TP Pro-Series® Scramjet Air Cleaner TP Engineering has recently designed, engineered and manufactured a new high performance air cleaner called the Scramjet. This new air cleaner features a machined billet-aluminum backing plate with an integral velocity stack, and chromed die-cast cover with a unique air scoop that aids breathing for superior performance. Each kit includes a high-quality washable filter element and comes complete with backing plate, mounting hardware and breather kit. Kits are available for all top-breather Evo and Twin Cam® engines with CV, S&S and Mikuni carburetors and Delphi fuel injection. Another kit is available that includes everything mentioned above plus a 45mm Mikuni carburetor with appropriate hardware. This kit is available for all TP engines and Harley-Davidson Twin Cams. We recently replaced the stock air cleaner and backing plate on a 2005 Harley Davidson Electra Glide (with Delphi EFI) with our new Scramjet air cleaner. With no other modifications, we realized an increase of 5HP at the rear wheel. Try it for yourself!