DavidM

This is more for the Ausie owners. Here in Australia we have a few car magazines and no matter how many tests (and how many different cars) they do, the times for 0-100km/h are way slower than what you're getting in the US magazines for the 0-60m/h sprint. The disparity is sometimes as big as 2secs (which is huge). For instance take the S2000 - in US mags it regularly is clocked at 5.5secs for the 0-60m/h sprint. I think the fastest one I've seen in the US mag is 4.9secs (missprint or not) but 5.3 is more common for a fast time there. Now here we've had about 4 to 5 comparisons with S2000 in it and so far the best time produced has been 6.6 secs 0-100km/h. They did complain about the clutch and did say that S2000 has more potential but still - in all 5 tests this is the best time achieved. Meanwhile they have had Boxter S at 5.7secs, M5 at 5.2secs, M3 at 5.8, S4 at 6.2 secs and even Boxter2.7 at 6.4secs. I have even seen a TypeR Interga clocked at 6.9secs. Anyway, I can't explain why the S2000 seems so much slower then other cars here (maybe the weak clutch gives) but I can explain in part why the cars here are slower than in the US. It comes to 2 factors:
1) 0-60m/h is really 'only' 0-97.5km/h. So car's here have to accelerate another 2.5km/h. Does not sound like much but check all the specks - it accounts for good 0.3secs at that speed (for a car like S2000).
2) In US your pertol has 100 octane while here the 'standard' petrol that you can buy for the S2000 has 96 octane. This is 4%less 'strenght' in the petrol than you have in the States. We do have 'special' fuel (here called 'Shell Optimax') that has 98 octanes but I'm sure that the magazines do not use that. So taking into account that the magazines here are using 96 octane fuel - that means that the cars they are running are another 4% slower than in the States -that is another 0.3secs.

So what we have here is 0.3secs lost with fuel and 0.3secs lost with the 'extra' 2.5km/h to reach. This gives us (taking 5.5secs as your usual 0-60m/h time):
5.5 + 0.3 + 0.3 = 6.1secs. This is the time I'd hope that the magazines here can reach - I do believe that it can run that time here from my experience with the S2000 here. Also, 6.1 secs fits very well with all the other cars they've tested. Let's hope they run some more test in the near future and really show the true acceleration potential of S2000.

ps. For anyone running 'Optimax' (98 octane fuel) - your car should be about 0.1 secs quicker than that 'cos you have 2% more power at your disposal (ie. 180kW instead of 176kW).

pps. I still cannot see (even with adding 0.6secs onto your time) how they can get low 5s with the S2000 for the 0-60m/h sprint. That would mean that a time closer to 5.7secs should be possible here for the 0-100km/h sprint.

ppps. There is point (3) also but that does not apply to the S2000. Some cars require an extra shift into 3rd gear for the 0-100km/h sprint while they might not need this shift for the 0-60m/h sprint. This would lose another 0.5secs or so, but it does not apply to the S2000.

john f

I don't know about the rest of the U.S. but in Florida we don't have anything close to 100 octane gas.
Hell, I would love to get that 98 ocatane you have.

We usually have 93 ocatane as the best available, and 91 oftentimes.

John

2kturkey

David, a very good summary. However, I still believe the reason we are seeing slow 0-100k times is because the mags are not side slipping the clutch but doing a normal release - this is also why they are reporting weak clutch problems (as per my experience with high rev normal clutch drops).

There is something else I have heard of which the US mags do and this is called 'power shifting' where the driver changes up a gear without releasing the throttle (and in some cases without using the clutch either). I am not sure how it is done in a car but it is is easy on a motorcycle where you can change gears anytime without the clutch (except from a stop of course).

On the topic of Octane ratings, after my flight today (flying Piper Warriors out at Lilydale) I had to refuel the plane and spoke with the owner of the airport. As you may know AVGAS is rated at 100/130 Octane and sells for $1 litre (for aircraft) but $1.50 for auto use (racing etc.). Apparently they way they get the Octane rating up is to use lots of lead (not good for cats) but I was wondering whether the OZ Stook will take advantage of the higher Octane (or whether you need higher compression or ECU changes).

I'd be interested to find this out and also know who is prepared to have their vehicle act as a mule for this fuel - coz if you want it I am sure I can get it!

UK Paul

DIAL IN 15,000 kM AND YOU COULD EASY NOTICE ANOTHER 0.5 SECONDS OFF THE TIMES.

Other factors can include launch surface and temps. another couple of tenths could be had up here if yuor testing at 10 DegC instead of 30 DegC.

so fuel ~~ 0.3s
62 mph ~~ 0.3s
temp ~~~~~0.2s
break-in ~~~~~0.5s.

1.3 seconds. 0-60 in 5.3 da naaaaaaa.

Some of the other test car might not loosen up as much as the S2000 does apparently, I think this could the biggest factor?

DavidM

2kturkey, as far as I know, the S2000 has it's own knock sensors in the engine and changes the timing of the engine according with the 'quality' of the fuel. As far as I know, the engine in the S2000 in Australia is exaclty the same engine that they've got in the US or UK. There's no 'detuning' of the engine for Australian models. I'd like this confirmed but this is what I know. Therefore, the better the fuel for the S2000, the better engine. btw, same thing aplies to my father's R8. It runs fine on the regular Premium (96 octane) but has more power with the Optimax (98 octane) ... HVS claims that it is somewhere between 265-270kW with Optimax.

About 'power shifting' - it's not a new concept and is possible with almost any car - you just need to time your shift well so the revs are reasonably matched. Sometimes it accidentally happens to me when I'm driving and do a real quick shift without properly pressing the clutch. The gear 'slides' in reasonably eazy and there's only a little 'crunch'. Though, this can account for no more than 0.1sec of the time so doesn't really make much difference in the 0-100km/h time. Though, on a track, where you have a lot of gearchages, it can get you a good second on your lap time.

One last thing I forgot to ask, what are the rules/criteria for the 0-60m/h sprints in the US? Here is Australia the car is always run with 2 people on board and full tank of fuel. Not only that but the car is run both ways (several times) then the best runs in each direction are picked and the average of these 2 times is then printed as the 0-100km/h time. How does that compare to the practice in the States or UK?

cdelena

All octane numbers are not equal. There is a RON measurement and a MON and in the US the pumps consumers use are by law labeled with the

MX5dude

DavidM,

I also think that the octane gas rating is related to faster acceleration/higher top speed. For instance in a portuguese auto-magazine a Audi TT Coupe Quattro (225hp) was tested with the following results:
With 95 octane gas (the lowest available)
240kmh (150mph) real top speed
With 98 octane superunleaded gas:
245kmh (153mph) real top speed
On a portuguese tv news channel there was a great "Boy racers" reportage? covering some high-speed racing going on on public roads. There was a camera inside a S2000 (one of the car

Sev

[QUOTE]Originally posted by DavidM
[B]
One last thing I forgot to ask, what are the rules/criteria for the 0-60m/h sprints in the US? Here is Australia the car is always run with 2 people on board and full tank of fuel. Not only that but the car is run both ways (several times) then the best runs in each direction are picked and the average of these 2 times is then printed as the 0-100km/h time. How does that compare to the practice in the States or UK?

Jay Li

[QUOTE]Originally posted by MX5dude
[B]
American owners don

swiss2k

the best time in switzerland is 5.8 (0-100km/h), with 98 octane gas...