Can MAF% on SAFC2 Estimate HP being produced??

[blues14]

I Realize there is really no 100% way to know what kind of power you are making besides a dyno pull, but does the MAF % displayed on the safc give you a good Idea of what kind of power you are making?? I am running a z32 maf on my rb20 and am topping out right around 51.1% at 6,800rpm 1.13bar. May be a dumb question, but I figured I would ask.

[mello88]

The amount of air coming into the engine is directly proportionate to the power, varying depending on your AFR, air temp, flow restrictions, etc. I think you can probably get a rough estimate if you know the max power the Z32 maf flows.

According to arc....html the Z32 maxes out around 550hp (not sure if thats crank or wheel, I assume it's crank). If you're seeing 51% of that, then the math says you should have around 281 hp. But that assumes the MAF output is linear with flow, so IDK.

Another method would be to figure out your lbs/min of air flow (based on displacement, boost and VE guesses) and go from there. My turbo calculator estimates your air flow at 34 lbs/min @ 6800 rpm, 16.6psi... It's a known rule of thumb that your power is roughly 10 * lbs/min of airflow -- so ~340hp.

Based on these 2 methods, I'm guessing you're in the low to mid 300s? You're right the only real way to know for sure is to dyno it! Interested to see what others have to say...

[blues14]

Thanks Mello., My friend who helped me street tune with wideband said it feels like around 300-330whp compared to other cars he's been in/worked on. My afrs are in line and a little rich up top. My duty cycle is reading 98.9% on my 440cc's but I hope to hell that number is off.

Does anybody have actual dyno numbers to compare to their MAF %??

Modified by blues14 at 4:38 PM 10/9/2007
Modified by blues14 at 4:39 PM 10/9/2007

[mello88]

NP dude. On a 6 cyl motor you can estimate the hp the injectors can support as 1cc ~= 1hp at 100% duty.. For instance your 440s should be able to provide fuel for ~400hp at >=90% duty cycle. Of course the actual #s would depend on your AFR and how clean the injectors are. Don't see how you could be maxxing them out already if you're just into the 300s, maybe that % is inaccurate. GL

[gawdzilla]

stock turbo? anything beyond 14psi is just pushing hot air probably. if your A/F is right, timing is right, you're probably ~250-275 rwhp

[blues14]

A'pexi turbo....actually produced as an rb25 upgrade turbo, but of course, it bolts on rb20det. According to a'pexi, it can support up to 450 hp