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hoi
2002.01.10, 03:38 AM
I am testing a brand new vipor with nothing addon, the car is jumpy (up and down) while corning.
Then I began to change parts one by one and then test one by one, e.g. front medium sprint, 40 front and 30 rare wheels, king pins, cambers, etc.
I still found my car is jumpy while corning.
Until I add the "middle rare anti-shock", the jumpy problem decrease (only high speed corning is jumpy). So, what cause that ? How can I solve it ? :rolleyes:
Thanks!!

Draconious
2002.01.10, 03:53 AM
Likely unrelated, but my car currently has rear wheel hop (the jumpyness) while cornering, because I have a REALY stiff (hard setting) carbon suspension plate... you could try softening the rear see if it decreases any.

hoi
2002.01.10, 03:58 AM
My vipor is usually jumpy on the front. The rare is ok.
I tested all hard, medium, and soft front sprints, but just the same... :confused:

Mondo
2002.01.10, 05:27 AM
Hoi,

Try a ball-diff.

What type of surface are you driving on? Carpet? Concrete? Tarmac?

Let us know

Mondo
__________

hoi
2002.01.10, 05:46 AM
Originally posted by Mondo
Hoi,

Try a ball-diff.

What type of surface are you driving on? Carpet? Concrete? Tarmac?

Let us know

Mondo
__________


Oh yeah! Good Suggestion and question.
I also try Ball Diff.
All I test is on Carpet tracks.
But still jumpy....
My friends car also jumpy too, his is Altessa. The track I test is commercial track, many people play. But many expert's cars won't jump... :rolleyes:

butler
2002.01.10, 06:00 AM
I few things you could check, some may sound obvious, but:

- Do your tyres spin true? I find you have to fit you tyres spot on otherwise they shake like crazy.

- Does the front suspension move up and down smoothly?

- Do you have adequate ground clearance.

- Also with such a small cars, problems at the rear can manifest them selves at the front too.

Hope this helps.
;)

hoi
2002.01.10, 07:54 AM
Originally posted by butler
I few things you could check, some may sound obvious, but:

- Do your tyres spin true? I find you have to fit you tyres spot on otherwise they shake like crazy.

- Does the front suspension move up and down smoothly?

- Do you have adequate ground clearance.

- Also with such a small cars, problems at the rear can manifest them selves at the front too.

Hope this helps.
;)

Very useful suggestion and questions: ;)

- Do your tyres spin true? I find you have to fit you tyres spot on otherwise they shake like crazy.
Well, my car do jump lilke crazy when I used slippy tires. The carpet is pretty slippy, and now I use 30 front and 25 rear. And the jumpy problem decreased.

- Does the front suspension move up and down smoothly?
Right, jumpy problem is crazy when I haven't changed the king pins and cambers. They do help.

- Do you have adequate ground clearance.
Well, the carpet is overall clean and smooth.

- Also with such a small cars, problems at the rear can manifest them selves at the front too.
Right, that's why I added a middle rear suspension. It helps a little. But I didn't fine tune it yet. I will try different sprints later to see if it helps.

Thanks for your help. :)

So, what elsecan cause this problem ?

butler
2002.01.10, 08:16 AM
In a problem like this on a 1/10th scale or even a full size race car, I would suggest softer springs and more dampening.

I don't know how you would apply to such a small car with fairly crude suspension.

I understand Kyosho do an oil damper. There is thread about it in Parts and Hop-ups. It may be worth reading.

http://mini-zracer.com/forums/showthread.php?s=&threadid=739

Mondo
2002.01.10, 08:40 AM
Hoi,

Try add some weight to the motor cover.
One big problem with Mini-Z's is that they are light.
They need a little more weight on the back axle.

This can help:

http://mini-zracer.com/forums/showthread.php?s=&threadid=91

The guys from the Phillipines said that the Mercedes CLK DTM bodies are the best because they use a wider wheeltrack (the back wheels are wider and the front wheels are 'offset')
Perhaps this is a solution.

Here is a picture of the rims with tyres:

Mondo
__________

hoi
2002.01.10, 11:54 AM
Originally posted by butler
In a problem like this on a 1/10th scale or even a full size race car, I would suggest softer springs and more dampening.

I don't know how you would apply to such a small car with fairly crude suspension.

I understand Kyosho do an oil damper. There is thread about it in Parts and Hop-ups. It may be worth reading.

http://mini-zracer.com/forums/showthread.php?s=&threadid=739


Mine is oil damper, and it does help a bit.
But jumpy inrease when the oil began to decrease....
I will refill it and try again! ;-)

hoi
2002.01.10, 11:57 AM
Originally posted by Mondo
Hoi,

Try add some weight to the motor cover.
One big problem with Mini-Z's is that they are light.
They need a little more weight on the back axle.

This can help:

http://mini-zracer.com/forums/showthread.php?s=&threadid=91

The guys from the Phillipines said that the Mercedes CLK DTM bodies are the best because they use a wider wheeltrack (the back wheels are wider and the front wheels are 'offset')
Perhaps this is a solution.

Here is a picture of the rims with tyres:

Mondo
__________


This is pretty new idea for me!
Today I discuss with a friend how to decrease the weight of the car and hope to decrease the jumpy problem and increase the performance and conring.
But this suggestion make me interesting to test the relationship of weight and corning. I will try it!

P.S. My card reader has problem. I can't import the pictiures I took from my digital camera.... Otherwise I will let you see how my car looks like. Maybe tomorrow when I come back to office, and upload the pictures again. :D

hoi
2002.01.10, 11:59 AM
Missed one thing.
I am using the rear wide tires... Yup! The benz wide tires for Vipor! ha ha... It works!
But I don't see it helps in jumpy problem...

Ken Mifune
2002.01.10, 01:35 PM
But jumpy inrease when the oil began to decrease....

hoi,
Does that mean it's leaking oil?

hoi
2002.01.10, 01:38 PM
Originally posted by Ken Mifune


hoi,
Does that mean it's leaking oil?

I think it's just dry out...

hoi
2002.01.11, 10:28 AM
Finally, I got my card reader fixed and I can upload my car's setting. ;)

hoi
2002.01.11, 10:29 AM
#2

hoi
2002.01.11, 10:30 AM
#3

hoi
2002.01.11, 10:52 AM
So, here is my Viper's setting

Front Tires: 30
Rear Tires: 25 (I am looking for 20)
(sticky tires for the slipery carpet tracks I play)
low friction king pins
hard front springs
Camber: +1
Tire rod: -1
Middle rear shock (oil added): hard shock
medium H plate
All bearing
Lowering car by adding 5 rings on the front and removing rear "triangle plastic plate" (which is originally attached with H plate)
All aluminium servo gears (ball gearing oil added)
Kyosho Ball Diff
Original Motor /w original motor cover
Removing Viper's mirrors (kidding, it's actually broken...)

So, what do you guys think? What can I do to reduce jumping ? :rolleyes:

Russ
2002.01.11, 11:29 AM
you might want to try removing the lowering spacers in front, and putting the triangle back on. I lowered my car once and if you run on carpet, the bottom of my chassis would rub on a few strands of the carpet's material.

So, try lifting the car back to it's normal height :)

hoi
2002.01.11, 01:06 PM
Originally posted by Russ
you might want to try removing the lowering spacers in front, and putting the triangle back on. I lowered my car once and if you run on carpet, the bottom of my chassis would rub on a few strands of the carpet's material.

So, try lifting the car back to it's normal height :)


Sounds REasonable, I will try !:)