Fuel system upgrade

[carl B]

OK so I am having a problem!

I want to drill a hole in the back of my tank in the GTS to draw fuel into the Weldon pump

Has any one done it as I am struggling to see how I can get to it?

Carl

 

[Viper TT]

Yes, I've done it for the same reason 2.5 years ago. I drilled from inside the tank. Be very diligent when doing this because that tank is not easily replaceable. In fact, I'm not sure you can replace it.

First and foremost, DO NOT USE AN ELECTRIC DRILL! You will need an air drill due to the fuel vapors that are inside the tank.

I opted to go with a -12AN feed to the Weldon pump and I used a small hole saw to make the hole. You'll have to place the hole as far to rear center of the tank as possible, but make sure you don't go too far as there is a large radius at the backside of the tank. Too far forward and you will be too close to the rear differential cover to install a fitting on the outside of the tank. You will most likely use a sump fitting and the large teflon washers will need to sit flat on the inside of the tank to seal. If you drill too far back, the radius will not allow the washer to seat flat.

 

[Viper TT]

To be honest, with the setup you have you would be better off with the following from http://www.leadingedgeperformance.org/ :

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[Qualitywires.com]

that's a pretty cool set up. Where do you get that and how much?

 

[Viper TT]

Garth W
Leading Edge Performance
702 375-4999
[email protected]

 

[Joseph Dell]

I don't think that this set-up will be big enough for what Carl is shooting for.

I know that David Weaver was using a similar set-up... his twin in-tank set-up was rated for 800rwhp. I have no idea what the real limits of a 3 in-tank set-up would be. anyone have any speculation?

JD

 

[Viper TT]

I've seen the Walbro GSS341 support 500rwhp on one pump. I would think that 3 pumps should be able to support ~1200-1300rwhp.

 

[Joseph Dell]

that's pretty stout. Carl would be pushing the limits of 3.... but it is a heck of a lot cleaner. If it would support 1500rwhp, i'd have done it!

JD

 

[Viper TT]

My Supra had 2 Walbro GSS341's and it made 800rwhp with no fuel issues at all. I didn't have enough turbo to push past 800rwhp, but that gives you an idea.

I've emailed Ryan Woon to see how far he has pushed 3 Walbro's. If I'm not mistaken, he's put down 1400rwhp with 3 Walbro's and been mid 8's @ 17x mph. I'll verify and post his response.

 

[Qualitywires.com]

What size line are the 3 intank pumps going into?

 

[Jack B]

I have one of Walboro's in the oem tank with a voltage booster and have done over 800 hp on a nitrous car.

 

[Viper TT]

that's pretty stout. Carl would be pushing the limits of 3.... but it is a heck of a lot cleaner. If it would support 1500rwhp, i'd have done it!

JD

Here is what Ryan Woon has tested with his Supra thus far:

"Two 950-990rwhp, three 1400rwhp."

 

[Qualitywires.com]

I don't know if you could compare the Supra with the Viper though...the Viper has four more injectors to feed than the supra does.

 

[ViperTuner]

I don't know if you could compare the Supra with the Viper though...the Viper has four more injectors to feed than the supra does.

The rated HP is a relation to the amount of volume 1, 2, 3 or 4 pumps can output. The amount of cylinders and/or injectors does not have any affect on this output unless your injectors are too small to deliver the amount of power you are trying to output from the pumps.

There is alot more technical info to this but I dont have enough time to get into the details... sorry

Woon is a long time record holder in the Supra community and has built some really nice parts. Some of these parts are on some of the Supras we have built in the past. One in particular has one of his triple billet fuel pump hangers along with a quantity of 12 160# injectors in order to feed the GT4788 Turbo to output 1400+HP.

Our 600whp 4 cylinder Subaru packages use a twin hanger that we have developed, used in conjuction with 4 120# injectors for street usage. Our other package for the 4 cylinder Subaru uses 3 pumps and 8 160# injectors.


So far the power "most" Street SC or TC V10 engines is just below the 1000hp mark...which can be achieved with 2 Walboro pumps and 10 75# injectors pretty easily. The installation must be done correctly (not one pump above the other) and a return style fuel system "should" be used to control the fuel with the proper 1:1 rising rate fuel pressure regulator. The return for this kind of fuel should be sent back into the surge container in the tank along with a few other tricks.

Howard

 

[vipzilla]

does anyone know what the factory lbs are for the difrent gens injector sizes????

 

[dansauto]

does anyone know what the factory lbs are for the difrent gens injector sizes????

55# for stock injectors in stock manifold.

 

[vipzilla]

55# For Stock Injectors In Stock Manifold.

Was That For All Years

 

[Viperless]

55# for stock injectors in stock manifold.

Not on a Gen1 or Gen2.

 

[Red Snake]

I have one of Walboro's in the oem tank with a voltage booster and have done over 800 hp on a nitrous car.

Mine is set up that way also. Walbro 255 in the oem tank hangar and Boost-a-pump. Mine easily supports 750/750 fwhp/trq++.

 

[vipzilla]

not On A Gen1 Or Gen2.

What Was Gen1 And Gen 2

 

[VIPER BAZ UK]

Is the OE pump a Walbro 255 ??????????

 

[Red Snake]

Is the OE pump a Walbro 255 ??????????

No. THe Walbro 255 is an upfgrade over the OEM pump.

 

[Qualitywires.com]

Who makes these? Where can I get them? No response from the email posted in this thread.

 

[dansauto]

Not on a Gen1 or Gen2.

?? What do you think it is....

I have mine set to 55#, I have also check several and they are also over 50# (between 50-55)

 

[99 R/T 10]

I believe the pumps pressurize the system at 55lbs. The injectors for the Gen II are 29lbs. The Gen I is 25lbs(I think). If a gen I has been upgraded and is starting to run out of fuel at the high end, an easy fix is to install Gen II injectors.

 

[vipzilla]

i Believe The Pumps Pressurize The System At 55lbs. The Injectors For The Gen Ii Are 29lbs. The Gen I Is 25lbs(i Think). If A Gen I Has Been Upgraded And Is Starting To Run Out Of Fuel At The High End, An Easy Fix Is To Install Gen Ii Injectors.

Thats What I Did Was Use Gen 2 Injectors And I Just Stepped Up The Boost And Am Running Out Of Fuel Again Thats Why I Was Wondering Whats Next Gen 3 Injectors ???

 

[V10TT]

The idea of three pumps scares me a little. What if one pump goes bad? how would you know?

 

[FATHERFORD]

I have personally got over 600rwhp on a nitrous fed 347 on a single 255lph pump.. Larger fuel lines and rails help a bunch.

 

[dansauto]

Thats What I Did Was Use Gen 2 Injectors And I Just Stepped Up The Boost And Am Running Out Of Fuel Again Thats Why I Was Wondering Whats Next Gen 3 Injectors ???

how much hp are you dynoing? Stock pump should support 600-650 Hp with Gen 2 injectors for limited bursts. You have two sides to this equation volume and pressure. The 55 # is need to only to properly atomize the fuel into the manifold. The volume is what is required to support Hp. (Gal per min) Do you have a fuel pressure gage and an external regulator? If you did you can tell if your running out of pump if your fuel pressure drops excessively when under boost.

 

[dansauto]

I believe the pumps pressurize the system at 55lbs. The injectors for the Gen II are 29lbs. The Gen I is 25lbs(I think). If a gen I has been upgraded and is starting to run out of fuel at the high end, an easy fix is to install Gen II injectors.

yes 100% correct (your a know-it-all Mike )