Venom, that is surprising about running faster with the nitrous fuel jet only, I’d expect the opposite. I will have to see what happens when I modify the MAF signal. By the way, I really do want to spray this thing one day.
I'm not surprised that the aftermarket MAF doesn't help. The MAF on the GXP is also used on the 2004 - 2005 CTS-V amoung other LS motors, so it is plenty big enough. Yes it has the screen, but the ID of the inlet is 3.75", so it should not be very restrictive. Not having the screen means the MAF signal will likely be inconsistent, which is nothing but trouble.
On the LS1 forums, that engine seems to respond very well to timing advances up to 26 – 28 degrees, and AFR of up to 12.9 when running premium fuel. I know, different engine, but I don’t think anyone really knows exactly what the Northstar likes.
I’ve decided to get this translator: MAF Translator
We will see if I can actually fool this PCM. "Big Brother" might figure out what I am up to and throw a code. In theory it ought to be ok. At WOT, it is not reading the o2 sensor, and relies on the MAF to know how much air is entering the engine. It only learns about MAF reading changes at part throttle, so the key is that with the translator, you only modify the signal at WOT.
Here is a thread I started in the support forum for the Gen 2: Will the Gen2 work for me? - Full Throttle Speed Tech Support
Regarding the Dashdyno, yesterday I tested the performance function. It is capable of measuring time to speed (0 - 60 for example) and 1/8 mile and 1/4 mile times. It does not have an accelerometer, but uses the VSS (vehicle speed sensor) to monitor acceleration. I found a good spot near my home where I can safely make an 1/8 mile run – great visibility and absolutely no side streets or entrances. I recorded the following times:
0 – 60: 6.3 sec
1/8 mile: 9.6 sec at 77.9
For reference, at the track I previously ran a best 1/8 mile pass of 9.5 at 76.5. So the numbers from this gizmo are definitely in the ball park. They can’t be relied upon as absolutely correct, since the slightest grade on the road will throw the numbers off. However, just like a G-tech, if this device can consistently record performance numbers, it will let me know what actual gains I am getting with any changes made. I will be making all runs on the same stretch of road. I am going to make a few more baseline runs to check consistency. It was windy when I baselined, so I might throw that one out.
I am going to reverse test the 3.5” CAI I am currently running against the fully gutted airbox. I want to make some additional baseline passes to make sure the times are consistent, then I can reinstall the airbox and see what the net change is (if any). Sure the 3.5 FWI looks cool, but the numbers won’t lie.
The dashdyno also has a dynamometer function. You enter a bunch of data including temp, humidity, and barometric pressure so it is corrected back to standard. Again the numbers may not be absolutely accurate, but should reveal increases and decreases in horsepower and the rpm where they occur. I have not yet tried the dyno function.