Kurt Trieb, 54, studied mechanical engineering at the University of Stuttgart for seven years, then worked designing engines for Porsche, Rotax and BMW before becoming a key figure in KTM's Motorsport department from from 2003.
He is therefore far from unknown to the world of Grand Prix motorcycling, having designed the 990cc MotoGP engine which raced briefly in 2005. He later helped run motocross engines and was responsible for the KTM returned to Grand Prix racing in 2012 with the original Moto3 GP engine design.
He explains his work concerning the Ktm RC 16 Ktm blog and actually justifies our doubts about the announced engine speed previously.
For KTM MotoGP, have you dusted off the 990cc engine that was used in the Kenny Roberts team chassis in 2005?
“No, we didn't start from scratch to try to avoid any of the mistakes we made in 2005, that's clear. But of course you have to take into account the previous design. Anyway, I was very happy to start such a project again, and it certainly helps if you have accumulated some experience before! »
Were you happy with this first KTM MotoGP engine?
“He was a strong mover who wasn't given a chance to show his true potential. There were some issues on the original engine, for sure. It was a different time; we built the first five engines and then went racing with them. It was a completely crazy situation! Now we have a proper test and development plan. »
Why is KTM deciding to use a V4 again?
“There are many advantages to using a V4, in terms of engine performance and mechanical reliability. I have experience with inline 4s and the problems that come with them, and I was comfortable with whatever decision was made. An in-line 4-cylinder was not considered a KTM feature. So in the end we didn't really have much discussion about which configuration to choose, but more about the angle of the V. A wider angle avoids the need for a balance shaft. This kind of decision. »
How difficult is it to build a MotoGP engine?
" Difficult ! We wouldn't have time to discuss everything (laughs). There are some restrictions in building a MotoGP engine. For example, the maximum bore diameter is 81mm. It makes no sense to build an engine that can spin at 20 rpm since the valve sizes are too small for that, to gain anything. So, there is a natural maximum engine speed that corresponds with this bore,
somewhere between 16,500 and 18,000rpm. We are in this range, but on top of that you're trying to have a good power curve. For example, the slowest corner at Jerez sees the engine speed drop to 5000 rpm. So if you have your maximum power at 17,500 rpm for example, you need to consider a wide power range to suit all tracks. Our first 990cc GP engine only really worked above 8000 rpm, and this was clearly a problem, and something we moved away from. »
Tell us about the engine side of the MotoGP department.
“There are a lot of projects in the factory competition department, but I am responsible for engine design and we are a team of five people. There is also a larger team that takes care of development and the workshop. But the advantage of having all the projects in the factory racing department is that there are aspects of other projects that can be incorporated into what we do for MotoGP. For example, with Moto3, what we learned about combustion and valve configuration can be transferred here. »
Will the KTM MotoGP engine help KTM customers?
“Whether the technology can be transferred? This is a really difficult question. If we don't produce V4, then maybe very little. KTM has such a wealth of experience with single cylinders, particularly being at a very high level with Motocross and Moto3, that this certainly helps other products. It will be very interesting to see how long it takes before we see seamless transmission technology come to production motorcycles. This shouldn't be too difficult. There are double clutches, which are not easy to make, but it's the same area of technology with an identical main problem. »
Speaking of Moto3, you were responsible for creating the original engine that was so successful.
“Yes, but I am no longer very involved in Moto3, since another group works on development and following the races. I'm trying to catch up and get an overview of what's going on. Surprisingly (and I don't say this out of disrespect), we found a good improvement on the engine side for next year. I thought we were pretty level, but we found good potential and we are optimistic for 2017. This shows that KTM is still very focused on Moto3 since by continuing the development work, we found a big improvement that gets everyone excited for next season. »
How about the sound of the RC16 engine?
“We started with a kind of silencer for burn-in, which for the pilots was clearly much more user-friendly and comfortable. But everyone thinks he needs to make more noise. So again, this is just an incidental issue. Perhaps the original engine would have damaged my hearing though! »
How much power do you need from a MotoGP engine?
“You see Ducati with the most powerful engine and, for example, Yamaha with less, but Yamaha wins the races. It's the compromise you have to find and be fast on every track; make great times everywhere and give a good feeling to the driver. »
What do RC16 engine drivers say?
“The return is good, a little too good! There was a bit of a turning point between testing earlier in the year. Before this, Mika (Kallio) said that the engine seemed very aggressive when he opened the throttle. Since then we have done three tests (in Brno, Mugello and Jerez) where he said he felt more comfortable. Is this an improvement in the electronics or just Mika getting used to the power? I think drivers need to feel that there is still sufficient additional power available when they open the throttle. Based on past experience, when a rider said an engine felt smooth or was easy to control, they often meant it was slow! And we want to be fast. We want to be fast on every track, but still provide the best possible feedback to the driver. It's a compromise, but something we've worked hard to achieve. »
