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Does a timing key effect the point at which fuel is delivered to the engine on an EFI sled. If so don't you think it would already being delievered at the optimal time. Or does the ECU take care of that. Does the injector pick up come from the fly/magneto?

Bottom line, just trying to figure out if a key is benefiacal in a EFI sled.

Any input would be appreaciated

Aaron
 

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Your not advancing the fuel injection timing your advancing the ignition timing so it sparks sooner. Don't understand it completely but it gives you a hotter burn.
 

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The key probably doesn't work as well as an EFI as a carb...but maybe a bit safer. The ECU in a EFI can sense coolant temp and adjust fuel delivery / timing. When the coolant warms the ECU senses that and reduces timing and or adds fuel. A carb sled doesn't do that so if you add timing you add timing and that's that. The EFI sled will compensate for hot coolant, but you'll still be advanced how every many degrees the key is all the time.

The key simply rotates the flywheel forward which makes the spark happen sooner in the cycle.
 

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I haven't ever heard of the EFI system controlling timing electronically. I thought that they were strictly controlled by the timing key.
 

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The ECU does control the timing curve. For example the 500' race box has much more timing than the stock box and both use the same flywheel. So the signal from the flywheel happens at the same time for each.

The CDI box for carb sleds can be re-programmed also. It can be set to advance or retard timing at different RPM's also.
 

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Hmmm...that's interesting. So how does the electronic timing interact with the timing key?

Also, do you know if the ethanol switch adjusts timing when its pulled. I have an argument going with my bud who swears that it does control timing....I think it just adds more fuel.
 

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This may be wrong, but I have been told by several people that when you pull the ethanol plug it does retard the timing.

Has anyone put a timing key in a F7 EFI? If so how many degrees, and how well did it work. I would like to put one in, but I don't want to risk burning up the motor. I also have a D&D pac system.
 

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<div class='quotetop'>QUOTE (snoman820 @ Jan 31 2007, 01:29 PM) <{POST_SNAPBACK}></div>
This may be wrong, but I have been told by several people that when you pull the ethanol plug it does retard the timing.

Has anyone put a timing key in a F7 EFI? If so how many degrees, and how well did it work. I would like to put one in, but I don't want to risk burning up the motor. I also have a D&D pac system.[/b]
I have the 2.5 degree key and BMP stock pipe mod.

Best $200 I've ever spent on a sled.

Noticeable improvement in midrange and topend.

Just enough to pull past your buddie's F7's but looks/sounds totally stock.

I also have a fuel restrictor, but its wide open.
 

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So with the electronic timing (EFI or CDI) if you put a key in it will always be advanced that amount...say 2 degrees. So if the EFI is trying to pull timing because of heat you'll still be advanced 2 degrees more than the computer thinks it is.

Ethanol switch is fuel only correct.
 

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So ethanol plug just adds fuel, glad someone cleared that up.

I fully understand how timing keys work. I just want to know from peoples experience how much is too much. HPE states that no timing keys are recommended for efi. Then they turn around and recommend the 1.5 degree, but not the 1,2,2.5,or 3. Then they list a 3.5 for efi for racing only. I want that extra edge, but do not want to worry about burning down. Hey bigblock, you put in a 2.5, how is that, too lean? Just want some input.
 

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I don't plan on running anything bigger than 2.5. If no one can give me any input on the matter then I will probably just get the 1.5 and see how it goes.
 

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I've benn running the 2.5 in my 05 f6 efi and love it.
 

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<div class='quotetop'>QUOTE (snoman820 @ Jan 31 2007, 09:12 PM) <{POST_SNAPBACK}></div>
I don't plan on running anything bigger than 2.5. If no one can give me any input on the matter then I will probably just get the 1.5 and see how it goes.[/b]
I have an 06 F7 and had a 2.0degree. On the first tank of fuel this year I burned down #1 piston. I cannot be certain it was poor fuel (I always run super) or the timing key. I have switched to the 1.5 degree key and it seems to run just fine. I would go with the 1.5 and super fuel.
 

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I know there were guys out there running 3.5 keys and no problems with premium fuel. I don't think anyone really knows how far to go and still be safe.

I do know this. There are thousands and thousands of guys out there running the 2.5 degree on F7's with no problems.

It only adds 2-3 hp at most, but really cleans up throttle response.
 

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So no matter which key I decide to go with I should be running premium fuel? Or is it something that I need to test out and just watch plugs?
 

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You CAN run a key without premium. I bet less than 1% of guys that run them run regular fuel.

If you do ANY modding to an engine at all you should be running premium fuel. I'd even consider it for clutching as the clutch kits generally work the engine harder.
 
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