this is for the one awd impulse rs, that they only made 800 of, but will it work for the subarus? it just tricks the computer right?

http://www.kipanderson.net/rs/fce.htm

i noticed on a gl-10 turbo there is a vacuum going from the turbo output to a component on the strut tower, and one coming from it to the wastegate.

 

on an xt turbo, there is a 2 inch hose from the turbo to the wastegate.

 

why the difference? and does the component on the gl-10 have anything to do with fuel or other?

The 85-86 Turbos(vane types) can have the fuel cut off bypassed by means of altering the above referenced vacuum switch.. 87 and newer(hotwire types) have to have fuel cut off bypassed by electronic means

my 87 has the hotwire MAF, and the vacuum lines off the turbo. it has the optical disty, too

 

the xt i mention of had the points type distributor, the one suited for CISturbo conversions!

 

maybe 87 is an odd parts bin year? crossover period? i have seen carb, spfi, and turbo on 87's

One of those strut mount vacuum switches is for the turbo light.. the other is for the fuel cut off(again, vane style MAF).. if you only have one, its for the turbo light

the fuel cut defender mentioned will.....sorry, this message left blank due to banana man intervention

 

 

BTW we have MAF's not MAP's in our cars.

They are a wee bit different arf arf

You seriously wont say becuase of the banana?

SOMETIMES i like to dance like the banana:banana:

OH YEAH !

skip... did you forget what you were typing, or what?

I think this is why ...

 

http:// http://usmb.ultimatesubaru.org/forum/showthread.php?s=&threadid=3160&highlight=banana+abuse

Skip hates the banana - can't say I like it much myself. He has said before that he will not answer any threads using emoticons. I think it's pretty funny actually, but I must admit - a good way to teach people to stop using them, and get their point across with real english words.

 

GD

thats pretty anal...

just have to keep using it then, putsin it up

thats pretty anal...

just have to keep using it then, putsin it up

almost forgot

OMG......

 

for me...and bump for fuel cut stuff.

hehe, das old stuffs.

 

those cars run map sensors.wonder if that matters.

 

remember the bananna stuff?

HI SKIP

Old thread alert! For a second, I thought GD was back.

I was thinking about a design for a FCD when looking over the wave-shaping ciruits section in my microelectronic circuit design text book and I came up with pretty much the same design as the one shown here:

http://www.kipanderson.net/rs/fce.htm

 

This circuit here is what is known as a clipping circuit. It will keep the signal from increasing pass the zener voltage (Vz) of the zener diode which in this case is 4.3V. And it will keep the voltage from decreasing pass the negative of the turn on voltage (Von) of the zener diode which we will assume to be 0.7V (we don't care about this because the signal voltage should never reach below 0V).

 

In other words, the signal will not be modified when its voltage is 4.3V (zener voltage) or less. When the signal voltage reaches the 4.3V (zener voltage), then it will stay constant at that voltage until the signal falls below that voltage. I hope you people understand this. I just want to let ya all know that this circuit should work for our cars (but don't blame me if something goes wrong). I feel confident to test this on my own car when it is ready. Right now, it doesn't even boost because of the stupid cracked crossover pipe. I am still waiting for my TWE Header .

 

One last thing, the 50 ohm pot is to adjust the voltage that the signal gets clipped at. So instead of it getting clipped at the zener voltage (which was 4.3V for this example) we can vary the pot until the clipping voltage is just below the signal voltage that the computer will accept without turning on the fuel cut.

 

Our MAF signal wire is white instead of the gry/red shown in the web page diagram. Our ground wire that we want to use is either the black one or the brown one. Not sure which one to use there.

Thought I would also mention that you need to make you hook the zener diode exactly as it is shown. If you reverse it, then the signal voltage will get clipped at the Von which is around 0.6-0.7V. And it will not let the signal voltage decrease pass -4.3V (but we don't care about this because the signal should only range from 0 to somewhere around 5V) If the signal gets clipped at around 0.6 or 0.7V, then the engine will run lean!! So make sure you got a A/F Mixture Gauge or DVM on the O2 sensor to make sure you don't blow up your engine.

After looking at the FSM, I think the ground that we want to tap into is the one labeled "B". I think that stands for Black.

 

Also, you need to verify what the max signal voltage that the computer can take without appling the fuel cut is. I assumed it was 5V.

 

I am still not sure what the resistance values should be, but the way the circuit is connected is correct.

So, if you were to cut the MAF signal at that point, eliminating the fuel shutoff, wouldn't the engine go lean above that point because the computer thinks that less air is going in?

So, if you were to cut the MAF signal at that point, eliminating the fuel shutoff, wouldn't the engine go lean above that point because the computer thinks that less air is going in?

If I were to cut the MAF signal voltage at the point or just below the point that the computer will accept as the max signal voltage without appling fuel cut, then the computer will tell the fuel pump to send the constant amount of fuel that is required for that amount of air. If you increase the boost very high (which means that more air is going through the air flow meter), the computer will not compensate by adding more fuel because it doesn't know that too much air is entering the engine. So, yes it will start to run lean. Does this make sense.

That makes sense. So if the engine will start to lean out, then why would anybody in their right mind want to do this?

That makes sense. So if the engine will start to lean out, then why would anybody in their right mind want to do this?

The fuel flow as calcualted by the ECU is not an exact science. under full boost, it runs rich anyway. So theres a little bit of leeway between full rich and lean. Enough leeway to go past fuel cut anyway.