I've searched the web for "injen dyno g35" and found just the two Dyno graphs done by "Injen Technology" themselves.

Did anybody else notice that all four runs, 2 per graph, were done in 3rd gear?

Does this not skew the end results? Aren't dyno runs supposed to be done in the 1/1 ratio gear in order to get hp/torque numbers that are unaffected by the transmission's gearing?

Gear 5 A/T 6 M/T
1st 3.540 3.794
2nd 2.264 2.324
3rd 1.471 1.624
4th 1.000 1.271
5th 0.834 1.000
6th - 0.794
rvrs 2.370 3.446

Yes, the "Injen" dyno graphs do show that the intake does improve the hp & ft/lbs over the stock intake. But using 3rd gear provides an advantage for the engine as it tries to spin up the dyno's drums. Since the dyno determines torque by sensing how quickly the known mass of the dyno's drums are spun up to higher rpms, the use of a gear ratio wider than 1/1 lets the engine overcome the drum's inertia with greater ease. This inflates the torque perceived by the dyno (and by calculation the perceived hp).

I.E. While the graphs show an improvement, we don't actually know what the max hp/torque numbers are unless someone can calculate the true numbers by factoring out the 3rd gear advantage over the 4th gear (assuming the G35 was a 5AT) or a dyno graph is produced using the 1/1 ratio gear for the stock and Injen intake runs.

Note: I did a dyno run in 5th gear on my Coupe w/5AT. I did this in order to determine if, in fact, the G35 had a speed limiter and if so, to what mph does the ECU limit the G35's top speed. I expected to see deflated hp/torque numbers due to the disadvantage the 5th gear has compared to 4th gear.

This can be seen in the following graph. Note the low max hp/torque numbers. Also, you can't see it on this graph but the ECU stopped the acceleration at exactly 155mph as measured by the speedometer (which is controlled by the ECU).

Screamin' Daemon - L5AT

 

The 5th gear Dyno graph.

Screamin' Daemon - L5AT

49914-Screamindaemon_DynoJet_Baseline_CAM01.jpg