Help with decat on a TII

[Prof]

FCD = Fuel Cut Defender or Defencer (varies depending on where you read it) is a device that plugs in near the stock MAP sensor, and basically \'lies\' about the boost level by capping off the signal. The effect of doing this is the ECU will not see the boost going above the fuel cut point, so it won\'t cut fuel. Now the bad bit - you\'re ECU is using the MAP sensor to adjust fuelling when on boost, along with the signal from the AFM. The AFM signal will drop to 0v at around 11-12 psi (varies a little depending on mods / filter etc), which means the ECU can only rely on the MAP sensor for fuelling amounts above that point. As you\'ve stuck an FCD in the path, it won\'t get that info, so you will run progressively more lean as you run higher boost. Timing is also controlled from this - so it won\'t be retarding the ignition as much as it should either !
 
Solutions to that problem:
 
1) Don\'t run so much boost (restrict intake or exhaust) - a boost controller won\'t do it
2) Run a chipped ECU or piggy back or standalone ECU to properly modify fuelling and timing for the higher boost.
 
Boost Creep and Wastegate porting:
 
This will be the next problem you hit. If you allow higher boosts by putting in freer flowing exhaust and intake or a bigger turbo, then the stock turbo wastegate can\'t get rid of the excess boost fast enough and it won\'t control the boost anymore. A boost controller can only keep boost under control if the wastegate is adequately sized, so fitting one is a good idea but only after a big enough opening in the wastegate is achieved. How do I know if I\'ve got boost creep - simple - get on a big hill, get into 4th or 5th gear and put your foot to the floor - if the boost goes straight to set value and stays there - no boost creep - if it goes to say 8 or 9 psi and then starts slowly climbing - you\'ve got boost creep and need to port the wastegate.
 
I got boost creep pretty much as soon as I changed the air filter and already had the exhaust done (Racing Beat system).

[Prof]

Just an add on - how the fuel cut works:
 
The guys at Mazda came up with a bizarre method to cut fuel on overboost.  When you hit the boost limit - nominally about 8.6psi but it can vary a little, the fuel to the REAR rotor is cut - not the front, with the hope that the loss in power will bring you back below that point.  Seems fair enough, except they also put another system in place that overides this - if you hold the accelerator to the floor (WOT) the fuel cut will be lifted and the ECU will attempt to stuff enough fuel into the engine to keep it alive.  It\'s not graceful and has probably been the cause of more than one engine death !  It feels a bit like hitting a limiter followed by another small boost kicking in.  If you ever feel this, back off for Pete\'s sake and sort the ECU out :yes

[TiddlesRX7]

Have you ported your wastegate Ade?

Yeah mate. I did mine when I had the turbo off a couple of years ago. Its not a bad job to do (the porting that is) the worst bit is getting the turbo off and on again. Also I never opened it up to its full potential as I didn\'t want to overload the stock actuator for now!

[L18M]

prof is always so much at explaining than me! :p

i got good oem cat (centre) and also fcd kicking about. £50 posted each

[XRMike]

prof is always so much at explaining than me! :p
 
i got good oem cat (centre) and also fcd kicking about. £50 posted each

 
Im interested in the FCD. Will PM you

[XRMike]

Infact I can\'t workout how to PM you.

[B.Martin]

It\'s because your a guest, you need to be a member to use the pm system

[TiddlesRX7]

I\'ve a spare FCD kicking about too if someone wants to give me £50 for it

Ade

[L18M]

Infact I can\'t workout how to PM you.

u can email me: w.liam.li (at) gmail.com :Thumbs-up

[XRMike]

Ah ok guys thanks. I will email you