335i driver does test-drive with M3

[lucid]

Originally Posted by bruce.augenstein@comcast.

OK, this is getting close to outright arrogance, and you guys don't even know what you don't know.

You don't know what the part-throttle characteristics of each engine are, and possibly even more important, you don't know what the rotational inertia effects are. Your quaint belief that a spreadsheet showing full-throttle torque at the drive wheels is hardly meaningful in this context, and your dismissal of the experiences of two (and possibly three) drivers in favor of a non-applicable spreadsheet really is arrogance.

I haven't driven a new M3, but my experiences with a couple of 335s shows that they are typical of today's street turbo engines in that they deliver a non-linear boost map when driven at part throttle. That is to say, half throttle, for instance, delivers more than half the allowable boost, so the car feels very responsive because it''s putting out a larger percentage of its max torque under those conditions.

There's also minor evidence that suggests the M3 is a little lazy at part throttle. I've read in a couple of comparison tests (in Car, and at least one other mag, the name of which escapes me), that the M3 is a little bit soft at low revs on the street compared to the RS4, yet in full-throttle roll-ons from low revs, the M3 is the quicker car, according to the acceleration results.

As far as rotational inertia is concerned, the first point is that it goes up as the square of the gearing, and the second is that in a given gear, 100% of the rotational inertia is right there with you, whether you're at part thottle or at full throttle. Therefore, at part throttle, the effects of rotational inertia are more apparant than when you're seriously legging it.

I'm willing to bet that because of gearing, the M3 has significantly more rotational inertia in first gear than the 335 does, and it's obviously more apparent at part throttle than at full throttle. It's also a bit heavier than the 335, which is another factor that's with you at 100%, all the time.

I'm with hwelvaar, footie and termigni on this one. Lucid and Swamp, you need to reconsider your position.

Bruce

See my post #37. I acknowledged that I built on steady state dyno runs, and brought up the response issue. The turbo car putting out a larger percentage of its max torque at half throttle does not mean that it will put out MORE than its max torque.

The full throtle charts are relevant because I am responding to the OP's "I prefer the torque of 335i for daily driving (and my 335i is still stock) - it makes your car real fast in daily traffic" statement. If you care about driving fast, which is what this statement seems to indicate, you drive close to or at full throttle. If you are in traffic, and do not care about driving fast or cannot do so, who cares about torque anyway?

In the same post, I also acknowledged that dyno runs at acceleration will result in different outputs, where the rotational inertia issues come to play. So, you don't know what I do or do not know Bruce.

The rotational inertia issues are open to discussion, but how severe do you think those differences are exactly? And are you saying that there is no correlation between the steady state dyno results and acceleration dyno results?

Yes, someone finally called me out on the weight difference, but that is like 5%. Not significant enough to give the 335 the upper hand.

And, again read my post #37. There are have been reports from owners on this forum who have expressed the opposite: that the car "feels fast" at any speed, including in traffic. So, I don't know what would happen to your driver opinion count if you were to search this site in detail.

As to the arrogance issue: the repsonses you copied were directed at termigni and I stand by mine. I welcome a technical discussion around this. I will even change my position if someone demonstrates that my analysis is incorrect and presents an alternative analysis. But when you start arguing solely on the basis of opinion and dismiss relevant data (he didn't even look at the data since he claims it came from a magazine), that's what you get.

[13eastie]

I would have the following subjective comments to make on this, based on the fact that I haven't driven the 335i, but have over 3,000 miles in the M3:

1. The throttle mapping makes a HUGE difference to the subjective impression of the responsiveness of the car and needs to be factored into any comparison, as well as the fact that, try as they might, most drivers simply don't have the pedal to the floor that much of the time. Then add in the traction control (or lack of it) and there's already a lot of things unrelated to the motor having a big impact on low-rev acceleration.

2. If rotational inertia is brought into the comparison, real numbers are needed (anyone?). Subjectively, the M3 loses revs very quickly, as evidenced by the need to be quite prompt with gear-shifts. I think the M3 motor has a relatively small moment of inertia, but I'm happy to be told otherwise.

3. Driving in London, the speed limit gets over 30 mph hardly anywhere. I'm sure lots of other places are not dissmilar. My drive to work averages less than 15 mph. It is simply not practical to suggest one needs to keep the revs over 4,000 revs or whatever - you'd be breaking the limit in any gear except 1st! Therefore, cruising around town in 4th or 5th, I'm not yet convinced either way, but I don't find it hard to believe the 335i might seem to offer more "oomph". But because of the points above, this subjective test would not really be proof of much. If you prefer the way a 335i drives, buy that car! When I have time I'm going to ask for a test drive to check this for myself.


(Epacy, did you mean a stock F-22 or a modified one?)

[sdiver68]

Originally Posted by lucid

The full throtle charts are relevant because I am responding to the OP's "I prefer the torque of 335i for daily driving (and my 335i is still stock) - it makes your car real fast in daily traffic" statement. If you care about driving fast, which is what this statement seems to indicate, you drive close to or at full throttle. If you are in traffic, and do not care about driving fast or cannot do so, who cares about torque anyway?

I think you misinterpret what the OP was saying. I take it to mean that when he is driving around at low-mid RPM's and wants that burst of acceleration, with the 335i it will pull harder. With the M3, it won't accelerate as quickly until it gets to higher RPM's.

Think of the same gear, roll-on, such as 30-50 or 50-70 tests. The 335i may very well beat the M3 is some if not all of these tests.

However, to your point, if the engine of each car is already in its ready for maximum performance RPM band, the M3 walks or runs the 335i at higher speeds. Both cars exceed available traction in the lower 2 gears, so at lower speeds traction is the limiting variable, not power.

Or do you really think the enthusiast M3 driver will cruise along at 6000RPM and 6 mpg all the time?

[Epacy]

Originally Posted by 13eastie

(Epacy, did you mean a stock F-22 or a modified one?)

Stock, that is how most 335 owners make their case.

[sdiver68]

Originally Posted by Epacy

That routine is getting old.
Leave it to a 335 owner to turn a harmless joke into another M3 v 335 pissing contest.

You said an owner would not agree, and I'm not pissing on anything, just getting the facts right. You can thank me and others like me for the M3's lower than anticipated price, BTW.

[lucid]

Originally Posted by sdiver68

I think you misinterpret what the OP was saying. I take it to mean that when he is driving around at low-mid RPM's and wants that burst of acceleration, with the 335i it will pull harder. With the M3, it won't accelerate as quickly until it gets to higher RPM's.

Think of the same gear, roll-on, such as 30-50 or 50-70 tests. The 335i may very well beat the M3 is some if not all of these tests.

However, to your point, if the engine of each car is already in its ready for maximum performance RPM band, the M3 walks or runs the 335i at higher speeds. Both cars exceed available traction in the lower 2 gears, so at lower speeds traction is the limiting variable, not power.

Or do you really think the enthusiast M3 driver will cruise along at 6000RPM and 6 mpg all the time?

The data demonstrate that you don't need to get up to 6000rpm to get the torque advantage in the M3. It already has more torque at the wheels than the 335 at 2000rpm. That is the main point of this argument.

Bruce is saying you only get that at full throttle. And I am saying, so what?

[Epacy]

Originally Posted by sdiver68

You can thank me and others like me for the M3's lower than anticipated price, BTW.

Ah, I see you are joking now. Very funny.

[swamp2]

Originally Posted by Epacy

I was talking about 335i owners admitting anything but a F-22 could beat their car.

[lucid]

Originally Posted by 13eastie

I would have the following subjective comments to make on this, based on the fact that I haven't driven the 335i, but have over 3,000 miles in the M3:

1. The throttle mapping makes a HUGE difference to the subjective impression of the responsiveness of the car and needs to be factored into any comparison, as well as the fact that, try as they might, most drivers simply don't have the pedal to the floor that much of the time. Then add in the traction control (or lack of it) and there's already a lot of things unrelated to the motor having a big impact on low-rev acceleration.

I'd say that's really a driver variable. I can cruise around and baby the throttle in the M3, and then jump into my 325 and gun it and drive around faster. Would that mean that I can now conclude the 325 feels faster because it has more torque? Of course not. That only means one of two things: I either don't want to drive fast, or I don't know how to drive fast.

I am not saying that's what you are saying, but that argument doesn't hold water in my mind.

Originally Posted by 13eastie

2. If rotational inertia is brought into the comparison, real numbers are needed (anyone?). Subjectively, the M3 loses revs very quickly, as evidenced by the need to be quite prompt with gear-shifts. I think the M3 motor has a relatively small moment of inertia, but I'm happy to be told otherwise.

Yes, as I mentioned earlier, we would need the data, but I have a hard time thinking the M3 will have significantly more rotational inertia.

[footie]

Originally Posted by lucid

The data demonstrate that you don't need to get up to 6000rpm to get the torque advantage in the M3. It already has more torque at the wheels than the 335 at 2000rpm. That is the main point of this argument.

Bruce is saying you only get that at full throttle. And I am saying, so what?

I am surprised that people are getting upset about the fact the 335i feels quicker on part throttle (town driving in other words), I think it's a plus for the M3 as it's now much easier the drive in these situations.

[gasman]

Originally Posted by Epacy

Ohh shit, hasn't this line gotten old by now.

It's always "if my car had this and this and this and this and this, then I would beat an M3. M3 is not worth the money suckas!!"

That routine is getting old.
Leave it to a 335 owner to turn a harmless joke into another M3 v 335 pissing contest.

Couldn't agree more. It's really, really sad. Now I'm confused. Which one should I get?

[footie]

Originally Posted by gasman

Couldn't agree more. It's really, really sad. Now I'm confused. Which one should I get?

Which ever amount you feel happiest paying for, both are great cars.

Though one does feel a bit quicker on part throttle and is quicker than a F-22.

[gasman]

You know...I have two great friends...one drives a 335 and the other an E46 M3. I have driven both and would have taken the E46 any day over the 335. IMO, there's no comparison.

[13eastie]

Originally Posted by lucid

I'd say that's really a driver variable. I can cruise around and baby the throttle in the M3, and then jump into my 325 and gun it and drive around faster. Would that mean that I can now conclude the 325 feels faster because it has more torque? Of course not. That only means one of two things: I either don't want to drive fast, or I don't know how to drive fast.

I am not saying that's what you are saying, but that argument doesn't hold water in my mind.

I'm speculating here, but if someone drives the M3 in Normal mode on a test-drive the same way that he drives his usual car (335i), it would not surprise me at all if the M3 seemed less responsive, because it is pretty easy-going in Normal mode. My argument is rather that the subjective impression of the test-driver would not be due solely to difference between the torque curves.

Originally Posted by lucid

Yes, as I mentioned earlier, we would need the data, but I have a hard time thinking the M3 will have significantly more rotational inertia.

Quite. It would not be surprised if it had less.

[E90ice]

Originally Posted by lucid

I'd say that's really a driver variable. I can cruise around and baby the throttle in the M3, and then jump into my 325 and gun it and drive around faster. Would that mean that I can now conclude the 325 feels faster because it has more torque? Of course not. That only means one of two things: I either don't want to drive fast, or I don't know how to drive fast.

I am not saying that's what you are saying, but that argument doesn't hold water in my mind.



Yes, as I mentioned earlier, we would need the data, but I have a hard time thinking the M3 will have significantly more rotational inertia.

Two of my friends have owned E46 M3's for years, before switching over to the 335. And both of them are saying exactly what the OP is stating: That the M3 FEELS slower at lower rmps than the 335.

I am assuming, since you live in the US, that you have NOT driven the new M3. So, why are you speculating so much? How do you know, based on some math, how the new M3 will FEEL or even DRIVE for that matter?

[southlight]

Originally Posted by 13eastie

2. If rotational inertia is brought into the comparison, real numbers are needed (anyone?). Subjectively, the M3 loses revs very quickly, as evidenced by the need to be quite prompt with gear-shifts. I think the M3 motor has a relatively small moment of inertia, but I'm happy to be told otherwise.

Indeed. If losing revs is an indication for rotational inertia the M3 must have a way smaller amount of it. M3 loses revs way quicker than a 335i, which keeps its revs for quite long after releasing throttle. As you said one has to be quick in doing shifts on the M3 (Wow, another advance over DCT: One can judge the rotational inertia ).


Best regards, south

[sdiver68]

Originally Posted by lucid

The data demonstrate that you don't need to get up to 6000rpm to get the torque advantage in the M3. It already has more torque at the wheels than the 335 at 2000rpm. That is the main point of this argument.

The data demonstrates no such thing, and neither do the reviews. I hope you aren't referring to your 1st gear chart, which is not applicable to this discussion. Both cars easily exceed traction in 1st gear.

[13eastie]

Originally Posted by sdiver68

I think you misinterpret what the OP was saying. I take it to mean that when he is driving around at low-mid RPM's and wants that burst of acceleration, with the 335i it will pull harder. With the M3, it won't accelerate as quickly until it gets to higher RPM's.

There is simply no evidence to support this claim, though. Supposing you are interpreting the OP correctly, this is nothing more than a subjective impression of a car he has barely driven, and with which he has almost certainly not become familiar with the M-settings. Low-mid revs mean quite different things in the two cars also...

Originally Posted by sdiver68

Think of the same gear, roll-on, such as 30-50 or 50-70 tests. The 335i may very well beat the M3 is some if not all of these tests.

This is nonsense. My car will not even be at the red-line in 2nd gear at 70mph. The cars would not be able to do this test optimally in the "same" gear.

Originally Posted by sdiver68

However, to your point, if the engine of each car is already in its ready for maximum performance RPM band, the M3 walks or runs the 335i at higher speeds. Both cars exceed available traction in the lower 2 gears, so at lower speeds traction is the limiting variable, not power.

Possibly (I have lost traction while accelerating in a straight line in 3rd gear on the motorway several times) but, people drive the whole car (not just the motor), and I doubt traction in the 335i beats that in the M3 (I'm thinking tyres, suspension, MDM and LSD) Therefore the subjective experience of the 335i accelerating harder would likely be quite wrong.

[sdiver68]

Originally Posted by 13eastie

There is simply no evidence to support this claim, though. Supposing you are interpreting the OP correctly, this is nothing more than a subjective impression of a car he has barely driven, and with which he has almost certainly not become familiar with the M-settings. Low-mid revs mean quite different things in the two cars also...

Yes there is, you choose to ignore it

Originally Posted by 13eastie

This is nonsense. My car will not even be at the red-line in 2nd gear at 70mph. The cars would not be able to do this test optimally in the "same" gear.

Except for the fact that this test has been SOP for car testing since I can remember, I've subscribed to C&D since 1982 or thereabouts...and that's the whole point that neither car will be at redline. Do the test in 4th or 5th gear, 50-70, whichever gear is selected for normal fuel efficient driving at the lower speed. It measures the subjective "Driver's" TQ, which is different from the dyno measured TQ.

Originally Posted by 13eastie

Possibly (I have lost traction while accelerating in a straight line in 3rd gear on the motorway several times) but, people drive the whole car (not just the motor), and I doubt traction in the 335i beats that in the M3 (I'm thinking tyres, suspension, MDM and LSD) Therefore the subjective experience of the 335i accelerating harder would likely be quite wrong.

Again, you don't understand the comment, nor the reasons for the test.

[sdiver68]

Originally Posted by footie

Which ever amount you feel happiest paying for, both are great cars.

Though one does feel a bit quicker on part throttle and is quicker than a F-22.

Actually, they both are at typical car acceleration speeds and distances.

Now a Navy jet such as the F-35 hooked up to an Aircraft Carrier catapult....now we are in Top Fuel dragster territory...

[lucid]

Originally Posted by 13eastie

I'm speculating here, but if someone drives the M3 in Normal mode on a test-drive the same way that he drives his usual car (335i), it would not surprise me at all if the M3 seemed less responsive, because it is pretty easy-going in Normal mode. My argument is rather that the subjective impression of the test-driver would not be due solely to difference between the torque curves.

Yes, I bet this would happen to anyone. I am sure one needs to get used to the car in order to learn how to drive it to its potential, which would involve getting used to the throttle mapping and when to floor it, etc. I agree that is a subjective issue since it is not coupled to the performance limits of the car.

Originally Posted by 13eastie

Quite. It would not be surprised if it had less.

Yes, I can't see how can an engine that revs up to 8400 rpms will have more rotational inertia than another engine that revs much less. I am sure BMW engineers have spent significant time on reducing this for the M3.

[lucid]

Originally Posted by E90ice

Two of my friends have owned E46 M3's for years, before switching over to the 335. And both of them are saying exactly what the OP is stating: That the M3 FEELS slower at lower rmps than the 335.

You somehow missed the rather small detail that we are talking about the E92 M3 here.

I am not responding to your other comment because it has been answered.