Erik

The foglights are taken away because of the need form more air into the engine. I like the fogligths for the looks, the practical effect is limited.

W210

Interesting I thought the fogs were removed to cool the brakes, but the engine?

I just like to have maximum illumination when driving the beast in the wet at night.

Erik

Not to cool the engine, but to give it air.......
I visited the M factory 2 weeks ago and got this information. I was also told how much more air this engine needed vs the 545i engine, I have forgot but the difference was HUGE.....

reggid

thats why it uses so much fuel

Gustav

Its double air as the as much as the 545i. Same goes for the 545i.

http://www.bmwm5.com/articles/m5e60w...tures/luft.jpg

M5KILLR

come again in english?

ndabunka

Don't lawyers "make up" their own premise and then surround them with plausible situations in an effort to make them "appear" as facts?

- Just joshingg you. Don't take too much offense.

c55m8o

hogully mogully ... you did =not= just say that...[~!~] I'm late to this thread, I know. But I just read that and I can't believe it. This type of mis-information serves noone.

Listen, I have a C43 and just put a 5.4L motor out of a 2001 E55. Click here (I'm 98c43amg on that board). Just say'n that to introduce myself that I am a die hard MB/AMG owner/enthusiast and not a BMW loyalist wanting to give you a hard time.

so with that said ... sorry, but you are so wrong...

YES, if one is able to hold torque fairly level as rpm is increased, the HP rating continues to go up. Using #s, here's the irrifutable facts or how HP is calculated:

hp = torque * RPM / 5252

Take an imaginary engine that produces 400ft/lbs. of torque regardless of RPM up to, let's say 8000rpm. Then produces 0 ft./lb @ 8001 rpm (just to make the example simple; yes I know it's not how a "real" eingine will operate ... bear with me)

@ 5000 rpm, hp = 381
@ 6000 rpm, hp = 457
@ 7000 rpm, hp = 533
@ 8000 rpm, hp = 609

...HP continues to go up...

now, if torque starts falling off @ say 1ft/lb. as rpm increases by 1rpm, look at what happens: (let's use 6000rpm as the point torque starts falling off)

@ 6000 rpm, torque = 400 ft/lb. : hp = 457 (456.96 actually)
@ 6001 rpm, torque = 399 ft/lb. : hp = 455.9
@ 6002 rpm, torque = 398 ft/lb. : hp = 454.83
@ 6003 rpm, torque = 397 ft/lb. : hp = 453.77
@ 6004 rpm, torque = 396 ft/lb. : hp = 452.7

...HP is going down...
jumping ahead

@ 6398 rpm, torque = 2 ft/lb. : hp = 2.44
@ 6399 rpm, torque = 1 ft/lb. : hp = 1.22
@ 6400 rpm, torque = 0 ft/lb. : hp = 0

Sorry, but it's a FACT. One of the single most important aspects of how much HP an engine is producing is its redline and torque curve -- as a friend of mine (speedybenz) likes to put it, how many times the engine can apply that twisting force (torque) to the crankshaft per second, thus how much work it can do.

vraa

C43AMG, I think you are just confirming what E55AMG99 just said. You cannot raise rpm, and expect hp to continue to rise, unless you are driving with the imaginary engine you stated above.

E55AMG99

Hey C43,
Nice job on the 55 transplant. Kudos.

The point of my post is that people mistakenly think they can simply raise the RPM limit of an engine and do nothing else to it and somehow magically get it to produce more HP. This is not the case as you illustrated in your more realistic second example.

I still stand by my post. The formula HP = Torque*RPM/5252 has nothing to do with an engine's *ability* to make more HP. It has to be designed into it in the first place.

c55m8o

I have to go back to the lead-up to the post.... Well no ... I mean, the point is of course, you're only raising redline if you can ensure torque does not fall off too quickly. If you raise the RPM and can continue to produce torque [you're able to increase input and output airflow of the engine, can provide the additional fuel to keep up with the increased airflow, and valvetrain is able to linearily handle higher RPMs], which is not an impossiblity and does not require the imaginary engine I used in my example, you can and will be raising your HP.

A good saying I once read is all things being equal, it's better to make torque @ a high RPM then a low RPM, because then you can take advantage of =gearing=. It's the trueth.

OK, sorry then. I guess I was reading into it [or not reading the intent] and assuming he meant RPM just did not matter.

To continue playing with numbers tho, if you raise redline and torque falls off @ say 1ft/lb. as rpm increases by 20rpm, not every 1rpm, look at what happens: (let's use 6000rpm as still the point torque starts falling off)

@ 6000 rpm, torque = 400 ft/lb. : hp = 457
@ 6020 rpm, torque = 399 ft/lb. : hp = 457.34
@ 6040 rpm, torque = 398 ft/lb. : hp = 457.7
@ 6060 rpm, torque = 397 ft/lb. : hp = 458
@ 6080 rpm, torque = 396 ft/lb. : hp = 458.4

The higher the RPM you can achieve while producing enough torque to keep the HP rating going in the right direction, the longer the engine can pull in one gear ... so you can use shorter gears and take advantage of its greater torque multiplication, because the engine can pull longer to a higher rpm without running out of legs ... that's why the current M3 can achieve the accel rates that it does with unimpressive sub 300 ft/lb amount of torque. And it's not that light of a car. But it pulls to 8K. If it can pull to 8k rpm, and another car can only pull to 6k rpm, the M3 can pull 33% longer then the other car, so can use gearing with higher gear ratios. That's major.

c55m8o

OK, sorry. I definitely didn't get your intent.

E55AMG99

No worries. Your posts are 100% correct by themselves.

Greg

Little

99% of the time you would shift a stick car 600-700rpms higher than the peak hp rpm numbers anyway, guareenteed to pick up a a few tenths in the 1/4 mile by doin this. I own an '01 E430 and love the car, looks, ride everything. But its just not sportier enuff at all. I drove the 545i maybe a week or ago, and man that thing is just awesome. But its basically the same thing, its comparing apples to oranges in my mind. The bimmer, sick turning ability, and to ME very aggressive looking. Also steering and everything is just rock solid. Now the benz, killa soft ride with excellent acceleration. Drop this car and throw on some rims, damn sexy. I just sit back and laugh at everyone that wanna prolly whip a G U N when someone steps up and says my car is better blah blah , lololol.

BTW, i just watched the video of the race.... i'd have to say the M5 just nudged out the Benz, i would have liked to have seen them go a little further and see if the M5 ran out of steam.

Rock

I understood almost all of your post but you lost me with this line.

E55AMG99

Read the fine print. "Your Mileage May Vary"
First, optimum shift points are not dictated by the transmission type but by gear ratios, TC stall speed and engine output. Second, there are no guarantees that your formula is correct.

My 1966 327cu 350HP Corvette peaks at 6000 RPM and fastest times down the track for it were at 6100 RPM shifts. Anything higher than that and the valves float! The difference in 1/4 mile time between 5500 and 6100 is barely 2 tenths. This is how I raced in 2 brackets with the same car.

If memory serves me correctly, the HP of the 430 motor peaks at 5800 RPM and fastest times down the track were achieved with 5900-6000 RPM (factory setting) shift points.