Steveman09

Ok well after a long heated debate with Turboviper (I got blocked on aim) LOL on the G1's HP output I would like to clarify some things about the differnce between the Manufactor's Ratings and the real world.





Manufactors give a Horsepower rating of 161HP for the G1 Legend with C27 Engine.



Now lots of people say "tight I have a 161hp car"


Well you do, but not really.

Let me expain :


There are 2 ways of measuring a engine's output :

Power at the Engine's Flywheel (manufactors method)

Power at the Car's Wheels (real world method)


Now when a manufactor dyno's an engine they dyno the engine out of the car on a Engine Dyno with only a flywheel on the engine. They dont install any accessories such as Alernator, Power Steering Pump, Pulleys, Belts, or Air Conditioning for testing.


So what you get is a 161hp at the flywheel

Now you put the engine in the car, attach a transmission, axels, accessories and such and such.

Now you dyno the car on a chassis dyno and you get a much smaller figure. You then wounder why this happened, well you see running accessories and transfering power through a set of gears and axels is allot of work and the engine has to do all this work on top of moving the car. This is where you LOOSE Power Output (drag on the engine)

The most loss is seen in 4WD Cars such as EVO and WRX.

They loose anywhere from 30-35% through the transmission alone.

Lots of people with EVO's were disappointed when Mistubishi said 271hp and the dyno said 190ish.

I hope this post resolved allot of misconceptions.

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94 Legend LS Coupe Type-II

 

illlojik

Damn..... Well sorry to here about the heat between two of my favorite board members. But also, I'm going into a slump of depression now. I've been living a lie, all these powerful cars really only have like under 200 horses Sigh... I've lost hope in the auto world................. **cry cry cry***


Oh well. My car still feels fast

__________________
<b><u>Goodbye to my sweet love</u></b>
<i>1989 Acura Legend: Blue 5 speed Sedan</i>

<b><u>Now own</u></b>
<i>2000 Sterlin Mist (basically Pewter) Maxima Se</i>

Steveman09

Legend's still are fast, the automakers just play a number game to sell cars. The new cars like 350z, TL-S. RSX-S are still very fast cars but they dont put down near the horsepower #'s to the ground that the manufactor advertises.

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94 Legend LS Coupe Type-II

Eric F

Another thing to remember is horsepower sells cars, torque wins races.

What you feel in everyday driving is a lot more torque then horsepower. If you look at Steve's dyno chart in his other post you can see that the torque curve is pretty flat from about 3000 rpm's up until into the 5000's. Horsepower doesn't kick in until the engine gets moving at a higher rpm.

Standard transmissions loose about 15-20% of their horsepower at the wheels through the drivetrain, assessories etc.
Automatics loose around 20-25%, more or less depending on the torque converter and other factors.

The same would apply for torque loss as power loss.

__________________
'87 5 speed L coupe

'90 5 speed base coupe (sold)
'88 5 speed L coupe RIP (tranny) - parts car
'87 5 speed L coupe (sold)

Josh S

Yeah but if you are bench racing that all mfg's ratings are all at the crank anyway. That's always what is reported in the mag, etc. When you dyno you get the number at the wheels, which is more of a real world number. but since most car's drive train losses are similar, the car with 250hp is going to put more power to the ground than the car with 240hp.


"horsepower sells cars, torque wins races."
-Not really, then desal trucks with 600 lb/ft of TQ but only 200HP would rule, but it doesn't really work that way. It has a lot to do with gearing and being able to take advantage of the high rev HP. It might be a bit harder to get off the line with low TQ (unless you luanch it right), but overall HP is what wins races.

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Legend - RIP 01/04

GREYLEGEND

The product of horsepower outputted x time is what wins races. Torque x rpm = HP. We're talking same cars here, so we won't get into power to weight ratios.

Having close ratios with multi speeds on a tranny allows us to stay close to the maximum horsepower peak at every shift so we are able to stay in the power band. A CVT transmissions is ideal because you keep the rpm where the HP is maximum and you keep varying the gear ratios to stay at that RPM as the car gains speed. Feels odd, but is effective.

Diesels pull away really quickly because their peak torque comes quickly at low rpms but it drops off quickly. They need a meag speed tranny but remember they are desgned to carry very heavy loads up hills and low speeds and not stall, so they need stump pulling torque for that.

The nice thing about the Legend is how "linear" the horsepower and how "flat" the torque curve is. That provides little flat spots and the power just seems to build as the speed increases. Like a Rotary/Wankel.

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cdndvl

Josh... It really depends on how the manufacturer has designed the transmission and what the engine is like... 250 HP in a Chev (for arguments sake... I HATE Chev.) could get it's butt wiped by a 210 HP Honda. It all depends on the gearing.

__________________
1990 Legend L 5 speed sedan
17" chrome rims
Weapon R intake
Tinted windows
Pioneer stereo system
GTech Pro
Brembo cross-drilled rotors/Metalmaster pads all round

Josh S

I agree. I was disagreeing with the ""horsepower sells cars, torque wins races." statement made as that is not really correct.

__________________
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Legend - RIP 01/04

Steveman09

yeah there are TONS of factors that go into a race.


I've seen many many cars with less HP beat cars with more HP.


And the drivers both shifted perfectly.

3 out of 4 races the car with less HP won.

The last race the guy misshifted.


It all depends on Tranny Design, Type, Gears, Metal used in gears (weight), Axel Weight, Wheel Size and Weight............I could go on forever.

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94 Legend LS Coupe Type-II

twg

assuming all things equal... GREYLEGEND is correct... generally HP over time is what matters.. and it's the whp that matters..

yes, for those that didnt' know, whp is less than manuf. stated hp. sticks are usually 15%, autos are 20%, depending on the car.

My other car, which is a 2000 Accord I4, stated to have 150hp... stock, dynoed, I got 133whp.. modded, I got a high of 144whp... and spraying a 75 shot.. i got 200whp..