Bad day on Astro

[TRF_Tastic]

I was looking forward to giving the 501 a thorough bashing on Astro yesterday and notching up a good win, however it turned into a nightmare.

Front and rear shock towers pair of rear wishbones and a new and intersting problem that the rear drive shafts keep poping out for no reason what so ever..

Grrr, did not have a very good day only finished one race all day and ended up going home early!!

[jimmy]

man that is bad luck! did the towers crack or break? Have you done anything to the shocks? rebuilt them without spacers inside? (I don't have any in mine though)
how about the washers on the inside of the rear axles (to space them in), are they in there?

[delanobe]

I also had lots of problems with my trf on a astro track in Kampenhout. Ball cups popped out all day and I had extreme grip roll

I used Jimmy his set up but this didn't help...

Does somebody have some tips how to reduce this grip roll???

TIA

[TRF_Tastic]

The rear tower is cracked to hell, but it would have only been one jump after that to destroy it completly the front one died proper style.

As for the shocks, done nothing to them at all same as they have been all season, and now a mystery problem with the driveshafts...... Strange.

Got rid of the grip role very quickly by running a set of worn mini spike instead of new ones and hey presto no grip roll.

[delanobe]

What set up did you use on the astro track?

Thanks

[chrispattinson]

I'm sorry you've had a bad experience with your Tamiya. Yesterday was my first meeting with the Tamiya TRF 501 X, and I must say it's the best 4WD Ive ever driven. Infact, I only finished 2 out of 4 qualifiers (due to runing belts too slack and them falling off the diff pulleys, but I still qualified 4th in the B. I didnt break any parts, though the jumps were not too severe, and I always made sure I landed on my wheels every time. I used Jimmys setup, however I brought the Roll centre a little closer to CoG to prevent lifting wheels. It really is ballistic, and made my driving look quick. As for your problems, I wouldnt class my self as a someone that knows everything about the car, and I know we should try to control who gives advice out, but my suggestions are: Reduce grip roll by bringing the roll centre closer to the CoG. Your driveshafts may be coming out due to too much droop. The tamiya ball studs are not the best fit, I use schumacher ball studs and RPM ball cups. As for your wishbones coming out, and shock towers cracking, I didnt experience any of this, and cant imagine these parts failing unless you crashed the car???

[delanobe]

What do you mean by coh?

Thanks

[josh_smaxx]

CoG means Centre of Gravity

[delanobe]

Ok

How do you bring the Roll centre a little closer to CoG?

thanks!

[chrispattinson]

The roll centre is the axis at which the chassis rolls around.
The CoG is the point at which the mass acts.

The CoG will be above the roll centre, hence your car leans away from a crner as you turn, and it grip rolls.

You need to raise the roll centre, so 'leverage' the CoG exerts on the roll centre axis is less.

Raise the roll centre, and reduce chassis roll, by lowering the inside camber ball studs (removing the washers below the camber ball stud braces).

Someone that knows better should hopefully confirm this, as I am not fully versed in racing car dynamics, particularly suspension travel.

Rich, Northy, Jimmy, Dan, can anyone confirm I am offering the correct advice? I dont intend to be offering incorrect advice, but I'd like to have a check with the 'experts'.

[stefke]

Originally Posted by delanobe

I also had lots of problems with my trf on a astro track in Kampenhout. Ball cups popped out all day and I had extreme grip roll

I used Jimmy his set up but this didn't help...

Does somebody have some tips how to reduce this grip roll???

TIA

Kampenhout : Use 2wd staggered ribs at the front or 2wd front mini pins if you need more steering (cut the outer rows of pins !).
Take Jimmy's setup and put some internal shock limiters in the shocks ((
I used 3mm at the front and 5mm at the rear).

That'll keep your car from griprolling over there.

The ballcups : there's a whole thread discussing the matter.

[delanobe]

I will try it next weekend!

What do you use for the internal shock limiters? A Silicon Tube?

Thanks