Switching Fuel Systems - Dual Pump back to single

[Murlo26]

So I have had quite a few issues with my fuel system working exactly how I wanted it to over the years. Nothing earth shattering until recently.

My current fuel setup is a blaqops dual pumper with a 255 and I am unsure what they used for the second pump but I think its different than a 255. I am running the progressive boost version, which has a set point where the second pump turns on and then a second set point at which the pump is "full on". So the idea is you have a progressive system that slowly ramps up the second pump to give you a nice smooth transition.

Well here is what I have noticed. The idea behind a progressive second pump is stupid and unneeded. Honestly, just using a hobbs switch is really all you need and the car is spooling fast enough to eat up the fuel anyway, so I don't ever see a reason to ramp up the second pump, just more complexity that isn't needed and I am now a firm believer in a simpler fuel system.

Right now I have my progressive controller almost set to hobbs switch. The 2nd pump comes on at like 2-3 psi and is full on by like 5-6 psi and everything works out very well.

The very first problem I had was the car wanted to lean out on spool up, which really sucked. My tuner eliminated most of this by lower the set points to almost hobb switch style, which I lowered even more for my newest tuner.

Ok first problem solved, but after lots of logging/tuning we discovered that the MAF/MAP tables were so far off that the car never added fuel so tuning played a big part in this too. Also the open loop/closed loop crossover needed adjusting, so those few things all were involved in my spool up issues.

Well we also noticed that my fuel pressure would not go above 50psi at idle so then we found out the 2nd pump had no check valve and fuel was leaking back into the tank. Well I installed a big ol Jegs E85 safe check valve and problem solved, was able to run up to 80psi at idle, maybe more lol. Obviously I turned it back down.

Even now though with all these smaller issues solved I still have always had a much worse fuel pickup problem then stock. Stock we have fuel pickup issues on turns with fuel slosh but the dual pump setup has amplified this and made it really bad. I have "ran out of fuel" at 1/3 tank before where I needed someone to bring me e85. Well this was annoying but not terrible, so I tried to keep the tank at 1/2 tank or more.

So most recently this was found while logging.

The lean run was at 1/2 tank of fuel, I then put 7.2 gallons in and the car ran the next log, which was perfect. no knock on either but just shows my pick up sucks!


So now I bought this:



My dual pumper setup obviously modified my stock hangar so now I needed a new OEM one. Well it is almost OEM, minus the lines as there was a 255 kit in here that was returned to OEM and those OEM lines were cut and replaced with whats on there, which will get replaced again.

So here is my plan for fueling...

-Wally 400 E85 version
-MAP Fuel Pump install kit
-MAP hardwire kit (run voltage right from battery)
-MAP fuel feed line
-6 AN feed line from rail
Re-use stock feed line for return since its bigger
-Drill out siphon to lower pressure

After seeing Mr. Fred's testing on the fuel feed line we (by we I mean MAP and I) are hoping there are some restrictions in the lines just like the 8/9. Mr. Fred saw almost 10psi of pressure drop I believe after upgrading the lines.

With the lines and fuel siphon mod we are hoping that there is a lot of extra pressure we can alleviate. The idea is that at lower pressures pumps flow a lot more.

The overall goal is to see ~600whp on E85 out of the single pump. After all the issues I have had with the dual pumper I want a nice single pump setup. In the future if I need more fuel pump I will throw on a BAP (kenne bell boost a pump) or simply run a surge tank setup with a giant weldon. I will report back soon with my findings, hopefully next week.

Also Chris Carey ran a Wally 400 before and might switch back, but he had no issues running it to the gas lights, so I am looking forward to this.

For reference: My other fuel mods are DW1300's and a MAP AFPR kit. Pretty basic setup.

Just thought I'd share my setup, issues and plans in hopes I find a solid single pump solution for people making 500-600whp so you don't need to go to a dual pumper.

[HappyMint]

I look forward to the new results man. I hope it works out!

[joey]

In for results

[bigstakk]

I'd ditch the DW 1300 immediately as well while you are switching out the other stuff (could be part of your fueling issues)...GL!

[Murlo26]

This is my 3rd set of DW 1300's, all have been tested, none have had issues. I had RC engineering test a set as well, all fine.

I don't think they are an issue, I think people just like to blame them.

[CrazyIvan]

Why are you switching tuners, and who are you switching to?

[Murlo26]

Originally Posted by ityn

Why are you switching tuners, and who are you switching to?

I am not switching, I switched already. Baka is my current tuner.

[Murlo26]

Car is back home!









Not a whole lot to show really, its a fuel pump in the fuel tank lol.

So few notes...

Once MAP had all the extra fittings sorted out, the lowest fuel pressure they saw was 65psi at idle. This is with the return siphon drilled out, unsure how much but as much as possible without screwing shit up. They also drilled out the pressure relief on the hanger too.

One thing they didn't do was turn my feed line into the return. It's only 1/16th bigger anyway, but with the stock hanger it just wasn't happening.

So now I have the hard wired wally 400 e85 version in the tank with a 6AN feed line and new Fuel lab fuel filter.

MAP was able to get idle pressure down to 50psi (without vac, with vac was 43 or whatever) by drilling out the fpr insert. I didn't have the bigger one so they modded the one that was in there. Then problem solved...so far everything is good.

I did have a scare on the way home. I was barely able to shift into 3rd and 5th was ALMOST impossible to get into. So i immediately knew my shifter linkage was all goofed up somehow. At first I thought maybe MAP dropped something on it or some weird shit so I was like WTF. When I got home though I noticed the return line sank low enough to get in between everything. One zip tie and we are back in business now!

HOpefully get some logs and tuning in this weekend. With a new base fuel pressure I will need some work from Baka I think!

[mantella]

I wonder if map revised there fuel pump install kit. the aluminum one they sale for say the 255 pump does not fit the 400 pump with out modifcation. It has a beveled edge the the 255 style pump sits on while the 400 has a wider base. I had to grind the bevel out.

[Murlo26]

Not sure, they made it work for me. You'd have to ask them