Power Level For Rb25Det

[Room42]

This is an excerpt from the Haltech website about fuel requirements and power levels.

If you can estimate the power output of a gasoline engine, you can make a reasonable guess at the fuel

flow requirement. A simple rule of thumb, thus, may be expressed in metric or imperial units.

Note: Every 100 hp needs around 50 lb/hr (8.0 US gal/hr) of fuel

(6.6 Imp gal/hr)

Every 100 kW needs around 670 cc/min (40 L/hr) of fuel

This assumes a brake specific fuel consumption of 0.50. The actual fuel flow necessary by injectors and

pump are likely to exceed a figure derived this way. This is due to the overheads in injector dead time and

pumping return fuel to maintain regulation.

I worked backwards with these figures and with my 910 cc injectors at 68 percent my power level came in at 554kw. This is at the flywheel I assume.

This seems a tad high. Who here can fill in some more information to get a more accurate power figure?

[zebra]

Rough rule of thumb is 1cc per hp

Thats when working out what size injectors you need.

Working out power by injector duty, is a very rough guestimate at best as just a couple of degrees of timing either way will affect it pretty badly, same with AFR's / VE etc

My suggestion is take it to the 'Plex and see what the trap speed it

[Room42]

Yeah I knew there would be a lot in the afr and the timing. I guess I better get it down the strip hey. I think the clutch might let it down a bit but I should get through there pretty quick. Top of 4th is 125mph. That's what it would do I spose.

[R31Nismoid]

All depends on if you actually get to the top end of 4th, and what RPM is used.

You can actually hit the limiter and still see a MPH increase in some instances, just depends how hard it hits.

Doesn't take a genius to workout though that the car doesn't have 554kw @ the fly with a GT35 so the figures provided initially are wrong, or the calculations are.

But ye for a RB 1hp = 1cc using the stock reg (for most intents/purposes). E85 obviously confuses this as do pressure adjustments.