Parallel Fuel Pumps
 

I'm working on fitting a second OEM pump into the passenger side of the saddle tank. I saw a closed thread from Accelerated Performance/Visconti about them doing so, but the kit was over $1k. Reason behind this is to prevent leaning out during cornering/powering out of a tight right corner under 1/2 tank of fuel. Also increased fuel volume for boost/E85.

I was wondering if anyone else has rigged up a setup like this. I'm planning on opening up the canister and tank to get a better idea what I'm looking at but I was thinking of splicing the passenger pump into the power for the drivers pump and putting a Y connector to send both pumps feed up front. Need to open the canister to see about mounting the pump still.

I'll document all my investigations when I get some time to work on the car, for now I'm asking if anyone has experience with this, and any problems they ran into.

Not sure what (if anything) is available but what about just getting a single higher volume pump and then just splitting the intakes off into both sides of the tank? Installing a second pump will be major surgery for very limited gains.

What about the hydramat for scavenging fuel?

http://www.motoiq.com/MagazineArticl...-Hydramat.aspx

Agree

It seems like the design of the venturi pump for the right side of the tank is either flawed or the location for the pickup is.

Just spitballing. I've wondered but never seriously studied the issue.

The issue is the venturi system to get gas to both sides of the tank especially when at lower levels. Are you talking about adding a pump external to the tank and drawing from both sides, or higher volume on the driver's side piped to pull from both sides?

You got me thinking now though. it might be easier to T the pump intake and run a line out of the canister across the tank to the passenger side. If I combine that with the smaller hydramats then I don't have to worry about air going through the pump from the empty canister.

That might work by keeping the fuel trapped on the driver's side. Connect it directly to the fuel pump, it would replace the canister. I will look further into this. Thanks.

Anyone used these on our cars in the stock tank by chance?

http://www.ft86club.com/forums/showthread.php?t=36231

Post #32 explains pretty well the issue. Just trying to avoid a $1k+ solution for it if possible.

Was thinking a stronger single pump on the right and teeing off to both saddles.

I think I've got it figured out. Radium engineering has an adapter to 5/16 line from the fuel pump, stainless steel T from there out to a 8"x3" Hydramat on each side of the saddle. Would cut the bottom of the canister out and essentially by pass it. All in it's under $500USD.

This is why I love the forum and no idea is a bad idea.

Yep that is pretty much what I pictured. Beats hell out of trying to add a second pump.

Radium has a nice surge tank. http://www.radiumauto.com/MPFST-Mult...Tank-P271.aspx

I'm looking to avoid surge tanks as I don't want fuel outside of my tank. Run into all kinds of issues for many different racing series and tracks.

I was talking with one of the TR86 Race Teams here in Australia (the Toyota spec racing series) about this. Their configurations are all specified by the race series organisers who do some engineering and determine what configs all the cars must run.

It is my understanding that they have installed a second OEM fuel pump in the left hand saddle. It's role is to pump fuel into the right hand side saddle where the standard pump and pickup is.

Seems like a simple solution that doesn't require an external surge tank. I'll try and find out some more info but if anyone has done this I'd like to see the details.

That works great until there is no more fuel on the rhs. The rhs pump continually runs dry and eventually fails.

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Maybe they are using the float to turn off the rhs pump (speculation only).

I was very surprised they didn't install a surge tank given it is a dedicated race vehicle - but they didn't.

The problem with the simple 1 pump drawing from a T into both sides is that unless you draw the EXACT right amount from each side (note: not necessarily even amounts) you will wind up emptying one tank faster. When one tank is empty, the pump starts drawing in air, and only air, from only that tank. The fuel in the other side would not be touched. If you don't have a float on either side and 2 gauges to monitor them, you could run dry without knowing it. Theoretically, you could treat each side as its own fuel tank and switch between them manually (aircraft style), but that defeats the purpose of a simple solution.

It seems to me that the best solution is to draw from one side only, and use some method to equalize the fuel level.

My guess is that's why the folks mentioned below have their fuel system setup that way.

Edit: Im dumb. Just looked at the Hydramat thing. Looks like what I am saying doesn't apply...

I'm not speculating, I've seen the dual pump setup fail. In fact, I've seen it fail on my dyno. My car has two hydramats, plus a surge tank and I'm just about to switch to a larger surge tank. Race cars should just use a fuel cell. Forget the race series down here as an example, a lot of things they do on those cars are pretty dumb.

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Radium Engineering

Has anyone tried this out from Radium?
http://www.radiumauto.com/Venturi-Je...-Kit-P760.aspx

Maybe add a hydro mat on the passive side to help with the pick up.

did you ever get this working? if you did, how so?

I don't know if it's bye or I just missed it but radium has a dual pump setup now that utilities the stock pump location and with the fuel trapdoor that they have mostly if not completely eliminates the fuel starvation under hard cornering.

I did not. The radium route is the way to go

as in surge tank setup?

and when you say you did not, what exact method did you attempt?

the T connection thing as suggested by the other user?

ive recently spoken to some folks who had some success mounting a 2nd pump that fed the first pump's basket. so im wondering on the specifics

thanks for responding!

I wouldn't connect them in a T, it is going to be best to fill the primary basket with the secondary pump. I am piecing parts together for this right now using two OE fuel baskets and running the secondary on a seperate motor controller with a switch to turn it on when I want and adjust the duty cycle. I have some hall effect sensors and in the future plan to build a setup that will automatically switch on during a left hand turn. Just not enough time in the day.

Hey, awesome, lets keep in touch.

I wouldn't do the T method either....but I was just wanting clarity on what OP meant exactly by saying "it" didnt work.

I plan to do what you are doing. But sounds like a simpler way. I plan to wire the second OEM pump in the passenger side to the same driver side power wire. And put a switch in the wiring there so its basically on or off. I got the tracbox and those racecargobrr switches and I plan to use one of those as the switch for this secondary pump. my plan is to switch it on while im on track and switch it off when I begin cooldown.

and that's it. nothing fancier than that. I am also a wiring noob. I've touched about every bolt on the car but electronics is a new foray for me. as such i am open to suggestions if something I said sounds inadvisable.

i do know of someone who used a Pi to basically turn on his aux fuel when he is on throttle. thought that was neat. but over my head.

"T"ing them will still cause fuel starvation if one pump is sucking air.

I will do a writeup on my setup when I put it together. At this point I am still grabbing fuel fittings that I will need. I want it all together to document it in one go.

If the pumps have check valves the check valve will close when one pump looses pressure(sucks air) so you should still have pressure in the fuel system. This is with teeing the pressure side. You would also need to arrange the jet pump system to work in this configuration to your advantage. As far as burning a pump up running it dry it shouldn't hurt the pump considering it would no longer be under load and drawing very low current.

Staged systems have to have check valves on the secondary pump(s) if in parallel.

I will have to test this with the stock pumps. "T"ing up top would be much easier.

What is your opinion on a 2nd pump being always on, and always feeding fuel into the driver side basket?

Basically wiring it up along with the driver side original pump

I had planned to use a switch to control it but would simplify my life to have it just be always on, if there were no drawbacks

I would probably just use two stock pump baskets teed with two controllers parallel. You could put a filter (or sock)on the crossover tubes and run them to the back or side of the tank.
3d print some flapper doors or buy.

Best would be build a surge tank that replaced the basket then a factory basket feeding the the surge tank.