[RICK LAKE]

Jerry Clayton If you are running a motor on a dyno, 80% of the time it is long tube headers and a either an extension on the collector in the 20"-36" range for getting the best power from that motor. Most dyno cells I have seen don't have enough room to install a set of cobra side pipes. All cobra side pipe are different inside the muffler area. I have 2 sets, one for street with a 2 1/4" outlet before the turn out. They are quiet and kill the HP in my car. I also have a race set with a 3" inlet and outlet inside the muffler housing and there is a big differents. The honest way to check any exhaust system is with a back pressure gauge. WOT throttle at 500 rpms past your max HP numbers. Looking for 1.5 - 2.5 psi buildup for the best exhaust. The cobra is also limited with having a short transition between collector and side muffler. This helps HP but IMO hurts torque. I agree with you drive train loss and exhaust loss to some degree but there are some variables with testing on a engine dyno and chassic dyno. Biggest is the air in the shop. Have seen a 15 HP change between good and crappy air alone. We didnot take into account for wheel slippage on the rollers. New rollers on a dyno perfect readings, worn out dyno wheels and you get silly readings. Had this happen to me for not being able to get the rearend of the car tight enough on the roller to not slip under load. I smoked out a dyno chassic cell with this problem. Rick L.