Reaching 0-60 ASAP

[ninjinski]

Looking at the TTE turbo plot below - How does this translate into the best point in the rev range to shift gears when accelerating  s:?: :?: s:?:  

[kanujunkie]

look for the highest point in the toque curve and short shift

[ninjinski]

look for the highest point in the toque curve and short shift

boy thats low down the rev range - need to get my gear changing arm in shape (its gonna need to be used quickly) - luckily its the same arm as i drink with so well developed already   s:D s:D

[kanujunkie]

luckily its the same arm as i drink with so well developed already   s:D s:D

  s:lol: :lol: s:lol:    s:lol: :lol: s:lol:    s:lol: :lol: s:lol:    s:lol: :lol: s:lol:

[TommyD]

Just try and change before you hit the rev limiter  s:twisted: :twisted: s:twisted:

[roger]

Just try and change before you hit the rev limiter  s:twisted: :twisted: s:twisted:

OK, I am sure there are plenty of posts about it, elsewhere if not here, but can somebody explain to me the relationship between torque and power (bhp).

On the above graph max torque is 3,500 - 4,500, but max power is at 6,500. Do you change at 4,500 or 6,500?

Sorry, i missed that lesson in Physics - and failed the A-level !

[Anonymous]

Gotta say that if I had a turbo, woulld be revving it out way beyond the highest point in the torque curve - limiter here I come!

[Bongo]

A quick google found a spread sheet that you can use to calculate it (admitedly for a bike but can't be that much different):

 m http://www.timberwoof.com/motorcycle/shiftpoints.html m


I don't know much but wouldn't you want to maximise the power and not the torque?

[kanujunkie]

just remember one thing, torque=available power to the gearbox, BHP=cock all without any torque. I'm no good at explaining physics i'm afraid Roger

[Anonymous]

here is good.

Power is what a car needs to accelerate. Power= revsxtorque over a constant (5252) You would also want to be changing high enough up so you hit the peak torque for the next gear.   s8) s8)

[Anonymous]

just remember one thing, torque=available power to the gearbox, BHP=cock all without any torque. I'm no good at explaining physics i'm afraid Roger

Depends on gearing. If a car has twice the rpm but half the torque, it can put out similar power to a car with half the rpm but the full amount of torque   s:? :? s:?

[roger]

A quick google found a spread sheet that you can use to calculate it (admitedly for a bike but can't be that much different):

 m http://www.timberwoof.com/motorcycle/shiftpoints.html m


I don't know much but wouldn't you want to maximise the power and not the torque?

Threw a few figures in....it suggested I should change from 1st - 2nd at 170mph!!

Told you physics wasn't my strong point

[Anonymous]

On a turbo'd '2, you'll be lucky to try and differentiate between shifting at 5K or 7K rpm in first and 2nd gear, as the needle swings round pretty quickly!

If I'm giving it some beans, I still shift at the same point as I did when I was N/A, which is at about 6.5K (or as near as I can get it bearing in mind my comment above).


I've yet to try a full-on launch whilst holding 3-4K revs, as it's too wet and cold and I just sit there wheel spinning at WOT.  s8) s8)

[Anonymous]

Surely the best time to change depends on where the revs land, once you're in the next gear. It's stupid changing at 3500RPM in 3rd when you drop down to 2000 – 2500rpm in 4th

so you really need to know the gear ratios.

[ninjinski]

here is good.

Power is what a car needs to accelerate. Power= revsxtorque over a constant (5252) You would also want to be changing high enough up so you hit the peak torque for the next gear.   s8) s8)

Very good article!!

[roger]

here is good.

Power is what a car needs to accelerate. Power= revsxtorque over a constant (5252) You would also want to be changing high enough up so you hit the peak torque for the next gear.   s8) s8)

Thanks Roo, very interesting. I can see now why people want an S2K. Also interesting to see an F1 car only produces about 260 lb/ft !

[ninjinski]

On a turbo'd '2, you'll be lucky to try and differentiate between shifting at 5K or 7K rpm in first and 2nd gear, as the needle swings round pretty quickly!

If I'm giving it some beans, I still shift at the same point as I did when I was N/A, which is at about 6.5K (or as near as I can get it bearing in mind my comment above).


I've yet to try a full-on launch whilst holding 3-4K revs, as it's too wet and cold and I just sit there wheel spinning at WOT.  s8) s8)

Mate how much quicker do u change gear now when pushing on hard? Silly question really but just trying to get an idea! ta

[edward.carter]

here is good.

Power is what a car needs to accelerate. Power= revsxtorque over a constant (5252) You would also want to be changing high enough up so you hit the peak torque for the next gear.   s8) s8)

Thanks Roo, very interesting. I can see now why people want an S2K. Also interesting to see an F1 car only produces about 260 BHP !

260 torques

"If 800bhp is produced at, say, 16,000rpm (and some Grand Prix cars can go far higher), that equates to a torque figure of only 262.6lb/ft"

[roger]

Caught me! As soon as I read it I realised I got the wrong unit   s:cry: :cry: s:cry:

[Anonymous]

Thats the thing with an S2K.
My old car, a Seat Ibiza Tdi Sport had loads of torque (330nm) at 2200 rpm, but only revved to 4000rpm so it felt like it was accelerating really quickly and you'd get a massive shove in the back. Put it against a petrol with half the peak torque and double the revs and see what happens! The optimum point has to be somewhere after the peak torque and before the peak BHP, where the torque tails off too much for the revs to multiply it more effectively than revving lower at a higher ratio - i.e. lower gear. The more torque at higher revs, the better = why an S2k has a good strong engine.

Gearing is v. important as is weight. As I said above chaging at peak torque would drop you below peak torque in the next gear. You are better to rev higher and multiply the torque by RPM for a fair bit before the laws of diminishing returns cause you to change up. I should think this would be quite near redline in our cars.

Cheers

Roo   s8) s8)

[Anonymous]

here is good.

Power is what a car needs to accelerate. Power= revsxtorque over a constant (5252) You would also want to be changing high enough up so you hit the peak torque for the next gear.   s8) s8)

Thanks Roo, very interesting. I can see now why people want an S2K. Also interesting to see an F1 car only produces about 260 BHP !

260 torques

"If 800bhp is produced at, say, 16,000rpm (and some Grand Prix cars can go far higher), that equates to a torque figure of only 262.6lb/ft"

262 lb/ft - my Ibiza produced 230 lb/ft  - could it at peak rpm out drag an F1 car..lol or would the F1 car have more power available through revving longer through longer gearing...lol lowerish torque over a higher rpm spread is better than higher torque for a very short rpm, multiplier effect.

[Anonymous]

Mate how much quicker do u change gear now when pushing on hard? Silly question really but just trying to get an idea! ta

A hell of a lot quicker is the answer. When I say that the revs just fly by, I'm not exaggerating at all (ask one of the other turbo guys, they'll confirm this I'm sure), and you really do have to take notice of what the rev needle is doing. It's a lot harder to shift by ear in 1st and 2nd, as the revs fly too quickly and you need to concentrate on holding the wheel steady. That's not to say it's an out of control fly by the seat of your pants thing, more that I tend to keep one eye on the rev counter and one on the road when giving it some.

You're technique will be the most important thing. Smooth and quick is the best way to go - I know that's the best way full stop, but it's more important on a turbo '2 than N/A. IMHO, obviously.  s:wink: :wink: s:wink:

[philster_d]

just remember one thing, torque=available power to the gearbox, BHP=cock all without any torque.

but who is saying any other kit is low torque ? higher power and same torque would be better still. I mean.

[ninjinski]

Mate how much quicker do u change gear now when pushing on hard? Silly question really but just trying to get an idea! ta

................It's a lot harder to shift by ear in 1st and 2nd, as the revs fly too quickly and you need to concentrate on holding the wheel steady. ........

Actually that reminds me someone did mention that the xtra power could cause front wheel unstability when accelerating  s:!: :!: s:!:   Comments  s:?: :?: s:?:

[Anonymous]

I've not noticed any major instability: It's no different than N/A, you just tend to hand on a bit more as you're going a hell of a lot faster much quicker!  s:D s:D