My Tuned AE86 project

[thanhngo]

I have had a brief look and have a solution (haven't tested it yet).

If you have a AP1 cluster, the Fuel Sensor Guage input is C8. There is no separate wire for 'empty light' as I am sure its built-in to the cluster. Hence when you reach that resistance (130-132ohms), the cluster will light empty. When I turn the cluster on with wire not connected, the empty lights up by default.

They are both resistance types (varied resistance gives different guage readings) so its not a hard problem that I can foresee.

There are 3 ways that I can see to solve the fuel problem.

1. If you are using a toyota sensor, you can use a mutlipot or fixed resister to linearise the signal. Problem is the guage won't read full bars but at least towards empty will show - easiest but not the most accurate.

2. Use the microchip to perform a ADC then DAC. This will give you flexibility but its a little more complicated than 3

3. Get a s2000 fuel sender! I brought one from a US car but it isn't a bolton affair as I read.

The fuel sensor is part of the fuel pickup but can be easily separated. I plan to disassemble the 86 one, then modify it so the s2000 fuel sensor can be mounted onto it. Wiring is easy, but the only other thing you need to think about is mounting/calibration.

My initial measurements indicate that the s2000 cluster has a -2cm displacement heigh over the 86 one. The solution I have planned is bend the float arm to reduce some of the angles to enable a "longer" float arm throw. This will allow the sensor to have the same displacement as an 86 guage and hence, calibrated to the same tank height. I will do a detailed writeup once I get to this stage but im confident this will work.

In addition, the 86 sensor is notorous for failing so hence why I ended up deciding to replace it with a modern unit which is of more robust design. Two birds, one stone.

If you guys are using aftermarket ECU with you f20c you will still have a temp guage problem as the temp bars use semi-pwm style output. http://www.modifry.com sells a temp guage adapter if you are interested.

I'm building this one myself, in addition to speedo corrector. I will post results soon. I have the temp guage bars working and working on a robust program to read a toyota VSS and display the speed on the cluster.

Hope that wasn't too detailed of a response