This is a plot for my chip, I'm the rare APR owner.

It's an off the shelf program over a remap as per Jabba. This if I'm right is the optimax plot. I've not put mine onto a RR, interesting to see though...

ps I know the graph is out for it's title, i.e. RS 150 Stock.

It's actualyl fine for me, as I had the 4x4 and was near enough considering.

And this is for APr's Stage III, again it's actually not a Skoda Engine and they are not the raw plots, but nice all the same I think...

Dutch 4x4,

Your'e absolutely right about the advantages of high higher revving engines.

My point was just to say that its torque at the wheels that carries out the physical acceleration of the car, not bhp.

Looking at my dyno plot, i feel that my torque curve actually tails off fairly slowly. If you look at colins plot his tails off in a similar fashion.

Of course, a Tdi wouldnt stand a chance against a 1.8T from 0- 120mph. Even a bog standard 150bhp one.

Also your point about gearing on the Porsche.. I dont think it would be geared any higher than a TDi, its just that it can rev higher in order to achieve a higher top speed.

E.G if my car was able to rev to 6500rpm with its current gearing, i'd get a top speed near 180mph!

if only! :cheers:

Originally posted by FabiaTDi in this post

My point was just to say that its torque at the wheels that carries out the physical acceleration of the car, not bhp.

Well, yes, but bhp happens to be a very good measure of torque at the wheels

All I was saying is that the torque referred to in brochures and tuning graphs is in fact engine torque, which says zilch about a car's actual acceleration capabilities. It's a figure that doesn't factor in revs and gearing, as it's simply a measure of how much rotating force the engine is able to deliver. But if a huge force is (only) delivered at low revs, the acceleration won't measure up to the prosperous figure.

Try climbing a mountain on a bike using a huge gearing - your feet will rotate very slowly, with big amounts of force (high torque) delivered at large intervals (low revs). Do the same with a tiny gearing and your feet will make lots of rotations, delivering little force at quick intervals. The end result is the same and is called horsepower.

power = engine torque multiplied by revs multiplied by a constant

acceleration = torque at the wheels divided by mass of the car

In F1 they've discovered that enormously high revs will do the same trick as the huge Auto Union V16s did in the thirties by giving huge amounts of torque at relatively low revs. But if modern materials will allow you to increase revs without breaking the engine, you will have an enormous packaging and weight advantage. Modern F1 engine technology has in fact turned into a "rev race".

Not trying to lecture here, so apologies if I make that sort of impression. And apologies too to people who already know about this - it's just that I've read so many times that "horsepower doesn't win races, torque does" that I thought it wouldn't hurt to try and de-myth that myth yet again...

:cheers:

for putting up with me!

Originally posted by Dutch4x4 in this post

is called horsepower.

In F1 they've discovered that enormously high revs will do the same trick as the huge Auto Union V16s did in the thirties by giving huge amounts of torque at relatively low revs. But if modern materials will allow you to increase revs without breaking the engine, you will have an enormous packaging and weight advantage. Modern F1 engine technology has in fact turned into a "rev race".

Well yes, but they have also been forced down this route as the max allowed engine capacity for F1 cars is 3000cc and turbos are also banned.

I completely agree with what you are saying btw..

:cheers:

As we were talking about torque and power (boy their used to be some serious debates on the Audi site when I was trying to convince people about my TDi Quattro!), I've done another in-gear timing for you:-

70-90 in 4th (timed from 76-96 on the speedo) - 5.4 seconds (Mattijs - its about 120-150kmh)

This is as good as my remapped Impreza was and shows the flexibility involved up the range when there's good torque (even on normal unleaded)

For the purpose of talking about flexibility and motorway acceleration only :-

OK, and here is the 80-100 time(well it could be kmh not mph) - 7.9 in 5th (Again 86-106 speedo, normal unleaded, half tank)

Just dug out the Impreza road tests I have to show some comparison on flexibility:-

70-90 4th Impreza 6.1, Skoda 5.4

80-100 5th Impreza 11.1 (4th 6.9), Skoda 7.9

Surprised ? The difference is the perception of speed, noise and power delivery, as the Skoda's power comes in much quieter.

The Impreza felt quicker on the motorway but it wasn't.

Gearing is shorter in the Octavia 4x4 in top (shorter than the vRS -I'm guessing at about 22mph/1000rpm instead of 24).

And I also know that the Impreza would disappear on most roads - but not apparently in the outside lane of the M1..:tomato:

You'd be surprised at how slowly an Impreza disappears, even on every day roads And we won't mention trackdays! :D

Here's my plot to add some extra material for discussion. Not actually that different a shape from FabiaTdi's but shifted up a couple of thousand revs.