December 1, 2000

Dear Friends,

      As we close out our second full year of manufacturing and installing the "Whirlwind" turbonormalizing systems in Bonanzas, we have some very good news to share with you.

      At the time we acquired the Turbo STCs from Colorado, we pledged past and prospective owners of these systems to do everything we could to improve the system. We have followed through on that pledge.

      Recent design changes engineered over the last 18 months and recently approved as part of our STC and incorporated into our current "Whirlwind System II" have shown remarkable performance improvements in the take-off, climb and cruise of the TAT turbonormalized Bonanzas. These benefits come from a combination of several modifications to the original Turbo-Flite™ design, but most significantly from the new "Rammer" intercooler kit. The "Rammer" intercooler kit involves replacement of all of the induction system from the compressor to the throttle body. This includes couplings, aluminum tubing, intercooler, inlet flange, Scat tubing and hardware. In addition, the kit provides for the recessing of the nose landing light in a cushioned mount for substantially better airflow into the plenum where the intercooler takes in its cooling air.

      As a part of this "Rammer" intercooler modification, numerous design elements were improved upon in the above group of components. These modifications result in substantially improved induction airflow, reduced exhaust backpressure and fewer convolutions of the induction air. Larger diameter tubing and an intercooler with approximately 40% more cross section provide for easier airflow through the intercooler system. The cooling air which comes off the plenum area behind the nose bowl has been changed from a 3" diameter opening to a 4" diameter. This improvement, alone, provides for approximately twice the available volume of cooling air to pass through the intercooler. These changes have improved the intercooler efficiency by approximately 50% from the previous system. Lower induction air temperatures result from the increased efficiency of the intercooler. More horsepower results from both the reduced backpressure as well as the lower induction air temperatures, by increasing the volumetric efficiency of the cylinders and providing cooler, more dense air for combining with the corresponding amount of fuel.

      The combined effects of the changes now incorporated in the Whirlwind System II, have produced a powerplant system for Bonanzas that is without compare in any other piston powered general aviation aircraft. The results have exceeded even our own expectations by significant margins. It is now apparent that the new design recovers approximately 25-30 HP (in an IO-550). In addition, the lower induction air temperatures provide for lower CHTs. If you are one of the group of pilots that manage power by virtue of limiting the maximum CHTs, this translates to more useable power at equivalent CHTs.

      We can show the increase in power by such performance improvements as reduced takeoff roll distance (particularly on hot days), increased rate of climb, and increased cruise airspeed. In comparison to the previous Flite-Craft™ design the specific performance numbers our "System II" is typically capable of are as follows: We expect the sea level, hot day takeoff roll distance to be shortened by approximately 25%. We expect the rate of climb to be increased by 200FPM under the same hot day conditions. We expect to see at least 5 knots TAS increase when operating at equivalent maximum CHTs (lean of peak, of course). These performance numbers are estimated as minimum expected values and are well below the average numbers we have seen on actual installations thus far. The typical installation will see a 5-8 knot improvement in speed and 250 to 300 FPM increase in rate of climb.

      Many of the V-35 and F33 airframes are now routinely seeing 195 and even 200 knots true airspeed , not at 18,000', but down at 12,000'. Speeds in excess of 200 knots at 17,000' are routine. We have flown several clean A-36 airframes that were capable of 195 to 198 knots at 12,500'. As always, we will not ask the engine to produce these speeds with any CHT hotter than 380F.

      It should be noted that these performance numbers are derived from the current configuration of our "Whirlwind System II" which includes all of the available upgrades to the original Flite-Craft™ designed system. Depending on precisely when your particular aircraft was modified with the Flite-Craft™ system, some of these upgrades may have already been installed.

The upgrade modifications include:
1. Composite airbox and relocation of the alternate air door to the left side cheek plate access area,
2. "Rammer" intercooler kit
3. Cooling kit for cylinders #2 and #6
4. Fully louvered cheek plates
5. Fuselage mounted louvers, and of course
6. turboGAMIjectors®.

      1. Composite Airbox/ Alternate Air Door Relocation - In accordance with a previously issued service bulletin, requiring replacement of the metal airbox/alternate air door with a composite airbox that allows more airflow and increases the efficiency of the turbo system. The alternate air door is then relocated to the left side where it is also not subject to icing. This installation is very easily accomplished in about 2 hours.

      2. "Rammer" Intercooler - Gain performance and efficiency with this larger intercooler that incorporates several significant changes in the induction sytem. The intercooler core area has been increased by 40%. The airflow into and through the intercooler has been streamlined for smoother transition and less back pressure. The induction tubing and couplings diameter downstream of the compressor has been increased and smoothed. The volume of cooling air through the intercooler has been effectively doubled. The landing light has been recessed to provide additional cooling air. All these changes serve to reduce the induction air temperature which has a number of beneficial effects such as improved takeoff performance, greater engine efficiency, cooler CHTs, and safer detonation margins. Retrofit installation including the recessed landing light is estimated at 12-14 hours.

      3. Cooling kit for cylinders #2 and #6 - For improved cooling of the two hottest cylinders, we have designed and certified new, additional components to provide more airflow to the right places on those cylinders. This design is so effective that these two cylinders which are typically the hottest, will probably end up amongst the coolest. With improved cooling comes the ability to use more horsepower = speed. By reducing these cylinders' temperatures by 30-35 degrees each, we can increase the horsepower enough to gain 3-5 knots of airspeed. Installs in about 6 hours.

      4. Cheek Plate Louvers - Fully louvered cheek plates as are found on current model A36s replace older style "shark gill" style providing for increased airflow out and increased airflow in for reduced CHTs. This modification typically drops Average CHTs by 10-15° F. Must be sized to fit your aircraft. Available primed or painted to match.

      5. Baffle Louvers - Louvers located in the fuselage below and slightly aft of the cowl doors provide enhanced airflow through the cylinders for lower cylinder head temperatures. Originally installed on only the IO-550 systems, these louvers are now standard equipment on the "Whirlwind 520" system and are available for your Bonanza if not presently equipped. Installation takes approximately 8 hours.

      6. turboGAMIjectors®- Improve the engine smoothness and efficiency by installing turboGAMIjectors® fuel injector nozzles to achieve improved fuel/air ratios. The benefits include more uniform EGTs and CHTs, smoother engine operation, the ability to safely run high power, lean of peak TIT for more airspeed and significantly improved fuel economy. Although most of the Bonanza turbonormalized family of owners have already made this simple modification, there are still a few who need to make this change. The installation takes only about 1 and 2 hours and the turboGAMIjectors® will pay for themselves in fuel savings alone. For more information visit the web site or download and read the "Suggestions for Operation of the Turbonormalized IO-520/IO-550" on the web site.

For aircraft being upgraded to the new "Whirlwind System II" package as described above, we will supply a new nameplate for the upper cowl door designating it as a " System II" conversion. This will provide continuing evidence and value as the premier turbonormalizing installation available on Bonanzas today.

IO-520 to IO-550 Engine Upgrade - Tornado Alley Turbo, Inc. is pleased to announce the recently received STC modification that now allows for the upgrading of the engine size from an IO-520 to and IO-550 when done along with the installation of the turbonormalizing system. The increase in horsepower from 285 to 300 (minimum) provides for shorter takeoff roll, increased rate of climb ~(150 fpm) and increased cruise airspeed ~(5-7 kts). With the excellent cooling provided by the "Liquidair" Baffle Kit, well controlled engine temperatures are possible even under high power operation. This IO-550 installation combined with the "Whirlwind System II" turbonormalizing system is the definitive, ultimate power package for your Bonanza. Call for pricing.

From your friends at Tornado Alley Turbo, Inc.

Tim Roehl