We have 2 Insights a 50k CVT and a 17k manual.
Prior to buying the CVT we began preparing the manual car for tarmac stage rallies. The car was fitted with an FIA spec rollcage, seats and harnesses and a free flowing exhaust system, and runs the control tyre for our championship, Falken 175/60/14. The only other mods so far carried out are weight related, removal of air bags interior trim rear wiper etc. The car is built to compete in the UK F1000 series for lightly modified 1 litre cars, in which the 16 valve Nissan Micra is totally dominant.
Whilst this car was being built we purchased a Jap import CVT to use as a road car, and after some hard use on demanding roads in the Scottish Highlands began to wonder whether the CVT car would make the better option for competition.
We have competed in 2 rounds of the 2005 championship as a learning exercise and soon realised that the tall overall gearing and wide space between first and second gears were spoiling the potential performance advantage of the hybrid system.
So before embarking on some expensive modifications during the close season, which will include bespoke suspension units, removal of aircon and ABS and uprating of the hybrid system, we decided to do a back to back test of the manual and CVT cars.
Typical format for these rallies are 12 tight twisty stages, each of around 3-5 miles length. On the 2 events we completed we never used higher than second gear.
The test constituted 5 timed laps of a Kart circuit, which included a variety of corners including a slippery chicane into tight hairpin and a fast downhill straight. Both cars used the control tyre , had the same driver, but the manual car retained its exhaust system. The stage length was 3.5 miles. The manual car ran first after a 15 minute warmup and completed the stage in 5 minutes 16 seconds. After a short warmup the standard CVT car completed the same course in 4 min 56 sec an enormous advantage in stage rally terms.
My assumption is that there are two key factors that produce this advantage. The first is that the CVT, in sport mode, finds the ideal gear for any particular road situation where the manual car requires constant up and down changing between first and second gear. The CVT also seems to damp out excessive torque, not allowing the car to wheelspin out of the tight slippery corners. There are obvious durability advantages here in terms of tyres, transmission, and engine abuse.
The other factor that contributes to the advantage is that the CVT allows the driver to quickly find a groove as a lot of effort is not being wasted working out the best use of two unsuitable gears, and as such effort can be devoted to smooth, ideal corner lines, application of the handbrake and anticipating the slight lag inherant in the CVT system.
It will also allow the driver to develop a left foot braking technique to balance the attitude of the car through corners.
This leaves us with the regretable task of having to restore the 'rally'car to road spec and conduct a reverse operation on the CVT 'road' car, and then with all the further mods hopefully kick some Micra bottom in 2006.
After our 2005 forays the Insight is regarded as a bit of an eco-oddity so it would be nice to educate the great rallying unwashed.
Fuel consumption was miles better on the CVT as well, as it was not spending time hard on the rev limiter.......