Fuel pump options

[toomanymodz]

With my current engine I'm running 60lb injectors and frequently hit about 78% duty cycle. I have a single Walbro, which I've heard they run out of steam once the duty cycle hits into the 90+ percent (with 60 pounders). Since my new engine will no doubt push these injectors closer to their limits, I may have to go with bigger injectors and it's probably time for me to think about upgrading my fuel system.

I see the Weldon external pump, good to 1800 HP. That of course is way over-kill not to mention is requires at least a -8 return. My engine will be making power less than half of that amount.

So my question is what are my options. I need more than a single Walbro, but less than the Weldon. I've heard of the double pumpers and I read somewhere about the troubles that can happen when the second pump kicks in.

Ideas, comments?

 

[blackgn1]

I have 60's in the 90% range so I'm subscribed. I have a new Reds pump I'm going to install but I will still be in the 90% range.

 

[just plain john]

Some have had luck with the Denso pumps for the Supra. There's a build thread about it on here. Search Denso pump.

 

[toomanymodz]

Some have had luck with the Denso pumps for the Supra. There's a build thread about it on here. Search Denso pump.

I found the thread:
http://www.turbobuick.com/forums/general-turbo-buick-tech/262481-280-lph-supra-fuel-pump-installed.html

That looks like it could be a viable option. I read the thread just now and I noticed that the thread started back in 2008 and at that time the Walbro 340 was rated at 255LPH. The Walbro has since been revamped:
GBodyParts.com Online
GBody doesn't mention the LPH output, but rather says it supports up to 600HP and 10sec quarter mile.

At any rate, the Supra pump is rated at 300LPH:
Denso Fuel Pump - 300LPH 1020 Toyota Supra Denso Fuel Pumps
Of course the output can very based on voltage and pressure. Not sure if it's apples to apples.

Looks like the factory wiring can be a concern too. A hotwire provides a beefy 12v feed to the factory connector at the tank, but the factory wire going to the pump is tiny. Looks like this is the solution:
Racetronix - G7 In-tank & Intermediate Harness Kit - Kit Configuration Page
After installing that, the pump has a heavy gauge 12v feed that it needs.

Did I miss anything? The thread was a long one and with my ADD it's hard to read the whole thing. Thanks.

 

[87GN_70GS]

The following is for injectors at 100% DC and 25 psi boost (45 psi base). If your DC is less than that (hopefully it is), scale the injectors accordingly (i.e. 60#/hr inj @ 100% is roughly 100#/hr inj @ 60% etc). Single pump.

A W340/0169 can supply enough fuel for 55# injectors.
Denso supra = 60 # inj
Red XP = 60 # inj
Bosch 044 = 70#
Apexi BNR32 skyline = 72#
Pierburg SL55 AMG external = 82#
Jay racing pro-series 044 = 85#

 

[toomanymodz]

Good info! That's what I was looking for. Now I just have to figure out if 60's will be sufficient for my new engine.

 

[87GN_70GS]

Monitor your A/F and fuel pressure at WOT and that will tell you a lot.

If you adjust your tune for part throttle, you can run higher base fuel pressure if you need to. This could give you a bit more fuel (if you have enough pump) in order to avoid having to get new injectors.

 

[toomanymodz]

Monitor your A/F and fuel pressure at WOT and that will tell you a lot.

If you adjust your tune for part throttle, you can run higher base fuel pressure if you need to. This could give you a bit more fuel (if you have enough pump) in order to avoid having to get new injectors.

Thanks for the tip. I have a feeling I may need to go straight to the 79 lb injectors seeing as how this engine will see 6000+ RPMs with the fully ported GN1s:
GBodyParts.com Online

The Jays Racing 044 pump looks like the best deal too. The price is really nice:
Jay Racing Pro Series 044 Fuel Pump [044001] - $189.00 : Jay Racing

 

[HighMileage]

I couldn't get the jayracing link to work.

Are we talking about the Bosch "044"? That is something I am looking into as well. But where to find fittings to adapt it to our cars? I'm willing to run a whole new line if necessary.

I have read here that lots of modifying needs to be done to make the Supra pump fit in the tank,plus to satisfy it's electrical needs.

Steve. '87 GN. 60's and a tt chip on the way.

 

[toomanymodz]

Link works for me. The Jay's Racing pump is not the Bosch 044, it outperforms it and has less current draw.

As far as the Supra pump is concerned, I didn't see where a whole lot of mods is necessary. Slightly bending a portion of the tank opening so that the pump can slide down inside, and using the Racetronix harness so that it has a beefy 12v feed. Remember, a hotwire kit runs a beefy 12 feed from the alternator back to the harness to the tank. It's just the harness from there to the pump that needs replaced. You don't want to leave that tiny 12v wire there. The Racetronix harness looks like it's pretty simple to install.

 

[87GN_70GS]

I couldn't get the jayracing link to work.

Are we talking about the Bosch "044"? That is something I am looking into as well. But where to find fittings to adapt it to our cars? I'm willing to run a whole new line if necessary.

I have read here that lots of modifying needs to be done to make the Supra pump fit in the tank,plus to satisfy it's electrical needs.

Steve. '87 GN. 60's and a tt chip on the way.

Detailed 044 install info is in this thread:

http://www.turbobuick.com/forums/e85-technical-forum/330596-bosch-044-custom-install-great-e85.html