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Several RC magazines around the world have asked us to write a monthly column. With the kind permission we will re-publish the column at our web site too so all of the XRAY fans can read the latest news and behind the scenes information. Enjoy.

Archive:
Column #1 - Behind the Scene Stories

Column #2 - Worlds Flashback

Column #3 - T2'007 Debut

Column #4 - Designing the T2'007

Column #5 - Worldcup Review and NT1 Testing

Column #6 - Developing and Designing the NT1

Column #7 - Developing and Designing the NT1 - Part 2

Column #8 - Back to the Races

Column #9 - XT8 Truggy Development



The last few months I was really enjoying the hobby and racing again, since I was going to lots of nitro races and test sessions with both new NT1 and XT8. I can even say that in the last few months I breathed more nitro than I have in the few last years combined. Both of these new projects were launched very successfully and the first feedback from customers worldwide was very positive… at last I could finally relax and know that I could (for at least a short time) shift my priorities to other projects.

With summer holidays coming soon and three European Championships on the schedule, we had to analyze our preparations, current performance levels of the XRAY cars for these races, team arrangements and plans, and all other activities. Between the nitro touring car NT1 and the off-road buggy XB8, I was confident about their current performance levels so I had enough assurance that our teams should do very well. Being confident of both these cars I could transfer all my time, energy, and focus on electric touring car development again.

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First we started with analyzing the last races we attended… what was good and what went wrong. The current T2’007 is definitely one of the best-performing touring cars on the market — having some of my most successful designs in it — but I still had the feeling there was something very small missing to boost performance to a new level.

Getting back from the European Championship Warm-up I had mixed feelings. Of course I was very happy that our team swept the whole EC Warm-up taking the entire podium and most of the A-main places. But I still had the feeling that at the EC when the grip and conditions will be much higher (and especially the competition level will be higher) that it may be some small details that will matter and decide the winners. With several weeks to go I decided to fully concentrate on the electric touring car.

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Electric touring cars are so highly developed today and the performance level has been raised so dramatically within the few last years that every single small detail matters and will help to shave tenths or hundreds of a second per lap… which at the end of one qualifying session may mean placing in a final or not. I can see it pretty obviously that it is these small details that are separating the very few top drivers from the rest of the crowd and that translates into the winners who deserve the trophies.



With brushless motors and current batteries, I still believe that cars are overpowered. However, these are the current rules and as a car designer and manufacturer we have to adhere to them. With the 2007 rule of 5-cells it made car set-up even more difficult as all cars in the market were purpose-designed for 6-cells; as such, using 5-cells the cars are distinctly off-balance. Considering that Asia (except Japan) and US are still running 6-cells, this makes it a nightmare situation for a car designer and manufacturer, since it is simply not possible to have one car design to cover both completely different racing conditions. To throw more variables into the mix, we not only have to keep our minds on the 5-cell versus 6-cell issues, but also foam tires vs. rubber tires. It seems that if the rules do not change that there will be three completely different electric touring car layouts: European (5-cells), Asian (6-cells), and American (6-cell with foam tires). This of course makes development much more difficult and demanding. Hopefully the rules will not change again for next year and that IFMAR, ROAR and EFRA will allow electric touring car development to settle down a bit. If some radical changes are on the schedule again, then I foresee that people will become really upset and frustrated. I still feel that the officials should step in and set some limits for both batteries and motors (like in the nitro engine class where both engine size and fuel tank capacity are exactly limited). There is already some talk going on about Lipo batteries (Lithium polymer), so if Lipos are legalized and race proven, this may again mix-up the whole development and movement of the market – and hopefully only towards the positives.

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With the European Championship scheduled in a few weeks I have put several ideas down on paper about what we should design and produce for testing. Meanwhile, at our own in-house indoor asphalt track, we have built the same track layout as will be used at the Euros in France. Jilles flew in from the Netherlands for a short weekend test session, as well as to help install the all-new AMB system. This new system was specially developed for us with multiple loops which would allow us to measure not only the lap times but also the mid-section times, so we will know whether or not which particular set-up changes worked better at various parts of the track. This will be another step to improve our testing and analysis of the benefits of different new parts (thus boosting development). Having all of these testing possibilities has moved our development efficiency to an all-new level. I cannot believe how we were able for so many long years to develop and test all the cars relatively quickly considering that if we wanted to test anything new we had to travel several hundred kilometers to the nearest track and even then those tracks were not real test tracks as they were dirty most of the time and so it was really difficult to gain any useful knowledge from those testing sessions.

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Today?
In the morning I give a new design idea for some part, our R&D makes the drawing and the production program sends commands directly through our intranet to the machines… and in the afternoon of the same day I walk next door to the test tracks and test the new part. The huge advantage is that the tracks are permanent and indoors with a special conditioning system, so the track condition is the same 24hours-a-day during the whole year, so every small detail and change on the car can be discovered and analyzed. The only thing we cannot do is reproduce all the different types of weather and asphalt structure that could possibly be present at the real race event.



Preparing for the Euros Warm-up we prepared several new parts and several different chassis configurations for different placements of the 5-cell battery packs to test the effects of weight balance and distribution. Testing all the different parts under the same permanent conditions, we find ourselves testing smaller and smaller changes. The smallest change in car set-up can have a significant influence on the handling of the car under the same track conditions. For example, changing shock position by one hole improved lap times by few tenths of a second and some other changes were even more significant.



The goal and strategy for testing was to work the design around the following:
- different balances to find the optimum balance for 5 cells
- analyze the flex and stiffness of the chassis
- different diffs and solid axles — which position, placement and materials have the most significant influence on drivetrain efficiency
- analyze and study the forward traction influence on handling of the car
- analyze the effects of different arm lengths
- to analyze and optimize hardness of caster blocks, arms and uprights
- analyze the effects of different shock positions

There are dozens of other areas which we have been testing and analyzing these days and we have turned several thousands of laps to gather all the data and feedback. Every day we improve and learn and experience new small things that help us to move forward.



These new testing opportunities are bringing us so much new data and new knowledge that I am very satisfied and happy for all the stress and endless work we have spent on making my dream come true – to have the most modern RC testing facility in the world. It is definitely worth everything we have done up to this point. It simply blows me away that it has brought us such huge benefits and improvements, and I am very confident in the future and further developments. Having the space and opportunity to build any race track in the world in-house — and indoors — is of great benefit for testing and preparing for races.

Now we will have to spend some time to analyze all the data and feedback we have recorded from all the testing in order to set-up the plan and strategy for further development. This may still take some time as meanwhile I have already thought again about some new ideas and parts, so we are again back to the same cycle – the parts are being designed and within a moment we will be back to the test track. This is what I love and enjoy. After the tests in house the team drivers around the world will get the parts I will be confident will be a further improvement and next will be turn will be on the drivers to test in all the different racing conditions around the world.

I am really looking forward to it and I will of course share the results and conclusions in future columns.

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Before ending up this column I wanted to share the latest great news received. The XB8EC has been doing very well worldwide at most of the races and recently we gained another very prestigious achievement and win – the European Off-road Championship “B” 2007. For pictures and a very nice report you may visit our website. We’ll see how much luck we will have this year at the upcoming European Championship “A” in France… only a few weeks away. Keep your fingers crossed.

Meanwhile, have a great time and we hope we’ll see you at some of the next races!


Enjoy the ride and ‘til next time…

Dipl. Eng. Juraj Hudy
Chief Designer XRAY