ok so i get the whole concept of the longer and shorter runners and the butterflys staying shut at low rpm and opening at high rpm. but how does it work on a 99 cobra what controls the butterflys to open? any detailed explanation of how it all works would be great. im not an idiot so you can speak to me like an adult haha
how does FR 500 intake work
- Thread starter 99vertcobra
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^ just get a turbo and your wouldnt have these kind of questions lol
When I had an intake with both runners, I used a window switch to control when the runners opened. The intake comes with a controller that has two cables and a harness(I believe three wires). The controller is what actually opens and closes the butterflies.
The window switch is used to send the trigger signal at a specified rpm to open or close. You wire it up to either supply a ground when trigged, or remove it. I can't remember which way I wired it, but it gives you an idea of how it works.
Its alot like the factory IMRC's on the 96-98 4v's.
Oh and also the butterflies are opened by default. You need the controller in order to transistion to the long runners.
The window switch is used to send the trigger signal at a specified rpm to open or close. You wire it up to either supply a ground when trigged, or remove it. I can't remember which way I wired it, but it gives you an idea of how it works.
Its alot like the factory IMRC's on the 96-98 4v's.
Oh and also the butterflies are opened by default. You need the controller in order to transistion to the long runners.
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My SVT Focus had it and I thought it was amazing. I love the concept. To bad we don't have them on our cars stock. Coolguy has it down pretty much to how it works.
i understand so on our cars the module to control the butterflys would be controled by a window switch. now i just need to find one for my car lol.
Msd digital window switch ~$100. I used one on an aviator setup I had.
How does the MSD unit work? Can you set it to whatever RPM you want?
On a '99 you wire it into one of the coils on plugs.
It has an open setting and a closed setting. You set the rpm for each and your set.
I used it to hold the long runners open until 4000. Then it switched over and used the short runners.
Do you need the switch on a 96-98 or is it more to keep you in the power band?
On mine I needed to use the window switch and a tach driver. Just splicing the coil wire did not give me an accurate tach signal.
You only use the switch to control the runners. You could probably wire it into the imrc harness and use the computer to control the fr500, but I didn't mess with it much. You would have to look at a wiring diagram to see what is available at the harness and then figure out how to adapt it.
I'll have to check with Todd to see what he says. Thanks Jeremy:beer:
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