Another dissapointing tear up

[Ice_Coffee]

Ok

Been doing 50-90 in my S4

All in 3rd, 90 is just at the limiter

I recon I'd do a B7 all day long

Will prove it at the Kent meet

As per the link I posted, the stats would certainly agree with you (regarding a B7 Rs4 cabriolet anyway)

[P_G]

Ok

Been doing 50-90 in my S4

All in 3rd, 90 is just at the limiter

I recon I'd do a B7 all day long

Will prove it at the Kent meet

But that's assuming that the RS will be in 3rd as well? If so then you will, but I'd be using 2nd to start off with and then 3rd.

[HYFR]

No, the RS can go 2nd to 3rd

I'll still beat it in the S4!

[wrekka]

Sounds like a def challenge!! Lol! Shame i'm too far away....

[P_G]

No, the RS can go 2nd to 3rd

I'll still beat it in the S4!

Wake up dk, wake up!

[HYFR]

Pg

I have both cars

Iv done both back to back

Bum dyno don't lie!

[P_G]

You have your cab which as said is a good bit heavier. Not doubting your bum dyno but apples and pears?

[neckarsulm]

DK, at least the RS will do better MPG

[HYFR]

Apples and pears I don't think so

The cab isn't that much slower than the saloon that I owned and did 10k in

Its all good banter

But the proof will be in the pudding

Who has a stock RS coming to Kent/ACE meet? Paul?

And btw, I hate the S4 and love the B7

[sonny]

Who has a stock RS coming to Kent/ACE meet? Paul?

Whats a stock RS4?

[PJC]

Yes I will be there if you need a playmate.

[adsgreen]

first what are the weights of the cars
and you can't differentiate between HP and torque, they are related (P = T x w) and 2 different parameters
one is a force the other the rate of application of said force

<sigh>
yes you can differentiate between bhp and torque.
100lbft at 8krpm is a he'll of a lot more useful than 100lbft at 1k rpm.
Torque on it's own is pointless.

[ArthurPE]

<sigh>
yes you can differentiate between bhp and torque.
100lbft at 8krpm is a he'll of a lot more useful than 100lbft at 1k rpm.
Torque on it's own is pointless.

sigh
it is even more 'pointless' without knowing gearing
and you're assuming you can't have it at both rpms...it's a curve, not a single point
and what work you want to do...a device running at 1000 rpm will last a lot longer than one at 8000
with the torque at 1000 you get an easier start of the load...with 100 at 8000 and very low at 1000, it may not start
oh yea, those pesky gears again

actually 100 at 1k is more useful
HP = 1000/5252 x 100 ~ 19 HP
HP = 8000/5252 x 100 ~ 152 HP
it's the exact same thing 100 lb ft, just different power which is easily manipulated via gearing
and since P = T x rpm (and torque is fairly constant in a combustion engine), if 19 HP at 1000 it would be ~152 at 8000
hmmm, the same as the 8000 rpm engine, and at 1000 it's power would be 1000/8000 x 152 ~ 19 HP

torque is a primary variable, a force
power is secondary derived from T (P= T x w)
torque can be measured all by itlsef, to determine power you need torque and rpm, hence the tach on a dyno

[adsgreen]

Big assumption that the 1k engine can rev as high as the 8k one - That was the point I was trying to make. Different engines, same torque but completely different outcomes.

Take a waterwheel - thousands of lb ft/torque but spins at 0.5 rpm so relatively low power.
At the end of the day high power is what counts as with that you can apply whatever gearing you want to get the required result post gearing. High torque without the rpm to make it produce enough work means you need to run long gearing - take a look at older diesels. Lots of torque just no power. Conversely the first thing you do when you have a high revving power plant is to fit a close ratio gearbox.

So the result is saying that one car has more low down torque than another doesn't mean squat on it's own. Our cars have more low down torque than a f1 car. A truck has more low down torque than ours. So what? The only time it makes any sense is if you a comparing like with like.

Finally - I really don't get the obsession with primary variables? So what if torque can be measured on it's own? Doesn't make it so important to the point of discounting everything else. It's no different to area as measure- just because its derived from length and width doesn't make it useful.

[Ice_Coffee]

the cars are not limited in the lower gears, it will make full torque <5000
what is limited is throttle position because you don't need as much air at low rpms (air Q ~ displacement x rpm)
they do this so the air velocity will be higher (air speed inverse to area)

I have 3 questions relating to the above statement

1) If limiting the airflow does not restrict torque, then how are audi using it to protect the powertrain (ie what is it protecting the powertrain from) ?
2) how come the R8 (with our engine) does not need to do this
3) If we can make peak torque sub 5K rpm then howcome I have never seen that on any of the DYNO graphs, (it always appears above 5K RPM)