[apolloxbgt]

Allright, yesterday at heathcote after my first ambismal pass, I lined up for my second and when i dropped the clutch I got so much shuddering trough the car I thought it must have been in third gear, so I ripped it out of gear and put it back in ans was acttully in first anyway. Another sh*tty pass.

Third time, same amount of axle hopping but I took of anyway. Since then whenever I give it curry taking off I'm still getting axle hop fairly badly,and never did before. I've had it up on stands and havn't been able to find anything wrong with the rear suspension or tailshaft.

Any ideas anyone?

BTW for those who dont know (proberbly everyone) my car is an xbgt coupe with stock rear leaves and a nine inch.


Cheers Ant

 

[Casper]

Shocks going bad?
Leaf springs were renound for axle tramp but good shocks should help it.

 

[galaxy xr8]

Good old axle tramp,the old leaf design is not the best design for drag racing,

 

[apolloxbgt]

Havn't checked the shocks actually. This may explain why its only started out of the blue.

 

[apolloxbgt]

Good old axle tramp,the old leaf design is not the best design for drag racing,

Not really, but I recall there being an xb coupe in street machine a couple of months ago, that had ran an 8sec quarter with leaves and very little done to the rear end.

 

[TruBlu351]

There's probably nothing mechanically wrong with your car. Imagine if your wheels didn't rotate and you let the clutch out - if it was strong enough, your can would flip over on its back - good old newtons equal and opposite force thing, but thats for the geeks!

Your axle is trying to rotate around where it is bolted to your leaf springs - and if they're whimpy thin ones they'll bend and flex big time.

I would expect it to be worse at the strip because the start line has heaps of sticky rubber on it and gives great traction compared to the street. You can get heavier duty springs with more leafs on them and/or you can put a set of traction bars/tramp rods/slapper bars on.

They bolt up under your springs in 5 min. They minimise the rotation of your springs and axle - quite cheap too.

Here's a pic:
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=945&prmenbr=361

In the mean time I'd be launching at a lower RPM....otherwise you may break something.

Cheers
AdrianXD

 

[Racer]

Something is soft in the rear end. Most likely the springs, shocks or bushes - or all of them!

Didn't XB GT's have factory tramp rods?

 

[clevo]

Ant check the shockers, on the beast, the front ones were replaced, but the rears were not, get some really stiff ones.

When I had the coupe at Calder I wasn't getting axle hop, but no traction, the beast was wheel spinning way to much couldn't get the power down. I only managed 15.48, that car should be good for at least 14's maybe high 13's

Paul

 

[xdc351]

Get rid of the springs.

I saw one of you launches (the last one I think) and its simply the springs are too soft/shocks are rooted.

I use new shocks, 6 leaf springs and traction bars and it leavs the line with no hop at all....

In fact it puts so much more torque back onto the diff that a stock BW LSD can't handle it! I'm sure if I had stock springs, no tramp rods and skinny tyers the diff would have survived because it would have either hopped or smoked 'em instead.

 

[ford4v429]

I'd agree with trueblue351- put slapper bars on it, problem will go away- ride will be slightly firmer, but not too noticeable. Had exact same problem on my mustang years ago- back then slapper bars were only $20 a set...looks cool too.

 

[apolloxbgt]

Something is soft in the rear end. Most likely the springs, shocks or bushes - or all of them!

Didn't XB GT's have factory tramp rods?

Yeah I'm begining to think springs/shocks myself, I've got some rear koni's and the gt sedan has good 6 leaf springs in it, it might have to donate them to the coupe. It will alll have to wait till I get the diff centers swapped and do it all in one hit.

Oh and the tramp rods seem to have dissapeared over the years, so have the ones on my sedan if anyone has any give us a yell.

 

[apolloxbgt]

Get rid of the springs.

I saw one of you launches (the last one I think) and its simply the springs are too soft/shocks are rooted.

I use new shocks, 6 leaf springs and traction bars and it leavs the line with no hop at all....

In fact it puts so much more torque back onto the diff that a stock BW LSD can't handle it! I'm sure if I had stock springs, no tramp rods and skinny tyers the diff would have survived because it would have either hopped or smoked 'em instead.

So with the traction bars how much wheelspin do you get off the line(with the 9inch of course? Are you running an auto? If so, what stall do run in it? And what diff gears do you usually run in it?

 

[xdc351]

So with the traction bars how much wheelspin do you get off the line(with the 9inch of course? Are you running an auto? If so, what stall do run in it? And what diff gears do you usually run in it?

Next to none.

It will either hook up or smoke them... but more often than not it grips. The 9" is a 3.5:1 LSD and that sits behind a top loader. I usually stall up around 1500-2500 depending on where i'm trying to run.

Note: the car has never made a successfully timed run down the quarter... but its not through lack of trying.

I've also run the car at the easternats for the past 2 years and gone in the go to woah, time trials, street drags, etc and the car hooks up great.

The traction bars have actually made a huge difference with the only down side being I need to be in water to get the fat tyers started, stockies aren't a problem though!

 

[XDman]

ive got the same problem as you in the XD, we are going to buy new shockers, extra leaf put into it, new urethlyne bushes with a nine incher, hopefully the hopping goes away, its pretty emabarassing at the lights when you take off with some curry and ur car looks like it gonna fall apart :AAHHH: the whole car shakes

 

[apolloxbgt]

Yeah I dont think mine is the most impressive sight you'd ever see!