IS-F vs M3 power to the road

[chicagobimmerboy]

In a recent test by Automoblie Magazine the Lexus IS-F was able to put 333 horse power and 318 lb-ft of torque to its rear wheels on the dyno. Question is; what does the M3 achieve, I though it had an 8% powertrain loss or close to that. Anyone know for sure?

Be interesting to see what the C63 puts down.

http://www.automobilemag.com/reviews/lexus/0710_2008_lexus_is-f_dyno_chart/index.html

[ChrisFastM3]

It depends on the dyno. Some offer higher numbers and some not so much.

[BNR32]

"The IS-F is rated at 416 hp and 371 lb-ft of torque at the engine - and it delivered 333 of those horses and 318 lb-ft of torque to its rear wheels."

http://img210.imageshack.us/img210/5306/15945426sx8.jpg

:fighting0030:

[K3N R3D]

This should be in the VS section

[rai]

which one is quicker?

end discussion.

[consolidated]

which one is quicker?

end discussion.

C63 at any on-ramp
M3 for rest of the world full of curves

[sayemthree]

the M3 should put about 368 HP to the wheels - 11 5 loss. Its also a M engine, not just a Yamaha hyped up engine from the Lexus 460.

the M3 has a much better HP per liter output than the Toyota

[malter2.0]

"The IS-F is rated at 416 hp and 371 lb-ft of torque at the engine - and it delivered 333 of those horses and 318 lb-ft of torque to its rear wheels."

http://img210.imageshack.us/img210/5306/15945426sx8.jpg

:fighting0030:

i think it is clear thats at the hub. you can also see it from the picture.

realistically, e9x m3 will should put ~340-350whp

[ToothDoc]

Some guy did a 344 HP to the wheels on an IS-F with only 700 miles. They did it in 5th gear (6th is 1:1). That's using Fujita's Dyno. You can search for it at one of the Lexus sites. My guess is that they'll both have similar dyno numbers as far as HP goes but torque will be higher on the IS-F. I'm expecting about 15% loss for Lexus and don't fool yourself.

[ToothDoc]

I forgot to finish the last part - I doubt BMW makes a tranny significantly more efficient. Just previous generations of BMW understating HP and most other cars overstating HP led to the discepancies in transmission % issues IMO.

[bruce.augenstein@comcast.]

the M3 should put about 368 HP to the wheels - 11 5 loss.

Why is this? Is this a hopeful opinion or fact based?

Its also a M engine, not just a Yamaha hyped up engine from the Lexus 460.

Other than fanboyism, is there any practical significance to this?

As you may or may not know, Toyota knows a whole bunch about building good engines which last a very long time, and Yamaha, like Porsche, has a rich history of doing engineeering projects for other companies.

the M3 has a much better HP per liter output than the Toyota

Other than fanboyism, is there any practical significance to this?

Nothing wrong with making a lot of power per liter, but it only matters when it actually matters. As discussed in another string, the LS3 Vette engine weighs about the same as the M3 engine, and occupies about the same amount of real estate while allowing a lower hood line because it's not as tall as the M3 motor. It also makes more power (and a ton more torque), and may in fact have better bsfc numbers. If this engine were installed in an M3, the M3 would be faster, handle a smidge better, weigh the same and almost certainly get better mileage when geared correctly for its torque curve (3.08s out back).

Not to take anything away from the M3 engine. I'm a fan myself, because it seems to break new ground in terms of how flat and wide the torque curve is.

The Lexus guys had their Lexus priorities in mind with the IS-F, and a stratospheric power curve isn't part of that scenario. It seems to be an admirable first effort, and in fact an admirable effort period.

Probably not a lot of crossover buyers between these two offerings, though. Each manufacturer is serving their constituency as best they can, and these are two very different constituencies, indeed.

Bruce

[gbb357]

^^ All very good points Bruce. I don't understand why people are dissing Yamaha. It has developed many high performance engines in the past and present, not to mention that they make high performance superbikes. In terms of the M3's engine having a higher output per liter, it does'nt seem to really matter that much since they're both equal in straightline performance and the ISF is able to equalized that with a much higher torque output. I'm guessing that in the handling department where the M3 will really show it's superiority. Hopefully we'll soon find out when one of these carmags or TopGear will compare these two.

[ZachV]

the M3 should put about 368 HP to the wheels - 11 5 loss. Its also a M engine, not just a Yamaha hyped up engine from the Lexus 460.

the M3 has a much better HP per liter output than the Toyota

It is from the LS600LH, not the 460. And the extra liter allows for 76 more TQ than the ///M.