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### Giddy-Up!

Posted: **Wed Oct 31, 2012 7:26 pm**

by **Rope-Pusher**

**TWIN-TURBO PONY**
Ford is beginning to use production components on some of its race cars, like this twin-turbocharged Mustang Cobra Jet Concept thatâ€™s at the SEMA show. Its turbos are based on units that are used in the Focus ST, but are 40 percent larger, allowing it to run an eight-second quarter mile.

http://media.ford.com/article_display.c ... e_id=37294
I'm not sure that my Jeep is fast enough to do an 8 second 1/4 mile - even with a running start at whatever top end it is aloud to run at.

### Re: Giddy-Up!

Posted: **Wed Oct 31, 2012 7:47 pm**

by **theholycow**

I think my Buick could do an 8 second quarter mile...anyone care to do the terminal velocity math from the other thread?

### Re: Giddy-Up!

Posted: **Wed Oct 31, 2012 11:01 pm**

by **IMBoring25**

The constant speed for covering a 1/4-mile in 8 seconds is 112.5 MPH.

This is 165 ft/s. At a standing start with constant acceleration, the final velocity must be twice this to average this speed. Thus, 330 ft/s in 8 seconds, 41.25 ft/s^2. This is 1.28 G acceleration. Even without accounting for drag, free-fall is not sufficient for a standing-start 8-second quarter-mile.

### Re: Giddy-Up!

Posted: **Sat Nov 03, 2012 5:45 pm**

by **Squint**

IMBoring25 wrote:The constant speed for covering a 1/4-mile in 8 seconds is 112.5 MPH.

This is 165 ft/s. At a standing start with constant acceleration, the final velocity must be twice this to average this speed. Thus, 330 ft/s in 8 seconds, 41.25 ft/s^2. This is 1.28 G acceleration. Even without accounting for drag, free-fall is not sufficient for a standing-start 8-second quarter-mile.

Ah, sweet sweet correct math. I mean, at least it looks correct. I read it, I didn't grade it.