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Old 06-14-2020, 05:45 PM
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twobjshelbys twobjshelbys is offline
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Join Date: Jan 2009
Location: Las Vegas, NV
Cobra Make, Engine: Shelby CSX4005LA, Roush 427IR
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Quote:
Originally Posted by Thunderbird123 View Post
What Roush 427 do you have? 427R? the reason I ask is I'm having mine built right now but I haven't decided on engine choice
The fuel injected version is 427IR. I had an early one in my Cobra. In the beginning they used Accel DFI controller, but with the problems I had and others eventually they changed. But universally, it doesn't like to idle at a low speed. The physics of the air flow through the throttle bodies and trumpets does not lend itself to low speed. You have to compromise the timing of the injector fire to the air flow and with the TB's almost closed, you get a very rich condition. This is because proper dispersal of the fuel into the cylinder depends on vertical flow with the blades open. The solution is to raise idle speed and open the TB blades a little bit.
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CSX4005LA
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