Hi All,
During my fuel pump research I haven't been able to come across anybody clearly documenting how and what parts they used when installing a single pump on the factory fuel hanger. I found some discussion in the thread Walbro 450 Questions but note really any specific details. My understanding is that the 525 pump is the same shape and design as the 450 so the comments from that thread should apply. My intent with this thread is to first put my questions out in the open to see if anyone has already answered my questions. Secondly I will try to well document the process; mainly how I did the install and any regrets after the fact to make it easier for people to search in the future.

First just a small touch of backstory.
I'm in need of a fuel pump upgrade as the current Walbro 255 won't cover the fueling needs of a 8374. A single Walbro 525 "Hellcat" pump should more than cover my power goals. These are F90000285 with a check valve and F90000295 without a check valve. My understanding is that having a check valve doesn't seem to be required, the result would just be needing to wait a few extra seconds prior to starting the car to let the system pressurize. I'm also Canadian so I want to minimize buying a bunch of specialized parts in multiple smaller purchases so I don't throw a bunch of money to shipping costs. I also intend to keep the functional fuel level sensor as well.

Here is some highlights from the Walbro 450 Questions thread.

• The pump is not a direct drop in pump
• IRPerformance developed a mount that could be used to mount the pump directly to the factory hangar but it appears that he is no longer around and no one else seems to offer anything similar.
• The general consensus is that the factory wiring plug is insufficient to supply the increased electrical load to the pump
• The install kit type may come with either the corrugated plastic in tank fuel hose or the rubber in tank fuel hose.
• the pump outlet is 3/8 OD and the stock pickup is 5/16 OD.
• There are comments that the filter that it comes with cannot be used
• Post #9 shows a Walbro 400 installed with some comments, it answers a few questions but still leaves me with some questions. There is also a comment saying the 450 is a little different from the 400 in the post

My thoughts are:

• The install kits seems like a waste of time as the plastic fuel hose and filter are likely not useful in our configuration.
• The general consensus elsewhere on the internet seems to be that a 3/8OD rubber hose can be clamped down onto a 5/16 size pipe but this wouldn't be the most ideal setup. Alternatively a 5/16 hose could maybe be stretched over the 3/8 outlet. Maybe just a straight 3/8 to 5/16 nipple adaptor would be the best option in the tank if intending to continue using the stock piping. Obviously the smaller hose would be a restriction but without a plan to upgrade the entire fuel line this isn't going to change.
• If upgrading the whole fuel line system to a larger size then the ideal solution might just be to cut off the stock fuel pipe, drill through the cap and use a bulkhead fitting.
• Potentially the physical install could be as easy as modifying the rubber bottom but doesn't there need to be more to hold the pump in place, Post #9 from the thread doesn't really show anything physically holding the pump to the stock arm unless I'm missing something.
• Maybe its either the rubber or some other physical mount as the other pictures ion the thread show the rubber not being used with the physical mounts. it also looks like with this solution any filter could potentially be used.
• The wiring should be upgraded. In the thread it was mentioned that these terminals were used by one of the installers to repin the connector. Sumitomo HX / DL / SL Sealed Series Female terminal 18 - 16 AWG Terminal, loose piece
• Does this re-pinning only correct the in tank side of the stock plug or are the same pins used on the external plug as well?.
• Banzai-Racing appeared to be working on a full solution but I couldn't find anything on their store.

So lastly assuming that there is no complete kit (which I have so far been unable to find on my own), I have tried to decide come up with my own parts kit:

1. Walbro F90000295 Fuel Pump from a trusted vendor
2. Unknown mounting mechanism, this is probably one of the biggest questions I still have, I've seen other peoples clamp styles so maybe I try to make my own design and make something up on the lathe and mill. I don't really just want to use a hose clamp or some other sketchy mounting method.
3. 17-0031 DIY Fuel Pump Wiring Kit I want to upgrade my fuel pump relay as well. so a kit like this gets me the relay and the lead for the pump inside the tank
4. I want to look into the pins more when I get out on the car but it seems that a quantity of Sumitomo HX / DL / SL Sealed Series Female terminal 18 - 16 AWG Terminal, loose piece or similar will be required
5. 18-0030 EFI Hose Clamp, 11.5-13.0mm I'm not a fan of worm gear clamps, something like this would probably be better
6. Submersible Rubber Fuel Hose for 10mm Barbs 1 foot of hose should be enough I think but I should probably go measure my carrier before ordering to be sure. I'll update this once I confirm.
7. The bulkhead fittings I'm a little less sure on. I was trying to find everything in one place to minimize the shipping but this is the closest thing I could find on the radium website. 14-0670 6AN ORB with 10mm Barb to 6AN Male Bulkhead I don't think it will work though, it talks about threading and chamfering the mating part which I believe the fuel tank lid would be too thin to do properly. something like Bulkhead, -6JICM»-6ANM»10mm Barb, BLK* is more what I think would be required.
8. Lastly something like 14-0203 PushLok Hose End, 6AN, 90Deg will be needed to get back to the fuel lines on the car. Depending on what I do this may change. Mainly if I go to an aftermarket fuel filter and depending on where I mount it I may change the outlet. Having a fitting instead of trying to pry the fuel hose off sure would be an upgrade over stock and is probably one of the main reasons to use the bulkhead. I'll probably leave the fuel return completely untouched.

 

I recently upgraded to a Walbro 450 and had a few of the same questions and issues as you. After sifting through numerous threads on the forum I decided on the following solution.

I bought a mounting bracket from Core Components for the fuel pump https://ccfablab.com/product/cc-fuel...pter-rx7-fd3s/ (decent piece but overpriced and fitment is not the best. I wish the IRP bracket was readily available.)

Also this fuel pump adapter from Radium to fit the 8mm rubber submersible fuel hose. https://www.radiumauto.com/Fuel-Pump...ers-P1041.aspx

I used the radium stud kit for the bulkhead connections/upgraded wiring passthrough. https://www.radiumauto.com/Electrica...ack-P1049.aspx (modified the sleeve length to fit the thin bulkhead of the FD)

Let me know if you have any questions but this seems to be working although still waiting on proper tuning.



-Richard

 

It been pointed out that the repining of the stock connector likely is a bad idea as the connector is still likely only rated for the applicable wire size. Since the larger size of cable for the connector (Sumitomo HX / DL / SL Sealed Series Female terminal 18 - 16 AWG Terminal, loose piece ) is 16AWG, the connector is likely only rated for about 10-13amps. for reference a Walbro 255 should only draw about 8-11 amps but the Walbro 525 would likely draw about 18-20 amps.
A better solution would likely be to either use a higher rated wire bulkhead or some individual stud bulkheads
Venom-X1 used the radium stud kit as mentioned in this thread
Molotovman recommended this bulkhead in my other general thread. Although looking at the specs each wire is only 14 AWG and the rating is still on edge of the 525's capability. you could use both sets of wires for one pump to double the effective rating.

in the radium fuel pump relay kit they have recommendations for wire gauge per distance.




Also can you not edit posts after a certain amount of time passes? I was going to edit out the poor information in my original post but it doesn't appear to be an option to me anymore.