1-foot rollout. What's hiding? [Archive] - Cherokee SRT8 Forum

: 1-foot rollout. What's hiding?


maansy
01-22-2011, 09:34 PM
I have been searching for information regarding the 1-foot rollout. some cars has this option from factory and it intended to make the car perform better in 0-60 and in 1/4.
I also read that 1-foot rollout invented because street tires really suck from a dig and looks like our jeeps fall in the same example.

Can this manually achieved or our jeeps?what's the trick if anyone know?

thanks

m4xm1l10n
01-22-2011, 10:52 PM
I thought It's measured by letting the car roll one foot before mashing the gas .. Lots of test Magazines like to use it . But is this an option on cars ??? Guess I'm lost here .

srt8ftw
01-22-2011, 11:26 PM
always thought it was just slowly rolling around one foot and then hitting it...

jkalbin
01-22-2011, 11:33 PM
I think what you mean is one of these rolled-out on the ground next to the Jeep at the drag strip....

http://kroger.daytona500.com/images/gallery/FruitByTheFoot_Packaging.jpg

If it helps, I got an extra .3 in the 1/4 :D

lol, jk

maansy
01-22-2011, 11:37 PM
I thought It's measured by letting the car roll one foot before mashing the gas .. Lots of test Magazines like to use it . But is this an option on cars ??? Guess I'm lost here .

The new 2011 cts-v has it. They claim:
0-60 is 4.2
0-60(1-foot rollout) is 3.9

StangSlayerMA
01-23-2011, 12:31 AM
The new 2011 cts-v has it. They claim:
0-60 is 4.2
0-60(1-foot rollout) is 3.9


What they mean is that they roll off the line and then punch it to achieve that 0-60 time. If they punched it from a dead stop, the tires would spin yielding a slower 0-60 time. Its something the driver does, not a feature on the vehicle.

m4xm1l10n
01-23-2011, 07:57 AM
Thanks for clearing that out Phil , I thought I was going crazy he he

nyjoed
01-23-2011, 08:09 AM
yea mee to i was like "i want one" lol

robjeep
01-23-2011, 08:20 AM
The new 2011 cts-v has it. They claim:
0-60 is 4.2
0-60(1-foot rollout) is 3.9

I wondered how they got the 60 time so low on that cts-v. I bet even 4.2 is questionable with normal drivers with stock tires.

waumo
01-23-2011, 10:36 AM
The 1 foot rollout has to do with how the staging photo eyes work at the dragstrip. Not being a dragstrip driver I don't fully understand it but it gives you a rolling start on the 1/4 mile if you understand how to use it.

I don't think it is appropriate for 0-60 times though because it is supposed to be ZERO to 60 not rolling to 60.

a990dna
01-23-2011, 11:34 AM
I would think 0-60, 0-1/8 mile and 0-1/4 mile can be obtained from a roll or standing start...

The difference would be the elapsed time.

If I recall correctly, at the drag strip, a "deep stage" (top staging lights off) can get you there quicker because of the shorter measured distance to the finish line. The downside is a potential red light and losing the race. But it doesn't matter if you're not racing.

.

SMG
01-23-2011, 02:02 PM
Courtesy of Edmunds Inside Line: How We Test Cars and Trucks (http://www.insideline.com/features/how-we-test-cars-and-trucks.html)


A Few Words About Rollout

The term "rollout" might not be familiar, but it comes from the drag strip. The arrangement of the timing beams for drag racing can be confusing, primarily because the 7-inch separation between the "pre-stage" and "stage" beams is not the source of rollout. The pre-stage beam, which has no effect on timing, is only there to help drivers creep up to the starting position. Rollout comes from the 1-foot separation (11.5 inches, actually) between the point where the leading edge of a front tire "rolls in" to the final staging beam triggering the countdown to the green light that starts the race and the point where the trailing edge of that tire "rolls out" of that same beam, the triggering event that starts the clock. A driver skilled at "shallow staging" can therefore get almost a free foot of untimed acceleration before the clock officially starts, effectively achieving a rolling-start velocity of 3-5 mph and shaving the 0.3 second it typically takes to cover that distance off his elapsed time (ET) in the process.

We believe the use of rollout for quarter-mile timed runs is appropriate, as this test is designed to represent an optimum drag strip run that a car owner can replicate at a drag strip. In the spirit of consistency, we also follow NHRA practice when calculating quarter-mile trap speed at the end of the run. So we publish the average speed over the final 66 feet of the quarter-mile run, even though our VBOX can tell us the instantaneous speed at the end of the 1,320-foot course, which is usually faster.

On the other hand, the use of rollout with 0-60 times is inappropriate in our view. For one, 0-60-mph acceleration is not a drag-racing convention. More important, it's called ZERO to 60 mph, not 3 or 4 mph to 60 mph, which is what you get when you apply rollout. While it is tempting to use rollout in order to make 0-60 acceleration look more impressive by 0.3 second, thereby hyping both the car's performance and the apparent skill of the test driver, we think it's cheating.

Nevertheless, some car magazines and some automobile manufacturers use rollout anyway and fail to tell their customers. We've decided against this practice. We publish real 0-60 times instead. But in order to illuminate this issue and ensure we do justice to every car's real performance, we've begun publishing a clearly marked "with rollout" 0-60 time alongside the primary no-rollout 0-60 time so readers can see the effects of this bogus practice.

a990dna
01-23-2011, 03:50 PM
So "rollout" is the same as a "deep stage" and the difference can be 0.3 from 0-60. That's not a secret, the concept has been around and used in drag racing since staging and timing lights were employed.

However a deep stage doesn't take into consideration all the other variables that play into running consistent ET's...

I believe the manufacturers will use whatever means necessary that will produce the best results.

The journalists are there to keep everyone "honest" so to speak.

I can't deep stage and manipulate my 0-60 times using my performance gauges on the EVIC... and neither can the manufacturers or journalists. Therefore maybe the 0-60 times on the EVIC are more realistic for everyday driving.

I guess when posting times we should all say 0-60 in 4.3 (0.3).

EDIT: after reading that article closer maybe it's the opposite. A shallow stage can reap .3 qiucker ET? .. doesn't seem possible. I was always told to deep stage to get the best results.

.

awdls2
01-23-2011, 04:32 PM
roll out is the same as a shallow stage, basically u just barely try to get the 2nd stage light to come on. so u have a little "jump" before the timer starts