Monday, 24 September 2007

Power to Weight...

With the engine out I decided it would be a good time to weigh my rolling chassis, so I loaded it full of everything I have for the car which will be fitted - loom, seats, bodywork, rad etc.

I then nipped to Tesco and bought 4 cheap scales (£12 for 4) and checked they worked correctly by weighing myself on all 4.

Now I know Locosts can weigh anything from 450kgs to 800kgs+, now 800kgs might not sound much, but when you think that the "magic" power to weight ratio for a car is 500bhp per tonne it becomes obvious that for every kg you add in weight you have to add more bhp to compensate, and as its cheaper to build light, than it is to build powerful - light is my approach.

Lightweight also adds to improved handling - so I was eager to fnd out the scores on the doors!

with mine not having an engine in at the time, along with a number of ancilleries which will all together will weigh approx 100kgs, I know I have to add that to my figure.

So I crossed my fingers, grabbed my trolly jack and went to work!!

it came out at 334kg's!! which is flippin ACE! considering I have a full integral roll bar and largish 15" alloys!!

In case you are wondering how accurate my scales could have been - I weight approx 15 stone, so I figured as long as none of the wheel weights were much higher than that, then they could be trusted to be relitivly accurate. The heaviest wheel weight was 16 stone, so I am happy that my figures are pretty spot on!

Now - this works out that my final car will weigh in the order of 450kgs, possibly 500kgs in case I have forgot anything heavy, with an engine power of 150bhp (from an r1 engine I am currently dreaming of!) It will provide the following performance:


Power at Flywheel (BHP) :
150
Weight without Driver (KG) :
450
Power to Weight Ratio (BHP Per Ton) :
338.68
0 - 60 (Secs) :
3.80
0 - 100 (Secs) :
10.27
60 - 100 (Secs) :
6.47
Quarter Mile (Secs) :
12.25
Terminal Speed (MPH) :
109.23
Drag Strip Quarter Mile (Secs) :
12.15
Drag Strip Terminal Speed (MPH) :
110.56

TO (using the 500kgs)


Power at Flywheel (BHP) :
150
Weight without Driver (KG) :
500
Power to Weight Ratio (BHP Per Ton) :
304.82
0 - 60 (Secs) :
4.04
0 - 100 (Secs) :
10.86
60 - 100 (Secs) :
6.82
Quarter Mile (Secs) :
12.49
Terminal Speed (MPH) :
107.26
Drag Strip Quarter Mile (Secs) :
12.39
Drag Strip Terminal Speed (MPH) :
108.56

These figures are from this stats calculator:

http://www.letstorquebhp.com/calculator.asp

now to put that in context, my car will do 0-60 somewhere either below or just a touch above 4s. That is nearly 1 and a half seconds faster than a porsche boxter, over 1 second faster than a 911, and only marginly slower (by 0.01 of a second) than a 911 GT2!

And before everyone moans, I know I would need ideal conditions to hit that figure, but do you think porsche tout figures that they got on a wet track with me driving?? It was meant to demonstrate that I will own a SERIOUSLY fast car. and i cant wait!