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Serpent 747: interview with designer Salven (13/06/2012)

By:: Reporter
Linked to:: Serpent 747 1/10 scale 200mm, Serpent 747-e 1/10 scale 200mm

Interview 747
Serpent has released the Serpent 747, the new 1/10 scale gascar. Below a brief interview with Michael about the development

Q: when did you start to develop the new 1/10 scale car?
A: Actually quite late, around November. But we had already tested some stuff on new geometries before that. So luckily I had some ideas what I wanted to have.

Q: what were the main objectives to achieve ?
A: We wanted to improve the 733 on several things. The main goal was to widen the car’s sweet spot so set-up would be less critical. At the same time we wanted to have more corner-speed with the car. And on top of all it should be an easy car, easy to drive, easy to set-up and easy to build. We actually have less set-up options on the 747 car than before on 733, just to make it easier.
Then in the middle of all the designing EFRA came with that “ ridiculous” 1550g decision, so I had to loose some weight on the car as well. All that we wanted to achieve with using as many as possible 733 parts.

Q: what are the key elements that changed compared to 733 ?
A: the suspension geometry has changed, front and rear. The rear lower arms are longer and the upright geometry has changed to accommodate these changes. In the front the upper arm is shorter and higher. The inner pivot is now possible to change in height and position.
To shave some weight the whole radioplate design is different. It also has the possibility to add some “flex” into it in the front. In order not to influence the flexing, the pipe mounting has moved away from the radioplate to the mid-shaft bearing block. But basically the chassis is stiffer than it is in the 733. You could say the 747 is more a racecar than the 733 is.
We also improved the diffs, using new internal gears for smoother diff action. We also got rid of the 4 additional screws on the back. So it is easier to fill and maintain.
Since the car is lighter than the 733, we need to put some weights to achieve the 1700g limit which is still valid this year. These (optional) weights are in the very bottom of the chassis and easy to change in position. It’s a very powerful set-up tool too.

Q: What are the main differences in driving characteristics compared to 733 ?
A: For me it’s the way the car corners. When you had good steering in the 733 it felt always as if it turned around its front end, like the rear was sliding. The 747 is more planted in the rear and all the steering is in the front. It is much more predictable and has more rear traction.

Q: which team drivers were especially used to give input and test the proto-types ?
A: I had some input about geometry very early already in Germany. As I said earlier I did geometry tests and most of these tests were done at local races with some drivers I trust. Also I had very good feedback about this from Allesio Mazzeo in Italy.
The prototype testing was done by Mark Green, Paolo Morganti and myself, in early February. After that test I changed a few parts like the front bulkhead design and the chassis, because we found that we needed a stiffer car.

Q: What do you think about the new weight limit in EFRA for 2013 ?
A: I think it’s going to far. Although the 747 is a light car, we can not reach the 1550g limit. I agree to go lighter, because most cars can be lighter than 1700g and lighter cars are using less fuel and tires. But we need to look at the general customer and the cars need to be reliable.
To reach 1550, the cars become too fragile and you need expensive - tuning - parts to get there

Q: Which are the main races to focus on for 2012 ?
A: Of course that will be the Euro’s and the Worlds in November in Bangkok. But I also want to defend my German National title, that would be nice.

Thanks Michael. We will follow your races through the year, and best of luck to achieve the planned goals.