Here is the old post from the CF. Results for peak HP were within margin of error but notice the average HP and Torque numbers show a small gain.
Today myself and forum member/dyno owner TJ Wong set out to find the truth regarding C4 air intakes. We dyno tested 3 different air intakes on my Lingenfelter 368cid LT5. Tested today were: stock with paper element, stock with K&N element and a cut lid, and finally SLP's "claw" tri-cone filter design. All dyno pulls were made with starting coolant temps at 195 degrees F. Here are the results.
Stock with paper, two identical pulls: 477rwhp. Avg. peak HP 477
Stock with K&N and cut lid, three pulls: 471, 475, 480rwhp. Avg. peak HP 475.3
SLP tri-cone "claw", three pulls: 477, 478, 481rwhp. Avg. peak HP 478.7
It would appear that the naysayers are mostly correct about C4 air intakes, not much to be gained here. Both Tom and I were rather suprised with the results. We had expected to see some small but visible gains with the cut-lid and SLP, instead we got a bunch of tests with peak numbers being basically the same or well within normal dyno pull to pull variation. The SLP unit does seem to have a small advantage over the others but suprisingly it's in mid range power not peak (see dyno graph average power #'s).
