The M Division sells its soul

[FStop7]

Originally Posted by footie

For those that lag will be an issue then maybe you should tell Ferrari this, because they are under the impression that it's a thing of the past.

Subject : Enzo replacement to get V8tt

Considering the F40 is still considered one of the most epic drives ever, and that the 911 turbo is a performance icon, anyone who doubts turbocharging looks kind of silly.

[MKParris]

Originally Posted by FStop7

Considering the F40 is still considered one of the most epic drives ever, and that the 911 turbo is a performance icon, anyone who doubts turbocharging looks kind of silly.

dead on.

[mkoesel]

Originally Posted by Radiation Joe

Seek and Ye shall find. The numbers for thrust may be off because I pulled the dyno numbers from a car mag. The idea that you should shift before redline in the higher gears is obvious, though.

Thanks Joe, much appreciated. Would have been nice have this when we picked up the car in Europe so I would have known not to rev it so high in 3rd and 4th on the autobahn.

One question: are you saying it was obvious the thrust curves for the higher gears would intersect without even having this graph? If so, I am curious to learn why that was obvious to you. It certainly was not to me.

So for non-illegal speeds (well, in the US, or most of it) shifting at redline is correct for max acceleration. I think a lot of people on e90post are pretty misinformed (or at least were in the past from what I know) as I recall people contending that the car could or should be short shifted due to the falling power/torque at higher RPM.

Oh and yes we've gone pretty OT here, but I think this discussion is interesting in that it demonstrates the different characteristics of different types of engines. Joe, if you get a chance you ought to plot these curves for BMW's N63 and S63 4.4L V8s. I think it'd be interesting to see how they compare.

[mkoesel]

Originally Posted by FStop7

Considering the F40 is still considered one of the most epic drives ever, and that the 911 turbo is a performance icon, anyone who doubts turbocharging looks kind of silly.

Speaking of, according to what I could find, the F40 redlined at 7750 RPM while the 997 turbo redlines at 6750 RPM.

Now, who thinks that any future turbocharged Ferrari will redline at less than 8000 RPM? The F3x M3 on the other hand may be more likely to be similar to the porsche in that respect, though we won't know for some time.

I think most people on this forum would probably take the GT3 over the turbo in an heartbeat. Of course, if you throw in the GT2, then things probably become more cloudy.

[FStop7]

Originally Posted by mkoesel

I think most people on this forum would probably take the GT3 over the turbo in an heartbeat. Of course, if you throw in the GT2, then things probably become more cloudy.

I dunno, the new turbo is about as fast as the original 997 GT3 around a track yet it is a lot more civilized and has absolutely insane acceleration. It's a rocket. I would have a hard time choosing between the two, all of that power is pretty intoxicating.

[mkoesel]

Originally Posted by FStop7

I dunno, the new turbo is about as fast as the original 997 GT3 around a track yet it is a lot more civilized and has absolutely insane acceleration. It's a rocket. I would have a hard time choosing between the two, all of that power is pretty intoxicating.

You're right - the new .2 is particularly insane. If I had to choose between the two, I personally would have no choice but to go with a turbo since I need a back seat (even the tiny back seat the 911 has). On the plus side, I could then get PDK and get a convertible.

What if the choice was GT3 RS vs. turbo? Would you still go turbo?

[Radiation Joe]

Originally Posted by mkoesel

...
One question: are you saying it was obvious the thrust curves for the higher gears would intersect without even having this graph? If so, I am curious to learn why that was obvious to you. It certainly was not to me.

...

I wouldn't presume the shift points. I was just saying that it becomes obvious after looking at the figure that one should shift nearer to 6200 rpm in 4rd gear and higher (6500 in 3rd gear).

[swamp2]

Indeed the speed vs. wheel torque (or force) diagrams are very useful. They come right out of CarTest and include all speed/rpm dependent losses as well. The examples RJ showed (more or less high rever/M3 vs. low rever/335i) show exactly if you shift before redline or not. Recall, at any given speed the maximum acceleration will come in the lowest gear possible which is the same as maximizing the power at that speed (not THE max power though). I've posted a few of these in the past as has mixja.

[mkoesel]

Originally Posted by Radiation Joe

I wouldn't presume the shift points. I was just saying that it becomes obvious after looking at the figure that one should shift nearer to 6200 rpm in 4rd gear and higher (6500 in 3rd gear).

Ok, right, I get you.

[footie]

I think what these graphs show is that the more torque the engine makes in relation to it's horsepower determines when it's most beneficial to shift. Take the M3, shifting as near as be damned at the redline yields maximum acceleration but the likes of a diesel where they produce far more torque than hp and usually their peak power is a good 500#750rpm below the redline it holds no advantage chasing the redline before shifting.

Though as these graphs will show the advantage holding even to like of the M3 right to the limit isn't that great compared to shifting 4-500 revs prior.

[ersin]

Darn, I go away for the weekend and miss Radiation Joe's graphs. Nice job Joe.

footie,

I think the biggest reason for shifting 4-500 rpm before redline is so that you don't hit the rev limiter (or overrev in older cars). I always try to do this since I am not good enough to be able to get right at redline without hitting the limiter. Of course, the rest of you are so much better you may as well shift as high as possible.

[swamp2]

Originally Posted by footie

I think what these graphs show is that the more torque the engine makes in relation to it's horsepower determines when it's most beneficial to shift.

But the LS3 Vette is an obvious counter example. It has a much larger ratio of torque to power as compared to the M3, it also has a peak power much less than redline. Nonetheless max acceleration is still achieved by shifting at redline (in all gears except one).

[ruff]

There is wisdom in judging a person by their actions rather than their words. If possible separate oneself from BMW marketing speak and look at the facts.

M marketing makes the claim for lighter weight, well how about upwards of 5400 lbs for the latest and greatest M track "sport activity vehicles." New Technology=weight savings in the car industry is nothing but a fallacy. Fact: every year the vehicles get heavier and every year we have more wonderful technology to gloat about. The vehicles are getting heavier because Americans, in particular, tend to be fat and spoiled. They need all the luxuries available in their car because it is too much work to lift a finger and shift their sports car manually. Fact: Manual transmissions are lighter more reliable and less expensive than automatics/DCT's.

Cars are also getting heavier due to all the burdensome regulations and ridiculous lawsuits imposed on car companies couched under the politically correct term of "safety."

How many here complain about the weight of their BMW's but their car is loaded with options? How many of us complain about are own weight but haven't went a day without a meal since are parents sent us to bed without dinner. How many of us complain about not getting paid enough in our profession but spend more than we make on nonessentials? How many of us complain about politicians but will vote them out of office the second they tell us the truth that were going to have to suffer and make actual sacrifices. Can't have it both ways. Da Nile is not just a river in Egypt.

Merry Christmas fellow sports car hard cores.