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I am building the FCD and need to know when putting it together do you solder resistors to all three terminals on the pot to the T1, T2, and T3? Or if its just from the one terminal on the pot to the T3 terminal?
 

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Mister2slow said:
I am building the FCD and need to know when putting it together do you solder resistors to all three terminals on the pot to the T1, T2, and T3? Or if its just from the one terminal on the pot to the T3 terminal?
Just follow his diagram closely.
You use only 1 pot, and 1 resistor.
Make sure to use the terminals too, they help a lot.

The part #'s he lists are still accurate, it works well.
I made this about 2 months ago, works great but you have to adjust it by VOLTAGE not by the general Ohms valuse he lists, they were way off for me.
i.e. I was in fuel cut before 14 psi when I had adjusted a hair over 17 psi according to the ohms values.
Dialed in the voltage and it's dead on every time.
 

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Mister2slow said:
I am building the FCD and need to know when putting it together do you solder resistors to all three terminals on the pot to the T1, T2, and T3? Or if its just from the one terminal on the pot to the T3 terminal?
Have you actually read the instructions??? They are detailed and specific, and there are accompanying drawings and photos. And...there is only 1 fixed resistor.

http://toymr2.tripod.com/fcd.html (instructions)

http://toymr2.tripod.com/BPSA.jpg (schematic)

http://toymr2.tripod.com/FCD.jpg (point-to-point line drawing)

http://toymr2.tripod.com/builtopen.jpg (photo of components mounted and wired)

BTW, kurdain's experience is unusual. While I recommend and prefer setting using the pressure procedure, he is the first one to report a significant discrepancy from the resistance setting.

bill
 

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i'm currently making one, and is there any optional resistor other than a 15k ohm resistor? i cannot find that exact part in any radio shack...i found a 15 ohm, NOT 15k ohm resistor...help
 

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AnDaLe said:
i'm currently making one, and is there any optional resistor other than a 15k ohm resistor? i cannot find that exact part in any radio shack...i found a 15 ohm, NOT 15k ohm resistor...help
The 15 K ohm fixed resistor simply increases the resistance between the "hot" side of the circuit and ground, minimizing the amount of current (amperage) that can flow through the circuit, and minimize any voltage drop. The added resistor (actual cost-5 cents) is probably unneccesary, but is cheap insurance and doesn't interfere with the operation pf the BlackBox FCD.
You could use ~15k ohm and get the same results.
 

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nuvoturbo said:
For anyone building the Billwot FCD, I have aprox 20, 15 ohm resistors. If you send me a SASE, I'll send you one for free. E-mail me at [email protected] and I'll give you my address.
Sam
SASE: The Society for the Advancement of Socio-Economics

??? What is a SASE?


Edit: Got it! SASE Self-Addressed Stamped Envelope. :D
 

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nuvoturbo said:
For anyone building the Billwot FCD, I have aprox 20, 15 ohm resistors. If you send me a SASE, I'll send you one for free. E-mail me at [email protected] and I'll give you my address.
Sam
I assume you mean 15K ohm! 15 ohm realy won't do any good.

Good of you to offer them to others. I also had several left and gave them away to others.

bill
 

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AnDaLe said:
i'm currently making one, and is there any optional resistor other than a 15k ohm resistor? i cannot find that exact part in any radio shack...i found a 15 ohm, NOT 15k ohm resistor...help

Resistors connected in series are additive. 5K+5K+5k = 15K. 10K+5K = 15K. 7.5K+7.5K = 15K. Etc.

Or anything close is good enough. The only difference is the pressure/resistance relationship in the instructions will not be correct. But if you set using pressure and voltage, it won't make any diference.

bill
 

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kinda a stupid question but was wondering when fuel cut hits? isnt there a hose u can tie up in the engine bay to take care of that or is that only stock boost cut?
 

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FC comes at ~ 12 psi.

you can eliminate it by disconnecting and plugging the hose to the pressure sensor.

But that completely eliminates the protection. My device allows to increase the setpoint, but keep the protection.

bill
 

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Well, after looking at the package they are in fact 15 ohm resistors, so according to Bill, thay won't do you any good. Sorry.
Sam
 

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does fuel cut occur if you are driving too fast? is there a limit to how fast the car can go without a fcd? i know it occurs for overboosting...just not speeding...
 

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AnDaLe said:
does fuel cut occur if you are driving too fast? is there a limit to how fast the car can go without a fcd? i know it occurs for overboosting...just not speeding...
It only effects max boost pressure.

Jspec cars also have a speed cut.

"Fuel-cut" is a safety sequence built into the MR2 turbo as a failsafe to protect the engine in the event that the boost control system should somehow fail. A pressure sensor measures boost pressure and translates it to a voltage signal and sends it to the ECU. By simply controlling the voltage between the sensor and the ECU, we can adjust the fuel-cut setpoint to any value we choose. "


http://toymr2.tripod.com/fcd.html
 
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