This plate is like a plenum spacer. Its purpose is to evenly distribute airflow to all cylinders through the intake manifold and not to add volume to the upper plenum like all previous spacers that do nothing. After extensive research and testing we have a profile that maximizes flow to all cylinders. This piece is 1/8" thick. It uses all the stock fastening hardware. It simply bolts on with nothing more to modify.
We designed this plate on a 2000 CFM airflow generator. We measure the actual airflow at the valve opening. Something like this plate or upper plenums can NOT be designed on a flow bench. They must be designed duplicating what is actually happening inside the manifold under boost. This is exactly what we have done and that is why our plate works so good.
After market plenums like the Kenny Bell, Precision and Acufab do not distribute airflow evenly either. We have developed a plate for each of these plenums. We could not use the stock power plate as they flow differently than the stock plenum.
We have found that although the Hemco plenum is better than stock it does not distribute the air even either. There is no way you can distribute the flow evenly with a square hole, period. We can not correct the Hemco plenums. They have to small of open area to manipulate the incoming air. The Hemco reduces the high/low cylinder airflow differential but actually makes the middle two cylinders the leanest. These middle two have shared head bolts, this is not the most ideal situation to say the least.
I have personally gone 9.77 @ 139 with the ADPPp and a precision plenum on my stock block TSM legal 3610lb. car at the 2002 GS Nationals
Dave Bamford and Roy Garcia have both gone 9.5s @ 142 with Airflow Distribution Power Plates with TSM legal Turbo regals. Dick Kerney has gone 8.95 @ 156 with a stock block car and the power plate.
The number 1 and 2 qualifiers in the TSM class at the 2002 GS Nats. were both running RJC A. D. Power Plates.
Now most of the cars in the TSM series race are running one.