[chonko]

Just thought I might share this with you guys. Pardon me if it has already being posted before.

HP from engine is 306, dyno result is 268= 87.5% efficiency
Torque from engine is 277, dyno result is 231 ft.lbs=83.40% efficiency

http://www.dragtimes.com/2006-Lexus-...aphs-8856.html

[foofighter]

that's some pretty decent numbers

[F32Fleet]

like to see a 330 compare.

[Ghunger]

You might notice, the run listed as #1 is the baseline run, the #2 run appears to be with a Dual Exhaust. The base IS350 appears to be 246hp 212ft/lb.

[Joe Bimmer]

Here's another 350, with similar HP numbers as the baseline run on the other car. Only upgrade is an intake inlet pipe -- stock airbox and filter remain.

http://www.dragtimes.com/Lexus-IS350-Timeslip-9020.html

[alpinewhite3]

the 246 hp # seems about accurate...80% efficiency for toyota drivetrain

The bmw will be closer to about 88-90% efficiency producing about 225-230hp.

[chonko]

Originally Posted by agent0986

the 246 hp # seems about accurate...80% efficiency for toyota drivetrain

The bmw will be closer to about 88-90% efficiency producing about 225-230hp.

I am yet to see a plot, but word has it that BMW is running around 93.5%.

[alpinewhite3]

Originally Posted by chonko

I am yet to see a plot, but word has it that BMW is running around 93.5%.

wow that would result in 240hp at the wheels. Is that possible ?

[new2the3]

In the engine section of this site, a few California members were nice enough to post up their dynos from a recent dyno get-together. The manual 330i put down in the range of ~210 and ~195 for the auto.

[akhbhaat]

Originally Posted by chonko

I am yet to see a plot, but word has it that BMW is running around 93.5%.

While the numbers would indicate that BMW's cars run in the realm of 90-95% efficiency, this is due to a problem with the numbers, and not a magically efficient drivetrain.

BMW, Lexus, and everybody else use the same basic drivetrain configuration (to such an extent that almost all of them subcontract the production and even the design of components such as transmissions), and most of the losses are due to friction within the mechanical portions of the drivetrain itself. Some companies have slightly more efficient drivetrains, though the use of more efficient alternators and other parasitic devices (like the electric water pump in the E90), but it's not so significant that it could account for 10% of a difference or more.

The bottom line is that virtually all manufacturers underrate the stated output of their engines to some extent for a number of reasons. BMW in particular has been known to significantly underrate - if a given car or model appears to have an unusually small drivetrain loss (a very efficient RWD drivetrain will lose 15%), it is almost certainly due to the fact that the engine is making more power at the crank than the manufacturer claims.

[Ghunger]

Originally Posted by Ethirtynine

Where are you getting 88-90% from?

http://www.e90post.com/forums/showthread.php?t=22625

You do realize the atmospheric conditions will affect the outcome greatly right? The difference between the Lexus and the BMW dyno sheets here is like 15 degrees and we have no idea what the barometric pressure and humidity are for the Lexus test. Must compare apples to apples. Same day, same dyno test would be best.

[chonko]

Originally Posted by akhbhaat

While the numbers would indicate that BMW's cars run in the realm of 90-95% efficiency, this is due to a problem with the numbers, and not a magically efficient drivetrain.

BMW, Lexus, and everybody else use the same basic drivetrain configuration (to such an extent that almost all of them subcontract the production and even the design of components such as transmissions), and most of the losses are due to friction within the mechanical portions of the drivetrain itself. Some companies have slightly more efficient drivetrains, though the use of more efficient alternators and other parasitic devices (like the electric water pump in the E90), but it's not so significant that it could account for 10% of a difference or more.

The bottom line is that virtually all manufacturers underrate the stated output of their engines to some extent for a number of reasons. BMW in particular has been known to significantly underrate - if a given car or model appears to have an unusually small drivetrain loss (a very efficient RWD drivetrain will lose 15%), it is almost certainly due to the fact that the engine is making more power at the crank than the manufacturer claims.

Thanks for pointing that out to me.

[ksfrogman]

Cool stuff. Thanks for posting this. That LMS aftermarket exhaust seemed to increase the wHP by 22, a 9% increase. Ambient temp was also only 69 degrees and about the same despite the different run dates.

The link to the California dyno runs is

http://www.e90post.com/forums/showthread.php?t=22625

and in my sig.

[ALPINE6SPD]

interesting