0-60 4.9sec! WTF!!!

[nullspace]

Originally Posted by bruce.augenstein@comcast.

That turns out not to be the case.

Car & Driver, Road & Track and Motortrend all post their acceleration times (all acceleration times) with a one foot rollout. That's how you get down to a 4.1 second 0-60 time, for instance.

Given perfect weather, a perfect surface and your best launch skills (no matter who you are), there's no possible way you're going to get a 4.1 second time out of your M3 when measured from a dead stop. The difference is very close to a half second with cars at this level of performance on street tires.

Bruce

They don't, and they are very clear about it. I even watched the Motor Trend video about their testing procedure today to make sure I wasn't remembering wrong. The very clearly state that they don't use rollout. Car and Driver and Road and Track have published similar articles in the past.

Of course, if you have some source for this info, I'll gladly admit I'm wrong. I'm not trying to spread misinformation or anything. But a quick search on their sites for the relevant articles showed just the opposite.

[bruce.augenstein@comcast.]

Originally Posted by nullspace

They don't, and they are very clear about it. I even watched the Motor Trend video about their testing procedure today to make sure I wasn't remembering wrong. The very clearly state that they don't use rollout. Car and Driver and Road and Track have published similar articles in the past.

Of course, if you have some source for this info, I'll gladly admit I'm wrong. I'm not trying to spread misinformation or anything. But a quick search on their sites for the relevant articles showed just the opposite.

Would you give me a pointer, please? Can't find it.

Edit: I did in fact find a test procedures video, but this one never addressed the issue in question.

Thanks

[TLud]

Bruce is exactly right. The major American car mags employ a 1-foot roll out in their straight line acceleration testing. Since nullspace cited Motor Trend as his reference, the following is a quote from an article Motor Trend itself published with respect to the GTR:

Originally Posted by Motor Trend

Employing our customary one-foot rollout and SAE weather correction (it slows the car down by 1.1 percent today)...

However, whether one test or the other is more "real world" is up for debate. Racing someone off the line (or even a formal timed run at a drag strip) will involve a roll out.

Shaun Bailey, an editor at R&T, shed some more light on the subject when specifically asked whether R&T and other mags employ the rollout (link):

Originally Posted by Motor Trend

Oh, yes...

If it was up to me we wouldn''t do this, but it''s something of a legacy in the , so we do it
for consistency.

One foot roll out as it s called stems from the world of
drag racing. We are talking about measuring quarter-mile acceleration, and that
is what NHRA drag racing is all about, so we don t want you to think we re
making all this up for no reason.

A quarter-mile drag strip is 1320 feet of acceleration zone.
Timing starts when the car trips the lights at the beginning, and stops timing
when it crosses a light beam at the 1320 mark.

So you buy a Honda Civic Si, drive it to an NHRA drag strip and
do a run. This means you drive the car up to the Christmas tree of lights, and
follow the procedure for staging. Which means you roll the car forward until the
stage lights are turned on. When you leave the line, the timing doesn t start
until the light beam re-connects. And this is the problem. A car rolls roughly
a full foot before timing starts. This foot takes on average 0.3 seconds.

The foot for all you nerds who want to know, is roughly the
distance across a round wheel when you measure it horizontally from the height
that the photo-cell is mounted on the drag strip wall. The NHRA limited front
wheel sizes because someone had the great idea of running a taller wheel, and
thus getting a bigger jump on acceleration before the timing started.

Before everyone gets their panties in a bunch let me say
that all North American magazines test acceleration this way. It is the
standard. Our testing is designed to give identical results as those that would
be achieved at any NHRA drag strip.

[nullspace]

Originally Posted by TLud

Bruce is exactly right. The major American car mags employ a 1-foot roll out in their straight line acceleration testing.

I stand corrected then. I guess there is some conflicting information out there, so I won't claim to know for sure either way.

[bruce.augenstein@comcast.]

Originally Posted by nullspace

I stand corrected then. I guess there is some conflicting information out there, so I won't claim to know for sure either way.

Unless you can come up with the pointer to the M/T video where they claim no rollout, there is no conflicting information out there save yours.

Bruce

[TLud]

Originally Posted by bruce.augenstein@comcast.

Unless you can come up with the pointer to the M/T video where they claim no rollout, there is no conflicting information out there save yours.

Bruce

+1

[IS350]

Isn't the DCT good for 2 tenths quicker 60mph times? Also, I wonder if the added weight of the 19s would actually produce slower times vs. the 18s?

[Nik1203]

It is not easy starting with the M3, I did several tests with NokiaN95-8GB, Connecto32 BT and RaceChrono.

It is not reliable but the result is excellent:




Starting at 2500g/m modulation of gas in first gear.

[MysticBlue]

Originally Posted by IS350

Isn't the DCT good for 2 tenths quicker 60mph times? Also, I wonder if the added weight of the 19s would actually produce slower times vs. the 18s?

19's are not heavier than the 18's.

[BMWI6]

Originally Posted by M-Maika

+3,

I´m Portuguese!!

+4 I'm Colombian

[MVEED3]

Originally Posted by Nik1203

It is not easy starting with the M3, I did several tests with NokiaN95-8GB, Connecto32 BT and RaceChrono.

It is not reliable but the result is excellent:




Starting at 2500g/m modulation of gas in first gear.

Nice. Looks like I need to buy a new cell phone.


Allen

[Bimmer Nerd]

Originally Posted by BMWI6

+4 I'm Colombian

+5

i am georgian !!!