QwkTrip

iTrader: (23)

Anybody know of an easy fit fuel pump that supports 600 RWHP naturally aspirated, while not cutting up the fuel pump bucket?

I have a plastic LS1 F-body fuel tank in my car with a Racetronix red pump. I think that is a Walbro 255 pump, right? I don't think that pump will support the next engine I am dropping in the car.

QwkTrip

iTrader: (23)

Or I could run a voltage booster for the pump, I guess. Not sure if the F-body regulator can handle that kind of return flow when engine demand is low.

HCI2000SS

iTrader: (2)

I run a Walbro 255 pump and hotwire kit from Racetronix, and I'm at around 600 rwhp on the 150 shot and it works just fine. If it holds 600 rwhp on nitrous it should hold it n/a I would think

Crf450r420

iTrader: (1)

You need about 50lb/hr for every hundred HP when N/A and only about 35lb/hr of fuel per hundred with nitrous, so you can get more power with nitrous from the same fuel by a little bit.

The 255lph will support 550HP safely at the flywheel normally. You can push that to 600 if you have over size injectors and tune it for the pressure drop, not the right way to do things. I'm not sure how much the boost a pump gains you, but I know it works so research that before going that way. I'm someone with experience will speak up. I would just fit a 340 or 380lph pump if it was me with a hotwire kit. I've seen a post of someone just doing light mods to the newer buckets to fit a Walbro 450lph pump and that will support about 850 flywheel N/A.

NHRATA01

iTrader: (10)

I'm about where you are too, although not sure what my motor build will make but it could do 600rwhp. I have the racetronix 255 and will run that through break in and see how the pressure holds at WOT. I've always heard 550rwhp is racetronix's rating but they can push 600 N/A.

But if you're going from a stock pump, I would probably just go straight to the racetronix 340 setup with the C5 fuel filter that WS6store sells. It's really not much more money, from what I've read should be the same level of work as the 255 but gives you factor of safety and/or room to grow a few more hp. I may have to go up to a 340 anyway.

QwkTrip

iTrader: (23)

Good replies, guys. Thanks.

I talked to Racetronix today. They have a 340 LPH pump, not sold on the website, that will maintain the venturi for the fuel bucket. Although, I'm not sure if he'll sell it to me or not. Knowledgeable guy but a bit difficult to talk with.

Talked to Nasty Performance, too. I have bought stuff from them before and Nate is fantastic to talk with. They have a Lonnie's double pumper that fits in the stock bucket. Second pump would run on a RPM switch, or TPS switch.

I also see that Lingenfelter sells a Bosch 350 LPH pump. I don't know anything about how it fits in the bucket and will call Lingenfelter tomorrow.

Still considering a Boost-A-Pump though. It would mean fewer changes to my car and easier to integrate than a double pump setup. Need to figure out the real differences between the Kenne Bell and the MSD, and which one better serves my needs. I tend to favor ancillary equipment that doesn't need laptops and software because all that stuff goes out of date fairly quickly. Stand-alone electronics is good in this case.

QwkTrip

iTrader: (23)

Perhaps this is the same thing,

http://www.ws6project.com/user_stor/...oducts_id=8399

Don't need the Hotwire kit though.

QwkTrip

iTrader: (23)

Hmmm.... seeing some posts where people say the stock pressure regulator gets overwhelmed with the larger 3xx LPH pumps. Maybe a Boost-A-Pump is the right answer, or possibly a small set of dual pumps that work on demand. That way return fuel flow isn't excessive when the engine isn't needing it.

NHRATA01

iTrader: (10)

In that link above you'll see at the bottom there's an option to include the C5 fuel filter and regulator kit. Install that it replaces the stock in tank regulator so you can run the larger pump and still keep a reasonable fuel pressure.

Crf450r420

iTrader: (1)

I don't know on the 340, but with the 450 pump I was idling at 68psi. The in tank one is not the best idea anyways as it's hard to service. Either go with the GM filter/reg or Holley also makes one like that, but the GM one is probably easier with the kit that is now made for our cars.

JoeNova

For the amount of money it costs to do 600whp N/A, I'm pretty sure you shouldn't be so worried about having to do something to the fuel tank.

Crf450r420

iTrader: (1)

It wasn't a good idea when it was new, but it makes mores sense when you build more power?

QwkTrip

iTrader: (23)

Just a quick update to bring this to conclusion for people that may find this thread.

The Racetronix pump (Walbro GSS340 255 L/hr) was not enough. Pressure would begin to fall when above 270 lb/hr, and got as low as 30 PSI with a wimpy tune in the engine. The AFR readings indicated there was adequate fuel flow, but the spark plugs clearly showed it was running hot (lean).

So I installed a Kenne Bell boost-a-pump at the standard 17.5 Volt, and am controlling it with my Holley HP EFI. Fuel pressure is now holding steady at 370 lb/hr. Seems to be successful.

JoeNova

The boost-a-pump costs twice as much as a drop-in 340 lph pump.

QwkTrip

iTrader: (23)

No, it's not that simple. The 340 lph pump would overwhelm the F-body pressure regulator, so you've got to redo the fuel system with an external regulator. And if you're going to do that, then you might as well do things proper with a full length return line, regulator at the rail, then you're buying more -AN fittings, etc etc. And you'd lose the neat venturi feature that fills the bucket and keeps the pump submerged. And it wouldn't be a Walbro.... those Walbro's are darn reliable.

But the bottom line for me was I just didn't want to redo my hard lines. I'd much rather do some wiring with a Boost-A-Pump! I don't have a 4th gen. I have a custom built car that just happens to use a 4th gen fuel tank, and a larger pump would have been a pretty big hackup of my custom made fuel system. I didn't have an ounce of fun building it out the first time!

That's just the nature of car building. You end up with a patchwork of incremental changes as you go along. Then one day you rip it all out and start fresh. Had I known back then what I know now, I would have built full return lines and put a regulator at the rail.

Dragframe

iTrader: (14)

That’s what I did with my car. New lines front to back with fuel rails and Magnafuel reg and cut the stock basket up

I’m facing the same predicament with my truck tho. My truck has a returnless style system. Stock regulator can not hang with the current go to walbro 450. So if I want to upgrade I got to change most everything 😒.

Kfxguy

iTrader: (1)

I have an aeromotive 340 in my gto and it doesnt overwhelm the stock dead head regulator.

Kfxguy

iTrader: (1)

did you try it already or just going by what some people on the internet say....who havent even tried it themselves......?

QwkTrip

iTrader: (23)

Cleaning up old thread subscriptions and found this. Figured I would finish this off and not leave it another dead end thread.

My Racetronix 255 L/hr pump was done by 5000 rpm. Installed a Boost-A-Pump and it worked out real nice. Did not use the provided vacuum switch. Controlling the BAP with Holley HP EFI instead. You get about +100 L/hr out of the GSS340 pump at 17.5V

When the Boost-A-Pump is active it regulates voltage to 17.5V, even if system voltage drops. So it's not just a voltage offset, it actually regulates to 17.5V. A pill can be plugged into the unit that will cause it to regulate to 21V, but that is not recommended as it will kill a Walbro 255 pump in quick fashion.

The BAP comes with a really nice connector on the fuel pump wires.... except they don't provide the mating parts and there are no instructions what to buy. So after playing Sherlock Holmes, I figured out the mating connector is Metripack 630 series connector, part number 12033769, with pull-to-seat terminals 12033997 for 10-12 AWG wire.

I programmed the HP EFI to turn on the BAP when engine MAP is greater than 90 kpa, or engine speed is greater than 4000 rpm. I've also programmed a delayed shut off until engine speed is less than 3000 rpm. The 4000 rpm turn-on is so that the BAP is already engaged if I'm rolling into the throttle. The delayed shut-off is so that I can play with throttle (change of mind) and not have the BAP unit cycling on/off.

QwkTrip

iTrader: (23)

So my hand was forced and I had to install a larger pump. The Walbro 255 L/hr pump failed after a few months on the BAP. I removed the BAP and installed a 345 L/hr pump.

Turns out that Walbro now makes a 345 L/hr pump that fits in the stock bucket and keeps the siphon system in tact. Racetronix sells it for just $250 installed in a brand new fuel assembly, ready to go. It does require an external fuel regulator. And it uses a Delphi GT 280 connector with higher current rating. In my case it was easier to buy and rework the Racetronix hot wire kit (FPWH-017) for my car than to fiddle with up-fitting my existing harness.

It kind of looks like a big brother to the 255 L/hr pump. On paper it flows more than an Aeromotive 340 L/hr, and Racetronix says it does in the real world too. Hopefully this pump will have a reliability reputation along the lines of the 255 L/hr and not the 400 L/hr. Whatever the case, it's definitely nice knowing my pump is always submerged inside the bucket.