fr500 intake differences

[32vApe]

Does anyone which fr500 intakes come with the longer longer runners? I have found the two part numbers that ford racing shows. M-9424-t46 has the upper lid for the 96-98 style inlet. The M-9424-dp50 has the 99-04 style inlet. I has seen two different lower plenums, the one that seems more common is the shorter longer runners and the other that looks like it would barely fit down into the valley has the longer longer runners. like the one on the left:



or the smaller lower plenum with the shorter runners like this:


Just wondering how what the difference is in the long runner length is and if the longer runner version would make similar midrange torque to the stock 99-04 cobra/mach intake. It seems like alot of torque is lost with the fr500 even with the long runners.

[EatonSnake]

Both sets of longer Runners for the FR500 are longer than the runners in the 99-04 Cobra/Mach Intakes. The reason you lost peak torque with the longer runners in the Fr500 is because the long runners of the Fr500 are too long and have too small of a cross section to work in a reasonable rpm range for a 4.6 4v, where your Stock Intake did. When the longer runners were optimized in the Fr500 Intake, your engine was at too low of an rpm to create peak torque numbers. In order to make use of an Fr500 Intake you just need to spin the motor high with the correct combination of cams/compression using the short runners. You wont be able to regain the average mid range power that the stock intake produced with any version of the Fr500 Intake. Because of this the Fr500 is a poor choice for a stock or near stock 4v cars.

[na svt]

Stick with the stock intake if you want mid range power and good tq. The FR intake will make decent power on a stock engine but only from 5500 and up; there's defintely a trade-off. If the car sees a lotta time in that powerband the FR500 is a good option, even for stock cammed combos. If the engine sees time above 7000rpm, the FR intake is a great option.

I've seen stock cammed (96-98 cobra cam) engines make over 370rwhp with the FR, one made over 400rw.

[32vApe]

I have a 5l stroker with tea stg 3 04 cobra heads, 228/228 cams, 10.6:1 compression I just finished building. This will be run n/a fora few months then will get a d1sc with 10-12 lbs. The stock intake seems to be the bottleneck on this combo. I cut the bottom off and have done a lot of work to it, but there just doesn't seem to be enough material around the injector boss area to get it to match up to the ported heads. I added a few beads of weld on the outside of the intake so I could grind down the injector bosses quite a bit. There just isn't enough cross section in the runner. I would like to see peak power 6800 rpm or higher and dont mind spinning the engine.

[na svt]

Originally Posted by 32vApe

I have a 5l stroker with tea stg 3 04 cobra heads, 228/228 cams, 10.6:1 compression I just finished building. This will be run n/a fora few months then will get a d1sc with 10-12 lbs. The stock intake seems to be the bottleneck on this combo. I cut the bottom off and have done a lot of work to it, but there just doesn't seem to be enough material around the injector boss area to get it to match up to the ported heads. I added a few beads of weld on the outside of the intake so I could grind down the injector bosses quite a bit. There just isn't enough cross section in the runner. I would like to see peak power 6800 rpm or higher and dont mind spinning the engine.

Unless the heads are hogged out a stock intake should have no problem matching up to a set of ported heads.

A stock intake's runner length will not allow your combo to peak any higher than 6300rpm. To get a higher peak power rpm the intake runners will have to be shorter.