At the recent Tamworth Hillclimb i suffered for the very first time ever, bad axle tramp when leaving the start line.
I quickly realized that if i left the line with a little less revs ie 4000rpm instead of my usual 5000rpm the car did not tramp.
The car was also popping out of third gear under deceleration which was very frustrating. After the Tamworth event i closly inspected all mounts with the car jacked up in the air and could not find any probs at all. I put the tramp down to a newly resurfaced start area.
I also removed the shifter rod and found it bent like a banana and the bush badly damaged. After replacing the bush and straightening the rod i was ready for Grafton.
First run at Grafton i again suffered bad tramp and for the rest of the weekend had to walk the car of the line ie 1500rpm to avoid tramp.
When i got home last Monday i decided to look under the car while still on the trailer, and spotted a tiny crack in the left hand banana mount. I must have missed it before because i had the car jacked up of the ground with no weight on the wheels.
So Monday i pulled the engine and removed the gearbox mount. The left hand banana mount had a small area were the rubber was coming away from the steel were it bonds. You would never see it unless you were looking for it, the crack is that fine.
After talking to Larry we decided to solid mount the gearbox and Saturday afternoon after work i installed the new gearbox mount then the engine. I also took the time to check all nuts and bolts and fuel lines etc to make sure everything was good.
So today i finshed the engine install and then gave the car a few drag race starts out of the shed. Thankfully all was good with no tramp. One tiny little crack in one mount caused a lot of headache but thats racing hey. A big thankyou to Larry for the solid mount and your advice.
Looking forward to the next event in two weeks which is Cooperbung Hillclimb.

Cheers Col

yep, always solid mount for motorsport

and a berg styled mid mount and an engine brace bar under the back of the engine.
Havent got a pic for the engine brace... but i believe tramping is the engine pulling down under take off and not being supported enough... makes the gearbox and engine move in different directions.

Good Luck

Hi Col

Do you have Kafer cups bars on your car? They can be made cheaply with some molly tube and rose joints.

I don't like braces under the back of the engine, it puts stress in a very weak part of the body.

Steve

Quote:

Originally posted by Craig Torrens yep, always solid mount for motorsport

im sure col has been in the game long enough to have mid mount and kafer bar system

steve the way my engine bar is mounted, i wouldnt agree it is stressing a weak area, from memory col has one too

Bring your camera col, i will get down there for this round on the sunday

Greg in this time?

Col, I'll send you some ear plugs and some Loctite.

Should throw those suggestions to this guy here :P

http://www.youtube.com/watch?v=B5-NSNNtkDs 

I,ve never been one to do what everybody else is doing or follow the leader.
Sure i take peoples advice on board but allways make my own decisions, if i listened to everyone i would not be racing a "heavy" Superbug.
I do have a Berg style mid mount and a Tramp Bar and believe the only reason i suffered tramp was the failed banana mount.
However to be safe, the solid mounting option was decided. No Steve i don,t run a Kafer style bar system allthough they look to be a excellent product.
I will get under the car again this weekend and look to design my own style of fork stiffening bracket, i have a few ideads in mind.
Daimo that would be great if you could take some footage for me.
Myself, Heath and Glen are definate starters and hopefully Gregs hand is okay for him to race as well.

Cheers Col

Sorry if you see this as a hijack but:
I am putting my entire chassis together at the moment and have gone with solid mounted gearbox. How much are you lock tighting/nyloc nutting, and where do you stop?

Cheers

Being a racecar you basically wanna loctite/nyloc/springwasher everything.

Solid mounts it just goes double, or you WILL have things work loose.

The only thing I remember consciously not loctite'ing body and suspension wise was the spring plate cover bolts... those suckers can be difficult enough to undo as it is.

What grade of loctite are you using?

I normally just use the standard blue stuff on most things... 243 I think it is.

I get a bit paranoid tho with things that are constantly moving like CV joints and suspension, so they get the red (263).

Cheers guys thats pretty helpful, got some blue loctite on the way home. will look at different specs as i go.

Hope your tramping is all sorted, there is not a worse feeling under load.

My hillclimb car was 830kg !

Quote:

Originally posted by Craig Torrens My hillclimb car was 830kg !

yes but if you do both, drive better and have a lighter car......... well you go even faster

I went faster each year, and I didn't touch the car................driving better is the answer in most cases.

Quote:

Originally posted by colin Quote: Originally posted by Craig Torrens My hillclimb car was 830kg ! Some people get really obsessed about weight. I,ve gone faster this year at every single track and i know it,s not because the car has more power or better handling, yes they all help but, it,s because i,ve had a bit of self analysis and said you can go drive faster. Cheers Col

are the weights with or without the driver? cause at home I have the RTA rego slip for my bug and it shows a weight of 710kg!

My '59 [No.8 Beetle] was also 710kg.......before the roll-cage and stronger body rails. Now it's about 780.

Weight is even more important in a hillclimb car, because, as well as accelerating, the car is being 'lifted'. It takes effort [read horsepower] to lift a car, and the steeper the hill, the more effort required.

Re. the tramp problem - my car was BAD, before I fixed it. The first sign of the cause was a pair of 'red' engine mounts, that had turned to powder. There is NONE of that red crap in my car anymore!

The engine is now solid-mounted, and braced to the chassis, body, and roll-cage - noisy, but stiff as buggery! I also made very firm torsion bar pivot bushes [almost no play], and braced the spring-plates. As mine is a swing-axle rear end, all this adds up to very tight control over the suspension. Wheel tramp is no longer!