[Mk2] [Turbo] Hks fcd question

[j10bex]

Bought this a while ago second hand off ebay, just occured to me there are loads of types. on the back is a sticker with st-05945 has four wires black red yellow and white can anyone confirm this is for rev 3 turbo also any how to fit quides on here?

[Martin F]

are you sure you need one for a rev3 as the fuel cut isn't till 18psi...

also pretty sure the paul port fcd is the only one compatible/recommended with a rev3...

[j10bex]

to be honest not sure really. lots of contasting views on here forgot to say will be instaling an ebc as well. Where would i get a paul port one from if needed?

[Martin F]

This is one of the very very few FCD's that actually work with the Rev 3 Turbo's allowing you to run upto 25psi - Why ?? well Paul's explanation is:

On a Rev3, fibbing the MAP sensor voltage into reading lower makes the car fuel less - resulting in trouble.

My "paul port FCD" as others named it is a fully electronic device. It still splices into the MAP sensor wire - but it does not affect the sensor voltage below actual fuel cut point. What it does there is clamp the voltage from going any higher... The clamp is released at a user settable higher point giving instant fuel cut safety.

What you have to remember about the Rev3 ECU is that essentially Toyota have given you fuel and ignition maps all the way up to ~17psi. My clamp FCD simply stops you going off the edge of the map. At 17psi, the ECU is fuelling like crazy, it's also at it's most retarded ignition wise - so you have room for a few PSI more at your own risk ;o)

The Rev3 map sensor works up to ~25psi so that's the maximum point you could set the release to.

not sure if they are still available, try items wanted or pm paul port, not sure if he's still about...

the 18psi is a good / safe limit on the standard turbo etc so raising it wouldn't be really needed for safety reasons etc...

[Slarty]

are you sure you need one for a rev3 as the fuel cut isn't till 18psi...

also pretty sure the paul port fcd is the only one compatible/recommended with a rev3...

What this man said!!

A normal FCD works thus. The ECU works the fueling ratio out from the standard MAP sensor (on rev3's I hasten to add). An FCD lowers the voltage that the MAP sensor sends to the ECU, to effectively raise the point at which the ECU sees "over boost".

What this means is that during normal opperation the ECU is seeing a lower boost than is actually present, thus making the fueling weaker. It all adds up to a melted engine.

[j10bex]

Thanks fellas so dont need one if i keep to 17psi or below thanks