ronttuk Posted February 28, 2011 Share Posted February 28, 2011 I found this on another forum does it work ?? Free fuel cut defenser (ffcd)? . The free fcd is basically a low-buck way to bypass the computer's fuel cut control. this is critical to maximizing your hp output when your boost levels go over say, 14-15 lbs of boost. here's how you do it within 5 minutes and for less than a dollar!! this modification requires no soldering or tapping into the harness and is reversible within minutes. please be aware though that with this mod, you have no fuel cut. you need to ensure you don't boost too high! to install the "free" fcd, completely remove the 4-inch vacuum line that connects the pressure sensor switch to the "y" connector. (you'll find the pressure sensor switch on the passenger side of the intake air manifold on the throttle body towards the top. the correct sensor is marked "sensor turbo pressure" in green.) notice that the vacuum line is attached to the bottom of the sensor switch. leave the wire connector attached. cap the bottom of the switch with a 1/8-inch cap. cap off where the 4-inch hose connected at the "y" with another 1/8-inch cap. (note: when you slip the cap onto the sensor turbo pressure, you must make sure not to trap too much air in the cap. one tt owner had some difficulties because the sensor thought it "saw" high boost all the time. just a warning.) back to start Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted February 28, 2011 Share Posted February 28, 2011 Not a good idea. If you cant afford a FCD then you shouldnt be going BPU FFS Quote Link to comment Share on other sites More sharing options...
Shane Posted February 28, 2011 Share Posted February 28, 2011 If you do this the ECU is always going to think the manifold pressure is at atmosphere and not see any level of vaccum or boost. Not a good thing. But yeah sure it will let you over boost, will run like a dog though and in the end something will protest in a supra expensive fashion I am sure. Quote Link to comment Share on other sites More sharing options...
Nic Posted February 28, 2011 Share Posted February 28, 2011 If you do this the ECU is always going to think the manifold pressure is at atmosphere and not see any level of vaccum or boost. Not a good thing. But yeah sure it will let you over boost, will run like a dog though and in the end something will protest in a supra expensive fashion I am sure. Quote Link to comment Share on other sites More sharing options...
drift_bear Posted February 28, 2011 Share Posted February 28, 2011 that just has expensive fix written all over that! nothing in life is free, it always comes at a cost and if its something to do with the supe then i wouldnt even bother cutting corners Quote Link to comment Share on other sites More sharing options...
ronttuk Posted February 28, 2011 Author Share Posted February 28, 2011 I thought it sounded dodgy but I had to ask !! Quote Link to comment Share on other sites More sharing options...
Awisto Posted February 28, 2011 Share Posted February 28, 2011 It'd only work on the VVTi cars, and as others have said, not recommended. Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted February 28, 2011 Share Posted February 28, 2011 thought the whole idea of a fcd was to move the cut higher rather than removing it completely. I know it clamps the map voltage but its still allows the fuel cut to come in at some point. Quote Link to comment Share on other sites More sharing options...
monsween Posted February 28, 2011 Share Posted February 28, 2011 thought the whole idea of a fcd was to move the cut higher rather than removing it completely. I know it clamps the map voltage but its still allows the fuel cut to come in at some point. From what i read on another thread (i think) you move the limit up so high things are gonna go tits up before it hits fuel cut. Quote Link to comment Share on other sites More sharing options...
Shane Posted February 28, 2011 Share Posted February 28, 2011 From what i read on another thread (i think) you move the limit up so high things are gonna go tits up before it hits fuel cut. Thats not quite how it works. The map sensor produces a variable voltage to the ECU, it's level is determined by how much pressure, or vacuum its seeing. When the boost hits around the 1bar mark the voltage the map sensor is sending the ECU hits a limit pre determined within the ecu that then instigates fuel cut. What a real fcd does is allow the output from the map sensor to the ecu to stay the same right up until slightly before the fuel cut point when it then clamps the voltage at that precise point and maintains that clamped level regardless of what the map sensor sends at 1bar or over. So, the ecu never thinks there is more than .95 bar or thereabouts (there seems to be a little variation on at what exact point fuel cut happens). I have been playing with some simple circuitry and a second 2bar map sensor from a ford so I can lose fuel cut until I hit 1.2 bar and then the output from my second map sensor provides me with fuel cut. Sadly the oem tt mapsensor doesnt provide meaningful outputs much above 1.1bar which is a shame. Quote Link to comment Share on other sites More sharing options...
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