rmtypeR

Is it just me or did they make something fairly simple seem very complicated?

peterhum

I thought I knew how to launch a car- maybe it's harder than I thought! Sure looked it on the vid.

In fairness, it's hard to describe the 'feel' for just enough slip/wheelspin to stop it bogging down, without toasting the clutch or losing traction completely.

Put it down to a mis-spent youth.

Ben v7

A general rule of thumb that seems to work quite well is to take your car's peak torque and peak power and launch at the rpm approximately half way between the two. I don't think just ripping the clutch up is best unless you really do have no mechanical sympathy.

On a WRX launching at 4,500 rpm, bringing the clutch up swiftly but smoothly seems to work for me.

Dill_typeR

It is more difficult than you would think (IMHO)
I've bin down the strip a few times now 3 times in a CTR, consistent 15.4secs 92mph, with a little practice probably shave a couple of tenths off.

In my scooby its totally different, had wheel spin in 1st and 2nd, spinning on the line, snaking off the line and struggling to keep it in a straight line and.... rears spinning pushing me towards the wall (that was today)

on standard 16" 195/50 £50 ditch-finders tyres
Japshow 05 couldn't get better than 99mph and 14.1 secs (embarrassing)

26th feb 06
times vary from 15.1 at99mph(that was the 1st full bore launch, dropped clutch, snaking all over the place)
to (5 runs later)......

diff set at 2 clicks fwd(i think), revs at 6000, clutch partly engaged pulling against handbrake 13.2@105mph

then today at the pod again (fast show test day)
17" 205/40 toyo R888
at pod ony got 3 runs in a 14, 13.9, and a 13.7 all at around 100mph
wheels still spinning off the line

wot am i doing wrong?
shud be getting 1.8 60ft time, wen i've only got less than 2 seconds once

tath

launching with the diff all the way back (free) is a bad idea. It's like launching a RWD car but with 4wd drag and weight.

Dill_typeR

Had a think, and cud be a load of bolx, but although the tyres i hav now will put more rubber on the ground, they have less side wall and are reinforced so will flex/twist less when torque is applied to them and transfer more energy to the ground under launching(i think thats why drag tyres are so high profile to spring the car off once they react), plus the fact, wheels are covered in cack at the pod after queueing and can't scrub em like 2wd cars can in the burn out bit

as to having DCCD in open position i see your point, what are normal scoobs set to then???

theicewall

My best launches involve a series of a few revs to 5k, on the last rev slip the clutch to 3/4 out and wait a quarter of a second before letting it out completely. This does two things... 1) you wear out your clutch instead of busting a gear box by minimizing the shock to the driveline. Clutches are cheaper than gearboxes. 2) You lose maybe 0.01 of a second to just dropping the clutch because your car doesn't make boost without load and if you just side step the clutch you are going from no load to full load and no boost and you have to then wait to build boost but if you slip and launch you build boost faster without any bog or drivetrain lash.

RB5_245

Ntice the 1st 60ft time you posted there was 1.74, that's very good. you won't get any better. stick with that teqnique

dan100381

i had a go at this last month at santa pod and i found that bliping the throttle between 2-4 k and feeding in the clutch worked best for me. I tried a 5 k launch but got too much wheel spin and it slowed me down.

My two runs at 2-4 k are as follows in a UK turbo classic running around 240 bhp:
RUN 1

REACTION .583
60 FT 2.036
330 FT 5.727
1/8 ET 8.866
1/8 MPH 79.49
1/4 ET 13.892
1/4 MPH 97.17

RUN 2

REACTION .877
60 FT 1.997
330 FT 5.765
1/8 ET 8.929
1/8 MPH 78.91
1/4 ET 13.952
1/4 MPH 97.39

here is the vid of my first run:

http://media.putfile.com/imp-vs-fto


and of the 2nd :

http://media.putfile.com/impreza-vs-impreza

Not bad for a first timer

rmtypeR

Those are good times Dan! I'd be pleased if I could do that in my Type R on my first attempt - really must get down Santa Pod - I've been saying that to myself all year. When Evo tested the 22B they only got it to do a 13.8 @ 102.

What do people reckon an absolutely perfect run in a standard Type R (Impreza that is) would be? Could it get into the 12's?

QuattroMNC

Don't own a scooby myself, but in the quattro the best launches come from something similar to theicewall's suggestion, but just adding to his advice, dont floor the throttle until the clutch is fully up just keep it steady till the transmission has caught up to the engine speed, then you eliminate wheelspin and dead clutches plus it gives the engine a chance to build boost before going flat out, it is very hard to get it right, in most cases it's hard to repeat a good run. A lot of it depends on natural instincts, the best suggestion would be practice

dan100381

cheers mate, sure you would be in the low 13's atleast? there are plenty of RWYB days at santa pod, get yourself down there and give it a go

assam

just to throw in my peice i always foung the higher the revs the better the pull, harldy ever bog down in higher revs.

Cornelius

iTrader: (2)

my best time on the 'pod (JDM WRX):

Reaction time: 0.160
60ft - 1.901
330ft - 5.520
1/8 - 8.526
1000' 11.069
1/4 13.353
MPH - 101.84

well chuffed as this was my first time. pulled away with a 4000RPM start

rmtypeR

I think we should have a 1/4 mile table on scoobynet like IMOC have... http://www.imoc.co.uk/forums/garage....de=quartermile

NoCatSTI

http://videos.streetfire.net/categor...41F9BD4827.htm

rentonone

iTrader: (1)

is it worth putting the standard 16in wheels on for a day at santa pod? would you get a better time? ive got 18in prodrive replica's. i would of thort that the standard wheels are quite a bit lighter. what do you think?

G_Sleigh_STi

Ive started doing it from about 4000rpm now and seems to work quite nicely a little slip of the line though works best