Just test driven ... the Focus ST

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First impressions were good. It really does stand out in the orange :cool: paintwork. Interior is pretty comfortable, and the seats are supportive. The wholl car feels well screwed together. We took it out for a spin and onto the dual carrageway.

At this point the salesman tells me not to be shy with the throttle - i was only too happy to oblige. Jeeeeeeeesus ... the noise it makes is gorgeous. The turbo whistles away and then you get a beautiful growl from the 2.5 litre five cylinder engine. Just when you think the acceleration isn't particularly impressive, you hit around 4.5k on the rev counter and it catapults you down the road.

We took the exit from the 70mph limit and headed down a fairly tight B road where the ST felt quite large, but handled well enough. Heel and toe is very hard to do and doesn't encourage it.

From the short time I drove it - around 25mins - it gave me a good impression of its capabilities. It's deffinetley something I'd consider and recommend for buyers in the hot hatch market at the moment.

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nam

nam

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mk1_salami said:
First impressions were good. It really does stand out in the orange :cool: paintwork. Interior is pretty comfortable, and the seats are supportive. The wholl car feels well screwed together. We took it out for a spin and onto the dual carrageway.

At this point the salesman tells me not to be shy with the throttle - i was only too happy to oblige. Jeeeeeeeesus ... the noise it makes is gorgeous. The turbo whistles away and then you get a beautiful growl from the 2.5 litre five cylinder engine. Just when you think the acceleration isn't particularly impressive, you hit around 4.5k on the rev counter and it catapults you down the road.

We took the exit from the 70mph limit and headed down a fairly tight B road where the ST felt quite large, but handled well enough. Heel and toe is very hard to do and doesn't encourage it.

From the short time I drove it - around 25mins - it gave me a good impression of its capabilities. It's deffinetley something I'd consider and recommend for buyers in the hot hatch market at the moment.

icon14.gif

Still awaiting my local dealers to get a registered ST for a test-drive. I can't believe it's taken this long, maybe due to low production numbers or is it high demand :(
 
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mk1_salami said:
Just when you think the acceleration isn't particularly impressive, you hit around 4.5k on the rev counter and it catapults you down the road.
The car will be accelerating at its fastest rate at between 1600rpm and 4000rpm, so at 4.5k the cars acceleration should be slowing down! :p

I reckon the growling makes it seem like it's accelerating faster.
 
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PMKeates said:
The car will be accelerating at its fastest rate at between 1600rpm and 4000rpm, so at 4.5k the cars acceleration should be slowing down! :p

Torque may be less above 4k, but that doesn't mean acceleration is. You wouldn't shift up at 4k if you were gunning it, would you?
 

olv

olv

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PMKeates said:
The car will be accelerating at its fastest rate at between 1600rpm and 4000rpm, so at 4.5k the cars acceleration should be slowing down! :p

I reckon the growling makes it seem like it's accelerating faster.

What makes you say that?

Acceleration = force / mass

so the greatest acceleration will be when the engine produces most power. I'd be very surprised if it makes 200bhp below 4000rpm

Reading from the ford site. Peak power, 225bhp is made at 6000rpm. You are only just getting started at 4krpm, not peaking...
 
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olv said:
What makes you say that?

Acceleration = force / mass

so the greatest acceleration will be when the engine produces most power. I'd be very surprised if it makes 200bhp below 4000rpm
Correct on one hand, wrong on the other.

Torque IS acceleration. At any point that torque is at its highest, you will be accelerating the quickest. The gearbox and axle/diff multiply the torque produced by the engine linearly. In 2nd gear at 2000rpm, the car will accelerate faster than in 2nd gear at 5000rpm.

The point you go wrong is where you contrive that power is a force, which it is not.

As a side note, the point at which a car will accelerate the quickest is at its peak torque point in its shortest gear - normally 1st or reverse.
 
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olv

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I disagree. torque isn't acceleration, acceleration is a measure of how quickly an object is gaining velocity.

The acceleration at a specific rpm compared to another value for rpm will be identical because the car will be maintain a constant speed.

There is more power available further up the rev range so the car will accelerate quicker as the revs climb, until you have to change gear.

Stick it in forth at 20mph and floor it. revs will be low and you won't accelerate very quickly. Stick it in 1st or 2nd where the revs are much higher and more power is available and you will accelerate quicker
 
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olv said:
I disagree. torque isn't acceleration, acceleration is a measure of how quickly an object is gaining velocity.

The acceleration at a specific rpm compared to another value for rpm will be identical because the car will be maintain a constant speed.

There is more power available further up the rev range so the car will accelerate quicker as the revs climb, until you have to change gear.
Very false. I am preparing a much larger post with the technical examples necessary to show you :)
 

olv

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i don't claim to know much on the subject, but this is my limited understanding. If you can show me where i'm going wrong, much appreciated :p
 
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Consider the MG TF 115. It has a peak power of 116PS @ 6250rpm and a peak torque of 145nm @ 4250rpm.

When you consider the ratios of the gearbox and differential, the drivetrain has the following multiplication effects:

1st = 12.47
2nd = 7.25
3rd = 5.15
4th = 4.07
5th = 3.01

The differential ratio is 3.938.

After the drivetrain, in 1st gear, 1808nm (12.47 * 145) of torque will be produced at 4250rpm. If you were to shift up at 4250rpm, it would put you in to 2nd gear's ratio of 7.25. Even if you assume that the engine can produce 145nm of torque all the way down at 2471rpm (Which would be the RPM in 2nd gear if you changed at 4250rpm in 1st), the overall torque would be reduced to 1051nm (7.25 * 145). THAT is why you wouldn't accelerate faster in the next gear up.

The fact that torque is the more important figure is the reason behind revving past the point of maximum power to maintain the quickest acceleration over a given period of time. If the torque produced by the engine when multiplied by the gearbox is still greater than that of resulting torque in the next gear up, then you do not change up. Only when you are getting less torque to the wheels than if you were to change in to the next gear, do you in fact change.
 
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Soldato
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PMKeates said:
Very false. I am preparing a much larger post with the technical examples necessary to show you :)

I think you may be getting confused with the angular acceleration of the crankshaft, rather than the acceleration of the vehicle.
 
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