Wanted to throw this out there, as I have not seen anyone comment regarding these pump setups. I am going to embark on a single turbo build, with a target RWP of between 600-650rwp.E85 or a mixture of E85 and gas to power the car. I know the Radium setup is really nice, but I came across the dual pump setup that is direct from TI(Walbro) and wondered why this wouldnt be a good solution?

https://aftermarket.tiautomotive.com...ank-dual-pump/

Out of the box, it has their hanger and both pumps are pre-wired. This does not solve the fuel starvation issue with a track driven car, but mine is a street car with maybe an autocross day every other year. I am planning to go with the Haltech R3 and would run one pump and have the second pump kick on when positive manifold pressure is seen.

Has anyone used or see an issue with this setup?

Thanks,

Eric

 

Seems like a great setup for the cost! The pumps have check valves so shouldn't be a problem configuring as you intend.

Always a good idea to add engine protection for low fuel pres, the R3 should serve you well.

 

the link didn’t provide the flow/amp graph, but it’s two of these pumps



.

assuming 650 whp on E85 with 45 psi fuel P and 30 psi boost P, seems a bit excessive …

 

If I was buying a drop in kit I would want one with a built in surge tank or at least some kind of weir setup.

 

they make a few different kits. I was thinking the dual 450s would be more than enough.

 

Thats their rating, a little less than 2x pump

 

actually 2x+, which is why I mentioned it

435 lph/115 gph is sort of a conservative expectation for 650 whp on true E85, thiugh I’d want some more for add’l safety factor, but not really that much …
.

 

Maybe I did my math wrong for the turbo I plan to run(S366 9180 sized). I was thinking I need at max 155GPH. I was factoring 43.5 base pressure and at max 30psi turbo. Factoring 80psi fuel pressure for fudge room. To get the fuel pumps there, the R3 PDM max out at 25 amps, and it looks like the pumps need roughly 23 amps.

 

let me double-check, I grabbed some numbers out of the fuel pump sticky and may have been gas rather than E85

 

this still works
Calculations

 

sorry, it was my bad for grabbing the Gas numbers in error , it comes up to 1.93 gph fuel pump and ~9100cc on E85 for 650 whp …

from this thread and applying 650/600 = 1.083x factor to them

https://www.rx7club.com/single-turbo...014-a-1062109/

I should have just run the numbers myself and not been so half-@ssed about it. Thanks for your patience.
.

 

i found you really need a surge tank in addition to proper delivery capacity. i agree w Slides.

i ran out of fuel pump on the dyno 2 weeks ago... i have the Radium surge tank w a 267 lift pump and a 285 primary pump. i had to turn my Boost A Pump up to 17 volts to get enough fuel... 70% ethanol 30% gas.

after examining my options i am simply adding a 274 pump. the second (285) pump will trigger only in boost off a Hobbs switch.

 

why not have your ECU control it?

 

probably do that.