DavidM

Would someone happen to have the acceleration numbers for a (stock) S2000 where a hard launch is not involved? ie. where the car was eased off the line, cluth fully engaged, and then thottle to the floor from somehting like 5kph?

I would love to see the numbers in 10kph increments to see how it would compare to something like a 2.0L NC MX5/Miata (as the MX5/Miata does feel pretty strong in the below 4000rpm range).

Also I would be happy to see similar numbers but in 2nd gear ie. from ~10kph and in 10kph inreaments all the way to the top of 2nd gear. This way there would be no gear-change involved so it would clearly show the car/engine's accelerative power.

I'm interested in partucular in the 2.0L (ie. F20c) engine. Numbers from G'tech or any other timing device would be greatly appreciated.

RED MX5

When you're accelerating hard in an S2000, you're only below 6,000 once, for a short time, in first gear. After you hit red line in first, you are right at 6k RPM in second, so acceleration below 6k only matters in first gear. Except for the launch itself, which of course varies widely, you can get a very good estimate of the acceleration given a dyno plot, and fudge factors for drag. A while back we had a thread were this was done; Have you seen the thread?
(I can probably track it down for you if you missed it.)


Best way to "race from a roll" is to start at 6k in first or second gear.

smurf2k

get a dyno graph, convert the RPM to MPH using gear ratio, and integrate the torque curve to compare

since both are 2.0 NA motors, they generally behave the same...except that since we high higher redline we take advantage of torque multiplication and output more torque for longer... so i dont think miata has any advantage anywhere at all

DavidM

When you're accelerating hard in an S2000, you're only below 6,000 once, for a short time, in first gear.

Yes, I know, but that is exactly what I'm interested in. Also I'm interested in acceleration in 2nd gear from very low revs (ir. ~1000rpm).

I'm interested in the actual, real-world numbers, not estimates / speculations. Anyone able to help here?

Thanks in advance.

ace123

Since you don't have any numbers yet, here are some rag numbers for 5-60 times to start from....

MY04 S2000:
MY07 MX-5:
[QUOTE=http://www.caranddriver.com/reviews/hot_lists/car_shopping/droptop_depot/2007_mazda_mx_5_power_retractable_hardtop_grand_to uring_short_take_road_test]C/D TEST RESULTS:
Zero to 60 mph: 7.0 sec
Zero to 100 mph: 20.2 sec
Street start, 5-60 mph: 7.8 sec
Standing

DavidM

Since you don't have any numbers yet, here are some rag numbers for 5-60 times to start from


Thanks Ace123. Would be great if they published the times in 10kph (or mph) increments as I'd like to see if the current 2.0L MX5 is any slower before the S2000 climbs to 6000rpm+.

But insteresting thing is that the S2000 looses 1.5sec in the spring to 60mph without a hard launch, while the MX5 looses only 0.8sec. Considering that there is 1.6sec difference in the 0-60mph time, it shows that 1/2 of the accelerative advatage that the S2000 has was removed when the 'hard' launch was taken out of the equation.

smurf2k

not that interesting if you think of the obvious differences in characteristics of the 2 engine

RED MX5

If the gearing is close, then your thinking seems correct. MX5 should be quicker through first gear from 5 MPH to redline. The plots below show why this is so.

While you can't compare dyno plots done on different days in different places directly, the difference shown below is "typical." I don't have gearing information on the MX5, but regardless of the gearing, it's clear that it's all over as soon as the MX5 has to shift into second. MX5 will clearly pull much harder at any speed IF the gearing is the same. The Mazda makes more torque across most of its power band than the S2000 makes at it's peak (but look at the huge difference in power once the S2000 hits it's stride).





Calculations based on dyno plots aren't perfect, but they do eleminate some of the biggest sources of error, including the driver and other test specific conditions. Calculations will tell you what the car can do, rather than what some particular driver can do with the car.

RED MX5

And the dyno plots above should make that crystal clear.

GT_NFR

where does the 150wtq come from? is that from a mazdaspeed miata?