legacycentral bbs

ok,
so I have a hks universal fcd left over from a prev project, and am thinkin about putting it in the wagon after I get theh intercooler in there so I can run about 14 -14.5 psi.
question is this,
has anyone put one in? if so, what wires were needed to tap in to ?
if you used the hks one, what setting did you use ( hks site says to run it on setting 10 for the wrx, I would assume ours is probably the same but not sure. )

thanks for any help.
Nate

I have one a friend custom-made for like .. 20$CAD .

but it's not in the car yet, need to solve hesitation prob. and weather must get warmer

nyway, if you ever install it, would be nice to have some details !

ok will let you guys know when I figure it out,
hks has install instructions on thier website for the wrx, and since I got the factory manuals for the wrx when I got mine I am going to see if I can track down what goes where with that. will post any info.
but if anyone has done this, please let me know.

thx
nate

morgie, what kind of circut is it? I'm thinking a voltage clamp? Could you maybe post a diagram of it?

the diagram i used use 5 wires. it assumes that the pressure sensor has 4 wires... i didn't checked the one in the legacy, wich has only 3 wires. nyway.

the circuit is simply a potentiometer set at a certain voltage.

Pressure is a signal from 0 to 4v. 8.7psi is like 3.2v. You set the Pot at this voltage, so everithing exceding 3.2v will be kept at 3.2v. So even if you push 14psi, the ecu only sees 8.7psi.

so now i'll have to see the diagram of our Pressure sensor so i can fit the wires

hehe

The complete doc. i used is there :
http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

(HKS FCD is 250$CAD + tax here... and the parts are worth 20$ that a big profit they make !! )

I thought fuel cut was at 16 lbs. it's art 14? That would explain why I'd get a single blip of hesitation at WOT when my MBC is set a little too high.

fuel cut is at 13 psi, if your boosting past 13 psi fuel cut should keep reoccuring, and it's a fairly violent experience.

Mark,

I always thought boost cut was at 13. guess that's at 12 or something. With my MBC I get a momentary spike if I downshift with the loud pedal instead of manually downshifting then hitting it. when the tranny is doing it's thing and the engine is under load, I'll get a spike. as soon as it's in gear, it settles back down. I think the spike is my problem.

I have one installed on my turbo legacy. I didn't install it, though. Here's the thing:

While wiring in some other mods, I accidentally disconnected the connection from the MAP tie-in. When I reinstalled the unit, I got a CE light. I disconnected the unit from the interface (it only requires a power, ground, and a tie-in to the MAP sensor) I got rid of the CE light. Funny thing is, I'm boosting to 1.1bar, well over the stock fuel cut . . . which makes me think either 1, the fuel cut isn't at 13psi, or 2, I have a very generous ecu.

Before you guys start doubting the validity of my boost gauge, let me just say this . . . I have the boost gauge T'd into the bypass valve AND I swapped out my mechanical HKS boost gauge for a Blitz electronic unit . . . both gauges showed the same amount of boost before and after the swap.

Boostjunkie, is it possible that you have a leak or intentional bleed in the line going to the pressure sensor from the manifold? That's kind of a poor man's fuel cut defender.

Not really sure . . . I'll have to check.

Thanks morgie, just what I thought. I'd try to set the clamp closer to the boost cut, let the ECU know what is going on up to around 12-13 psi.