[DIY] Turbo Fuel Cut Defender

[infotechplus]

I've made an FCD for my Aristo:



This is the link to the original design:

http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

This was then updated and improved (less wires, simpler design, adjustable) on SoarerCentral:

http://soarercentral.com/sc-forum/me...282/46553.html

However, tests showed voltages were not within the required range. We got 8.5V with the components originally specified.

Furthermore, using the diagram and components in the original Soarer TT Fuel Cut Remover does not yield an appropriate range of adjustment. These components gave an adjustment of between 5V - 10V for a given input (eg. 12V). Ideally you want between 4V - 5V, as stated on the original spec sheet.

My FCD gives a range of 4.05V - 5.05V with an adjustment of 10% per turn - there are 10 turns from 4.05V to 5.05V.



I made the following changes:

330kOhm R1 --> 15kOhm
100kOhm R2 --> 15kOhm
50kOhm TRIM RV1 --> 10kOhm

Testbench results showed a consistent 4V - 5V. Set in the middle of the dial yielded 4.5V.







I've added a small interface of 4 screw terminals where the wires can be screwed down, as labelled.

I haven't installed this in the car yet but will over the next week.

Anyone care to comment?

Cheers,

Peter

Peter

[Duk]

All these results are with 12 or 5 volt input?

[infotechplus]

All these results are with 12 or 5 volt input?

Constant 12V input from testbench power supply

Cheers,

Peter

[Hen]

Looks the goods. Will it make any/much difference when the car's running and it'll be getting ~14V

[The Witzl]

there is actaully a jaycar kit that does this now....

http://www.jaycar.com.au/productView.asp?ID=KC5439

Its a "soft cut" FCD... meaning it slowing trims off the 5V MAP sensor signal... rather than just stopping hard.