is designed for maximum power. The Cobra Jet intake takes any 11-14 GT500 throttle body and the intake manifold comes with an adapter plug to make the changeover simple. “We sell the Cobra Jet manifold and the throttle bodies for off-road use because of that.” “The big concern is idle and potentially emissions,” continued Kershaw. ![]() The other noticeable change was the throttle body opening that was converted to a GT500 style. “The CJ manifold started as the BOSS with the oval throttle body and cleanup around the injectors.”Įliminating the recess at the top of the manifold that was previously designed for strut tower clearance helped increase plenum volume. “It’s slightly different but negligible amounts,” explains Kershaw. We basically took the list of things the OEM program wanted to do but couldn’t to meet standards for idle quality and noise.”įord Performance’s Cobra Jet intake manifold can best be described as the next generation BOSS 302. Slight changes were made to optimize flow around the injector because we didn’t have to worry about noise that would be a concern in the production program. Using what we had available was fairly straight forward adapting the dual bore or oval throttle body to the same basic design. “The ‘runners in a box’ approach yielded solid results but we also knew the throttle body was the limiting factor. “We knew that the BOSS was directionally where we wanted to go,” Jesse Kershaw of Ford Performance recalls. Ford Performance experimented with a BOSS-like recess for the strut tower brace on the Cobra Jet manifold but it hurt the power too much to keep it. Removing the strut tower brace clearance and enlarging the throttle body opening is where the magic happens. The BOSS 302 and Cobra Jet manifolds are very similar.
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