Jon,

For Norm it matters, for most of us non-racers we just have to push the pedal down an extra 1mm to get that 5HP when required

Great info Blue, as always. I have a 4" lathe and some solid core PVC stock thats 1" thick. I think I'll try turning out a set similar to example 11. Good stuff.

I like the percentage gains/losses shown, but at what airflow was that calculated? Across the board, or at what RPM was the percentage power gain/loss measured

for a stock 240Z with SU's, a 5.5% increase in power would be around 7 HP. That is not totally trivial. You would probably notice your car feeling a bit more 'spritely' with that.

Edited November 8, 201113 yr by Zedyone_kenobi

Another observation: There is a rolled edge on the snorkel (intake) of the original stock orange air box.

Bonzi Lon

I like the percentage gains/losses shown, but at what airflow was that calculated? Across the board, or at what RPM was the percentage power gain/loss measured

for a stock 240Z with SU's, a 5.5% increase in power would be around 7 HP. That is not totally trivial. You would probably notice your car feeling a bit more 'spritely' with that.

Excellent question. Unfortunately I do not have the associated data for the configuration of the test bed... 6,4,2,1 paired webers? 2or 3SU's? I don't know. However the data was compiled from a renowned performance investigator named David Vizard so it was proven somewhere.

Given this,the only safe assumptions that we can make is that there are differential differences between geometries and the absolute performance gains (according to Norm's drag strip HP improvements) can be extrapolated to be in the order of magnitude of the drawing above.