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IAC Restrictor Plate

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Old 04-18-2010, 10:49 AM
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sonicx
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Lightbulb IAC Restrictor Plate

Doing some mustang research here and I came across an IAC restrictor plate. I know what a restrictor plates does from watching NASCAR races but not what it does on a mustang. So I searched around a tad bit and found my answer: All the plate does is limiting the amount of air when letting off the throttle, which drops the idle quicker....car is more responsive without the annoying rpm hangs between shift. For me, I wasn't planning on installing it but im just wondering if any of you guys have it installed on your cars?
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Old 04-18-2010, 12:16 PM
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MU71L4710N
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if you look in the how-to section theres more information about it.

i tried it then took it off. it was better to drive with a 5sp because you didnt have to wait so long for the RPM to come back down between shifts. some cars won't hold idle or will idle poorly though. my car would damn near die when the AC or heater was on full and i was at a stop.

just check out the how to section you can make one out of an aluminum can or a sheet of gasket material from an auto store and see if you like it or not. if you don't or your car doesn't like it, then take it off no harm done.
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Old 04-18-2010, 01:37 PM
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Thank You. Yea im aware of the info out there, like i've said before i did some of my own homework on this but I was more or less interested in knowing about people's own experience/personal thoughts on it. thanks for your input. Wasn't planning on b4 and still am not now but i just wanted to get a general idea from the guys around here.
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Old 04-18-2010, 02:21 PM
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huey_33
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Originally Posted by sonicx
Doing some mustang research here and I came across an IAC restrictor plate. I know what a restrictor plates does from watching NASCAR races but not what it does on a mustang. So I searched around a tad bit and found my answer: All the plate does is limiting the amount of air when letting off the throttle, which drops the idle quicker....car is more responsive without the annoying rpm hangs between shift. For me, I wasn't planning on installing it but im just wondering if any of you guys have it installed on your cars?
I made one and installed it a couple months after I bought my car because my car idling high and I had a major case of hanging rpm's. I personally think it works really well. My car was idling around 1100rpm's before the install and now sits at 800rpm's. Also when youre driving down the street and let off the gas, it helps slow the car down faster without pressing your brakes. Sort of like an engine brake.

Last edited by huey_33; 04-18-2010 at 02:23 PM.
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Old 04-18-2010, 04:47 PM
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^^ Interesting & good to know. Luckily I don't have any high rpm issues knock on wood.
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Old 04-18-2010, 05:54 PM
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This was a good trick for the old speed density cars. We wuld use them to help it idle w a cam...along w other things related to the map sensor
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Old 04-18-2010, 07:47 PM
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I had one till I put the cams and stuff in and figured it would cause problems with them. It worked great when it was in! It's biggest benefit is that you can finally use engine braking!
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Old 04-18-2010, 07:51 PM
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MustangMan00
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^^^ i had the opposite approach

I had to make my own out of gasket material after my cams and underdrive pullies to get my idle right.

I have an auto and with the reg. gasket it would idle fine, but I would put it in gear and it would allow too much, so the car wanted to lurch forward.

I found a happy hole(if your will) hole size hah and now its fine
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Old 04-18-2010, 07:55 PM
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01MGGT
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Originally Posted by MustangMan00
^^^ i had the opposite approach

I had to make my own out of gasket material after my cams and underdrive pullies to get my idle right.

I have an auto and with the reg. gasket it would idle fine, but I would put it in gear and it would allow too much, so the car wanted to lurch forward.

I found a happy hole(if your will) hole size hah and now its fine
Interesting Hey not to hijack the thread but did you gap your plugs at .030 or .035 after your blower? I had to do mine at .030 to really get it running good at WOT. JW.
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Old 04-18-2010, 09:33 PM
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How has this affected your guys' horsepower & fuel mileage... if any?
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