STOCK AFM maximum HP flow?

[rev210]

For those interested in guessing my horsepower at the moment the AFM signal indicates it has reached 82.1% of its maximum flow at 6800rpm. This is according to the S-AFCII.

Anyone know the 100% figure?

Then I guess my % can be worked out as engine power roughly.

[Sydneykid]

Hi rev, our experience has been that around 420 bhp is 100% on an RB25DET AFM with an optimised air fuel ratio. So all things being equal, 82% would be 340 bhp which is roughly 90 bhp more than standard.

Only difficulty with doing this is the air fuel ratio may not be optimised (eg; too rich) and you may be achieving less horsepower than the airflow would be able to support if the a/f ratio was optimised.

We get about 25 bhp from cat back exhaust, dump and free flowing cat adds another 15 bhp. Boost, usually 0.2 bar equals 30 bhp. Pod or panel airfilter adds about 8 bhp.

If I remember rightly, with your mods you could be looking at

250 + 25 +15 +30 +8 = 328 bhp.

So I would guess that maybe the a/f ratios are about 5% too rich (say, 11.4 instead of 12.0). All things being equal of course.

Hope that helps

[rev210]

Yeah it doesn't 'feel' like I'm making that (320HP) sort of power so I guess my AFR's are a fair wack out.

I've got the exhaust cam gear on as well now at 4degrees retarded.

The airflow figure doesn't say much without the the AFR I guess.

[Steve]

Rev, it may be that it can vary from car to car. On mine it showed 100% (5.1V)at 4500rpm with 191rwkw peak, once the Z32 went on, it tuned to 203rwkw at 4.4V (7200rpm)

Sorry thats not much help.

Steve