Late Model Cobra Intake Manifold
cobra_d
07-20-2003, 01:12 AM
Has anybody used the FR500 variable geometry intake manifold for 99 and 01 cobras? It is really pricey, and wondering if perhaps I should just buy an SHM stage 1......does anyone know the difference in torque, power range, etc? Is the FR500 manifold worth that 3K? Also, would like to know a good, high-lift cam with power in the 4000~7500 RPM range for the 4.6L Cobra engine. Looking at the SHM stage 2 and the FRPP FR500 Kit....I already built my heads with good components and did some porting and polishing, so I probably just need a good cam. With these mods is it worth it to upgrade my throttle body to a BBK twin-62mm...I've heard that the larger throttle body won't really help a stock 4.6L DOHC....Any advice appreciated. Thanks...
Unit 5302
07-20-2003, 02:22 AM
For the money you'd save on not going with the FR500 intake, and no throttle body, you could nearly pick up a supercharger. The variable geometry intake manifold design was discontinued for the 99+ Cobra's after a tumble port head revision was performed. The 1996-1998 Cobra's came with IMRC (intake manifold runner controllers) that changed the length of the intake runners switching from the long runners to the short runners at about 5500rpm. This was done so the engine would produce more torque. They restricted performance somewhat, and when removed top end power improved while bottom end suffered greatly.
Don't expect your engine to pick up a ton of power with switching to the variable runner FR500 intake, especially considering how much power forced induction adds on those cars.
Don't expect your engine to pick up a ton of power with switching to the variable runner FR500 intake, especially considering how much power forced induction adds on those cars.
cobra_d
07-20-2003, 02:41 AM
Thanks for the info. Don't want to really go S/C, maybe a 100 horse shot of NO...but I am interested in getting the most from what I have. Same thoughts about the FR500 intake manifold....though I heard that the improved variable geometry design is really hot--too damned expensive. (The FR500 had 415 HP naturally aspirated...) Still think a SHM stage one intake and Mr. Dremel will do almost the same...for less than half the price. And how about a high-lift camshaft? My Cobra has a crapload of power already from the mods I've done...and lots of torque at around 4K RPM. Thanks again. DS
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