joe-96z1le

What would cause two somewhat similarly built engines to have different HP vs Tq value? In other words, one engine has about 500 HP but close to 600 TQ and the other engine has 600 TQ but closer to 500 HP? I've seen these differences in particular with supercharged engines. Thanks in advance for any responses.

96capricemgr

Do you understand exactly what HP and TQ are????? HP is a measure of ability do do work, TQ is a measure of force.

TQ times RPM divided by 5250 is how HP is calculated after torque is measured.
That said GEARING and torque converter are needed to use HP, so in a street car torque is rather important beause you often can not optiomize gearing to fully utilize HP.
To accomplish the hp/tq differentials you are talking about would mean signifigantly different rpm ranges because like I said HP is calculated off of tq times rpm.

Severous01

dude...you answered nothing about what he asked, and you're making it sound as if he's retarded

he asked what makes one care more powerful when they are of similar build...answer is that even though everything is generally made in the same manner they all have a specific tolerance. so...if you have a bore of 4.030 it's not exactly .03 over. it's actually +/- so many %. since every engine is different with different tolerances in just about any part of the engine...you'll get a percentage difference between any car.

could be that someone ported the heads on one vehicle and someont ported and polished the heads on the other. factory could have used a new casting mold for the intake manifold so tolerances are tighter and more acurate...could be many things. also, with the superchargers power is predictable. for every 14.4xxxx...whatever the magic number is...power is doubled. if you have a SBC NA running 400 HP then you'll have 1600 (400 x2 x2)at 28.8xxx lbs of boost.

another thing is the cam. even though they may both be using ... say the CC306 cam they arent the same. a few degrees of lobe sep causes many different things to happen. when i got my cam i read on my card that it wasnt what was advertised but one degree off on intake and exhaust. another guy that had the same model cam was one degree lower on intake and dead on for exhaust...again it's the tolerance issue.

WS6NIGHTMARE

Am I the only one that caught this in the question?

So these engines are actually....pretty dead even huh?

Anyways, any of those variables can effect its output like he said. And Joe, you got way to specific with your response, even if thats the answer to what he had asked. When youre going to explain Tq and Hp to someone, that means they are pretty much a rook at these things so keep it simple: Horsepower is how fast you hit the wall, Torque is how far you take it with you.

MTL_Z28

LOL I'm assuming he meant one engine (A) has 500 HP/600 ft-;bs of torque, the other (B) has 600 HP/500 ft-lbs of torque

If this is the case, then applying the formula that 96capricemgr mentionned before, we can see that engine A likely has a torque curve that peaks earlier in the RPM range, with lots of torque down low but it dies down a little in the upper RPM's. Engine B has less torque, but shines (relatively to A) in the upper RPM's.

There are alot of things that can cause 2 similar engines to have this difference in torque curve, eg. intake manifold tuning (long vs. short runners), camshaft design, airflow in the heads... I would think it would have to do mostly with the engine's ability to breathe in the upper RPM's.