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1/4 mile launch help tuned 20vt
#1163784
30/01/2011 04:02
30/01/2011 04:02
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jonnybgt1759
Unregistered
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jonnybgt1759
Unregistered
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Hi guys New 1/4 mile season starts soon Previously I ran a 13.7 @ 109 @ crail with 2.4 to 60ft. This time i aim to take this to about high 12 low 13 with some advice from the more experianced guys on board. what advice can you give to improve my time ie launch rpm change gear time and tyre pressure adv. To be honest the time at crail was decent for the day(slippy) but looking back hyper ran 13.3 with lower power car than me  not on the same day.
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Re: 1/4 mile launch help tuned 20vt
[Re: Nigel]
#1163852
30/01/2011 13:16
30/01/2011 13:16
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jonnybgt1759
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jonnybgt1759
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Its running gt28rsr all supporting mods and flea mapped dynod at 358bhp. 2.0 to 60 I doubt i could get that at crail 
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Re: 1/4 mile launch help tuned 20vt
[Re: Nigel]
#1163971
30/01/2011 18:54
30/01/2011 18:54
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BoostMeCoupeUp
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BoostMeCoupeUp
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2.318 60ft on way to a 13.61... pzero's with 18s with about 19psi front 40 rear full fat LE 305bhp. So 2.0 is definitely possible although 0.3 is still a lot.
Last edited by BoostMeCoupeUp; 30/01/2011 22:33.
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1164011
30/01/2011 20:46
30/01/2011 20:46
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johnnybravoturbo
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johnnybravoturbo
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Jonny,i have only managed to get a 13.2 in mine so far,so your time is good. I ran a similar setup and got a 13.7.
Theres nothing that can be taught here,usually you'll have 10 launches and maybe only 2 good times.
So many variables. Your car was deceptively quick after i built it for Rob and would give most high powered cars a good run for there money.
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1164041
30/01/2011 22:34
30/01/2011 22:34
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Joined: Dec 2005
Posts: 1,985 In an Audi
Taffy20vt
My life on the forum
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My life on the forum
Joined: Dec 2005
Posts: 1,985
In an Audi
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Practice, practice, practice. I ran a 13.7 @ 109 with 270bhp at Santa Pod. It took 16 runs to get that 
Ex 432bhp '00 Sprinty 20vt6 '17 S3 Sportback '69 Amazon 131
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Re: 1/4 mile launch help tuned 20vt
[Re: Taffy20vt]
#1164105
31/01/2011 01:02
31/01/2011 01:02
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leon1
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leon1
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lol ive had a 13.7 aswell how odd
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1164167
31/01/2011 10:33
31/01/2011 10:33
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Joined: Dec 2005
Posts: 17,374 Staffordshire
Nigel
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Forum veteran
Joined: Dec 2005
Posts: 17,374
Staffordshire
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OK - for what it's worth, this is my launch technique
1) Hold revs at about 2,000rpm for a second or two 2) Floor the throttle, and as the revs rise, lift the clutch quickly 3) You will almost certainly get wheelspin - this is desirable - control this by moderating the throttle (probably between 75% - 100%)
Another method, which I've tried only once...
1) Hold revs at about 2,000rpm for a second or two 2) Floor the throttle, and as the revs rise, lift the clutch fairly quickly but not fully engaged 3) Balance the reduction of revs by slipping the clutch
Personally, I find it easier to control wheelspin than I do to modulate the clutch slip. The added bonus of the first method is that tyres are a lot cheaper than a Helix Organic clutch. The clutch smoke and horrible smell from method two was not something I care to repeat, but it did give me a 12.5
There are two main issues with method 1
1) The balance of throttle required to get a tiny bit of wheelspin and no clutch slip AND not bog down the engine is difficult to master and impossible to teach. I do it purely by 'feel' - that knowledge of your own car that only you can get from many thousands of miles behind the wheel
2) As I found out to my cost, if there is too much grip, the shock load through the transmission can be sufficient to break something. If you're lucky, the weakest point in the system will be your clutch, and you'll get some clutch slip. If you're less fortunate, something will break. If you're lucky, it will be a driveshaft (easily replaceable and in plentiful, cheap supply). If however, you're having a bad day, your differential will shatter, which in turn will punch holes through your gearbox casing. At October's Santa Pod meeting, two Coupes and several Pugs broke gearboxes, simply because grip levels were unusually high.
My recommendation is to go to a 'tuner' day at Santa Pod, where the number of entries is quite limited - you would probably manage a dozen or more runs. On a public day, you'll be lucky to get four runs in.
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Re: 1/4 mile launch help tuned 20vt
[Re: Nigel]
#1165060
01/02/2011 22:23
01/02/2011 22:23
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johnnybravoturbo
Unregistered
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johnnybravoturbo
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OK - for what it's worth, this is my launch technique Give it the limiter,drop the lot and hope the diff holds . If it does great. Not the best for times but geat croud leaser  Nice n simple
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1165064
01/02/2011 22:37
01/02/2011 22:37
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porkypaul
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porkypaul
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OK - for what it's worth, this is my launch technique Give it the limiter,drop the lot and hope the diff holds . If it does great. Not the best for times but geat croud leaser  Nice n simple 
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Re: 1/4 mile launch help tuned 20vt
[Re: Taffy20vt]
#1165080
01/02/2011 23:11
01/02/2011 23:11
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jonnybgt1759
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jonnybgt1759
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Practice, practice, practice. I ran a 13.7 @ 109 with 270bhp at Santa Pod. It took 16 runs to get that the terminal speed seems high for 270bhp was it fully stripped?
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1165127
02/02/2011 06:29
02/02/2011 06:29
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Joined: Dec 2005
Posts: 1,985 In an Audi
Taffy20vt
My life on the forum
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My life on the forum
Joined: Dec 2005
Posts: 1,985
In an Audi
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Practice, practice, practice. I ran a 13.7 @ 109 with 270bhp at Santa Pod. It took 16 runs to get that the terminal speed seems high for 270bhp was it fully stripped? No, just spare wheel removed. I've also had a 13.7 @ 118 @ Brize Norton but that was with about 320bhp.
Ex 432bhp '00 Sprinty 20vt6 '17 S3 Sportback '69 Amazon 131
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1165158
02/02/2011 10:51
02/02/2011 10:51
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Davie
Unregistered
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Davie
Unregistered
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OK - for what it's worth, this is my launch technique Give it the limiter,drop the lot and hope the diff holds . If it does great. Not the best for times but geat croud leaser  Nice n simple Funnily enough from my mini drag racing days, we found we got less breakages setting off at higher revs keeping the motor away from peak torque, we used semi slicks though and did proper burnouts to get plenty of heat in the tyres, low rpm getaways we found broke diff pinions and stripped gears off the drop gear assembly. Moral of drag racing " go hard or go home "
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1196178
04/04/2011 11:15
04/04/2011 11:15
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Zsowner
Unregistered
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Zsowner
Unregistered
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I went to crail yesterday. Im running a k&n filter and a gtec 1 chip nothing stripped shitty Tyres and ran a 14.3 but wasn't out to kill ma car so wasn't giving it full throttle launches .
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1203499
18/04/2011 13:30
18/04/2011 13:30
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The_Squirrel
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The_Squirrel
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I cant give you advise on a coupe but i cant imagine its much if any diffrence to any other turbo car at the strip
My old car was a r5gtt with 2.0 turbo conversion and i ran a 12.5 @ 108 mph and 60ft of 1.7 been hitting pod for a good few years now so heres what ive picked up along the way
1st tings 1st get yourself drag racing slicks, smallers the better but with as high side walls as possible, tire soften this up for a few weeks in advance if possible
Warm those slicks up good and proper with a burn out before you pull up to the line, you will want a fully working handbrake to do this properally
If you can get space savers on the rear, nice and pumped up nothing sift here this will cut bk on drag off the rear tyres
Suspenion should be as solid as a rock on the rear and medium to soft on the front
If its a time you after then forget trying to hit the throttle just because the light goes green, your time doesnt start till you move, remember this is for a time slip not a race against the person next to you
Moderator: text speak removed
You dont want to be sat on the limiter or sat at a constant rpm as this just creates vacum and you will bog down, hence why you keep the revs movin and fast between the 2 rpms to create boost
Then when youve found this use this as you launch position at pod so for instance you found yours was comin on boost about 4.5k at stand still, quick revs back and forth between 4-5k so you hitting on boost ready for when the light changes, when you feel ready as you rev up to 5k drop the clutch keeping the throttle planted this time and you should see a nice diffrence in your launch
You can slip the clutch in if you feel like its not the way for you just to drop the clutch
From then on in its perfect gear changes all the way up the strip
Best of luck
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1203887
19/04/2011 09:56
19/04/2011 09:56
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sediciRich
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sediciRich
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er most space savers have limited max MPH rating, please check the speed rating!
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Re: 1/4 mile launch help tuned 20vt
[Re: ]
#1203890
19/04/2011 10:13
19/04/2011 10:13
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The_Squirrel
Unregistered
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The_Squirrel
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er most space savers have limited max MPH rating, please check the speed rating! Yes sorry should have added this, skinny wheels with correct speed rating will also work very well Also you will need to play with tyre pressures on the slick, if i remember rightly we went down to around 8-10psi (cold temp) for my m+h drag slicks Also another saftey tip when you pass through the line at the end dont back straight off the throttle and hit the breaks, let the car coast for abit, theres plenty of run off plus the surface like superglue so will soon shave the speed off you before you have to start heavy braking
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