Bigpower

So far I've eased my Scoob off the line then nailed it. Mechanically sympathetic but not very quick. This year I'll be competing in the JISC series rather than just dicking about so I ought to sort out these launches...

It's a decat STi4 with AP organic clutch on standard 5speed box, and is soon to be remapped with PFC/Datalogit/AVCR/Walbro fitted.

When I raced 250cc bikes the technique was to hold it close to redline and ease the clutch out (slower than you might imagine) whilst feeding in more gas. What revs do people prefer in the Scoob, how abrupt with the clutch, and does the standard box cope ok with standardish power?

cheers
Andy

Andy, basically in the dry, you need 5500ish rpm and then just lift your foot off the clutch as quickly as possible, any lower revs than that will see you just bog down in my experience.

If its wet then its a case of trying lower revs, but circa 4k rpm is usually okay for minimum wheels slip.

As to wear on the box etc then I'm sure at your power levels it'll be okay, and the clutch will be fine as long as you don't slip it to often.

Revs= not a clue as it's model and spec specific

Technique= as taught to me by the Jedi of launching that is the Madenglishman :notworthy:
Bring the car up to the line and apply the foot brake. Immediately bring up the hand brake. Bring the cars revs up to the prescribed limit and try and get 'comfortable' at those revs.
Sprint launch- bring the clutch up slowly until you feel the biting point and then release the handbrake. Using the handbrake will take up the load in the launch, it is the energy of all of the shock going through the transmission that kills things.

Good luck. I followed the above at North Weald and got some good getaways for an 80bhp front wheel drive shed.

Normally you don't have to hold it on the handbrake tho as they chock or hold you in position, Sundays was different.

I know Logan, but the technique I prescribe to takes anyway most chances of blowing up various driveline bits.

Personal preference I guess.

With my red wrx I used to launch at 5k and slip the clutch to keep it on boost rather than send the shock through the drivetrain. It cost me about 0.5sec when compared to one of Gerrys launches on video to the first shift point.

Ironically I didnt break the clutch, although it had nearly torn its centre out when I removed it, but it did get through 2 boxes last year running 310lbft. An Sti4 box should be stronger than a 93WRX box though.

Best way to develope a technique is spend years doing traffic light grands prix in low power sheds.

It can be very satisfying when a Xantia diesel gets the drop on a BMW or Audi. Silly I know but :roll:

Or you can just program launch control into the ECU map and off you jolly well go!!

Once the trial and error bit is over you have the perfect launch :D:D