Max Cooper's RX-7 Web Site www.maxcooper.com
GalleryParts InformationVendorsMy CarHow-ToLinksSearchContents

 

A'PEXi BNR32 Fuel Pump

I had RC Engineering test my fuel pump that I purchased from SR Motorsports. SR modifies the pump to accept the stock "sock" pickup filter, which makes it pretty easy to install. This was the original SR "Ultimate" fuel pump, but I think they are selling another pump now. 

I had RC test the pump at 13.2 volts because I could then compare it to the Bosch pump. However, I am quite sure it does not get 13.2 volts while it is installed in the car with the stock wiring. I plan to upgrade the wiring and do some before and after testing to see what voltage it will really be operating at. But I haven't done that yet...

Here is a flow graph, showing flow in gallons per hour versus gauge pressure:

I was really happy when I saw this. This is "one hell of a pump", as RC's Russ Collins put it. You will notice that the graph stops at 75 psi. The reason for this is that the pump has an internal pressure regulator that limits pressure to 75 psi. If you go over this pressure, flow drops off very quickly. Don't use this pump if you plan to run more than 75 psi of fuel pressure.

Here is the full data sheet:

Volts: 13.2
Test Fluid S/G: 0.76
Fluid Temp: 72

Horsepower value @ BSFC of 0.6 is shown in last column at right.

(Note that 0.65 is more appropriate for a rotary, so the BHP values are about 10% higher than should be expected for this application. Also this does not take into account the pressure drop from the fuel system plumbing.)

PSIG Amps Lbs/Hr Gal/Hr Ltr/Hr Ltr/Min CC/Min Gr/Min Gr/Sec BHP
35 11.4 506 84.33 319.24 5.32 5320.73 3825.39 63.76 843.3
40 11.5 498 83.00 314.20 5.24 5236.61 3764.91 62.75 830.0
45 12 494 82.33 311.67 5.19 5194.55 3734.67 62.24 823.3
50 12.7 493 82.17 311.04 5.18 5184.03 3727.11 62.12 821.7
55 13.2 493 82.17 311.04 5.18 5184.03 3727.11 62.12 821.7
60 13.6 485 80.83 305.99 5.10 5099.91 3666.63 61.11 808.3
65 13.9 463 77.17 292.11 4.87 4868.57 3500.31 58.34 771.7
70 14.2 433 72.17 273.19 4.55 4553.12 3273.51 54.56 721.7
75 14.5 402 67.00 253.63 4.23 4227.14 3039.15 50.65 670.0
 

 

The information on this page is Copyright 1999-2002 Max Cooper
If you have any questions or comments about this page, send email to: rx7@maxcooper.com