I had an idea, my Dad and I are building a 650-680 FWHP 383 LT1, I have a GS 340 pump for the tank with the Racetronix harness. I have inquired about a dual intank pump setup with little info in return. My Idea is this, my combo will be normally aspirated, how can I get an MSD volt booster or similar product to boost fuel pump voltage under low vacuum(WOT) with say maybe a MAP sensor? Anyone ever thought about it? Can I change some wiring on the map sensor to make the volt booster think I am in boost under WOT low vacuum? Gotta be a way to make this work.

Big Dave

 

I'm assuming you are using fuel injection. What ECU are you planning to use?

The first question would be why are you even considering a voltage booster for the fuel pump? They are generally used in setups that have widely disparate fuel requirements.... e.g. with boost, without boost.... or to make up for undersized injectors or limited fuel tuning capability. If you are doing your setup right, you shouldn't need a voltage booster. Insure the fuel pump, plumbing and regulator can supply at least 120% of the peak fuel requirement for the engine, select the fuel rail pressure you want, and tune the car accordingly. Make sure the wiring system keeps the voltage where it belongs. Do it the right way, with the correct components, rather than putting a band-aid on it.

Or did I miss the point of your question?

 

Well I have a GS 340 pump and a Racetronix harness, Performance Trends latest version of software says the 340 will be on the edge with 42lb injectors@ 50 PSI, I will use stock lines. I have seen dual pump setups on the net, but cant find one in "kit" form. Performance trends says this engine will make well over 600FWHP on pump gas. Before you crack me, this is NOT a run of the mill 383. I will be using a LT1 edited PCM. If I can find a dual pump setup I will definately do that, no inline pumps for me. I will be running Wilson Manifolds fuel rails. Just because someone else gets away with a single 340 running the same HP as I want to, doesnt mean I will get away with it. Trust me there is alot of money invested in this combination, I want it to be fuel happy LOL. We are trying alot of new stuff with this combo.


Big Dave

 

It was not my intent to question (or "crack"?) your capability to make the HP or your combo... not sure why you felt the need to get defensive. I was simply trying to suggest that the correct way to design the system is with the basic building blocks, not with "add-ons". It's your setup, take the risk where you feel it is appropriate. If its squeezing by on an undersized pump, using a voltage booster, so be it.

The next question would by why complicate things by trying to tie pump voltage boost to MAP? Why not just boost the voltage any time you go to WOT (= low vacuum). MAP output voltage on a 1-bar sensor, at low vacuum approaches 5.0V. TPS output voltage at WOT approaches 5.0V. A 2- or 3-bar MAP sensor approaches 5.0V at high boost.... they would all appear to compatible with regard to output voltage.

 

The next question would by why complicate things by trying to tie pump voltage boost to MAP? Why not just boost the voltage any time you go to WOT (= low vacuum). MAP output voltage on a 1-bar sensor, at low vacuum approaches 5.0V. TPS output voltage at WOT approaches 5.0V. A 2- or 3-bar MAP sensor approaches 5.0V at high boost.... they would all appear to compatible with regard to output voltage.


The precise reason I posted this question, tieing to TPS is a much better idea. Would you agree a GS 340 pump would be marginal on this setup? BTW I was not getting defensive at all, sorry you took it that way. DO you know where I can get a dual intank pump setup in "kit" form? I am trying to get around a $1000 fuel system. If I can run stock lines I will, I have seen some guys put down some serious number with stock lines. I feel I can go with stock lines with the proper pump setup. DO you agree?

Big Dave

 

Without seeing the pump curve for the GS 340 I couldn't tell if its big enough or not.

I run dual Bosch 205LPH pumps. Each one is good for about 500HP. One is in the stock in-tank location, the other is connected to a -10AN fitting welded to the back/bottom of the tank. There is an internal baffle and screen. The discharge of each pump combines in an NOS "Y" fitting. Supply line is -6AN, which is about the same inside diameter as the stock lines. Return is also -6AN, which makes it a little larger than stock. I've supported 800HP at 0.53 BSFC (nitrous) with that setup.