Sheetmetal intake measured performance

[jp455]

Hello all...was looking through the folder with my project wish list pics and got to thinking about the sheet metal intakes. They really do look great but are there measured performance figures out there comparing them to stock (or factory style) LS intakes? Ive looked around and havent seen anything.

The intakes in C5Rs are way trick but I assume they use the large plenums to deal with the intake restrictors.

[jp455]

I found a comment by Nick Agostino from Agostino Racing Engines that said;

"...there wasn't one that outperfomed the ls6 intake under 6500rpm. They all lost trq, some over 50ft/lbs and never regained even at peak."

So Im guessing my initial though that the big plenums often seen in sheet metal intakes are more useful when using a restrictor cause it seems the air speed is way reduced thus making low RPM torque. Would still be interesting to see a dyno chart back to back.