Scooby2.5

"Also, you're still suggesting to run higher voltage through the fpcm, although several pages ago, when you first linked the nasioc thread and zorro's work, i thought you were saying his way is a better way to do it? That way you don't risk voltage drop through the fpcm? I'm happy to run it through the fpcm or not - it doesn't bother me either way. Just trying to figure out the best way to wire it and retain full pwm from the fpcm, whilst getting maximum possible voltage to the pump." I was merely trying to say you can run higher voltage to the module and it should be enough to the pump through the module. OR You can run the voltage from the battery straight to the pump via the relay. Either way will work I think. YOU WILL get more voltage to the pump by going direct through the relay instead of through the relay and through the module. The reason I said zorro's is better is because then you dont need to worry about a voltage drop through the module on the positive side. Once I realized from Frank and my own testing that the PWM signal is the ground side, I realized you may as well run voltage straight to the pump via the new relay and let the module just worry about the negative lead. Seems a bit more safe to me this way.....

What would be the purpose of relaying the negative signal that is essentially the ground reference whether it is 0,6 or 8 volts? so in essence why relay the PWM signal going out of the module to the pump?

oy vey! Id say send me a PM, Ill give you my number and you can call me at this point Seems you are making this waaaaaay harder than it is IMHO. Now you are talking about controlling the new relay with the positive output of the FPCM. I guess you could but why would you want to?

dr20t if you are in AUS, I would def get the fuse from hkb like I posted earlier.

The diode trick works great, and the MK3 fuse with diode I posted works GREAT and is factory like. Its a bit expensive but by the time you purchase the wire if you dont have any, and make one up like others have done to plug into the fuse block its worth it I think, but I am OCD a bit...LOL

What I plan to do to mine is put larger gauge wire from the module to the pump on both the negative and positive wires just like the STI. Then I am going to feed the FPCM with the relayed battery voltage with the DW kit. This way I have max voltage going to the Module (just like the STI) I will use the TINY old feed line that went to the module to turn "on" the relay. That is the way mine is wired now, I just dont have the larger guage wire running from the module connector to the pump. I purchased a factory STI fuel pump plug and I am going to splice it in or remove the pins and wires to make it as factory as possible. The whole point to this was not only was the STI using larger guage wire to and from the module to the pump. The STI had larger wire with more voltage feeding the Module off the fuel pump relay. Our factory wire off the fuel pump relay (actually under the dash on passenger side in US) is too small and drops way too much voltage to use as a feed to the STI module. I guess you can but Im trying to mimick the STI setup and see what happens. If it doesnt work, Ill run the positive side to the pump, feed the module with the factory voltage lead, and use the larger wire from the module to the pump on the negative side as you suggest. Good luck!

Ok first off the POSITIVE lead to the pump is not PWM Only the NEGATIVE lead is. Just use a regular old good quality relay to turn on and off the direct battery feed from the battery using the old fuel pump relay signal Now you have two choices. Off this new battery fed relay....... 1. Feed the FPCM 2. Feed the pump direct The NEGATIVE lead off the FPCM is THE PWM signal. Just run a larger wire from the FPCM connector to negative side of the pump. Lets say your alt/batt voltage is 14v The POSITIVE side of the pump will have 14v if you wire direct to the pump off new relay. If you feed the module off the new relay and go through the module to feed the pump like factory you may have a smaller voltage on the positive side like say 13.7 This drop could cause the potential difference between the neg PWM signal and the positive to not quite be the 13.5 or above you need. It depends on how much voltage on the positive side the module drops on its output. So do it however you want and see what you get. The negative side (PWM signal) is not relayed or anything. You just run a larger wire from the module to the pump so there is less voltage drop on the changing ground. This make sense? Feel free to correct me if I'm wrong Frank

Yea as some of the other guys pictures show they ran and large gauge wire from the battery to a block in the back. Then fed the relay and the module if I remember correctly. I did forget to mention that this last time but of course you have to feed the module something or it wouldn't be powered at all. Sorry about that Again you could try feeding the module off the new relay and running larger wire from the module to the pump and see what it does. Either way you are still feeding the module more voltage than before.

Like Frank said, just feed the batt voltage from the new relay to the pump and to the FPCM. If you want to try it you could just feed the FPCM and then replace both wires from the FPCM to the pump with larger wire and see what you get. I think if your initial voltage from the battery is good then you should get at least 13.5 if not more to the pump from the STI module. We didn't mess with KCs anymore but he did at some point have to change his alternator out and it puts out 14.2 so his could be at 13.5 now but don't know. Don't forget we were using a meter so the readings we were getting could have been off since that neg leg is PWM. If I remember correctly if we measured his positive leg in reference to true ground he was getting more. The PWM neg leg can give you weird averaged readings so as others said best to use a scope. When I re-do mine I am first going to increase wire gauge both pos and neg from module to pump and see if mine is at or above 13.5. If it is I am going to keep it that way. If not I will wire from new relay straight to pump on pos side and just use larger wire on neg side like I suggested above. Don't forget Franks suggestion of the alternator mod. Subaru alternator voltage is notoriously low, so none of this helps too much if your alt is only putting out 13.5-13.8 in the first place. The goal here is to have 13.5-13.8 at the pump and with voltage drops etc the alt needs to be putting out more to begin with

1. New wire From battery to new relay 2. Existing fuel pump relay wire, which used to feed the fuel pump control module now controls the new battery relay (turns new relay on and off with key on). 3. From the new relay large wire to the pump. This will give you true battery voltage at the positive side of the pump...... The negative side wire that comes from the fuel pump control module to the pump needs to just be replaced with a larger wire, its the PWM signal. Done. Now you have direct battery voltage to the pump via the new relay and wire from the battery, controlled by your factory fuel pump relay (on off key signal). You also have a large wire now going from the module to the pump on the "negative lead". The negative out of the module is a changing voltage leg (ground) depending on what the ECU asks for. 33, 66, 100. All the module does is change the ground reference. At 100 percent the module outputs basically 0, at 66 percent it is approx 12 and at 33 percent it is approx 7. That way the difference between 13.5 to "ground" 0,7, or 12 is what determines the potential difference at the pump and drives the pump at the different speeds. see post 127 and 131. Only difference is the negative lead to the pump should be coming off the module instead of just straight to ground which gives you the varying speed at the pump.

Well I am starting to have a problem with mine. Its seems some of the leds are not lighting up. For example where it says boost during boost, one of the O's looks like a backwards C. Its doing this on both displays. I havent had this very long 4/5 2012 so maybe I can get it replaced?

I just did this mod with the MK3 PTC diode fuse from Australia. They have been doing this for years on the japanese imports. Notice he has added Subaru to the list as I ordered and installed one of these MK3 diode/PTC fuses. http://www.hkbelect.com If you email this guy he will give you a discount Here is a thread on NASIOC and this will for sure help the fuel pump voltage issue, although wiring should still be changed etc. http://forums.nasioc.com/forums/showthread.php?t=1602651 My alternator voltage is around 13.8 when warm. By the time the voltage drops through the circuits in the car I was low. Now I am putting out 14.5 pretty much all the time. I have a AGM braille battery which when fully charged should be 13.8 volts, 12.6 at rest. It needs 14.5-14.7 to charge it properly according to braille. After doing this mod my battery is 13.84 when car shut off and 12.6-12.8 after resting. I am sure my pump is now running easily 13.5 volts.

Correct output wire of FPCM will not control relay as heiche said. You have to do it like many others have said and the many drawings in this thread. The wire from the stock Fuel pump relay is used to trigger the new relay. dr20t Why change it from what the pump manufacturers recommend? See wiring diagram posted in this thread from Aeromotive but just keep you FPCM in place. If you dont think the FPCM (sti or otherwise) can handle the current then I would just purchase the DCCDpro.com FPCM and be done.

Yep JDM = right hand drive so booster would be on the opposite side of car and tube would be on inside closee to manifold The ideal STI master cylinder set up is the 05-07 (?) Bosch unit with the numbers I posted in another post somewhere. If it didn't have Bosch and those numbers I wouldn't get it personally. Just my opinion but that is what I did

Need to get on that my man some of us waiting.........LOL! Sent from my iPhone using Tapatalk 2

I posted somewhere in this thread the numbers to look for as well as Bosch on the sticker....

Get a hold of these guys if you want an older STI one. http://y2kimports.com

The 2011 STI booster seems to be similar to the legacy and the WRX I wanted the Bosch booster so I looked around until I found a good older one. Let us know how it works out

^Simple fix on the wiring harness...... Pull the yellow tab on the connector plastic. Pop the pins out and insert them in the new plastic and then reinsert yellow tab http://www.ebay.com/itm/Subaru-Ignition-Coil-Wire-Harness-Terminal-Plug-Set-Impreza-WRX-STi-Connector-/300843950050?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ASubaru&hash=item460bb25fe2&vxp=mtr

Good Job

Good luck putting the AVO one on without removing the intake manifold. It is very large and not an easy task. I chose to go with the Perrin because it is smaller and much more easy to install with the intake still on the car. Even with the Perrin It's still not the easiest thing to do especially if you have an aftermarket turbo

Looks like from reading the mapdccd instructions you can add the vehicle speed sensor signal in. You are going to have to pick it up somewhere in the car but not sure where. We dont use the transmission signal so what I would do is try to intercept it down by the ECU under the passenger side carpet. That is where I picked up TPS signal so I would do it there. DCCDpro included those red or blue knife splice connectors to just intercept the signal without a cut and splice so its in parallel.