Noob question. When folks speak about invalid readings with the hood open (with short-tube intake mods), I'm guessing that is it due to lower temps in the engine bay, right? I'm only familiar with dynos for motorcycles (DynoJet w/Power Commander, etc).

To take it a step further, when a car is in motion (cooler air being drawn into the engine bay), numbers should be higher than a stationary vehicle on a dyno, right?

Temps are part of it, but airflow is also a big (if not bigger) issue. When you have your hood open, the filter elements are free to draw in as much air as they want. But when you actually drive, you drive with the hood closed (hopefully), and with the hood closed, the air is much more restrictive (and hotter). Let me put it this way, the inlets for the G3 intake sit in front of the radiator behind the bumper cover. A test was performed (by RCZ I think) comparing dyno numbers with the bumper cover on vs off. Not surprisingly, the numbers were better with the cover off. So we have the same principle at play here. Air flow is going to be more restrictive with the bumper cover on than it will be off. So dyno numbers with the bumper cover removed are going to be somewhat elevated -- "invalid," if you want, because we drive with our bumper covers on, not off.

Regarding the car in motion and how that affects airflow, yes airflow will be better with the car in motion. That's why dyno shops typically aim huge fans in front of the car during dyno runs -- to simulate driving conditions as much as possible.

Now I have to find a local Protuner :D

Dyno Pics

caneman88,

If you're willing some time, I'd love to get a ride in your car. I live in San Antonio and have still not started the modding process but would like to get a feel for what is possible with bolt on's AND a tune.

Thanks,

Tony

I sure we could make that happen I live in Encino Park area 1604 & 281

Sounds great! I'll try to get in touch with you next week sometime. I appreciate it!

Tony