Racing Green TVR News
Electronic power steering for TVR Chimaeras and Griffiths
23/04/2008
Racing Green TVR has developed an electronic power steering system for TVR Griffiths and Chimaeras. This system has been developed to cater for the Chimaeras and Griffiths that left Blackpool without the power steering option. Due to the fact the parts to convert to the original system are getting almost impossible to obtain this alternative has been developed. Electronic power steering systems are now going in many current generation vehicles and the hydraulic systems are seen as complicated and heavy. Electric Power Steering or EPS works by adding a controlled level of torque to the drivers steering input by means of an electric motor assembly positioned in the steering column. There are no hydraulics and the original steering rack remains standard. The EPS assembly consists of a torque/angle sensor, motor, worm gear & ECU and is mounted in axial alignment with the steering column. There is an additional speed sensor fitted to give the road speed input to allow the programming to reduce assistance at higher speeds.
This main assembly is mounted in the steering column in the drivers footwell with the ECU box hidden behind the dashboard. The system takes inputs from the speed of the vehicle and the torque request from the driver and modulates the drive motor system accordingly. The driver’s steering input is measured internally by an opto-electronic sensor and a corresponding motor input is then derived from the control algorithms in the ECU, this motor output is then amplified through the gearbox assembly and assists the driver against the steering load. The EPS system works with conventional, manual rack and pinion steering or steering boxes, although with the extra power available higher ratio’s can be utilised or suspension geometry better optimised. Additionally, there is very little power consumption until steering inputs are made so this technology offers a more efficient, lighter & easier to package alternative over the traditional hydraulic power assisted system where hydraulic pumps are running continuously.
Racing Green TVR have fitted this compact and powerful system to a TVR Chimaera where the heaviness of the non power assisted steering was compromising the use of the car. The system was programmed to match the car and gives full assistance from stationary but then this assistance reduces to virtually nothing with speed to ensure the that the steering of the Chimaera or Griffith feels good at speed and not too light. The self centring has been optimised by modifying the active return facility and this steering system works exceptionally well at all speeds. The system is light and unobtrusive, silent in operation and is remarkably powerful at low speeds. Fully guaranteed this system is derived from a major manufacturers original equipment part and is a perfect match for the TVR Griffith or Chimaera. It is maintenance and leak free and once fitted needs no further attention at all. For further information on this exciting new product please contact Racing Green TVR.
The system has been tested by TVR Sprint magazine and they were very impressed. See the article coming soon.
Our first customer for this system is extremely pleased with the results and and after having had his TVR Chimaera back for a couple of weeks states:-
The team at Racing Green have identified a market opportunity and developed a product that completely fulfils the prerequisite requirements.
The system provides excellent low speed assistance for manoeuvring and parking without degrading the handling and "feel" at higher speeds. Component fabrication and fitting is to a very high standard. "Time will tell" but the conversion should also provide for increased levels of reliability over traditional "hydraulic based" PAS systems.
Excellent job guys!!
"AKA Santapod"
TVR Sprint magazine have recently road tested the Racing Green TVR power steering system and have given it a very good write up in the July 2008 edition. To download the TVR Sprint article click on the link below:-
Click here for a pdf of the article featured in Sprint magazine
