Wheels Bouncing At Start Of 1/4 Mile

[Pal]

howdy guys, was at the drags on wednesday, stretching the legs on the skyline and seeing what the new mods did for my 1/4 mile time and am now having a problem of the back wheels bouncing badly on the start line when i dump the clutch, has anyone had the same problems and what can i do to rectify it as it is robbing me of a good start. the only way i got around it that night was taking off off boost then putting the boot in once i got rolling.

[Trust33]

Ride the clutch a bit more.It's called axel tramp.

I think it's what happens when a shock sudden movement is sent to the tailshaft then comes back towards the gearbox to bite you in the but.It happens back and forth continueally untill you take your foot off the accel.

It you want a good launch you should take off at 3-4k using the clutch as the launch controll for your wheelspin.Otherwise mix it up between your accelerator and clutch untill you find a compromise.

I find that with my h/d 5 puck ceramic sprung center clutch that the launching can and will be off or smash on,at a certain point in the change between the grab and no grab point of the clutch take up.

When driving on the street and you come to a complete stop,start experimenting with your launches,they dont have to be fast just feel for that point where it was giving you the trouble.Give your clutch a few pumps prior,then hold it there untill you feel the take up.If that doesnt work and it starts to tramp still repeat the process.You will feel the car and the way it behaves anyway.You should be able to work it out from there.

[gtst1976]

Mine does the same thing. As mine is basically stock disregarded axl tramp. I was told it was just my rear shock absorbers. As they are the original and its done 125,000. Getting new ones soon so will be able to tell you if its that in a few weeks.

Edited April 8, 2006 by gtst1976

[Pal]

yeh i was thinking it was my shockies too. i have just put in a extreme 9 puck h/d clutch. i was trying to take off to gently (about 2000rpm) maybe? Will have to give it a few more herbs and see what that does. thanks for the tips Trust33, will give it a go next month when i go down again

[blind_elk]

It is axle tramp - caused by the shock absorber unable to control the rear suspension.