64 Foot Times

[IC]

I thought that I'd post up this article on 64 feet times with permission from the author Alan Harris. Just having a look at my times I've found a selection of times recorded in one day at an event at Combe:

2.96
2.95
2.83
2.82
2.81

So my best 64 feet with a S70R with a stage 2 MTE and complete Feritta system for that day was 2.81. I'll have a look for other times. Anybody else got official times for 64 feet standing starts?

Iain

64ft TIMES

Allen Harris
It is increasingly common for timekeepers at speed events to set up additional sensors to trap the time taken to cover the first 64ft off the line, and a speed trap on the fastest part of the course. The value of a speed trap is obvious enough, but what can be learnt from the 64ft time? Clearly, cars with the best power/weight ratios should achieve good times, but more importantly it’s an indication of the level of traction achieved. The more wheelspin, the slower the acceleration, so the 64ft time enables the driver to check the impact of variations in starting technique. A lot also depends on whether you change up a gear in the first 64ft – if your first gear takes you past the sensor you’ll post a better time. The choice of 64ft may have something to do with the fact that a time of 2.0secs equates to an acceleration of 1g – an alluring target to aim for!


Or, if you prefer, here are the figures in graphical form:


The table illustrates the speeds achieved for different 64ft times, assuming constant acceleration. Make of it what you will! TIME
SPEED
2.0
43.6

2.1
41.6

2.2
39.7

2.3
37.9

2.4
36.4

2.5
34.9

2.6
33.6

2.7
32.3

2.8
31.2

2.9
30.1

3.0
29.1

3.1
28.2

3.2
27.3

3.3
26.4

3.4
25.7

3.5
24.9

[st5ve]

I was not sure of the purpose for 64ft times I get it now. I don't have all my 64ft times but the best one that I have a record of is 2.83 at the Dick Mayo Sprint Castle Combe.

This vid is an example of the timing equipment.

http://www.youtube.com/watch?v=f0o-XJaoCG8

[Ross9]

Never heard it described as 64ft times before, always 60ft, but I'm assuming it will be the same thing, all UK drag racing etc refers to it as 60ft at all strips so I assume your times IC will be a 60ft beam.

best I ever managed was 1.7-1.8 in my R32 GTR, fwd my best ever is 2.21 in my Rover turbo, managed a 2.4 in Jacqs T4, pretty sure she did a 2.3 on it once as well.

also pleased to see I was over 1g in the skyline coming off the line...I could well believe it.

[st5ve]

Originally Posted by Ross9

Never heard it described as 64ft times before, always 60ft, but I'm assuming it will be the same thing, all UK drag racing etc refers to it as 60ft at all strips so I assume your times IC will be a 60ft beam.

best I ever managed was 1.7-1.8 in my R32 GTR, fwd my best ever is 2.21 in my Rover turbo, managed a 2.4 in Jacqs T4, pretty sure she did a 2.3 on it once as well.

also pleased to see I was over 1g in the skyline coming off the line...I could well believe it.

I have heard about the T4 that is great figures she is doing the same time if not better than Evo's and Scoobies that both IC and myself compete against. Would that include reaction time

[t4 tony]

hello,please excuse my lack of racing knollage,but why 64ft ???

[IC]

Originally Posted by t4 tony

hello,please excuse my lack of racing knollage,but why 64ft ???

Hi, to quote a certain Dave Slater: "32ft per second per second, is acceleration due to gravity, so doing the 64ft times in two seconds means your'e pulling 1g IIRC" .

Iain

[Ross9]

Originally Posted by st5ve

I have heard about the T4 that is great figures she is doing the same time if not better than Evo's and Scoobies that both IC and myself compete against. Would that include reaction time

No, not inc reaction time. A FWD is never going to get 60ft times like EVO's etc, especially not one like Jacqs, approximately 400 bhp (most likely over) and FWD, it doesn't exactly hook up and go in 1st, especially at Crail in Scotland which is a rough disused airfield. Would love to get it on Avon or Santa Pod though and get some traction, see how it gets on.

At the same strip, Crail, my Skyline GTR did a 1.7 60ft, and a 12.6 @ 108 1/4mile off of that, my Rover could only do a 2.21 60ft, but a 12.8 @ 114mph 1/4 mile once it got grip and got going, and that was it 2 years before I sold it, it was much faster than that by the time it sold, it would still only have done a 2.1-2.2 60ft at best on crails surface, car weight and traction given from tyres is limited, once they grip then the pwoer comes into it. 4wd's can split the power between 4 points instead of 2, so they launch better, in reality my 13 year old 2 litre turbo rover would have made my R32 GTr skyline look like a milk float acceleration wise. Skyline was 340/350 bhp, Rover was 331 bhp, 296 lb/ft without gas, 380 bhp with gas. Skyline had 4wd losses and weighed 1450kg, rover had 2wd losses and weighed 1050kg.

Ross.

PS - once rolling it'd take a big bhp number in a scoob or evo to keep up with Jacqs t4, given the 4wd losses and extra weight, probably in the 450-500 bhp region at a guess.

[Chesh740R]

In a borrowed mostly stock 740 turbo i was achieveing 2.0 second 60fts the other weekend at santapod.

Certainly amused a lot of people at how well the thing hooked and kept its nose well in the air.

[Chris_C]

Similarly I was getting pretty much consistant 2.2secs in the 340 at the same day, shame she couldn't keep it up

[Chris_C]

Originally Posted by IC

Hi, to quote a certain Dave Slater: "32ft per second per second, is acceleration due to gravity, so doing the 64ft times in two seconds means your'e pulling 1g IIRC" .

Iain

No idea why... and it's an epic blast from the past, but was thinking about this the other day (more thinking that the numbers didn't add up and if I was nearly hitting 1g accelerating that I should have crossed the line much quicker than 15.8 @ 86mph )

Doing 64ft in 2 seconds surely can't be 1g, as gravity is 32ish ft per second per second.

Soooo, the first second, you have to cover 32 ft. In the second (2nd) second, you have to cover 64 ft (as speed is increasing 32ft per second, add another 32ft onto the first second), so total distance is 96ft in 2 secs to acheive 1g. Extrapolating back that'd give you... something like 1.6 seconds for a 1g average 64ft?

Or have I missed something?