<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:<hr /><font size="1" face="Verdana, Helvetica, sans-serif">Originally posted by Kristian Benning:
<strong>Car companies seem to be spending alot of money developing ever more complex gear boxes, where I feel the money would be better spent making the car lighter (especially say the drive shafts and anything else that spins).
The advantages of reducing overall weight (especially anything that spins) would help with acceleration, braking, handling, (fuel economy) which would far outweigh the benfit of changing gear a 1/2 a second quicker.</strong><hr /></blockquote><font size="1" face="Verdana, Helvetica, sans-serif">Yep totally agree mate
Ever driven a Caterham or Westfield?
Unfortunatly the need for crash protection, toys and build quality have pushed up the weights of modern cars. Light weight materials are used extensively in the 156 and this shows mainly in performance figures where engine for engine the 156 is quicker than the smaller 147. It also is the main reason why the 156 is more expensive, the light weight suspension and magnesium seats etc. cost more than the standard steel items of the 147.
The first 2.0TS 156 was homologated at 1190kg Kerb weight which is good by modern standards, a 2.0 Ford Focus is 1240kg.
To go futher would mean stripping stuff out or extensive use of carbon putting up the price. Both of which the current market wouldn't stand.
Look at the M3 CSL as too how much money it costs to shave a couple of hundred Kilo's.
As for the optimum point to change up? I used to rally in the late 80's early 90's and have an engineering background but it still was a total headache choosing gear ratio's and final drives for different events.
Something like the 2.0TS has maximum torque at 3500rpm. The more torque you have at the wheels the quicker the rate of acceleration. In any given gear you will accelerate at the fastest rate at peak torque. So in 2nd gear we would accelerate at a faster rate at 3500rpm than 6400rpm.
But its not that simple. The higher the engine will rev while producing torque allows us to make use of gearing. This is why the power is important, power is just a figure derived from torque x rpm. Power indicates how well we will be able to utilise the torque through the use of gearing.
So as Kristian pointed out hanging onto a gear longer multiplies the torque available at the wheels by staying in a lower gear. Look at the torque curve and it drops away massivly at around 6300rpm. You would need some exact figures to work out if the torque in first at 7000 to 7200 rpm is quicker than being on the torque in second. I would have thought the change point selcted for the selespeed would have taken this into account, although is that a bit too much to ask of Alfa do you think? wink
What is certain is that holding the revs past 6500rpm in 1st does not make any difference to your rate of acceleration in 2nd. Maximum Torque is at 3500rpm so as long as you enter 2nd above 3500rpm you will be acclerating at the optimum rate in that gear.
You also have to remember that high revs and high speed increases the feeling of acceleration. You may feel you are are accelerating faster in second at 6000rpm than you were at 3500rpm, this is not so but change up too early and you loose the benefit of holding first.
This is why diesels feel so relaxed on the road, you get the rate of acceleration without the screaming engine. May not feel as fast but there you go.