My dual FPDM progess

[Black306]

Seems that going dual FPDMs is quite popular lately. :lol:


I'm still waiting for a couple more parts to arrive before I can complete the whole project, but I do have enough to start mounting the FPDMs and do in-trunk wiring.

This was how I decided to mount the dual FPDMs.

It doesn't look like it in the pic, but I can actually get my hand between the FPDM and quarter panel, and there is a enough room between the FPDMs to get my fingers between them.

Now that I had the mounting mocked, I started work on the harness.

I still have to secure the relay, wire in the ground for the 2nd FPDM and relay, and install a plug for the power wire, but for the most part it's done. After I'm done with the above, I'll finish up the harness with wire loom and tape.

Next up, wires to the fuel hat. :thumbsup:

 

[03 DSG Snake]

Looks very clean so far.

How difficult is it to tie into the factor wiring?

 

[Sniperdog]

looks great.,., why two :shrug:

 

[Black306]

Looks very clean so far.

How difficult is it to tie into the factor wiring?

Thanks.

The way I'm running the wires allows me to easily remove the dual FPDM harness and not cut into any of the factory wires. Other than keeping track of what wire goes where for the dual FPDM harness, it's fairly simple.

 

[Black306]

looks great.,., why two :shrug:

Thanks.

I have a Fore hat and GT pumps to go along with it. ;-)

I had a BAP with stock pumps, but my duty cycle was at 90%. I wanted to get it down closer to 80%.

 

[03 DSG Snake]

Thanks.

The way I'm running the wires allows me to easily remove the dual FPDM harness and not cut into any of the factory wires. Other than keeping track of what wire goes where for the dual FPDM harness, it's fairly simple.

Wanna come do mine? epper:



Any more details on how to wire it like this?

 

[Black306]

Wanna come do mine? epper:



Any more details on how to wire it like this?

I have specific lengths on each wire I've setup so far, so it would be pretty easy for me to duplicate. ;-)

What kind of details would you like? I've searched the internet for different schematics and made a few tweaks of my own. I actually edited them and printed a couple pages out while assembling my harness. If you want, I can post them later tonight.

 

[Jomo1994z71]

Yes please do...wiring is so intimidating, lol...even though I did a speedhut gauge install write-up with Brad...

 

[04sleeper]

Looking good Bro! :thumbsup:

I agree that it's not that difficult. You just have to follow the factory wiring and make 1 FPDM harness into 2.

Good idea for the mount. I might have to try something similar.

 

[03 DSG Snake]

I have specific lengths on each wire I've setup so far, so it would be pretty easy for me to duplicate. ;-)

What kind of details would you like? I've searched the internet for different schematics and made a few tweaks of my own. I actually edited them and printed a couple pages out while assembling my harness. If you want, I can post them later tonight.

Anything you can share. The extent of my knowledge is that there is a single FPDM stock, and the harness that connects it.

Not sure how to go about replacing it with two.

I just wrapped up a wiring job on a Nav Headunit no problem, but it when it comes to fuel pumps I'm a lot more nervous. :lol:

 

[boosted2000si]

Yeah that mount looks great!

 

[TheHolyCobra]

I have specific lengths on each wire I've setup so far, so it would be pretty easy for me to duplicate. ;-)

What kind of details would you like? I've searched the internet for different schematics and made a few tweaks of my own. I actually edited them and printed a couple pages out while assembling my harness. If you want, I can post them later tonight.

Any information you have and could post would be greatly appreciated by all of us. :beer:

 

[FlaSeaDude]

Looks good! :beer:

One other way to mount the 2nd FPDM is to make a bracket so that it will attach to the stock FPDM. I actually used part of the bracket from the new FPDM and managed to get them lined up where the connectors are adjacent to each other:

 

[Black306]

First, kudos to whomever first made these pictures available. All I did was take these pictures and make my edits.

This is the basic schematic of my wiring harness.

And here is the pinout for the factory plug.

Let me try to explain what is going on.

In the pin layout picture

• Split means that the wire is split to go from the factory plug to each of the new FPDM plugs.
• Straight means that a single wire goes from one pin on the factory harness, to a pin on either FPDM harness.
• Relay is a split wire coming from the relay, splits, and goes to each FPDM.

I'm going to utilize the factory FPDM plug-to-pump wires to drive one pump. I figure that the stock 14ga wires are rated at ~17A and can power 2 stock pumps to ~400 factory rwhp. There should be no problem powering a single GT pump, supporting half of ~550rwhp, and drawing ~13A. So to keep things equal, I'm going to use a couple unused pins on the factory FPDM plug to run another pair of 14ga wire to power the 2nd pump. This means that there will be a pin cross over on the dual FPDM harness from the 2nd FPDM to the plug which connects to the factory FPDM plug (from pins 3 and 10, to pins 5 and 6 which are pins I selected). I also will be using the factory ground for the Master FPDM. The 2nd FPDM will have the ground wire come its plug, straight to ground. Using the factory wires will reduce the additional wire I need to run, and by using unused pins on the factory harness the dual FPDM harness I made can be easily removed.

Hope this makes sense. :lol:


EDIT: Don't be confused with Master and Slave names for the FPDMs. One FPDM does not drive the other. I simply labeled the "Master" FPDM as the one that returns duty cycle info to the ECU and uses factory wires. The "Slave" FPDM does not return duty cycle info to the ECU and has new wires for ground and to the fuel pumps. I just got the labels from computer hard drives.

 

[CobraBob]

That is a nice setup and a great write-up.

 

[03cobra#694]

First, kudos to whomever first made these pictures available. All I did was take these pictures and make my edits.

This is the basic schematic of my wiring harness.

And here is the pinout for the factory plug.

Let me try to explain what is going on.

In the pin layout picture

• Split means that the wire is split to go from the factory plug to each of the new FPDM plugs.
• Straight means that a single wire goes from one pin on the factory harness, to a pin on either FPDM harness.
• Relay is a split wire coming from the relay, splits, and goes to each FPDM.

I'm going to utilize the factory FPDM plug-to-pump wires to drive one pump. I figure that the stock 14ga wires are rated at ~17A and can power 2 stock pumps to ~400 factory rwhp. There should be no problem powering a single GT pump, supporting half of ~550rwhp, and drawing ~13A. So to keep things equal, I'm going to use a couple unused pins on the factory FPDM plug to run another pair of 14ga wire to power the 2nd pump. This means that there will be a pin cross over on the dual FPDM harness from the 2nd FPDM to the plug which connects to the factory FPDM plug (from pins 3 and 10, to pins 5 and 6 which are pins I selected). I also will be using the factory ground for the Master FPDM. The 2nd FPDM will have the ground wire come its plug, straight to ground. Using the factory wires will reduce the additional wire I need to run, and by using unused pins on the factory harness the dual FPDM harness I made can be easily removed.

Hope this makes sense. :lol:


EDIT: Don't be confused with Master and Slave names for the FPDMs. One FPDM does not drive the other. I simply labeled the "Master" FPDM as the one that returns duty cycle info to the ECU and uses factory wires. The "Slave" FPDM does not return duty cycle info to the ECU and has new wires for ground and to the fuel pumps. I just got the labels from computer hard drives.

Right click save.Copy and paste.
Good stuff,Thanks.

 

[Double-D]

Great write up and pics, Super clean install. I was planning to use two 30amp relays in the system, one per each FPDM/pump. Any opinion on using two?

 

[Black306]

I was planning to use two 30amp relays in the system, one per each FPDM/pump. Any opinion on using two?

Here is my thoughts on the subject. I think 2 relays are overkill and simply add more work/clutter. From what I've read, GT pumps will pull a max of about 25A combined. Having a single 30A relay should work no problem. Even if GT pumps pulled more than that, I would rather run thicker wire and a single 50A relay than wire in 2 relays. Plus, if a relay failed, my car will shut off completely. If a relay went out in a dual relay system, some fuel will still be pumped and may cause the engine to run lean long enough to cause damage.

 

[jm@ReischePerf]

I would rather run thicker wire and a single 50A relay than wire in 2 relays. Plus, if a relay failed, my car will shut off completely. If a relay went out in a dual relay system, some fuel will still be pumped and may cause the engine to run lean long enough to cause damage.

Agreed... keep it simple.

Very nice work with this write up and pics :thumbsup:

Setting this up looks a bit simpler than I thought it would be. Seems everthing is just split to both FPDMs, besides the duty cycle back to PCM. And then each FPDM drives it's own pump... right?

 

[Black306]

Setting this up looks a bit simpler than I thought it would be. Seems everthing is just split to both FPDMs, besides the duty cycle back to PCM. And then each FPDM drives it's own pump... right?

Actually, the only wires that are shared is the control signal and power wire from the relay (if you go with 1 relay). If you go with 2 relays, only the signal wire is shared.

Here is a better pic of the harness I'm making.