For the fun of it, I had the stock fuel pump and the M2/Bosche upgrade pump flow tested at RC. Both are at 13.8v, and flow is in gallons per hour.

psi stock M2
40 60 62
45 57 61
50 54 61
55 52 60
60 49 59
65 46 58
70 40 57
75 35 56

 

bosch sounds like a pretty good pump...dont it..

thanks for the data

 

newRX7fan, thanks for getting those tested. I think it is great to finally get some solid test data for these pumps. I am still not sure what voltage is right (and I think both our voltages are higher than you'll see in the car), but it is a start anyway.

I had my SR Ultimate / A'PEXi BNR-32 tested at 13.2V. Here's the flow:

Psi Gal/hr
35 84.33
40 83.00
45 82.33
50 82.17
55 82.17
60 80.83
65 77.17
70 72.17
75 67.00

More details:
http://www.maxcooper.com/rx7/parts_i...exi_bnr32.html

Muhahahaha! Fuel pump BIG!

-Max

 

Isn't the rule, add a zero to the GPH a pump can flow at a given psi, and that's how much HP it can support at that given psi? I heard that somewhere, but not sure where and if it was true. Like, if I needed a pump for 500 HP, I'd need a pump to flow 50 GPH at the needed psi for the pump. Oh, and that Skyline pump can sure flow some serious #'s.

 

That is a good rule of thumb, which means it is accurate but not very precise. And remember to ask for a corresponding pressure when someone gives you a flow rate -- as you can see here, flow changes significantly at different pressures. For more exact calcs, go here:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

-Max

 

According to RC, 13.8 is the standard measurement voltage, but yeah, probably won't see that at the pump. I've got to measure that sometime!

I ended up going with the SR Ultimate II pump- I asked for a few flow rates for it. Unfortunately they only had it at 12v.

psi gph
43.5 73
50 65
60 58

Looks like it's better than the M2 pump at lower pressures but falls off faster.

The big unknown in this is what the pressure drop is through the fuel line....