charlierevell
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| posted on 7/6/08 at 10:30 PM |
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Launching a BEC
Well.... Did my first 1/8th of a mile today. Was only really going to watch but as there were only about 20 cars i thought I'd chuck in my £20
for as many runs as possible!
In the first 3 runs (Never drag raced or really launched my IndyBlade) got down to 8.6 - Fastest time of the day when i left was 8.1 by a Spire with
ZX-12.
Couldnt get any better the more i tried, it was very warm and I kept loosing grip off the line.
I've got no LSD and 12000 revs to use, whats the best way to get a light weight (450kgs ish) 7 Off the line quickely??
Any tips GREATLY appreciated!!
I could catch most things down the strip, scoobys, evos etc etc but i just couldnt beat them as I couldnt get off the line that quick! (Yes i know the
are 4*4 but im sure i can be quicker!)
Tango orange is an 'IN' colour!!
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worX
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| posted on 8/6/08 at 05:28 AM |
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If it was warm and you were losing grip off the line then you were using too many Revs when you started or were maybe being far too violent with the
clutch?
Steve
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Paul (Notts)
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| posted on 8/6/08 at 06:38 AM |
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I have just changed my open diff to an lsd and it FEELS like I can get the power down much better from a standing start.
Paul
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charlierevell
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| posted on 8/6/08 at 09:08 AM |
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Well I think you might have something there Worx... I dont like slipping the clutch in the indy that much as its a bike jobber but maybe I should slip
it a bit more!
Tango orange is an 'IN' colour!!
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BenB
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| posted on 8/6/08 at 12:05 PM |
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There was discussion about this a few days on the BEC list.
Quite a few people said to give it 7-8k then sidestep the clutch, then feather it in a little bit and then feather it out to fully engage it...
But different people have different opinions...
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Hellfire
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| posted on 8/6/08 at 03:36 PM |
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We generally tend to drop the rear tyre pressures to about 10 psi when on the drag strip. Balance the car at about 6,000 rpm on the start line and
feather the power in/out whilst trying to stop the rears spinning up.
Phil
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charlierevell
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| posted on 9/6/08 at 08:27 AM |
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Didnt think of droping the pressures as i didnt have a pump to get them back up for the way home.
I think clutch control could be key to getting it quicker over the first 60ft.
Its on a disused runway by the way.... so concrete with grass on it.
Not a proper drag strip.
Tango orange is an 'IN' colour!!
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wheezy
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| posted on 9/6/08 at 02:10 PM |
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You just need to fit a ZX12R mate
By the way the fastest time on Sunday was 7.3 from what I believe was a Scooby with a few electronic gizmos.
Dave
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charlierevell
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| posted on 9/6/08 at 02:34 PM |
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Was that not on the sunday? Dazza or something like that???
He has 4wd and thats cheating!
ZX-12 is an options (or14)
I just need to launch better!
A quick skyline lost a good 1 - 2 car lengths on me when you'd left! You forget how quick these things are!
Tango orange is an 'IN' colour!!
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PAUL FISHER
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| posted on 9/6/08 at 09:45 PM |
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This is how its done,this is Mark aka "carnut" on here,at York dragway,Ive never seen a bec launched as good,I have seen him run a 11.7
with a blackbird on nos,with slicks
http://www.youtube.com/watch?v=4XkeJkSO8CY
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PAUL FISHER
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| posted on 9/6/08 at 09:49 PM |
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But this is how not to do it
http://www.youtube.com/watch?v=wF7Aq9zH7Bg
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eccsmk
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| posted on 9/6/08 at 10:43 PM |
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now that was quick (first vid)
whoops (second vid )
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wheezy
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| posted on 10/6/08 at 01:04 PM |
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Ive posted a video of a couple of runs from last saturdays drag strip event. Unfortunatly the camera wasnt on for my fastest run of the day.
Dakota drag video
The first run I had lots of wheel spin of the line. On the second the take off was much better using far less revs.
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phoenix70
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| posted on 10/6/08 at 02:19 PM |
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quote:
Originally posted by charlierevell
I could catch most things down the strip, scoobys, evos etc etc but i just couldnt beat them as I couldnt get off the line that quick! (Yes i know the
are 4*4 but im sure i can be quicker!)
You will be hard pressed to beat a AWD car down the track, they can put the power down so much more efficiently than a RWD car. To get a good
launch, you need to get the balance between traction and wheelspin, as hellfire said you need to modulate the throttle to kill some of the wheelspin,
but you've also got to avoid the engine bogging down, so it is a difficult balancing act, but practice makes perfect. Dropping the tyre
pressure will also help with traction, also the type of tyres makes a big difference (a nice set of street legal slicks.) A LSD would also help get
better grip off the line
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