Horsepower, the whole story.

**BowTied** · 01-08-2009, 04:04 PM

I've been around a few forums, read various articles, and even talked to several Mechanical Engineers...

And you hear and see all over this LS1 whipped this Mustang...and they'll go into the LS1 pushing 360hp and pulled 3 cars on a Stang that had 380hp. And then you get many musings (torque, gears, weight, response, etc.) as to how this can happen.

But I never hear anyone, ANYONE, talking about the curves! Am I just missing it being spoken on. HP, is always @ some rpm, and the report is the Maximum.
The problem with this popular measure is we don't run or race at 3850rpm.

I think both my LT1 and my LS1 has let me kill Mustangs (w/ work) and worked Nissan's that thought they had the number to beat me because I got them through the range!

Why haven't we graduated to a number like ARHP (making my own term here) Average Real Horse Power, that being the avg from 1500 to 6000rpm? And why do I not seem to hear anyone talking about this?

**blue02Z** · 01-08-2009, 04:18 PM

because an engine is measured at its peak hp, what it is capable of putting down. that is why we have the graph to see how well the power curve is. that is why we got peeps on here like Wesman(no offense Wesman:chair: ) who stronly dislike a turbo 4 because your "arhp" are dead usually untill they boost up.

i prolly didnt answer your question but i tried

**01 SS Vert** · 01-08-2009, 04:43 PM

it's not HP that wins races, it's torque. If you can build torque and then rev it high enough, you will build HP 99 times out of 100.

Torque and Horsepower, for 4-stroke engines, ALWAYS cross at 5,252 RPM. Keep this in mind when looking at dyno charts and engine building in general.

**BowTied** · 01-08-2009, 04:45 PM

I know the measure is peak. But you rarely hear about the range, especially when someone is talking about beating another car that has more peak HP!

**01 SS Vert** · 01-08-2009, 04:48 PM

In other terms, think of it like this:

You want a horse to plow your field, or an ox? The horse is quicker in speed, but can't plow as much per pass. The ox, on the other hand, is slow but powerful (torque). To plow the field the best, you want a combination of power (really called torque) and speed (horsepower).....in this case you want the horses speed with the ox's power.

Torque is the ability to create force....HP is the rating at how fast you can create that force.

In na engines, typically large cubic inches make more torque do to their larger pistons and better piston to rod ratios.

I want an engine with a large flat torque curve, but brings on the horsepower quicly without the torque dropping.

**BowTied** · 01-08-2009, 05:03 PM

Common knowledge. Torque measures rotational force. To get to Energy you need a time differentiated measure, that gives hp. Horsepower measures energy, and other countries use Watts. Basic physics.

Not what I was asking...I am not asking a technical question. (But torque plays a significant role in what I am talking about.)

All I want to know is why people don't speak on HP through the entire RPM range! You mostly just hear HP, not quite as big of a deal if we are comparing LS1's...but when you are comparing 2 different engines and then 2 different drive trains...it is big!

**01 SS Vert** · 01-08-2009, 05:33 PM

Originally Posted by BowTied

All I want to know is why people don't speak on HP through the entire RPM range!

Probably b/c most ppl don't think in the same terms we so. They only hear a # and that's what matters to them. I know how you feel, b/c I feel the same way most of the times I hear bench racing.

**TransAm11973** · 01-08-2009, 05:34 PM

nothing like beating a dead horse

**BowTied** · 01-08-2009, 05:44 PM

Ha!!!! I can't believe I have never heard that. Just so natural! &

**BowTied** · 01-08-2009, 05:55 PM

Originally Posted by 01 SS Vert

it's not HP that wins races, it's torque. If you can build torque and then rev it high enough, you will build HP 99 times out of 100.

Torque and Horsepower, for 4-stroke engines, ALWAYS cross at 5,252 RPM. Keep this in mind when looking at dyno charts and engine building in general.

If they'd give you the peaks and the 5252 #'s then you'd know much more!

**hutch1999** · 01-10-2009, 06:20 AM

they wont understand what you guys are saying, its the same way when i tell my import buddies FWD is terrible from a dig and that even tho a honda has a high hp number it cant get the power to the ground. They just dont get it.

**BowTied** · 01-10-2009, 06:51 AM

And you'd be right! And those fwd cars are the worst about power at a specific rpm. They have like twice the % HP drop 500rpm from peak than the LS1.

I know when I was growing up and somebody was telling me something that sounded more technical than I understood, I knew to stop talking and do more asking. You don't get that much anymore.

Now you have to go ahead and stomp them by 7 cars. Let them make excuses, then stomp them by 8 cars. (Rinse and repeat)....then they call you a liar (about your car). Then you show them, walking them through....then stomp them again (rinse and repeat)...

....then maybe they are ready to ask questions!

**mark21742** · 01-10-2009, 08:46 AM

Originally Posted by BowTied

And you'd be right! And those fwd cars are the worst about power at a specific rpm. They have like twice the % HP drop 500rpm from peak than the LS1.

I know when I was growing up and somebody was telling me something that sounded more technical than I understood, I knew to stop talking and do more asking. You don't get that much anymore.

Now you have to go ahead and stomp them by 7 cars. Let them make excuses, then stomp them by 8 cars. (Rinse and repeat)....then they call you a liar (about your car). Then you show them, walking them through....then stomp them again (rinse and repeat)...

....then maybe they are ready to ask questions!

it is sad just how many people out there think they know everything

**Sarge** · 01-10-2009, 01:45 PM

Horsepower sells cars.
Torque wins races.

**Too Fast** · 01-10-2009, 02:07 PM

I think it's because most people don't want to hear about average numbers, they want the peak. And it's about advertising, the advertisers don't have to explain the number they get thru the RPM range. Just the peak is easier for the masses. That way the person who says their engine makes 350 HP is superior to the person who only makes 345, even tho that 350 number may only be in a 300 RPM window and the 345 is for 1000 RPM. To the dumbass mainstream people, it doesn't matter. The 350 wins every time!

**BowTied** · 01-10-2009, 03:44 PM

Exactly! Perception dominates reality.

In mechanics it is one of the only things I had luck using Calculus to show. (Integration will yield area under the curve...math don't lie!)

You'd think 8 car lengths wouldn't lie either! Guys that know cars don't have to waste time on the math, they can feel it and see it in action.

**karpetcm** · 01-10-2009, 08:16 PM

probably doesnt have much to do with what were exactly talking about, just recently i had a 01 E46 M3 6speed car although it would have no issues beating the new stangs and pulling on a couple of LS1 cars it was horrible to drive. Im used to just tapping the gas peddle and staying below 3000rpms around town and thats most of my driving and in the M it was just bad on power way that low in the rpms. Also it would have power surge meaning i would keep it at the same throttle and as it slowly rises in the rpms it would shoot up in the rpms all of the sudden and just didnt appeal to me at all. Even though it would mostly pull above 7k rpms till about 8100rpms it did really well with many cars with much bigger motors and i think one other thing that most people dont talk about is GEARING which is critical to take advantage of the power you have. If the gearing is off you wont be in your power range and be there long enough to take complete advantage. Lots of cars pump power out but gearing is horrible amoung other things but either way thats my stab at it.

**BowTied** · 01-11-2009, 03:34 AM

Gearing...hand in hand with where the power is in the engine range...you have to get it to the ground.

A drive should be set up to compliment the engine. If you have that Asian approach high rpm power zone...you need gears to get you through the weak range. I drove some (never owned, never, ever owned) of those blenders before and you go from 1st trough 3rd awful quick, at least shifting. Speed wise I've seen that translate into 55 to 70 mph....which is our 1st gear to mid 2nd in the M6 models depending on gears.

(I think this is one reason guys think they are doing something is those quicker early shifts. "Man it comes out of the whole...it really gets through the gears!")

**BowTied** · 01-11-2009, 03:34 AM

Gearing...hand in hand with where the power is in the engine range...you have to get it to the ground.

A drive should be set up to compliment the engine. If you have that Asian approach high rpm power zone...you need gears to get you through the weak range. I drove some (never owned, never, ever owned) of those blenders before and you go from 1st trough 3rd awful quick, at least shifting. Speed wise I've seen that translate into 55 to 70 mph....which is our 1st gear to mid 2nd in the M6 models depending on gears.

(I think this is one reason guys think they are doing something is those quicker early shifts. "Man it comes out of the whole...it really gets through the gears!")

**slp1122** · 01-11-2009, 10:04 AM

Originally Posted by BowTied

I've been around a few forums, read various articles, and even talked to several Mechanical Engineers...

And you hear and see all over this LS1 whipped this Mustang...and they'll go into the LS1 pushing 360hp and pulled 3 cars on a Stang that had 380hp. And then you get many musings (torque, gears, weight, response, etc.) as to how this can happen.

But I never hear anyone, ANYONE, talking about the curves! Am I just missing it being spoken on. HP, is always @ some rpm, and the report is the Maximum.
The problem with this popular measure is we don't run or race at 3850rpm.

I think both my LT1 and my LS1 has let me kill Mustangs (w/ work) and worked Nissan's that thought they had the number to beat me because I got them through the range!

Why haven't we graduated to a number like ARHP (making my own term here) Average Real Horse Power, that being the avg from 1500 to 6000rpm? And why do I not seem to hear anyone talking about this?

I like that. It's interesting because horsepower is defined as work done over time. so it would make more sense to have an average horse power reading.

but then again, if you have a chance to use a bigger number or a smaller number, you will go with the bigger number (in terms of bragging, etc). And i've found that many people on sites like these, let the track times do the talking.

Another interesting tidbit, when they do the land speed runs in the desert, they get official speeds by determining the average speed over a mile. so you could have a racer that hits 220mph, but the official time might turn out to be slower.

end ramble