It is my understanding that BMW is one of the few manufacturers that post HP and torque at the wheels.

To lose 20-30% through the drivetrain with Acura's and Honda's are common. As for an earlier comment about a 100% efficient engine. They do exist. The thing I would like to see and is imposible, is a 100% efficient drivetrain.

As for swapping stock rims for lightweight rims there is an advantage. By having lighter wheels you reduce the inertia that is required to turn a wheel. however, the difference will be negligable and to the average person any effect would be a placebo.

 

Our sister operation Park Ave BMW says BMW quotes HP at the crank just like everyone else.Jens

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1992 mazda Miata lowered with Eibach springs KYB AGX adjustable struts Sparco racing buckets 4 point safety harnesses Momo steering wheel lo profile headlite system with PIAA superwhite bulbs Custom audio system Custom gauges Jackson racing supercharger with header and Greddy cat back exhaust and a ton of other stuff 2000 Honda Civic on APEX coilovers Full Alpine Audio system factory fogs with Piaa bulbs Catz ZETA headlamp system tinted custom taillites and on and on

 

Read the article about HP to the wheels in which they test various cars including the BMW 328i, Toyota Celica GT-s etc (check out the results by clicking the car-links on the top right corner of the article):

http://www.edmunds.com/editorial/fea...824/index.html




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3.2TL with NAV

 

260hp down to 208hp at the wheels equates to a perfectly round 20% loss in horsepower, so I'm actually kind of wondering if Comptech just guesstimated based on the industry standard of 20% loss for an automatic. You guys might need to confirm if this is this is a real number or an estimate.

(For purposes of comparison, a stock IS300 goes from 215hp down to 174.3hp, for a 18.9% loss.)

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051/LP/SR/LD/HH

 

Only 18.9% loss, eh? That is very good and quite rare. I think a more typical loss is in the low 20s. The CL-S seems to average a loss of more like 24% which is consistent with other Honda automatics. They tend to be on the high side of drivetrain loss unfortunately. Comptech's website shows a before and after dyno, so I don't think their hp increase was a "guesstimate". It's what they actually measured. One of our members did a before and after dyno and, I think, got even slightly better numbers than Comptech!!

 

I have a 540 and BMW claims 282HP, in actuality it's more like 240HP to the wheel. BTW, TypeS I belive has more like 194 to the wheel, but remember you have a front wheel drive car and it's automatic. It's not only Acura misleading you, it's also AUDI, BMW, LEXUS, MB, should I go on? Don't feel bad cuz all those Maxima, IS300, even M3 owners are in the same boat.

 

Well, two cars were dynoed on separate occasions on different dynos, one car producing 174.3hp(4th) and the other car producing 174hp(4th), 162hp(3rd). On the other hand, SRT pulled some runs and it ended up being 155.5hp in an unspecified gear, so that seems odd. Until somebody else pulls a similar figure, I think it's better to put faith in the majority.

This brings up an interesting point, that cars are dynoed on the gear closest to a 1:1 tranny ratio. Both manuals and automatics produce 1:1 ratios by eliminating any power transfer through gears, minimizing losses. For the vast majority of cars, this is 4th gear. It seems like the CL-S 4th is rather overdriven, and a better choice would be 3rd (but still transfering some power through gears, although not much), which is 1.02:1.

Unfortunately, the Comptech dyno.pdf does not tell whether the run was done on the conventional (but improper for the CL-S) 4th gear.

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051/LP/SR/LD/HH

 

All CL-S dynos I've read about have been done in 3rd gear. It is the closest to 1:1. 4th gear is definitely too tall to use.

 

All CL-S dynos I've read about have been done in 3rd gear. It is the closest to 1:1. 4th gear is definitely too tall to use.

 

Really nice car. With the mods you got, it can run a 0-60 in 5.5 seconds?? Thats very fast for a automatic!!!! you gotta use that steptronic shift in order to do that, right???

Do you have comtech springs too??
How come you didnt have a pic of the headers?? Does your car have "strange noise" with the headers??

Anyway, very nicely fixed CL-S!!!!!

 

hey Jens, you may want to ask someone that acctually knows something about cars over at your sister operation. The M5 is rated at HP to the wheels. Compare the dyno from BMW and Dinan and you'll see what I mean. Turbos

 

one way a dyno is exactly correct is when comparing horsepower/torque from two cars, one after the other. the difference in true hp/tq from the two will then be measured acurately. then you can say that that zo6 has 130 more horsepower that my car

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type-s
silver/ebony
35% tint
jl audio 2 10w3's, jl audio 500/1 amp
honda vtx 1800
106hp & 120 ft torque. soon!!!

 

Article I read said about 400 hp to the flywheel

can you pay for a dyno for us?

 

the dyno runs in different gears is like doing test runs up different grade hills

there is going to be some variation in measured power

ever wonder why they put such high gear ratios in high powered loweight cars

a big fat car would BOG. a light car's engine with big motor gets through the gear so fast, that the air in the intake is moving really fast and making lots of torque and hp

now take that same car and put it on a hill, it doesn't pull so well up hill -- the gas flow is really slow until cam cuts in

i think it is time for a trip to the auto car bookstore

I also dont know of any dyno investigators or policeman checking cynos out

:* :\

 

All cars that sell in the US show power as power at the engine. Read the disclaimer.

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01 3.2 CLS Non-Navi
San Marino Red
Tinted 35% all the way
Winter Rubber mats
Piaa High Beam lights (Not worth it)

 

Damn...this freakin' topic is still going?!?

Anyway, MNCLS is correct, all cars SOLD in the US are rated at the flywheel....



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1998 Iced Blue CL 3.0 ** Some mods, but who cares, I want a Type-S!!

Moderator - 1st Gen Forum

Email: juniorbean@acura-cl.com

 

That's called torque. The "feeling" you get when driving a car hard is torque. You don't really feel horsepower. If I'm not mistaken, the S4 has quite a bit more torque than the CL-S, plus it makes it at a lower rpm.

My 99 M3 is rated 20 hp less than a CL-S, but if you were to take a ride in it, you'd think it was waaaay faster than a CL-S, judging by feel alone. And it is faster.

It's all about torque, baby.



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dead CL-S and M3

 

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dead CL-S and M3

 

I'm really really sure that I understand all this but, if there is loss from the crank to the wheels, do we gain any advantage as a front wheeler? Do we lose less since the drive wheels are closer to the crank?

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CL-S #22,299 Black/Parchment/Nav, spoiler, door & fender guards, wood trim, PIAA 19169 & 9005, V1 w/remote, trunk & winter mats, no headers, no sway bars, no springs, no money!

 

That's a good question, but difficult to answer. Think of it like this-- Once the power is transferred from the crankshaft, it has a long way until it reaches the drive wheels.

A 15% drivetrain loss is the accepted standard, when running on a dyno, but this percentage varies sooooo much.

To try and answer your question, though, think about the transfer of power through a drivetrain. On a typical RWD car, the output shaft of the tranny (by the way, manual tranny losses much less than an automtic tranny) transfers power to a U-joint, driveshaft, U-joint, differential, spider gears, axle shafts, hubs, etc.....you get the picture. On a FWD car, w/automatic transaxle (notice that I did not write "transmission"), you have power transfered from the trans output shaft to CV joints, axle shafts, CV joints again, hubs, etc....again, you get the picture.

So in theory, you have less "stuff" for the transfer of power in a FWD car, thus they should have a more effecient drivetrain. But since it varies so much, this is not always the case.

Damn, my fingers are tired.



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dead CL-S and M3

 

While it's true that torque makes cars fee "fast", the extra couple hundred pounds your M3 doesn't have to lug around is helping out a lil bit too!!!



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2001 Acura 3.2CL Type S
Comptech Springs
Comptech Sway Bars
Comptech Headers
PIAA 19169

 

most of the people who have written about "transaxles" have stated that they are more efficient (Porsche AND front wheel cars = Acura)

the drivetrain of a front engine -> rear wheel car has lots of intermediate parts that add intertal (rotating mass). Also, u-joints bend, rubber donuts bend, all of these cause for power loss.

On the other hand, some of the fwd engine/rear wheel cars used encased, slender shafts to deliver power to a rear "transaxle", thus saving power and keeping weight distribution equal from front to rear. this saved some of the rotation weight and flexing joints from robbing power.

a creative solution is always possible and there are absolutes when it comes to clever minds and engineers.

the front wheel drive looses out in the rear world with weight transfer. when the car is launched it lifts the very wheels it needs to get power to off the ground and transfers the weight to the back. in the case of a porsche this is perfect, since the engine with a lot of weight is sitting right over the rear wheels and getting even more help on acceleration to plant the wheels for good traction.

hp isn't everything.

if your talking dynos -- its the transaxle and lack of reciprocating weight that makes for high output to the wheels on a drum type dyno.