skydivepaul
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| posted on 28/7/06 at 10:54 PM |
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0-60 times
a bit of information for anyone who is interested in 0-60 times.
I have just analysed my video footage from elvington sprint last saturday (to see why i didnt win )
i tried 3 different launch rpm settings, 8000, 9000 and 10,000 and each one resulted in 60 mph coming up in 5 seconds dead. my car weighs 480KG
without driver and i am using A539 yokohama rubber. i recon you could shave half a second off that time with list B tyres like A048 or R888.
My best time around the sprint course was 82.39 which ws enough to place me 5th. i had a theoretical lap time of 79.50 if i added up all the best
sector times posted which would have put me 2nd. must try harder next time
http://www.smartideasuk.com
http://www.smartmapping.co.uk
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RazMan
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| posted on 29/7/06 at 10:05 AM |
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I am not sure about bec times but a cec similar to mine with a 3 litre V6 producing 330bhp and weighing 700kg ....... 2.9 seconds! 
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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OX
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| posted on 29/7/06 at 10:32 AM |
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im sure the z cars mini does it in under 3 seconds on there website,but iv slept since i last saw the clip so i could be making the whole thing up 
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furyblade35
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| posted on 29/7/06 at 02:09 PM |
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Just thought I would add a bit to this as it is something I spent quite a bit of time doing when I was running BECs. Busa's and blades
mostly.
The DigiDash (ETB one) uses either the pulses from the prop/wheel to kick off a 0-60 run.
Now if you pickup speed from the propshaft then you will travel in general, worst case a fraction of a metre before getting a pulse which will start
the timer. (Only uses this technique when start speed == 0) otherwise it uses the recorded speed to start the timing e.g. when speed >=
start_speed.
Going off the prop or wheel means we pretty much start timing when the car starts moving. Prop is better, but both methods would work as well is you
lined the magnet/bolt up just before the trigger for each run....
Now the standard calibration of the digidash (ETB) from the DigiTools calculator actually gives values that will make your speedo read 3% of reading
over speed. You can tweek this out by chanigng your speedo_cal by 3%. THis also assumes you have put all your tyre sizes, regrowth of tyre under speed
etc etc to make sure you are truly calibrated.
Otherwise, the timer will stop sooner than it should, e.g. your 0-60 times would be quicker than expected.
Then you need a flat surface, no wind, standing water etc and give it some bananas.
For later digidash systems you can plug in a GPS, a fast one, e.g. greater than 5Hz to start using GPS to give true vehicle velocity. But then you add
another £150 when you may as well say,
"well it feels bl**dy quick" and buy a pint.
pocket the £148 for the NOS conversion!
IMHO.
Cheers,
Al.
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furyblade35
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| posted on 29/7/06 at 02:14 PM |
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forgot to add:
My blade cars:
520 kilos with me in it.
110bhp at rear wheels.
Generally 4.5s
My Busa cars:
570 kilos with me in it.
150bhp at rear wheels.
Generally 4.0s (did see 3.6-3.8 but rarely)
Nothing scientific, DD2 reading calibrated for correct speed and a huge grin on my face.
Miss the BECs.
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skydivepaul
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| posted on 29/7/06 at 02:52 PM |
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"so what your saying then Paul in theoretically no matter how good a lap you put in you would have only finished 2nd, time for a engine change
me thinks "
there is still plenty to come from the driver and the suspension set up. But more power will be added this winter. shortlist so far is:
turbo charge the motor ~ 240bhp (1000cc x 1.5 turbo factor = 1500cc)
zx10 / zx12 engine
1600 4age ~ 190bhp
please feel free to add any suggestions although i need to keep below 1700cc to remain in the same class.
I am going to try to use the VR2 data logger when i work out how to use it. this has a sensor on the front wheel so you get a true speed reading
without wheelspin.
I used the video counter and the R1 clocks to guage the time, as soon as i could see my clutch come up the speedo started. I will re time them again
to see if i can get a more accurate reading.
http://www.smartideasuk.com
http://www.smartmapping.co.uk
HD CCTV
3D design solutions and integration
IP security systems
access control systems
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RazMan
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| posted on 29/7/06 at 06:43 PM |
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furyblade - If your speedo pickup is on the prop or driven wheel, then wheelspin will give you amazingly quick times! 
The more accurate way is to put the sensor on the front wheel or as you say, plug in the GPS.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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furyblade35
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| posted on 30/7/06 at 09:02 AM |
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Yes you can mount the speed pickup for the DD2 on any wheel, prop or driveshaft.
It will not effect times though. Unless you are wheel spinning at 60MPH! or as you launch you achieve 60MPH in wheel spin........!!! Front wheel mount
will negate that!
Anyway, I still think BEC are great, but the Honda s2000 must be a serious contender for a robust alternative. That's what I'm looking at
now.
Al.
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DarrenW
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| posted on 31/7/06 at 10:17 AM |
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Ive used DD2 pro 0-60 timer. I didnt set the speedo using the digi-tools, instead favouring setting au at SVA which proved i was less than 1mph out at
70. Does this mean i should get an accurate 0-60 time?(oh and yes i should point out to the non-believers that a Pinto can get these cars past
60).
Road conditions and technique are of course major factors. I know i dont have a good road but always use the same stretch which is at least a fair
comparitor.
Another interesting point. I always assumed road cars quote 0-62 due to the fact that 62mph is roughly 100kph. However i have had it on good authority
from a learned friend in the automotive business that most manufacturers actually record 2-62mph times but report them as 0-62 to save confusion with
the marketing bumf. Reason is something to do with getting the cars rolling slightly before the timers start. Of course this is not valid for those in
competition who employ other methods - im just talking about std manufacturers here. With this in mind it is kind of valid to set your dd2 to record
2-62. As with most things emotive in the car world after 110 years of smoke and mirrors / myths and legends the following debate is largely futile as
we will never know the truth. For me its just nice to know if your technique / mods are improoving the pleasure and if we really want to know whos car
is faster etc we will just have to arrange a shoot out at some point.
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