DavidM

The August issue of "Car and Driver" has a head to head compariosion between the S2000, 350Z Roadster, Z4 3.0, Boxster 2.7 and TT-Roadster. Not a bad read and the S2000 comes up on top. Here are some numbers to compare:

0-60mph (96.5kph)
- Z4 3.0 = 5.3 sec
- S2000 = 5.4 sec
- 350Z Roadster = 5.5 sec
- Boxster 2.7 = 6.0 sec
- TT Roadster = 6.9 sec

0-120mph (193.2kph)
- Z4 3.0 = 21.5 sec
- 350Z Roadster = 22.6 sec
- S2000 = 23.6 sec
- Boxster 2.7 = 24.3 sec
- TT Roadster = 33.6 sec

0 - 1/4mile (400m)
- Z4 3.0 = 14.0 sec @ 99mph (159.4kph)
- S2000 = 14.1 sec @ 99mph (159.4kph)
- 350Z Roadster = 14.3 sec @ 99mph (159.4kph)
- Boxster 2.7 = 14.6 sec @ 98mph (157.8kph)
- TT Roadster = 15.2 sec @ 91mph (146.5kph)

5-60mph (96.5kph)
- Z4 3.0 = 5.9 sec
- 350Z Roadster = 6.3 sec
- Boxster 2.7 = 6.7 sec
- S2000 = 7.0 sec
- TT Roadster = 8.3 sec

Lap time (1.53miles)
- S2000 = 1:10.8
- Z4 3.0 = 1:11.5
- 350Z Roadster = 1:11.6
- Boxster 2.7 = 1:11.9
- TT Roadster = 1:16.4

The 5-60mph times are very interesting and very much as expected for the S2000. Though, the 5-60mph for the Z4 3.0 is only 0.5sec slower than it's 'fully launched' 0-60mph time ... must be one incredibly torquey ingine.

dhess

Very impressive acceleration numbers from the Z4.

How does it do it? Especially bettering the S2k 0-120mph acceleration even though it has an inferior power to weight ratio.

My guess would be better drag coefficient and larger area under the curve on a dyno?!?

Austblue

Damn I read the top and seen that you were talking about the Z4 but then forgot because you wrote Z3 3.0 on the times

14.1 is a good 1/4 time for the stock S I wonder if that was a best time or an average? My guess is the former.

I guess like any other experiment there are so many variables that aren't controlled that the results that come so close shouldn't really be taken as a clear win.

That is of course unless the S2000 wins

DavidM

Very impressive acceleration numbers from the Z4. How does it do it? Especially bettering the S2k 0-120mph acceleration even though it has an inferior power to weight ratio. My guess would be better drag coefficient and larger area under the curve on a dyno?!?

The drag coeffiecient has something to do with it, but it's not that much better than the S2000's. Z4 = .36cw while the S2000 = .38cw (all with the roof up). It's really the engine that gives it all tha 'go'. Look at the specs:
- power = 170kW @ 5900rpm
- torque = 300Nm @ 3500rpm
- weight = 1395kg

and compare it to the S2000:
- power = 176kW @ 8300rpm
- torque = 208Nm @ 7500rpm
- weight = 1269kg

So, as you can see, the Z4 3.0 has a measly 7kW less (at the peak) and has a massive 92Nm (ie. 44%) torque advantage over the S2000. Not only that, but look how low it has all that torque ... the power curve in the 3.0L Z4 must be so fat it's not funny. The 5-60mph times above seem to confirm that.

So, in other words, it's the 'large area under the power curve' that gives it all that go. Not too dissimilar to a WRX (older shape in particular) ... same weight as the S2000 and 'only' 150 - 155kW and it does not give an inch to an S2000 in a drag up to about 130kph.

ps. Sports Auto tested the Z4 3.0 recently as well and here are the perfromance numbers from there:
- 0-60kph = 3.1 sec
- 0-100kph = 6 sec
- 0-160kph = 15.3 sec
- 0-180kph = 19.6 sec
- 0-200kph = 27.5 sec
- 80-120kph in 4th = 6.4sec

S2000's figures from the same publisher (but different date of the test):
- 0-60kph = 3.0 sec
- 0-100kph = 6.2 sec
- 0-160kph = 14.8sec
- 0-180kph = 19.2 sec
- 0-200kph = 24.5 sec
- 80-120kph in 4th = 7.2sec

Oddly enough, the S2000's top end was a bit better here, but these cars were not tested back to back.

Damn I read the top and seen that you were talking about the Z4 but then forgot because you wrote Z3 3.0 on the times

Sorry about that ... fixed now :-) Though, here are the Z3 3.0 numbers from Sports Auto (different day of the test to the Z4):
- 0-100kph = 6.2 sec
- 0-160kph = 14.8sec
- 80-120kph in 4th = 6.6sec

14.1 is a good 1/4 time for the stock S. I wonder if that was a best time or an average? My guess is the former.

It's probably the 'best time' with 1 person on board. Though, I'm not 100% sure what methodology the US mags use for their testing.

Iggy_Type_R

BTW the article can be read online at:
http://www.caranddriver.com/article.asp?se...article_id=6846

On another point, I picked up the Z4 brochure at BMW Sydney last nite. I went in to get the deposit back, and they said "Please, come in and drive it and then we'll chat". So besides having a test drive booked for monday, I looked thru this brochure, and it has a 0-100 time of 5.9 in there. Funny how 0-60mi/h is 5.3s ... does it take 0.6 seconds to cover 2mi/h? hmmmmm ...

AusS2000

Different ways of testing. The <insert car manufacturer here> method is one occupant, a whiff of petrol and keep going until you get your best time. The Australian standard is driver and passenger, half a tank of petrol, and the average of a run in each direction.

Iggy_Type_R

But that's the thing, the C&D got a MUCH better time than the manufacturer.

AusS2000

Oh!

Iggy_Type_R

OK ok I get the point... me being pedantic.

DavidM

looked thru this brochure, and it has a 0-100 time of 5.9 in there. Funny how 0-60mi/h is 5.3s ... does it take 0.6 seconds to cover 2mi/h? hmmmmm

For one thing what AusS2000 said has merit. Each manufacturer (and Magazine) have their own testing method. For instance the German manufacturesr (like Porsche, BMW and Merc) often publish the 'average' or the 'guaranteed' result (ie. they do 10 runs and publish the slwowest). Therefore, German manufacturer 'claims' are often pesimistic and often bettered by independent testers (in particular US magazines who run 1-up and publish the best run). German manufacturers do the same thing with power - they often publish the lowest possible figure for your engine (ie. when they say 150kW, then your engine will have at least that) while other manufacturers publish the 'average' and sometimes even the 'best' result from the sample-group.

Anyway, I'm getting sidetracked - back to the 0-100kph in 5.9sec BMW claim. That claim seems to be a direct copy of their US/UK brochure. So if I am correct, then that claim is meant to be "0-60mph (ie. 96.5kph) in 5.9sec" and the Australian dealers just changed the 60mph to 100kph in the brochure because it's a common misconsepion that the 60mph = 100kph.

Last of all the difference between 60mph and 100kph is about 0.3 - 0.4sec for a car of this calibre. Look at it this way - you need to cover extra 3.5kph and if you can do 100 - 110kph in 1sec (or the closest interval without a gear-change) then you need 3.5sec (on average) to accelerate 'extra' 3.5kph. So the Australian dealer's 'claim' should be more like 6.2secs for 0-100kph.

Though, none of the above discounts the effect of different conditions which account easily for 1sec differentiations in the 0-100kph times. Chances are that when the Z4 3.0 will be tested localy, that the times (with 2 on-board) will be anywhere between very-low and very-high 6s (maybe even in low 7s).