Turkeylord Posted October 20, 2013 Author Share Posted October 20, 2013 I thought about it, but I think you'd want to replace the supply to the relay too. Pretty sure I remember reading that it's in the passenger kick panel. Link to comment Share on other sites More sharing options...
Th3Franz Posted October 20, 2013 Share Posted October 20, 2013 (edited) The factory fuel pump relay is in the passenger kick panel. Might be trickier to run the wire from there to the FP, but maybe not. You still have the problem of the voltage drop through the FPCM harness. Has anyone experimented with running the PWM voltage+ signal from the FPCM straight to the new relay sense input? Most relays have a 25ms delay so with a high frequency PWM signal, the relay should stay latched and not care. I am considering trying this out first. I ran the 12AWG wire from the battery to the fuel pump area. I'm going to perform this experiment this week with extra long wire in case it doesn't work out. Also, a small shunt capacitor could be added to level out the PWM voltage if the relay doesn't stay latched closed. Edited October 21, 2013 by Th3Franz -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 21, 2013 Share Posted October 21, 2013 (edited) Did anyone consider running a thicker wire from the factory fuel pump relay to the FCM (and then from FCM to the pump)? Essentially replacing the wiring only and avoiding the extra relay? One less thing to malfunction (and the generic relays are often of dubious quality). If you add the relay for wiring direct to the pump it really is not changing it much from stock. Stock has a keyed on relay. So power to the coil on the relay and direct feed from that relay to the FPCM. With that said as small as the wire is feeding the stock relay I would guess that the rating on that relay is pretty small and wouldn't handle the voltage and current draw of the larger pumps. The way it's being wired now we are just using the old one as a key on signal for turning on the new relay so it should be fine. Purchase one of the premade kits from DW or aeromotive. Both seem to have good wire and the relays seem robust Edited October 21, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 21, 2013 Share Posted October 21, 2013 (edited) The factory fuel pump relay is in the passenger kick panel. Might be trickier to run the wire from there to the FP, but maybe not. You still have the problem of the voltage drop through the FPCM harness. Has anyone experimented with running the PWM voltage+ signal from the FPCM straight to the new relay sense input? Most relays have a 25ms delay so with a high frequency PWM signal, the relay should stay latched and not care. I am considering trying this out first. I ran the 12AWG wire from the battery to the fuel pump area. I'm going to perform this experiment this week with extra long wire in case it doesn't work out. Also, a small shunt capacitor could be added to level out the PWM voltage if the relay doesn't stay latched closed. First the positive leg is not PWM, only the negative lead out of the module is. See original thread. Second someone did that in the other thread and sometimes the new relay would not turn on. Its in the last few pages. Why everyone is trying to come up with a different way to do this all the time is baffling me. Even the pump manufactures are providing drawings on how to do this for their pumps. The only thing different we are doing is leaving the FPCM in the circuit. Why we have two threads to keep track of now on the same exact subject is irritating. We could have just put the write up that was done at the beginning or end of the other thread Edited October 21, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
SBT Posted October 21, 2013 Share Posted October 21, 2013 I'll merge these two if you all want to do that. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Turkeylord Posted October 21, 2013 Author Share Posted October 21, 2013 No, that thread has tons of good info but its sooo spread out and some of it contradictory/learning process. I'll try to get general questions directed over there & add a note to the OP. Some of the recent questions/answers could get moved over there maybe... Link to comment Share on other sites More sharing options...
Th3Franz Posted October 21, 2013 Share Posted October 21, 2013 First the positive leg is not PWM, only the negative lead out of the module is. See original thread. Second someone did that in the other thread and sometimes the new relay would not turn on. Its in the last few pages. Why everyone is trying to come up with a different way to do this all the time is baffling me. Even the pump manufactures are providing drawings on how to do this for their pumps. The only thing different we are doing is leaving the FPCM in the circuit. Why we have two threads to keep track of now on the same exact subject is irritating. We could have just put the write up that was done at the beginning or end of the other thread I see now that Turkeylord tried what I had in mind. No doubt the capacitors would keep the relay latched after the key is turned off. So, I'll tap into the black/red wire. I was just looking at a possible easier/cleaner way, but I know better now. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 21, 2013 Share Posted October 21, 2013 (edited) By the way franz where did you source the pins. Id like to get some. I cannibalized some other connectors to get mine but would love to have some. I think it was you that found them? Edited October 22, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
Th3Franz Posted October 21, 2013 Share Posted October 21, 2013 Yeah I put them in a post on the previous page. I'm planning to finish wiring it all up on Wednesday. pin: Sumitomo HX|SL|DL Sealed Series 090(2.3mm) 1.25-2.0mm2 Female Terminal [Copper/Tin] 9882 http://www.newunitedracetech.com/shop/sumitomo-hxsldl-sealed-series-09023mm-12520mm2-female-terminal-coppertin-p-9882.html?cPath=19_658_676_681_931 Sumitomo HX/HW/DL/SL Sealed Series 090(2.3mm) Wire Seal 1.7-2.4mm2 [Green] 5mm Dia 10057 seal: http://www.newunitedracetech.com/shop/sumitomo-hxhwdlsl-sealed-series-09023mm-wire-seal-1724mm2-green-5mm-dia-p-10057.html -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
SBT Posted October 22, 2013 Share Posted October 22, 2013 I plan to go through this and the other thread and develop a spreadsheet of everything I think I'll need to do this plumb, square and true, end-to-end. I'll post it up when I get through with it. Few other admin things ahead of this, but on my TD list. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Guest Posted October 22, 2013 Share Posted October 22, 2013 ^ I am about to place an order with Waytek for the relay/socket/fuse/wiring. I think DW's kit is overpriced and who knows what quality relay they are including. I will add part #s. Btw, I think pins/crimping is definitely the way to go. I have been always under impression that soldering wires is not recommended for car environment. Link to comment Share on other sites More sharing options...
quick4dr Posted October 22, 2013 Share Posted October 22, 2013 http://shop.zzperformance.com/store/p/72-Fuel-Pump-Rewire-Kit.aspx someone should make this Link to comment Share on other sites More sharing options...
SBT Posted October 22, 2013 Share Posted October 22, 2013 You realize that Deatschwerks already does, for about the same price, right? Link - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Turkeylord Posted October 22, 2013 Author Share Posted October 22, 2013 I just bought a 22750AA010 from an '06 STi. I'll do some direct A/B comparisons to the stock FPCM when I get it. Link to comment Share on other sites More sharing options...
SBT Posted October 22, 2013 Share Posted October 22, 2013 (edited) Here's the spreadsheet as promised. Let me know if I've missed anything, or if there's anything else someone wants to add.Legacy GT FPCM Wiring Upgrade Parts List.pdf Edited October 22, 2013 by SBT - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 23, 2013 Share Posted October 23, 2013 (edited) Give credit to Zorro, for doing this and figuring it out first. When it comes to wiring direct to the pump on the pos side and then leaving the neg PWMS alone. IMHO 10GA:eek: wire is complete overkill for a 13.7 15-20a circuit. 12ga is more than adequate and fits in the pins much better. Edited October 23, 2013 by Scooby2.5 Edited-out deleted quote Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 23, 2013 Share Posted October 23, 2013 ^ I am about to place an order with Waytek for the relay/socket/fuse/wiring. I think DW's kit is overpriced and who knows what quality relay they are including. I will add part #s. Btw, I think pins/crimping is definitely the way to go. I have been always under impression that soldering wires is not recommended for car environment. Relay seems to be top notch from what I saw. I installed the DW kit. I am an EE major and work for a one of the 4 main Xray companies Toshiba. I deal with this stuff all the time and the stuff from DW and Aeromotive seemed to be great stuff. I personally would crimp and solder the pins but thats just me. I did that as well as heat shrink wrap the connections. To each his own though..... Link to comment Share on other sites More sharing options...
Turkeylord Posted October 23, 2013 Author Share Posted October 23, 2013 No upgraded 12v feed to the FPCM. We only need the FPCM to handle the ground side for PCM fuel pump duty cycle. We tap into the +B terminal to power our relay's coil, completing the upgraded 12v feed direct to the pump positive side. the positive pump connection to the FPCM is disconnected (I unpinned the terminal). I'll take a hack at your diagram. Link to comment Share on other sites More sharing options...
Turkeylord Posted October 23, 2013 Author Share Posted October 23, 2013 IMHO 10GA:eek: wire is complete overkill for a 13.7 15-20a circuit. 12ga is more than adequate and fits in the pins much better.Yes, it's not like the stock wiring is burning up as it is, but if the idea is to eliminate as much voltage sag as possible bigger is always better. Taking a look at the admittedly academic example below, anyone wanting to do this mod can determine their own point of diminishing returns and pick a gauge to go with. Great point. Just doing a little exercise in the maths... Assumptions: 30' of wire in the circuit, DW65c pulling 11.65A@45psi, 13.8V alternator voltage, ignoring connection losses. You could expect to see: 18awg: 11.84V 14awg: 12.95V 12awg: 13.25V 10awg: 13.45V So even with 14awg you'd pick up over 1V. I had the 10awg Green/Yellow laying around so I went with that. Link to comment Share on other sites More sharing options...
quick4dr Posted October 23, 2013 Share Posted October 23, 2013 has anyone used the DW kit yet? or recommend it? Link to comment Share on other sites More sharing options...
Turkeylord Posted October 23, 2013 Author Share Posted October 23, 2013 (edited) I rolled my own, but that should be everything you need. Can anyone confirm that the 15' red and 5' black wires are long enough to get the job done? *EDIT* I'm pretty sure I needed more than that. Edited October 23, 2013 by Turkeylord Link to comment Share on other sites More sharing options...
Th3Franz Posted October 23, 2013 Share Posted October 23, 2013 I'm installing the DW kit later today. The relay looks decent enough with pig tail wires. Solder and heat shrink the other wires and go. -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
SBT Posted October 23, 2013 Share Posted October 23, 2013 Updated wiring diagram with changes incorporated. Thanks everyone for the input on this. LMK if we need to fix anything else. Can create alternative solutions as well, just let me know what you want/need.Legacy GT FPCM Wiring Upgrade Diagram (SBT) 10-23-2013 v2.pdf - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 23, 2013 Share Posted October 23, 2013 has anyone used the DW kit yet? or recommend it? I did and with the pigtails on the socket it was long enough. you can see my pictures earlier in this thread I believe. Link to comment Share on other sites More sharing options...
Scooby2.5 Posted October 23, 2013 Share Posted October 23, 2013 Yes, it's not like the stock wiring is burning up as it is, but if the idea is to eliminate as much voltage sag as possible bigger is always better. Taking a look at the admittedly academic example below, anyone wanting to do this mod can determine their own point of diminishing returns and pick a gauge to go with. Yea I understand the math BUT, 10ga massive wire into the connector pins, through the fuel pump rubber plug etc etc is not worth .2 volts. I am not sure you would even see that much drop on an actual meter. If you want to pick up a few more tenths of a volt do the diode mod. 13.8 is low for a alternator anyway hence the reason the toyota guys came up with the HBK fuse. If you have a Braille battery like I do, 13.8 isn't even enough to charge it well according to the Braille specs. I used 12ga throughout my whole modification. Link to comment Share on other sites More sharing options...
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