Air Cleaner

made by Thunderbike

Airbox Cover Oval and Powerfilter-Kits

The standard air filter can be replaced with relatively little effort itself against a Thunderbike product. If it’s just a matter of putting an accent on a design part, our TÜV-certified air filters and airbox covers are the first choice!

Airbox-Kit Oval

Our oval air filter can be combined with various Thunderbike covers and is suitable for all Twin Cam models with throttle by wire. The base plate is equipped with a filter element that makes the conversion from a round to an oval filter a breeze.

The Thunderbike Airbox Cover Oval are suitable for combination with the oval original air filter of Milwaukee-Eight 114 cui models (Softail & Touring) or our Air Box Kit Oval for a 107cui conversion.

Airbox Kit Oval

Airbox Base Plate

Airbox Cover Oval Drilled

Airbox Cover Oval Grand Classic

Airbox Cover Oval Grand Prix

Airbox Cover Oval Torque

Airbox Cover Oval Torque with Thunderbike Logo


Thunderbike Powerfilters are the perfect allround-aircleaner for all Harley-Davidson models. All are EU street legal / TÜV-approved up to Euro 4 and also tested in combination with Dr. Jekill & Mr. Hyde exhausts. By a minimal modification you can turn it into a real Race Filter, that boosts your horse-powers after ECM calibration (not for road use).

The disassembly of the series part is very simple and requires no further instructions. The required mounting material is included. For installation, the original bleeder screws are reused later.

In the original filter is an electronic throttle, which is controlled by the ECM (Electronic Control Module). Instead of the connector, the dummy is plugged in, which supplies the controller with the right signal and prevents an error code from being set. This is included in our EFI kit, which must be ordered separately for injection engines. For carburetor engines it is not needed.

For the subsequent assembly of our design filters, only the existing holes and threads are used. The new bracket is attached with the existing engine bleed screws. The adapter ring, also supplied, is placed on the holder and the ventilation hoses are attached. Then comes the new base plate and everything is fixed with three screws on the throttle body. The new design housing is screwed onto the base plate with the included K & N filter element.

After one hour, the screwdriver’s work is completed.

The Thunderbike air filters are prepared so that the air passage corresponds to that of the factory filter. Consequently, no further modifications to the EFI control need to be made.

in our open version, devote ourselves to customizing the software. That sounds complicated, and it actually is. There are several ways to influence the controller. Either with an additional component, with the complete replacement of the so-called black box or with the direct reprogramming of the Harley-Davidson control unit. The latter variant has obvious advantages and is generally preferred by us as well. With the Super Tuner, you do not get an additional component that is mounted on the bike, but only an interface between the motorcycle and computer, which is to bring along with you at your next workshop appointment, if changes of the mapping should be necessary. The Screamin ‘Eagle Supertuner does a lot more than just update the mapping for our air filter. It can be used to influence all parameters of the control unit. For example, it is possible to regulate the idle speed as desired (at least 800 revolutions per minute). Above all, however, the possibility of increasing performance with this measure should be interesting.

However, the reduction plate can be removed in a few steps and the air flow increased in this way many times. In conjunction with an adapted engine management system, the performance of the engine can be significantly increased.

Do you have questions about the performance increase with Thunderbike Power Filter or Screamin ‘Eagle Super Tuner? Gladly our workshop team will help you on +49 2852 / 6777-66.

Incidentally, a new mapping may also be required if only the exhaust is replaced. If you want to know how big the power increase at the rear wheel actually is in the end, it should still be determined with original air filter and without new mapping on the dynamometer. The bike was thus connected via Supertuner with the computer, on which in turn the appropriate software is installed, which holds various basic mappings ready. After changing our filter and switching the Super Tuner between the bike and the computer via USB port, you can test several of these predefined mappings. Every change is immediately displayed on the monitor. The situation on the test bench is largely realistic, but the load of the bike is not yet one hundred percent road use. Now follows a long test drive of the mechanic, including connected Super Tuner. On the housing of the tuner there is a pressure switch, from the moment where it was pressed, the device records all parameters, after which the mapping can be tuned exactly (Smart-tune). The result is impressive! Depending on the engine speed range, we were able to easily achieve an increase in horsepower of up to eight horsepower in this case. Using a printed performance diagram, the changes made are visible to the customer.

Powerfilter-Kit Drilled

Powerfilter-Kit Cross

Powerfilter-Kit Grand Classic

Powerfilter-Kit Open Mind

Powerfilter-Kit Torque

Powerfilter-Kit Torque with Thunderbike Logo

Powerfilter-Kit Thunderbike Logo

Any Questions?


Nico Schnepel

Customparts, Dealer Support

0049 2852 - 6777-30
Send an email


Roman Reiners

Customparts, Dealer Support

0049 2852 - 6777-30
Send an email


Steffen Eckhardt

Product Management

0049 2852 - 6777-22
Send an email


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