Roy LoPresti


Comanche 260/260B owners realize a 25 MPH increase with
LoPresti Speed Mods

"Once a Comanche owner sees and flies his GTO,
he is going to realize it's a whole new airplane."

-AOPA Pilot, May 1994

LoPresti Wholey Cowl

The WHOLEY COWL mod for the Comanche 260 and 260B consists of a new polished Hartzell spinner, new spinner backing plate, an all new cowling firewall forward, constructed of carbon and fiberglass, 2 new long nose gear doors that close the entire stock cooling air exit in the Comanche’s belly, a dedicated electromechanical actuator and mechanical linkages that drive the nose gear doors. Also included is a sequencer for the nose gear system (the dedicated actuator is required to keep the doors tightly closed during high speed flight), a new induction system, a new induction system air filter, a new and larger oil cooler placed behind the engine with the appropriate new oil lines and air duct lines, a single cowl flap with a locking mechanical cowl flap control in the cockpit. This mod also includes the new baffles at the front end of the engine plus new engine baffle seals all around.

The reduced drag provided by the WHOLEY COWL mod provides 15 MPH in additional cruise speed at 75% power. This 15 MPH is in addition to the speed provided by the three under wing mods also available for the Comanche that provides an additional 9 MPH. The WHOLEY COWL is much easier to remove than the stock cowling and provides better access to the engine.

The transformation provided by the cowl mod and the other mods makes such a dramatic change to the airplane’s appearance and performance that the airplane has been renamed the Comanche GTO. See articles in AOPA PILOT magazine, May 1994 and FLYING magazine July 1994. The AOPA PILOT says

"Once a Comanche owner sees and flies his GTO airplane, he is going to realize it’s a whole new airplane".

The new cowl mod does not require a new propeller. However, a propeller designed specifically for the 260 and 260B Comanche, and the Comanche GTO airplanes has been designed to optimize the airplane’s performance. This new propeller is called the SynchroPulse propeller. The propeller raises the engine’s critical altitude by providing a little bit of supercharging and provides an increase in the cruise speed of 3 MPH. The SynchroPulse propeller has a curved leading edge, a swept back tip and a flap just outboard of the spinner. The flap forces a pulse of air into the induction system inlet, with pulses arriving at each cylinder while the intake valves are open. The static thrust is increased 15% yielding snappy acceleration and better take off and climb performance. What the Comanche customer gets is 25 MPH more speed, approximately 10% more range, improved climb, better fuel efficiency and shallower glide.

The Wholey Cowl Mod includes

Click BLUE TEXT above to jump to pictures below.

Wholey Cowl for PA24 Single
Cool New Look!

LoPresti Wholey Cowl Kit
Complete Wholey Cowl Kit

Installation Photos

Completed bottom cowl with removable nose bowl.

New nose gear door actuator installed on firewall.

 New baffles and seals installed just aft of propeller.

New larger oil cooler installed on the right rear side of engine.
Nose Gear Doors
LoPresti Aviation
772-228-9745 or fax 772-228-9750 Info@
Sebastian Airport (X26) 210 Airport Drive East, Sebastian, Florida, 32958

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