Does anyone have any experience doing a dual intank fuel pump setup, specifically a 91? Ive posted a thread on ls1tech but they say is very hard to do because you need to do it in peices because the size of the hole is too small to slip them through together. I've done some searching on here but the threads were ancient and all the pics were no longer up. Any help is appreciated.

 

I am doing it on my 87. I am just running each to a nipple on the top plate. Then from the top plate each will bc a seperate -6an, then those to a dual -6an to single -8an then -8an straight to the motor (with an inline filter)

Also they will have there own relays and one ran off the computer and one triggered by a window switch.(turn on/off at a certian rpm)

Jay

 

I'd like to do it without changing any of the external lines though.

 

a 255 lph pump should supply a upwards to a 650-700 hp motor, if that cannot do it put a external aeromotive pump on

 

I should easily be making 550 rwhp, at that level a single intank is going to be questionable. And i'd rather not do an external pump. Most high hp 4th gen guys are using dual intanks.

 

You can do it with stock lines too....just clamp the pumps nect to each other (using rubber in between them) then run the hose up to a T fitting then the T fitting to the stock line. Done.
I think with stock lines 800-900 is attainable.

Jay

 

Yes, you'll want to get your hands on, or build something similar to, a Syclone/Typhoon sending unit, as they are setup from the factory with dual intank pumps. My buddy has one out of his truck, and I compared it with one of my stock TPI sending unit's. The same line(s) after (going from) the dual intank pumps on the Syclone/Typhoon unit is equipped with a splitter, in which merges to one line, then up and out of the tank. Could easily build one....

 

My 1990 ZR-1 has duel in-tank fuel pumps (factory) as do all 90-95 ZR-1s. It also has two injectors per cylinder as well though. If you could find a wrecked ZR-1 you can get the fuel pump assembly since they just pull out. There is about 10 10mm bolts around the filler neck and then they come out very easily without having to drop the tank or anything. I have an extra for my vette but I would not cut it up since they are hard to come by. Go to zr1.net and you can see an exploded view of one.

 

Your talking about in the tank right? Will the two pumps fit through the tank hole if its assembled onto the sending unit?

 

Yes both in the tank...just use a couple big hose clamps and a peice of hose between them and strap them together.

Here is a link of how people did it...also here are some pics.
http://www.camaroz28.com/forums/show...ht=dual+intank

 

Using the Walbro data sheet for the 255LPH at stock pressure it is good for around 550 BHP. As the fuel pressure goes up (to equalize boost pressure if not N/A) then it gets worse.

What 255 LPH pump supports that much HP at stock fuel pressure?

 

Make sure you use in tank EFI hose and not just regular SAE 30R9 EFI hose. SAE 30R9 EFI in a tank will deteriorate quickly.

 

I have done dual intank walbro pumps. Currently I'm buildnig a new fuel system due to I need bigger lines. Pic are at my site if you dont find them PM or email me and I can send pics to you.

/N.

 

Can these set-ups feed a blow-thru carb set-up or will i be sending way too much pressure. Of course i would use a good regulator (aeromotive). I'm just looking to up the volume not the pressure. I'm currently feeding my 750 Demon on my 383 using the stock 305TBI intank pump, and i think its not pushing enough volume at full throttle. I have an Aeromotive A1000 sitting on my shelf. Should i go the dual pump route or go external?

 

Damn, pretty sweet setup.

 

Walbro 340M pump with hotwire kit and voltage boost a pump setup will support 600-650whp from what i'm told by Racetronix. There are a few guys up there using a setup like that, i believe they were lsx guys. I cant remember where i seen it

Not sure if this counts but i was around 520whp with a wet nitrous kit and walbro 340m and it was still on the rich side. I figure if the pump is feeding the injectors and the fuel solenoid, then the overall fuel delievery would be the same as if i was running a dry nitrous shot and used the injectors to make the extra fuel. Then again i may be totally wrong