Your all wrong.... EDIT: Harry spotted this 3 posts above me I see now...
Rate of change of displacement is what pins you in your seat...... how you get this is a different question and it'll be power that you'll need (it's a rate after all...)
Trust me its not power you need torque is the only force you feel in a car lots of things effect this such as weight and gearing but ultimately its torque nothing else!
BHP is simply a calculation made directly from torque rolling roads do not measure bhp its just calculated from the torque made.
torque x rpm divided by 5252 = BHP
The reason hondas are able to get high bhp figures from small engines with hardly any torque is because they rev so bloody high!
Take a 2001 civic type R
These are the peak figures from a type r which mean very little in the real world without a full dyno graph but peak figures do a grand job selling cars!
Peak power = 197 bhp @ 7600 rpm
Peak torque = 145 ft·lb of torque @ 5900 rpm
Honda only tell us the peak torque made which is at 5900 rpm so a simple calculation tells us the following
145ft.lb x 5900rpm = 5252 = 162 Bhp
So the type r only makes 162bhp at 5900 rpm to get 197 bhp we have to rev to 7600
and obviously further down the rev range we go even less power is being made! This is why they are gutless under 6k!
You can work out the torque from the bhp as well
197bhp x 5252 divided by 7600 rpm = 136 lb of Torque so when the type r is making its peak power its only making 136lb of torque!
On paper they look awesome with 197bhp but to get that 197bhp you have to build up the revs 1st and hold it pretty much between 6-8k at all times and because the power is made at such high revs it means it drops off rapidly lower down the rev range.They rely on been light and revved, put 3 people in the back or drive it up a hill and it will struggle. overall they are well designed the gear box works well with the revvy engine but in reality day to day driving around town although they have enough power to get you from a-b they are gutless low down,anyone that says they aint aint drove a car with **** loads of torque before to get any kind of decent power you have to drive it around like a complete loon at 8krpm
Car's with loads of low down torque are effortless to drive have tonnes of low down power and you don't have to drive them like a loon to make them shift they have big huge fat surges of power as soon as you blip the throttle, the high revving boys still think there cars can do this by cruising at 5krpm and then flooring it THIS IS NOT THE SAME LOL! im talking cruising at 2k rpm then flooring and have the car plant your cheeks on the head rest and if you try and pull you self forward you neck hurts! you dont need big bhp to do this you need masses of torque. The kick i get out of fast cars is purely this stuck to the seat neck hurting effect how fast the car can go is irrelvent to me. you can have **** loads of torque and not much bhp which results in a car that will stick you well and truley in the seat from 2-5k but 5-7k power will drop off hard and you run out of poof, if you want to win races ita all about balacing the torque and power if you simply want the push you back in your seat sensation then you want masses of torque
If you compare the power and torque from a type r to a saab 9-5 aero for example
Type r Peak torque = 145 ft·lb of torque @ 5900 rpm
Saab Peak torque + 370 N·m (270 lb·ft) @ 1900 rpm
The saab makes more than double the civics maximum torque at only 1900rpm!
while the civic is making 145 ft lb and 162bhp @ 5900rpm
The saab is making 250 hp and 247 ft lbs at 5300 rpm
The above is not a fair comparison but it shows the difference between low down torque and just peaky bhp figures.
A well set up car will have the perfect balance of torque and bhp fo its weight and gearing. Torque is low down power and bhp is top end power you can have loads of bhp but if you have no low down power a car with less bhp and more torque will be quicker overall.
bhp sells cars torque wins races is true to an extent so many people think bhp is the be all trust me its not.
There was a thread on here the other day a guy with a subaru sti got wasted by a saab 9-5 he said it just seemed to take off making very little noise just a slight turbo whistle.
here's a better comparison
2007 subaru sti
270 bhp @ 6500 rpm
306.0 Nm (226 ft·lb) @ 2800 rpm
Saab 9-5 aero again
250 bhp @ 5300 rpm
370 Nm (270 lb·ft) @ 1900 rpm
As you can see the sti has 20bhp but the saab has 64Nm more of torque + it makes both its peak power and peak torque lower down the rev range and quicker than the subaru, from a rolling start in the dry i know from experience there is nothing in these two cars on the road, i would say the saab that wasted the subaru was most likely a stage 3 aero which my best friend has which would be pushing around 280-290bhp at around 5000 rpm and around 450 NM of torque from around 1.9krpm! so a stage 3 aero would have 10-20bhp more and nearly 150nm more torque! again i know from experience a stage 3 aero will smoke a sti once moving in the dry and in a straight line of course.
I have another friend with 380bhp evo and it doesent try to push me through the seat and hurt my neck like my mates saab watching them race is fun and you can see the difference in the torque,from a standstill start the evo smokes the saab but from a 30mph rolling start he race goes like this
Saab pulls ahead but starts to run out of poof high in the rev range (less hp)
evo slowly gains on the saab and finaly over takes
saab changes up a gear mid range clout kicks in and starts gaining rapidly but dosent over take
Saab starts to run out of top end again
Evo pulls ahead gradually even further
saab changes up another gear and starts gaining rapidly again but evo is alreay well ahead
saab runs out of poof again
evo gradually gains further ahead and so on and so on
You can see the evo just gaining and gaining all the time and you can see when the saab hits its sweet torque spot as it starts gaining rapily for a few seconds before it runs out of poof again.