I can only think that the car would suit a lazy driver like myself in that you wouldn't need to change gear as much, any other advantages or disadvantages even?
Ta

 

They are interelated and the argument goes on for ever. If you have more torque than BHP, does that mean you have a shortfall in power, or an abundance of torque?

Best looking at the complete curves and not peak figures. A peak torque of say 320ft-lb @ 5500 sounds like a revvy engine with no bottom end pull, but if you looked at a curve and saw 300ft-lb at 2000 too, it wouldn't look too bad would it? It would also have more power than torque.

Conversly an engine with 330ft-lb at 3000rpm, sounds very torquey, better than the previous engine, but if it's only got 200ft-lb at 5500 you can see it's not going to have an advantage on the road, despite having more torque overall than engine 1, and more torque than power.

Paul

 

Interesting point there, my car has got slightly more torque than power other cars that you see are the other way round and in unusual cases they are the same. So is it possible to map to a specific torque curve as opposed to the traditional attitude of, map it so that both power and torque are as high as this set up will allow and then dial in some safety.
Reckon that could be a way forward. We already know that power isn't everything and fun can be had with much less powerful vehicles, wonder if its worth going on a quest of driveability/grinfactor with as little bhp as possible or as close as possible to OE settings.
Could you keep the BHP deliberatley low and concentrate just on torque?
So many questions

 

the way i see it is......bhp is for top speed.......torque is for sheer grunt!

 

Raises eyebrow, I agree

Torque is what sets the wheels spinning, bhp is for how long the black lines last

 

Amazing how many people state something similar. Once you actually add a gearbox into the equation, such comments fail.

Note that bhp = lbft * rpm/5252 (IIRC). Therefore, high torque, low bhp = lower revs and hence longer gears and smaller torque multiplier. High bhp, low torque = higher revs, shorter gearing and higher torque multiplier. Hence, if matched to appropriate gearbox, two cars with the same bhp will produce the same torque at the wheels, irrespective of what revs and therefore what torque they produce. (Admittedly, second order corrections for transmission losses versus input rpm would complicate that equation slightly)

What Paul is saying about curves versus figures makes more sense. Ultimately, your acceleration figures over a period will be an integral of the torque at the wheels over that period (with drag, weight etc thrown into the equation). Therefore, a car with a very large flat power curve will comfortably out-accelerate an otherwise identical car with the same peak power but a much peakier delivery.

What that doesn't take into account is that different types of delivery will be perceived by the person experiencing it in a different way. It somehow feels more "grunty" to do 50-70 in 2.5 seconds at ~2500rpm in a high torque TDi than it does to do the same 50-70 in 2.5 seconds at ~8500rpm in a VTEC - but ultimately you're still doing 50-70 in 2.5 seconds.

 

What hades says makes a lot of sense. The big question you need to ask, is how you drive your car when asking the mapper to map it for you. If like me you prefer not to rev the nuts off the car all the time, then more mid range grunt would be preferable to a really high power output. If i decide to get mine sorted and mappped all my mods and my map would take that into acoount, so for me a high torque output compared to power would be more preferable.

 

UK cars or TD04 cars probably don't hold boost at higher revs enough to make the big BHP numbers. The engine might want to make power at 6Krpm but the turbo's wheezing a bit.

I've noticed UK cars showing 300lbft and 250-290bhp whilst for classic STi imports, it tends to be the other way around, i.e. torque is usually less than BHP.

For a road car, a nice plateau style torque distribution over the widest rev. range should mean the car's tractible and easier to drive with less gear shifting.

Big torque at low revs is another way to slag gearboxes, especially when the gearing is longer (compared to STis). Each tooth (and its oil) has to do more work over a longer period of time.... Well that's my interpretation of it.

J.

 

Big torque at any revs is the way to slag gearboxes, as the torque on a given shaft is proportional to the force on a given tooth (again, first order approximations etc). If you shock load things (e.g. side stepped clutch), it makes matters worse for the gearbox, as does having lots of traction and hence being unable to wheelspin some of the torque away.

 

Thats good to know.....i recently achieved 232bhp but torque was
up @ 250lbft -> MY00ppp.

Will be interesting to see how a green cotton filter and full decat affects it.