I don't know about that, the dyno shows a 20 ft/lbs jump in torque at 6000rpms, an 18% increase that doesn't show up in the times. In the higher gears I can buy that the increase in wind resistance cuts into the 18% increase, but under 62mph (~100kph) I find it harder to believe. But my road and track numbers don't give me the level of detail needed to dispute the german numbers...

 

I don't know about that, the dyno shows a 20 ft/lbs jump in torque at 6000rpms, an 18% increase that doesn't show up in the times.

From what I see in the Honda published power/torque plot, the torque jump/increase looks more like 15% with the 2nd cam. Still, pressuming 20% increase in torque, and ignoring air resistance alltogether, would indicate ~0.2sec improvement for the 2nd cam in the the 2nd gear (over a20kph interval). This small a variation might be too hard to pick up in the numbers posted, but one could argue that they do show it ...

1. For 2nd gear, 2nd cam cicks in at ~60kph, and in the 60-80kph increment the 'slower' times show a 0.2sec improvement.

2. For 3rd gear in the 100-120kph increment (again where the 2nd cam kicks in), both the quicker / slower times show a 0.4 and 0.2sec improvements respectively.

3. In 4th gear this occurence is harder to pick up as we don't have numbers that show the increment from where the 2nd cam kicks in. Though, there does seem to be some improvement in the 120 to 140kph increment which includes the change to the 2nd cam.

Considering the torque curves, it makes perfect sense, but it's still interesting to see the numbers translated into seconds!

Yeah, I found it interesting myself ... and that's part of the reason why I was looking for actual acceleration times.

For the 06 Mx-5 we'll have to use 30-50 since 2nd gear tops out at 52.

FYI. The year 2000 S2000 (ie. AP1), for which we have the acceleration numbers, reaches 106kph in 2nd gear (ie. 66mph) ... so it will reach 60mph in 2nd. Though, for the sake of your example I don't think it's a problem as US also has different gearing for the MX5 than what we do have here. The NC MX5 here (ie. in Australia) reaches just over 60mph (ie. 97kph) ... as we have different final drive.

So I think your example / numbers stand.

Honda 1.6 seconds for 20km jump in 2nd gear. Mazda 1.8 seconds for 20km jump in 2nd gear

So that should be something like 12% advantage to the S2000 even when going from a ~3000rpm.

ps. I'll try and find some local MX5 numbers to see how they compare with the ones you linked to.

 

I found some info/data on an MX5 from one of the local magazines/tests as local NC MX5 have a different final drive (ie. slightly taller gearing than in the US). They did not publish data anywhere as detailed as Autorevue, but still clocked/listed some rollong start times (which seem on a quicker side). Tough comparing numbers from different mags, but just get some idea, here they are listed together with the S2000 times (from Autorevue ie. fast / slow):

In 3rd gear:
MX5 - 80 - 120kph (ie. 3,900 to 5,900rpm) = 5.6sec
S2000 - 80 - 120kph (ie. 5,000 to 7,500rpm) = 4.8 / 5.2sec

In 4th gear:
MX5 - 80 - 120kph (ie. 3,000 to 4,500rpm) = 7.2sec
S2000 - 80 - 120kph (ie. 3,900 to 5,800rpm) = 6.9 / 7.5sec

In 5th gear:
MX5 - 80 - 120kph (ie. 2,700 to 4,000rpm) = 8.6sec
S2000 - 80 - 120kph (ie. 3,100 to 4,700rpm) = 8.8 / 9.6sec

In 6th gear:
MX5 - 80 - 120kph (ie. 2,100 to 3,200rpm) = 11.1sec
S2000 - 80 - 120kph (ie. 2,700 to 4,000rpm) = 11.3 / 11.8sec

So in 3rd gear (where the S2000 get's into Vtec for 1/2 the run), the S2000 has a serious advantage (whether looking at the quick or slow times) ... no surprise here.

In 4th gear the S2000 does not come into Vtec, and it looks like it would be pretty close at speeds/revs below Vtec (ie. below ~120kph). The data we have here shows the S2000 a tad quick with the quicker times, and a tad slower with the slower times. This is probably the best indication of what would happen between these 2 cars at relatively low / pre-Vtec revs as the 4th gear (and lower) are pretty similar.

The next two / higher gears (ie. 5th and 6th) are much taller in the S2000 and therefore it's not a direct/fair comparison here. ie. S2000 is geared to reach much higher speeds. Still, these figures are showing an advantage to the MX5 in these gears (and below 5000rpm). So one would expect the MX5 to be pulling away in either 5th or 6th gear at speeds below 120kph (ie. ~75mph).

ps. The rate of acceleration for the NC MX5, to cover 20kph increment looks to be:
- in 3rd gear = ~2.8sec
- in 4th gear = ~3.6sec
- in 5th gear = ~4.3sec
- in 6th gear = ~5.6sec

Compared to the S2000 (when talking speeds below 120kph, and looking at the quicker numbers):
- in 3rd gear = ~2.4sec
- in 4th gear = ~3.4sec
- in 5th gear = ~4.4sec
- in 6th gear = ~5.7sec

 

The myth has been busted!

 

gotta love rolling start races in our S's, esp from 10-40mph rolls! Thats how I was able to stay ahead of an STi a few times, until he caught me as I approached 100mph

 

I can't prove this becase my car is no longer stock, but when it was stock, the front of the car would rise an inch or more when I hit VTEC at WOT. If there is not a significant increase in acceleration at 6,000 RPM, what causes the front of the car to lift?

 

I think their may be a law against using the words "smart" and "street race" in the same sentence, but in a street race, the smart racer makes the other guys play his game. In the S2000, that means racing from a roll, so that you're running at 6,000 RPM in first or second when the race starts. That's how I managed to outrun Tripper's R-33 Skyline GTR, and Tripper simply gave up before he caught back up.

If you start below 28 MPH (with an AP1) you've got to diddle the clutch or wait, and entier one gives away any advantage you could have had against a quicker car.

 

[QUOTE=TwinTurbo540,Mar 10 2008, 09:14 AM]The myth has been busted!

 

RED, you hate this thread, don't you?

I can't get the tone in the typing, but I'm trying to gently prod and give you a hard time.

 

LOL, no, I don't hate the thread; I just don't understand the question.