Hi friends of KTM -single cylinder- motorcycles. In this short report/ story I will tell you the experience I made with my Duke engine upgrade. The Duke 690 R is from 2011.
Already in the winter of 2012/2013 I got a 796 ccm Big Bore Kit of Josef Frauenschuh. The result was 81 HP and 91 NM torque at the engine - not at the rear wheel.
In below diagram you can see the different between almost stock (Akra under floor exhaust and Akra mapping and the modified JF engine. Even with Akra the Duke had less than the promised 70 HP.
Dia 11.pdf
Before/ after first upgrade:
Compare to almost stock we have 24% more NM torque and 21% more HP.
Maintenance:
In the summer 2013 and 2014 I drove a little bit more than 20.000 Km. During that period I only changed oil and I checked valve clearance once- but changing shims was not needed. The spark plug I changed after 10.000 KM. This was the all maintenance I did within the two year period.
Gas- and oil consumption:Oil consumption was below 150ml for 1000 km. When oil consumption is that low it is better to change oil more often, so the recommended interval for changing oil, was every 2500 km. The Gas consumption was between 4,8l and 6,5l on 100km. The average consumption was 5,5l, this is not much, compare to stock engine and to some light modified engines.
Injection and air box:
Throttle response of this engine is sensitive, so I put in the RC8 accelerator throttle kit for a smother gas response. The air box got the second air filter –on top of the air box - and some extra holes at the back side. Sound of the air box is good and not too loud, but this is just subjective. I don’t like the sound of the open KN replacement filter, they are too noisy. In general the engine is quieter than a stock engine.
Fun Factor:
To ride an 82 HP motor bike – with only 150 kg - is really funny. Power is always available; accelerating is on a different level than before. Acceleration together with Japanese big bikes is actually my favourite. Gas-wheelie at the third and forth gear is quite easy to do, even in fifths gear it was possible- depending on weather conditions (gear ratio was 15:40). We are always talking high BHP, but higher torque is more important. So far so good.
Why again an engine upgrade?
In general, 81 HP is more than needed, but it is always nice to have a little bit more. You all know about this phenomenon.
And due to the high inflation and no - or negative - interest on bank accounts, my money is melting like ice in the sun. So I decided again to have an “investment” in my Duke 3 engine.
What did JF changed for the second upgrade?
• cylinder and piston were still very good, no wear after 20.000km. We changed only the piston and we put it DLC coated piston rings. The old piston will be used for a test engine.
• forged connection rod was already installed in 2012, no measurable and visible wear within the first 20.000 km, so it was installed again
• ***fully new casted and machined cylinder head, designed by JF and some experts***. The cylinder head was machined for 3 hours in a 5 axis milling machine. Inlet and outlet are oval now.
• bigger intake and exhaust valves (they are huge)
• all valves are made from titanium (US brand), special softer springs were mounted
• camshaft with huge cams was already installed in 2012/2013, no changes here
• ***new connection between throttle body and cylinder, made from oil resistant plastic *** the challenge was the to have a smooth change over from round to oval
• original throttle body was already optimised (bigger diameter) during the first session in 2012/2013,
• modified first part of the KTM-cup exhaust system. The first part is now oval and not round anymore
• stronger gear shaft, stronger gear wheels and stronger bearings for the gearbox, this is needed, due to high NM torque now
• better oil distribution in the gearbox
• oil cooler, was already installed 2012/2013
• and much much more details has been changed, but this is secret and the advantage of JF
Testing and experience:
Before a new concept is launched (street or race track), all parts have been tested to their limits on his Dyno (Ammerschläger P4) and on the race track. The test engine has been tested up to + 9.500 rpm or even higher. After testing the new setup test engine were dismantled to see the wear out on all moving parts. Only when everything is perfect a new setup is ready for customers.
Before/after second upgrade:
So, now we’re talking about 90,5 HP and 98,0 NM torque at the engine. (In the morning with some more oxygen in the air the result was 92,0 HP.) Compare to almost stock we have now 34% more HP and 34% more NM torque. This performance is impressive, and for me this is quite a Big Bang for an one cylinder engine. I checked the www several times, but could not find a one cylinder suction engine how is close to this performance. But maybe I am wrong...
My set up is the street version, the race track version of JF has
• a higher compression ratio,
• higher RPM,
• more pre-ignition, and some other details.
As you can see, 100 HP and 100 NM for a one cylinder engine is not a dream anymore.
Conclusion:
This second update of my engine was really not needed, but – after only some km I can say, and this you can believe me – is worth every dam cent. After the break in period I will bring the Duke to my local KTM dealer for another DYNO run, to compare the diagrams. So you will get an update in some weeks.
Best Regards Satellit
PS: I did this short report in English language, because I know a lot of KTM fans abroad (The Netherlands, Scandinavia etc.) how are interested in this topic. It would be nice for all KTM fans how don’t speak or understand German, to keep this thread in English language. Thank you.
PSII: If you want to know details, dimensions or costs/price, you have to ask JF yourself.
warte noch auf die Übersetzung in Kisuaheli 
Why are you selling the Foodpegs?
) . hat er eine Seite? Has Josef a link? Thats looking awesome.
was du dir da hast bauen lassen 
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