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anyone here have any experience in using this piece of equipment? i have heard nothing but good things about this WHEN USED PROPERLY but then there's the ocassional horror story associated with equipment of this nature.

i was just reading in a magazine about this thing. a tuner shop installed one on a mildly modded 1st gen eclipse. this thing made 47hp and 24ft lbs at the wheels on the dynojet.

just curious. while it can severely damage the motor if not properly used, it can apparently also give you a huge gain at the wheels, all for $125.

any opinions, stories, experience is welcome. thanks.
 

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omg!

qbbraveheart said:
a fuel cut defender does just that....I dont see how it can give gains in HP
Because it allows fuel to continue to be added in conjunction with additional boost. But yeah, by itself it doesn't do anything, only if you modify the stock boost.

-st
 

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so basically that hp/tq gained would be where you normally would die off due to fuel being cut and such *basically able to raise the boost a little and such* or running full fuel to redline?

Robert~
 

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staticx313 said:
so basically that hp/tq gained would be where you normally would die off due to fuel being cut and such *basically able to raise the boost a little and such* or running full fuel to redline?

Robert~
I've never used it, but that is how I understand it yes. The ECM will try to match the correct amount of fuel to maintain a given A/F ratio at a given boost. I guess this modifies the signals to the ECM though, so I'm not sure if it maintains the factory A/F or what. Of course the ECM does run pretty rich from the factory, so there is a little cushion there.

I haven't been able to find any really good technical info on the FCD, just some general advertisement type crap. If anyone has anything I'd be interested. I would assume (we all know what happens when you assume) that it just runs the injectors at 100% IDC all the way to redline.

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Well also... scuba steve has this product and ran like 21 psi (granted it was at 5800 ft), but... his a/f ratio was fine.. so I guess it does compensate?

Robert~
 

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A FCD is simply a voltage clamp for your MAP sensor. It appears that the Subaru ECU employs both a MAF and MAP sensor and the MAP sensor is primarily used to detect overboost situations. The MAF sensor is primarily used to measure load for fueling.

A FCD alone will net you no hp gain. It is only when used with more boost that you will see gains. The reason ScubaSteve was able to run 21 psi is partially due to our 3.5psi atmospheric pressure loss. This means Steve running 21psi up here would be like running 17.5psi at sea level. PLUS he ran that boost in the midrange where you have a greater fuel injector DC (Duty Cylcle) available due to the lower engine revs. If Steve could hold 21 psi to redline I GUARENTEE the horror stories would start... since the stock fuel system couldn't even support that up here. That would be like running 17.5psi to redline at sea level of which most of the tuners seeing the injectors going near static at 16.5-17psi.

A FCD is particularly useful at high altitude becuase the higher you go up the lower the fuel/overboost cut comes in at. Example at 6000ft we get fuel cut in the mid-high 16psi range. At 11,000-12,000 the ECU lowers the fuel cut boost threshold to around 15-16psi. Just a defense mechanism that was programmed in with the stock turbo efficiencies, or lack there of the higher you go up, in mind.
 
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