0-60 query....

[dirty boy]

Just looking at some statistics, as i've been comparing Caterhams to Elises.

Lotus Elise S1
118bhp
725kgs
162bhp/tonne
Quoted 0-60 = 5.8 seconds


Whereas..

Caterham Academy
125bhp
525kgs
238bhp/tonne
Quoted 0-60 = 5.9 seconds

What am I missing here?

I know gearing has something to say here, but is the Caterham really slower than an S1 Elise to 60mph?

[ewenm]

Traction? Elise has the engine sitting over the driven wheels, Caterham has it at the other end of the car. So it might be easier to get the Elise off the line while in the maximum torque band.

[jleroux]

ewenm said:

Traction?

I'd imagine tyres will help with this too. The elise has about twice as much contact patch as the fuel-saving van tyres fitted to the academy cars.

Jonny
BaT

[Aeroscreens]

I'd imagine that aerodynamics or lack of it on the Caterham will also play a part.

[thinfourth2]

jleroux said:

ewenm said:

Traction?

I'd imagine tyres will help with this too. The elise has about twice as much contact patch as the fuel-saving van tyres fitted to the academy cars.

Jonny
BaT

yep the tyres the academy come with are made by tupperware

They just don't wear as the racers get a season out of them.

Stick some sticky tyres on the car and its much quicker

[Sam_68]

jleroux said:

ewenm said:

Traction?

I'd imagine tyres will help with this too. The elise has about twice as much contact patch as the fuel-saving van tyres fitted to the academy cars.

Ironically, it becomes progressively more difficult to put the power down cleanly with lighter cars, too: the ratio of sprung:unsprung weight is much worse, so you need very, very, effective damping to keep the loads at the tyre contact patch consistent.

...and in this respect, it doesn't help that the Caterham is a beam axle (high unsprung weight and bumps at one side are partially transmitted to the other side).

[dirty boy]

Sam_68 said:

jleroux said:

ewenm said:

Traction?

I'd imagine tyres will help with this too. The elise has about twice as much contact patch as the fuel-saving van tyres fitted to the academy cars.

Ironically, it becomes progressively more difficult to put the power down cleanly with lighter cars, too: the ratio of sprung:unsprung weight is much worse, so you need very, very, effective damping to keep the loads at the tyre contact patch consistent.

...and in this respect, it doesn't help that the Caterham is a beam axle (high unsprung weight and bumps at one side are partially transmitted to the other side).

I'm not going to pretend I understand any of that!

So it's safe to assume, that with wider sticky rear tyres, a Caterham will get the power down better than the figures suggest.

Even the Toyota powered Elise with a 4.7s 0-60 dash is less on the bhp/tonne figure.

I assume acceleration from 30-70 would be pretty impressive.

[GetCarter]

I just drive them - but whatever a Seven loses in traction on a start line (whoever does that: Seven v Elise?), it makes up many times under braking around a track.

I've driven many hundreds of laps in different Sevens, and the only Elise I've ever seen is the one going backwards in the rear view mirror.

...and Yes, I've owned Elises. Great cars, love 'em. Just not as quick round a track.

Edited by GetCarter on Tuesday 23 November 16:55

[SimonY]

I would say gearing is a key issue, they feel like a different car when you swap to the smaller CR500s from the fuel savers.

[thinfourth2]

Oh and another point

Anyone who measures the enjoyment of a car by any measurable number is an idiot until the gigglemeter has been invented

[sam919]

I think if you actually put them both head to head 0-60 the caterham would have the elise irrespective of quoted figures.

[Sam_68]

dirty boy said:

So it's safe to assume, that with wider sticky rear tyres, a Caterham will get the power down better than the figures suggest.

Not necessarily: wider means more unsprung weight (all other things being equal), for a start, and unsprung weight is already a problem.

But as others have said, the Elise has an inherent advantage in terms of traction by way of its greater rearward weight bias (and independent rear suspension).

Another factor to bear in mind is that for very quick standing start acceleration, you have to do a very brutal juggling act between mechanical grip and the engine's power. If you've got enough traction, one standard technique on very quick, powerful cars is to rev the engine to peak torque revs, then simply sidestep the clutch and let the tyres sort out the resultant wheelspin (assuming nothing breaks...) - but if you get it wrong, or the balance of power to traction isn't quite right, you can either bog down or just sit there spinning the wheels. Or there's a big 'BANG' as the clutch or one of the driveshafts lets go!

Though it has to be said that the more extreme Caterham variants can put the power down well enough to get <4 second 0-60 times, so if you've got enough power to waste (and ultra-sticky trackday rubber), you can overcome the shortcomings in terms of traction.

[dirty boy]

thinfourth2 said:

Oh and another point

Anyone who measures the enjoyment of a car by any measurable number is an idiot until the gigglemeter has been invented

I'm a great lover of acceleration, and I'm (hopefully) getting a Caterham on a sidetrack from a Cerbera, where the acceleration is brutal, so not the whole story, but a tool for me to measure things by without actually ever being in a Caterham. I'm aware it will feel completely different too.

[TubbyNorman]

Forget pussy cat soft Elises, try a 7 up against a VX220 turbo, the VX will win every time. Similar to a Lotus, but thankfully not a Lotus.

[ewenm]

TubbyNorman said:

Forget pussy cat soft Elises, try a 7 up against a VX220 turbo, the VX will win every time. Similar to a Lotus, but thankfully not a Lotus.

Which 7?

[TubbyNorman]

Why ask me which 7, the thread starts with the details.

[ewenm]

TubbyNorman said:

Why ask me which 7, the thread starts with the details.

You said A 7, not THIS 7. If you're changing the Elise to a VX220T why not change the Academy car to a R500 for example? Would the VX still show "a 7" a clean pair of heels?

Edited by ewenm on Thursday 25th November 21:21

[TubbyNorman]

Take a top of the range 7 with all the bells and whistles, and a tubby with all the bells and whistles and you're still left for dead in a 7.

What I am saying is their are other cheap cars just as fast and just as much fun, Atom's for example. Or of course, any motor bike!

[Ca11um]

As the title says 0 - 60...

"Take a top of the range 7 with all the bells and whistles, and a tubby with all the bells and whistles and you're still left for dead in a 7.


Info taken from HERE for VX220:

VX220 turbo 4.7 seconds (4.9 on Wikipedia)

R500 - 2.88 seconds
R400 - 3.8 seconds
R300 - 4.5 seconds

Edited by Ca11um on Friday 26th November 10:01

[Noger]

Ooo, a new Trollface

p.s. we take our bells and whistles off. Or get carbon fibre ones