Dual hellcat 525's
 

In considering various fuel systems, the Dual Hellcat 525's is one option where you run them staged, through the use of a hobbs switch or better yet, control it through Holley EFI. These are the same physical dimensions as the walbro 450's so getting them both in tank should be no problem. Dual 450's max out around 1100hp on E85 at 85% duty cycle using ID2000's, so dual 525's will give you some more room to play. This entire system combined reflected in the parts list below cost less than a single 3.5 Aeromotive brushless pump. There are several threads on modifying the stock bucket to accommodate multiple pumps. These can be seen in the following links:

https://ls1tech.com/forums/fueling-injection/1530926-my-plastic-bucket-mod-dual-walbro-pumps.html
https://ls1tech.com/forums/forced-in...omplete-2.html
https://ls1tech.com/forums/fueling-i...k-cheap-5.html
https://ls1tech.com/forums/fueling-injection/1345276-dual-walbro-wiring-install.html

So I wanted to generate a parts list that is specific for a 99-02 F-body for running these pumps in tank based on the knowledge accumulated over the years. Everything from fittings to electrical. There are several companies that make wiring harnesses to accommodate dual pumps. You can even make your own. There are several types of submersible in-tank wiring harnesses for various pumps, but the use of dual Hellcat 525 pumps will require the dual in-tank wiring harness described as "ITWH, DP, MP150/280 > 2 x DCSS" The 450 walbro pumps use that same harness, while racetronix pumps tend to use ITWH, DP, MP150/280 > 2 x GSS. There's 2 different part numbers for each, depending on if you want 8" in length or 12" in length. An easy plug and play solution is to go with the racetronix DPWK-022 kit and select the DCSS in tank harness. You may want to see if a 2 PSI pressure switch can be used. There are other options from other vendors. Now you can make your own in tank harness to a custom length and purchase the individual parts contained in the kit separately, but you'd only be saving about $30. I'd rather deal with the extra wire length in the bucket than have to make my own harness.

DPWK-022 comes with:

UDP HD Fuel Pump Wiring Harness (MP280) UDPH-005
HIH-001 - Hobbs interface harness 72" DPK
HPS-? - Hobbs Pressure Switch, ?PSI, SPST M/P280S (select PSI based on application.)
IDPH-F99-HD - Intermediate Double Pump Harness Kit F99 (note that this part on it's own currently doesn't have the option to switch out the GSS harness for DCSS)

Walbro makes a stand alone kit for the 450 or the 525 part number 400-1168 which includes the filter, single pump harness, submersible hose, clamps, etc but it would be a waste to purchase 2 of those since the wire quality is not as thick as what you get in the racetronix harness. Plus you'd have to modify 2 harnesses into one, so it makes more sense to simply purchase the filters and shorter length 10mm submersible PTFE fuel hose separately rather that buy two of the 400-1168.

Below is a schematic for the system being described, but note you can use your factory feed line as the return line. I figured I'd just run an 8AN return line an future proof the system. Injectors and fuel rail not included. Again, this is only one option and there are several ways to go about this.

https://cimg6.ibsrv.net/gimg/ls1tech...31ea5e470d.jpg

https://cimg5.ibsrv.net/gimg/ls1tech...1f6e5b4744.jpg

You are much better off running the fuel in a full circular path than the way it is depicted in your diagram.
Our FLK-F99 is all you need for lines, fittings, filter, reg, rails etc. One source, one brand, one knowledgeable source of support.
https://www.racetronix.biz/customkit...asp?kc=flk-f99


We offer a DPC and bulkhead for coupling the pumps:
https://www.racetronix.biz/product.asp?ic=dpc-jm8b38

Harness solution for F99
UDPH-005
IDPH-F99HD
DP-ITWH-042
HIH-001
HPS-7 =>

I can see running it in a circular path on a dedicated track car, but for a mostly street car, do we really want all that heat getting in the fuel and dumping it back into the tank? Long trips would not be good. I was told that for a street car, the system should be setup as a dead headed configuration. Am I mistaken and the cons of running it dead headed even for a street car outweigh the pros of running it in a circular path?

Do the fuel rails in the FLK-F99 work with the holley sniper 822102-1 intake? What O ring size do the fuel rails in FLK-F99 accept? I like the fact that these are 3/4 fuel rails. The ones holley recommends are 850002 and those are only 3/8"

An plans for a Dual Pump Coupler, -10ANF » 2 x 3/8" Barb in the future?
I see that your kit is 8AN / 6AN. I was told to run 10AN / 8AN to future proof it.

Full circular flow is best for ALL apps. Regulator should be the last item in-line before returning to tank for most stable regulation at all rail points.
Deadhead config is junk!
Our rails take std 14mm LS1/LS6 injectors.
Rail mounting is same as factory. We are pretty sure some customers have used them with the Sniper intake.
-8 Teflon fittings and hose flow enough to support 1500HP so why would you require -10?

Will get rid of the dead head routing. Since I'll be running Bosch 2000 injectors on E85, will probably also get pulsing because of the injector size if going dead head route. Bosch 2000 injectors 0280158821 are available in 37.5mm length in Denso and 48mm in EV1. O-Ring is 14.5mm Viton and will be swapped for 14mm. Sniper intake and fuel rail combo calls for 37.5mm injector length. Originally not looking to not have to mess around with adapters to accommodate length of injector or adapters for wiring harness, but the fact that your fuel rails are 3/4" may cause me to reconsider. Was planning on running holley dominator setup but don't see an option for Denso plugs. Do you sell the Denso plug ends so that I can just modify the holley dominator EV1 558-200 wiring harness so that it has denso plug ends?

We offer connectors, pigtails and PnP injector adapters for Denso type A & B connectors.

I believe I need type A which is RCS-042. Thanks again! I'll just get those along with a 10 Way Delphi Metri-Pack 150 Female Connector Kit and make a nice harness for my injectors.

https://docs.rs-online.com/ffc8/0900766b812ba8a5.pdf

100% agree with this. I'm glad I'm not the only person who thinks this. Having the regulator AFTER the rails ensures both rails are getting the most possible flow/volume from the tank.

We normally run the feed line to a Y at the engine, then to the front of both rails, the out of the back of the rails we go into the regulator then obviously back to the tank. We run the feed in the front, so under a hard launch, the fuel is going the same direction.

Looking at the racetronix kit above, the routing would be something along the lines of the image below based on the fittings included in the kit. Very straight forward and simple. If running it the way you suggest, only a few more fittings would need to be purchased. Do you run a continuous line from the engine bay all the way back? The pic below shows where dlandsvZ28 used 45 degree fittings in order to route the line because of the space required to make a 90 degree arc in the fuel line. Certainly something to consider if using line that is not flexible, which most stainless steel PTFE isn't very flexible.

https://cimg1.ibsrv.net/gimg/ls1tech...ff45e57805.jpg


https://cimg1.ibsrv.net/gimg/ls1tech...ba3bafe73d.jpg

The filter on that might get a bit tricky. You may have to Y off in front of the filter, put dual filters and Y it back. Or put a Y, run 1 line to each rail, put a Y after the rails to your regular, then back. I used an Earl's filter as it had enough flow for 2-450 lph pumps. I do not recall if it could handle 2-525's or not. Also, if you have no messed with the 525's, they use an 11mm outlet, not the 10mm that all the rest use. Maybe an easy fix, maybe not depending on your set-up.

Nice image!
This configuration is simple and provides the most stable pressure possible. A y-block is not required unless HP starts approaching 1500. If the PTFE fitting nipples are used to measure the length of hose it is possible to be accurate within 1/4" which enables use of the 90° -8 ORB fittings for the crossover line. The FILTER-1212B in our kit c/w a billet bracket so it is easy to mount it at the back of the car. The 10-micron SS magnetic element flows more than enough fuel for 2 x F90000285 Walbro (525) pumps. All these parts are included in our FLK-F99 kit.

I think I ignored the Racetronics filter because they have no specs posted. This one flows 460 gph @ 10 micron:

Earl's 230631ERL -12AN Fuel Filter

Thanks for actually looking this all over. I did see that the 525's require the 11mm outlet, but I don't think racetronix sells 11mm ID so I'm assuming 10mm is just used in that application? If not, I can source the 11mm PTFE corrugated line elsewhere.

Your kit is actually cheaper than what I priced out separately. I'm assuming the fuel rails are compatible with the BTR IMA-03 intake? Do you offer a pump that is equivalent to the F90000285 Walbro (525) pump?

Fuel tubes can be thermally expanded as done from the factory.
https://www.racetronix.biz/product.asp?ic=f90000285

Since I did not see anyone specifically mention this, running a deadhead system is still heating up all your fuel going through the pumps. It probably dumps more heat into your fuel tank than having a return line running the full length of your car radiating some of that heat away.

Boiling fuel over a hot intake is a problem with deadhead systems.
Great for manufacturer's cost reduction, terrible for performance apps.

Yup.

That's why they went to 4 bar on returnless systems.