Desiger interview on the project 4X EVO with David Ehrbar

Hi David,

We like to ask you some questions on your updated Project 4X Design

Q: How was the overall feedback on the original Project 4X car, and what were the biggest results to date?
A: Drivers really liked that the design was really different from the mainstream cars and still worked really well. The drivers did notice that the set-up approach was different and not all their experience from before worked as expected. Once they get used to the different way to set-up the Project 4X most were really happy and excited both in stock and mod class. After having expected a good performance on high grip surfaces because of the low CG of the car, many were surprised how well the car runs on low grip, as the suspension creates a lot of grip.

Our biggest result with Project 4X for sure was the podium finish at the 2016/2017 Worlds by Viktor Wilck in China. I really enjoyed racing the Project 4X myself as well, but racing wise my focus last season was more on the Serpent F110, for which I took the 2016-2017 ETS championship title.

Q1: What were the main area’s to focus on to improve the Project 4X?

A1: An area that needed improvement was the tweak of the car, as after a bad crash it was not easy to make the car straight again. During the year we introduced the vertical top deck solution, which basically prevents the car to tweak and made it even easier to drive as well. At the same time it stiffens the longitudinal flex and provides torsional flex.

A2: We also developed the linear links, which improved steering on high grip surfaces quite a lot. Both A1 and A2 solution will also be in the EVO version.

A3 Then I worked on making the front and rear bulkhead and upper bracket construction stronger and easier to work on, and I really like the final result.

A4 On the motor mount side we also tested a lot and in the end a motor mount version similar to our ERYX 3.0 car worked best and has been adopted. It has more flex and with some optional parts flex can be modified towards softer or stiffer.

A5 I put another focus on the heave damper as we felt that we did not have enough oil volume to work with. Space is limited but I designed a nice new heave damper which uses foam as compensator and is very effective and still compact enough in size. At the same time the friction is reduced. Also the heave shock spring diameter has grown, which makes the spring more effective and less critical.

A6 When checking cars from drivers I often saw that the pull rods were not always assembled correctly lengthwise, so we decided to make 5 different fixed length moulded pull rods, so it’s easier to control.

A7 the front and rear bumpers as well as the carbon chassis have been revised to allow for easier access, and at the same time reduce the inertia of the car for a quicker direction change.

A8 The brackets to mount the rear RRS links have changed and allow for lower mounting points than before as needed and more optionals to follow for special conditions (## this is optional).

A9 the front spool now uses a bladeless system to lower maintenance rates.

Q: When do you expect to release the new project 4 X EVO versions?
A: Shipping will start 25 march 2018

Q: Will some of the new parts for the 4X EVO also fit the 4X?
A1: Basically all 4X EVO parts can be used on the original 4X, however, some only in combination:
- Bulkhead together with upper brackets
- Motor mount together with chassis plate
- Vertical top deck set

The following parts fit the original 4x without modifications:
- Bumpers
- Heave dampers
- One-piece pull rods
- Spool outdrives

Q: Who are the key drivers for 2018?
A: We have Viktor Wilck, Tim Benson, Dionys Stadler for Europe, Ralph Burch for USA and Felix Law for the Asia market. There are still talks with other drivers and of course we focus on the very important regional and national level drivers, so support the cars everywhere.

Q: What are the key races for 2018?
A: For sure the ETS series, AOC when possible, then also the EC and ofcourse the Worlds. Serpent Team drivers will also attend major national championships everywhere around the world and are ready to help as needed.

Thanks for your answers and we look forward to the Project 4X EVO release.

Serpent Performance Team

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