I'm just interested in seeing MAF and load readings under WOT pulls especially. Or can anyone tell me what is the typical peak gram/second and lpeak oad reading on a stock or mostly stock n/a car?

 

As the OE MAF calibration sees it (with no add-on intake or exhaust), the MAF can range from 190 to 220 g/sec around 8000 RPM, where it typically peaks.

FYI - The highest MAF reading I've seen so far (on a turbo car) was 454 g/sec. The lowest peak MAF reading I've seen on a totally stock car (a 2004 that probably had a "soft" engine) was 176 g/sec.

 

Jeff... please call me.

 

All over the map right now.
If you need me, please use e-mail only. Thanks.

 

190 - 220 g/sec... what absolute load rating are you measuring at that peak rpm and airflow ?

 

best i can do -- intake and exhaust only

 

so I was tuning a friend's Subaru Legacy GT today using AccessTuner. Those are basically STi's with smaller turbos, so 2.5 liter 4 cylinder boxer engine.

Interestingly enough, his peak MAF values (stock MAF stock intake stock turbo) were slightly lower than your log there ^ and he was running peak boost of 16psi tapering down to about 12 as the turbo ran out of breath. That's with a full 3 inch exhaust, stock turbo, catless uppipe. The car was on a dyno that is not known to read high (Land & Sea Dynomite) and it did 220rwhp/260rwhp torque. With less airflow than a stock Rx-8. It peaked at about 220 g/sec around 4000-4500rpm and held flat up to about 6500 rpm as the boost tapered off.

I'm not sure what's more impressive, how much air a rotary can flow or how little power it can make with that flow? I really hope Mazda makes some big strides with the new combustion chamber design, this is kind of ridiculous.

 

Maybe your expectations and understandings are ridiculous?

 

Rotary motors have a lower BSFC and the torque lever arm is significantly lower.
Its just the design.

 

recently heard of a stock port NA Renesis engine pulling 290 g/sec peak

 

The Grand Am cars were almost that high.
That's a lot of air - 240 RWHP worth.

 

ive been told of 260hp engine dynos by a team or 2 last year. but this would be more like 270-275 yeah? not on straight gas?

 

stock port? like in unmodified?

 

Hears a non - stock

 

Yes factory stock unmodified at sea level

VP100 unleaded gasoline

 

Here is a log I took tonight from Grungepups stock 8.



Higher RPM's but not red line (obviously)

 

Here's a lightly modified 2005 RX-8 with a healthy motor.

WOT.CSV

 

Meh, no CSV iPhone app .......

 

I like that 240 up there at 100% load.

 

For those of us at higher elevations I assume the same 4% power loss per 1000 feet also applies equally to the MAF rate?

 

I never really sat down and did the math for this, but that seems logical to me.

 

In that case, wow ....

 

256g/s ..........

































wow