Torque v's Horse Power ??
Discussion
Ok so what is best? My griff 500 serp was 269.6 HP at the growl but 342lb Torque with over 300 from about 1500rpm.
I also saw quite a few graphs that were 300hp but only 280lb torque. What is the difference? which would be quicker? what would you prefer more HP or Torque?
Just curious very happy with my results and the car has more power than I will ever need on the road.
Chris
I also saw quite a few graphs that were 300hp but only 280lb torque. What is the difference? which would be quicker? what would you prefer more HP or Torque?
Just curious very happy with my results and the car has more power than I will ever need on the road.
Chris
Edited to correct typo
Edited by chris52 on Monday 3rd August 23:21
Torque and horsepower are linked. However are completely different.
I'm no expert, but to my knowledge: torque is how each how much force each revolution carries measured in ib/ft ie how many pounds 1 foot away from pivot. Horsepower is this figure multiplied by RPM (divided by 5250 or thereabouts).
So torque is really not really important compared to the horsepower curve unless you want to compare the two for tuning. Horsepower is always the final force from your rear wheels as of the result of torque.
It also depends on the kind of drive you like, having 'power' low down has a torque curve low down giving more horsepower from lower revs as well as higher revs typically resulting in a 'flatter' power curve which makes it easier to drive and may even possibly make it feel faster.
I'm no expert, but to my knowledge: torque is how each how much force each revolution carries measured in ib/ft ie how many pounds 1 foot away from pivot. Horsepower is this figure multiplied by RPM (divided by 5250 or thereabouts).
So torque is really not really important compared to the horsepower curve unless you want to compare the two for tuning. Horsepower is always the final force from your rear wheels as of the result of torque.
It also depends on the kind of drive you like, having 'power' low down has a torque curve low down giving more horsepower from lower revs as well as higher revs typically resulting in a 'flatter' power curve which makes it easier to drive and may even possibly make it feel faster.
chris52 said:
Ok so what is best? My griff 500 serp was 169.6 HP at the growl but 342lb Torque with over 300 from about 1500rpm.
Chris
Unless your engine peaked at below 3,000 rpm the combination of above to figures sounds more than a bit implausible - 269.6 bhp and 342 lbs/ft would be about sport on for a 500...Chris
Power is merely an expression of the amount of torque you have a particular rpm;
(Torque x Engine speed) / 5,252 = Horsepower
If you made 342 lb.ft max torque, which on a typical road cam will be around 4-4.5k rpm then using that calculation you should have made 260-293 bhp as you passed through that peak torque rpm. As your revs increase above that so the torque decreases and its dependant on engine health and cam profile to how quickly the torque drops off giving you increasingly deminishing returns for the additional rpm, to the point that max bhp can actually start dropping before you hit the rev limiter. That is why it is often better/quicker to change gear at lower than max rpm.
Torque is the important one in real world performance, and you want as much as you can of it for as long as possible, the ultimate torque curve would be one that is very steep at the start levelling at 2-2.5k rpm and staying on a gradual incline for as long and possible, at least to 4.5k rpm and then a very gadual drop off. Whilst this won't always give you bragging rights on a rolling road due to lower rpms of a lazy V8, in the real world you will slaughter any modern jap car with a high revving peaky cam/turbo engine that makes the same max bhp as you in a start line drag, purely becuase you have much more useable power lower down the rev range than they do.
If you look at one of their graphs, their torque curve often looks like your rising bhp curve as a result you actually have more power than them for more of the rev range, only losing out towards the top of your rev range.
(Torque x Engine speed) / 5,252 = Horsepower
If you made 342 lb.ft max torque, which on a typical road cam will be around 4-4.5k rpm then using that calculation you should have made 260-293 bhp as you passed through that peak torque rpm. As your revs increase above that so the torque decreases and its dependant on engine health and cam profile to how quickly the torque drops off giving you increasingly deminishing returns for the additional rpm, to the point that max bhp can actually start dropping before you hit the rev limiter. That is why it is often better/quicker to change gear at lower than max rpm.
Torque is the important one in real world performance, and you want as much as you can of it for as long as possible, the ultimate torque curve would be one that is very steep at the start levelling at 2-2.5k rpm and staying on a gradual incline for as long and possible, at least to 4.5k rpm and then a very gadual drop off. Whilst this won't always give you bragging rights on a rolling road due to lower rpms of a lazy V8, in the real world you will slaughter any modern jap car with a high revving peaky cam/turbo engine that makes the same max bhp as you in a start line drag, purely becuase you have much more useable power lower down the rev range than they do.
If you look at one of their graphs, their torque curve often looks like your rising bhp curve as a result you actually have more power than them for more of the rev range, only losing out towards the top of your rev range.
It's not that much difference to the loss of power from the TVR quoted 340 bhp down to the real figure. But we can't afford to loose another 100 BHP!!
Interstingly, my 500 produced very similar figures to this last year on the same dyno, with max torque 342 lb/ft @ 3200rpm. If I'm not mistaken,in some cases the balance between BHP and torque can be altered by changing the cam timing. I would like it a lot if someone with knowldege on this would explain or correct me if I'm wrong.
Interstingly, my 500 produced very similar figures to this last year on the same dyno, with max torque 342 lb/ft @ 3200rpm. If I'm not mistaken,in some cases the balance between BHP and torque can be altered by changing the cam timing. I would like it a lot if someone with knowldege on this would explain or correct me if I'm wrong.Bluebottle said:
Power is merely an expression of the amount of torque you have a particular rpm;
(Torque x Engine speed) / 5,252 = Horsepower
If you made 342 lb.ft max torque, which on a typical road cam will be around 4-4.5k rpm then using that calculation you should have made 260-293 bhp as you passed through that peak torque rpm. As your revs increase above that so the torque decreases and its dependant on engine health and cam profile to how quickly the torque drops off giving you increasingly deminishing returns for the additional rpm, to the point that max bhp can actually start dropping before you hit the rev limiter. That is why it is often better/quicker to change gear at lower than max rpm.
Torque is the important one in real world performance, and you want as much as you can of it for as long as possible, the ultimate torque curve would be one that is very steep at the start levelling at 2-2.5k rpm and staying on a gradual incline for as long and possible, at least to 4.5k rpm and then a very gadual drop off. Whilst this won't always give you bragging rights on a rolling road due to lower rpms of a lazy V8, in the real world you will slaughter any modern jap car with a high revving peaky cam/turbo engine that makes the same max bhp as you in a start line drag, purely becuase you have much more useable power lower down the rev range than they do.
If you look at one of their graphs, their torque curve often looks like your rising bhp curve as a result you actually have more power than them for more of the rev range, only losing out towards the top of your rev range.
There was a really interesting link posted somewhere on a previous thread about the reasons why horsepower is the only number worth bothering about .. you should look it up (Torque x Engine speed) / 5,252 = Horsepower
If you made 342 lb.ft max torque, which on a typical road cam will be around 4-4.5k rpm then using that calculation you should have made 260-293 bhp as you passed through that peak torque rpm. As your revs increase above that so the torque decreases and its dependant on engine health and cam profile to how quickly the torque drops off giving you increasingly deminishing returns for the additional rpm, to the point that max bhp can actually start dropping before you hit the rev limiter. That is why it is often better/quicker to change gear at lower than max rpm.
Torque is the important one in real world performance, and you want as much as you can of it for as long as possible, the ultimate torque curve would be one that is very steep at the start levelling at 2-2.5k rpm and staying on a gradual incline for as long and possible, at least to 4.5k rpm and then a very gadual drop off. Whilst this won't always give you bragging rights on a rolling road due to lower rpms of a lazy V8, in the real world you will slaughter any modern jap car with a high revving peaky cam/turbo engine that makes the same max bhp as you in a start line drag, purely becuase you have much more useable power lower down the rev range than they do.
If you look at one of their graphs, their torque curve often looks like your rising bhp curve as a result you actually have more power than them for more of the rev range, only losing out towards the top of your rev range.
spitfire4v8 said:
There was a really interesting link posted somewhere on a previous thread about the reasons why horsepower is the only number worth bothering about .. you should look it up
Please do expand, I'm all 
...without torque, you have no horsepower.Edited by Bluebottle on Tuesday 4th August 11:22
hi chaps,
Gatecrashing from the Chim forum, i posted results of my torqueflowed 450 a few months ago for general info - also below. Aside from full decat, torqueflow & spacers / insulators the motors in its standard form. Initially i was disapointed with my max torque but Rich @ Dulford who fettled it said the shape of the curve was pretty much spot on.
Certainly quick enough to keep up with the 500's i've encountered (so far!)
hodgo
Gatecrashing from the Chim forum, i posted results of my torqueflowed 450 a few months ago for general info - also below. Aside from full decat, torqueflow & spacers / insulators the motors in its standard form. Initially i was disapointed with my max torque but Rich @ Dulford who fettled it said the shape of the curve was pretty much spot on.
Certainly quick enough to keep up with the 500's i've encountered (so far!)
hodgo
Edited by hodgo on Tuesday 4th August 18:26
There’s something to be said for not having torque arriving suddenly, but building steadily. Yet people seem to advocate a straight up, across, down torque curve.
When you have a point in the rev range that has a sudden increase in torque, this can cause loss of traction when you’re not expecting it. You can be driving along, just a few more revs and the back steps out if it’s slippery.
The progressive curve gives greater controllability in normal driving. I’m not advocating less torque, just the manner of delivery. Something like this.
When you have a point in the rev range that has a sudden increase in torque, this can cause loss of traction when you’re not expecting it. You can be driving along, just a few more revs and the back steps out if it’s slippery.
The progressive curve gives greater controllability in normal driving. I’m not advocating less torque, just the manner of delivery. Something like this.
Uncle Fester said:
There’s something to be said for not having torque arriving suddenly, but building steadily. Yet people seem to advocate a straight up, across, down torque curve.
When you have a point in the rev range that has a sudden increase in torque, this can cause loss of traction when you’re not expecting it. You can be driving along, just a few more revs and the back steps out if it’s slippery.
The progressive curve gives greater controllability in normal driving.
Sense, finally... When you have a point in the rev range that has a sudden increase in torque, this can cause loss of traction when you’re not expecting it. You can be driving along, just a few more revs and the back steps out if it’s slippery.
The progressive curve gives greater controllability in normal driving.
Often I get a feeling people are fettling their engines with scant regard to the car around it... 
Very well thought out, balanced set of mods IMO. pincher said:
Just think of it like this;
Horsepower is how fast you hit the wall.
Torque is how far you take the wall with you.
Understeer is when you hit the wall with the front of the car.
Oversteer is when you hit the wall with the rear of the car.
HTH
Horsepower is how fast you hit the wall.
Torque is how far you take the wall with you.
Understeer is when you hit the wall with the front of the car.
Oversteer is when you hit the wall with the rear of the car.
HTH
Hi Chris See below
hodgo said:
Certainly quick enough to keep up with the 500's i've encountered (so far!)
My names Del We haven't met Great numbers Uncle
Must admit i prefer the torque slightly flatter :canofworms: The green line is 
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