[EmPower]

http://www.motorauthority.com/cars/b...etter-results/

[RodB]

It's been discussed before that BMW without question underrated the output of the 335i engine. Some speculate that by doing so, they make the new M seem that much more desirable and had they published the "real" output of the engine, it might have compromised M sales. I've read that BMW tends to underrate all their engines for real world conditions. Who knows........

[BK]

I think it shows how dyno results can vary depending on conditions. The first results pretty much jive with what everyone else is seeing on dynos in their before/after PROcede installs, so take it with a grain of salt.

[EmPower]

I know they underrated the engine... that was not my question... 375 bhp??? isnt that a little too over optimistic? I mean the figures floating around were close to 330hp.

were these test results a one off or are they a general property of this engine?

[BMW F22]

BMW does not underrate their cars. They just have less powertrain losses than other makers.

[TurboFan]

A driveline loss of 25%? I don't think so. Maybe a chevy Impala, but not the 335, and definately not on an MT. I'd believe about 15-18%.

[RiXst3r]

actual drivetrain loss is stated as 13-15% MT and AT by BMW... they are using incorrect loss figures

[Cookiemonster]

Originally Posted by TurboFan

A driveline loss of 25%? I don't think so. Maybe a chevy Impala, but not the 335, and definately not on an MT. I'd believe about 15-18%.

My 2004 GTO had exactly 15% drive train loss for HP and about 12% for torque.

15% is good all around number for a rear wheel drive car.

20% to 25% is to high on a rear wheel drive car.

I have always suspected that the real crank HP of our cars is labeled on the rear trunk lid.........335.

[e90AW335i]

Originally Posted by Cookiemonster

I have always suspected that the real crank HP of our cars is labeled on the rear trunk lid.........335.

[turbocoins]

Originally Posted by Cookiemonster

I have always suspected that the real crank HP of our cars is labeled on the rear trunk lid.........335.

Very, very well put.

[remydlc]

Originally Posted by Cookiemonster

I have always suspected that the real crank HP of our cars is labeled on the rear trunk lid.........335.

Interesting, 323, +2 325, +3 328, +2 330, +5 boom 335. Should had been 332i or 333i maybe.

Marketer1= how should we named this car?
Marketer2= 333i?
Engineer= it has 335bhp, why dont you name it 335i?
Marketers1-2= Oh yeah, and It's a nice number too,
Engineer= You owe me one!
Marketer2=but wait, we can't say it has 335bhp, we wont sell the ours 2006 M3s.
Engineer= Just say it has 300bhp and 300lbtq, once they see 300-300 they wont question much.
Marketer=2 Wow, you are very smart, do you want to work for us?
Engineer= No, just give me a beer.

LOL

[bimmerlex]

Originally Posted by Cookiemonster

...I have always suspected that the real crank HP of our cars is labeled on the rear trunk lid.........335.

This could be valid for 335i model only

[judec]

I like the comment posted there:

You are saying the car made 275whp wheels and estimate 350hp at the crank, you are talking rubbish. If that is the case a 75hp engine in this car wont move at all because all the power is loss. Loss at the wheels is a constant hp not in % figure. Also following your theory if you were to boost up this car to 1000hp the loss is about 200~250hp. again, rubbish!

[Maestro]

I was about to say the same thing, I am not sure why we keep seeing hp loss as % because it usually is a fix number or a range and you do not get more loose the more hp you add. I guess efficiency is usually measured a % and they generally talk how efficient drive train is thus a % loss.

Originally Posted by judec

I like the comment posted there:

[judec]

I dunno, imho it should be a more complex formula, cuz I'm sure the loss is higher with higher friction force added by more HP and TQ, but I'm also sure it's not a linear relation.

Anyway, if I imagine the heat generated by 200HP loss in the tranny, I get goose-flesh

[turbotko]

Yeah, you wanna talk drivetrain and accessories loss, I once read that the blower on a typical top fuel car takes 350-400 hp to spin at full boost.

Of course, when you're making over 7500 horsepower, 350-400 hp isn't much to complain about.

I've always though most of BMW's engines were overated until the 335 was released. I've seen quite a few E60 M5 dynos in the 390-400 rwhp range and E46's dyno 260-270 rwhp.

[kiki]

all good comments, but the reality is that Automag uses an accelerometer, not a dynamometer. The accelerometer (like dynojet) with an inertial drum make an "estimate" of horsepower at the tires, and are known to have inherent variance between devices. They are, however consistent over a short period of time.

So the estimates in the article, while worth mentioning, are not as accurate as the high-dollar water dynos that BMW uses. And 25% DLL is way too high. In fact this should be improving as the years roll by.

We use 20% DL loss on Viscous coupling cars and 14% on FWD cars, and 16% on RWD cars ( I can't remember how we arrived at those numbers-- sorry), plus we build in an additional +/_ 5 points on the dynojet for errors (but they would never admit to that-- and this error is really only significant when comparing 2 separate vehicles, not one vehicle against its own baseline over a short period of time.)

[derryck]

BMW does not underrate their cars. They just have less powertrain losses than other makers.

LOL...that's a good one. Sales of the 335 and E46 M3 overlapped a bit and rating the 335 at it's true 330-340hp would have hindered the E46 M3 sales a bit. Also I'm sure they knew they would carry the N54 into the 5 series and eventually other cars but who wants to pay the premium for a 550 if it were only 10-20hp more than a cheaper 535?

[TurboFan]

Originally Posted by derryck

LOL...that's a good one. Sales of the 335 and E46 M3 overlapped a bit and rating the 335 at it's true 330-340hp would have hindered the E46 M3 sales a bit. Also I'm sure they knew they would carry the N54 into the 5 series and eventually other cars but who wants to pay the premium for a 550 if it were only 10-20hp more than a cheaper 535?

Uh, cause you need more room? Not everyone buys a car based on the HP, 1/4mi or some track time around Willow Springs. If I end up in a 550, it's becuase I need the room, and it hauls ass. I don't care how it compares to a 335, because the 335 may not have the room I need in a year or two.

[sdwilly]

Originally Posted by TurboFan

Uh, cause you need more room? Not everyone buys a car based on the HP, 1/4mi or some track time around Willow Springs. If I end up in a 550, it's becuase I need the room, and it hauls ass. I don't care how it compares to a 335, because the 335 may not have the room I need in a year or two.

I think he was comparing the 535 to the 550, not the 335.

[TurboFan]

Oh yeah, my bad.

Think what you could do with a blower on the 550