[Steve03GT]

quote:Originally posted by GLH_TC 16V

I wrote a paper on this subject as it is always topic of controversy.

Basically, torque is that kick in the back that you feel when accelerating. Also, torque makes HP (torque x RPM / 5252 = HP) Torque across the rev range is good, provided you are starting from xxx RPM.

Peak HP is important to everyone because it is the energy used to keep the vehicle moving. HP is used up in wind resistance, drivetrain loss and friction to the road. When racing, you are usually shifting at the higher RPMs around where the peak HP is so the entire torque curve is not needed. For example, you are drag racing and are now accelerating in 2nd gear to redline, say 6300RPM, you shift in 3rd and the revs drop back to say 4300RPM. We now don't care about the torque below 4300RPM because we'll never see it again! Peak HP is important because it tells us where to shift so we stay in that powerband. That is why torque at high RPMs is desireable, which co-incidentally is the equation for HP.

edit: Sorry, I forgot to mention that I do agree that parts advertising + X HP is misleading. I know that a lot of those fart sounding exhaust systems for the imports add peak HP, but at the cost of low end torque.

I've always believed the Tq "area under the curve" is important in straight line performance because of the initial acceleration advantage. My Vette (supercharged) Tq curve jumps (near vertical) to over 400 lb-ft from 2400 to 2600 rpms and stays horizontal to 6600 rpm (rev limiter setting); whereas, most naturally aspirated Tq curves climb at a 45^ angle. The area under my Tq curve is > that of my friend's modified '02 Viper, although his peak Tq is > than mine. My premise has been based on me spanking his Viper one night for about an 1/8 mile on the street by about 1.5 car lengths before having to shut down due to road conditions. I'm not disagreeing with your post, just telling what happened in my particular situation, to which I attributed to my Tq curve advantage.