Gerry, further to Owen's observation. In an electric motor, torque can be taken as proportional to armature current. In the article on the Geneva Motor Show in April's Miscellany; the Plus E is described as having a 70kW motor producing 300Nm of torque, similar to a Plus 8 (it states). The figures for the electric motor means that the speed of the motor is 2200rpm.
The 3.9 litre Plus 8 from 1990 produces 140kW at 4800rpm, the torque consequently being 279Nm at that engine speed. The maximum torque is 305Nm at 3500rpm. At 2200rpm these figures are respectively 609Nm and 485Nm. Changing down to 3rd say, the Plus 8 would have about double the propellor shaft torque. There is a similar argument with regard to the dreaded diesel, the proponents expounding the torque of the diesel compared with the petrol engine. The diesel is a low speed engine and so if giving the same power as a petrol engine will need a higher back axle ratio. Fairly recently, some diesels were developed to give too much power and the torque resulted in crankshaft failure. I understand that recent BMW diesels are also suffering from turbo-charger failure. Stick with the high speed, naturally aspirated petrol engine. Going back to the original point, torque is reasonably constant from say 1000rpm but gradually rises to a maximum then declines at an ever increasing rate. Maximum power occurs when the rate of decrease in torque equals the rate of increase in engine speed. That will explain the Prodrive / Cosworth statement. Brian of SpotMog On Wed, Apr 25, 2012 at 12:58 PM, Owen Jenkins <[email protected]> wrote: > ** > Gerry, what they are telling you is that their engine delivers more torque > at EVERY RPM than Cosworth. Only reciprocating steam and pneumatic > engines give maximum torque at 0 rpm, and then only provided one of the > pistons is in mid-stroke and it is set in full gear. > > At 0 rpm in an internal combustion engine, you get 0 torque - it's turned > off. > > Regards, > Owen. > > ----- Original Message ----- > *From:* Gerald Wallace <[email protected]> > *To:* mogtalk2 <[email protected]> > *Sent:* Wednesday, April 25, 2012 12:36 PM > *Subject:* [mogtalk2] FORD V6 > > *Spotted in Prodrive's 'showroom' at Banbury, their engine for the BTCC > racing Mondeo. An interesting conversion for some of you Roadster chaps- if > you can find room for the induction system under the bonnet!* > * I'm puzzled by the statement in paragraph 5, 'The changes ensured that > the minimum torque in the Prodrive engine was actually higher than the > maximum achieved from that for the Cosworth'. I would have thought that the > minimum torque from any engine would be produced at idle, and surely no-one > would attempt to go racing with as little as that. I await enlightenment > from the engineers amongst us.* > * > Gerry.* > > ------------------------------------------- View posts on The Mail Archive http://www.mail-archive.com/[email protected]/ [http://www.mail-archive.com/[email protected]/] Modify Your Subscription: https://www.listbox.com/member/?member_id=22459785&id_secret=22459785-4a39ddf8 Powered by Listbox: http://www.listbox.com
