What's the top speed on your car?

[Unit 5302]

Originally posted by dinomite:
Aerodynamics is a bigger factor than weight in top speed, but think of it this way: What is *your* top speed? now put on a 50 lb. backpack.....

dinomite, you are fighting a losing battle.

Let me illustrate.

1998 Panoz AIV Roadster. 305hp 2500lbs.
0-60 4.6sec, 1/4 mile 13.3@101.5, Standing mile 35.1sec@129.9, Top speed 134.0mph.

1998 Porsche 911 Carrera. 296hp 2900lbs.
0-60 4.9sec, 1/4 mile 13.4@105.2, Standing mile 33.0@150.3mph, Top speed 174.8mph.

1998 Aston Martin DB7. 335hp 3800lbs.
0-60 5.7sec, 1/4 mile 14.3@98.1mph, Standing mile 35.2@142.4mph, Top speed 163.5mph.

Breaking down those performance's on Ford's AZ 5mi Testing track you can see the trend. HP vs Weight vs Aerodynamics.

The Panoz, by far the lightest of the 3 managed to outaccelerate both the Porsche and the Aston Martin (which get's killed thanks to ta 3800lb curb weight) in both 0-60, and 1/4.

If you look at the 1/4 mile trap speeds though, you can see the Porsche is pulling on hard on the Panoz at the end of that stretch. The Aston Martin is still getting stomped.

At the end of the Standing mile, it's a totally different story though. The Panoz is now dead last amongst the three and the Aston Martin is overtaking the Porshe in accleration from the end of the 1/4 to the end of the standing mile with it's additional 40hp. Dispite being 900lbs heavier. That span is where the real transition from weight being the major factor to aerodynamic drag being the factor is the most noticeable.

Then as you can finally see, the Porsche's eventual terminal velocity beats the Aston Martin because of aerodynamics, and the Aston Martin dispite a 1300lb deficit, KILLS the Panoz, which hits a brick wall at about 130mph. You can argue that the Aston Martin has more top end because of more hp, but the Porsche has less hp than either, yet weighs 400lbs more than the Panoz, and it beats both.

From 0-60 power:weight is the most important feature, again for the 1/4 mile, but it begins to get tight at the end, between the 1/4 mile and the standing mile, drag becomes more important and weight goes out the window. By the end, drag wins the contest, even versus significant hp differences.