XRAY - Model racing cars

hi guys,
it's Ali from Kuwait again
well i raced my car for the first time last weekend and i had a blast, basic set-up and freaking fast with the TZ-5P/ nova pipe and team Titan's cooling head.

my questions and remarks are:
1- do you guys ever run softer rear tires? i always see you guys run softer front (saw this in your setting sheets).

2- everything went ok during the race (car was fast, nice response and good clutch engagment) BUT when i took my car apart today to clean it, i saw that my cltuch is not sitting right, so i took it apart too AND GUESS WHAT, i found only one FLYWEIGHT instead of 3 !!!!!, outer ball-bearing (small) damaged, thrustbearing assembly damaged !!!!!!
any ideas on what went wrong and HOW IT RAN WITH ALL THIS DAMAGE ??

thanks alot

Ali

I usually try to get the car to rotate more due to the high rear weight bias, so I use softer (numarically softer). But if you take a nitro touring front tire (26-27mm) and feel them they are actually quite a bit harder than rears of the same number. a tire thats 2-5 degrees softer in front is common. On this car I have yet to run a softer tire rear. If the car is too loose look for ways to tune it out in suspension.

The 5 X 8 bearings in the clutch die fast, its a fact of life. The rest should last a while. Make sure your flywheel nut is tight, the 3mm allen size through bolt is tight.. usually when you throw flyweights on a centax clutch its because something came loose, but mostly when you set the clutch gap to large. ie over 0.7mm gap. Also with the thrust bearing, make sure the small hole is against the keeper flange(stationary part). how it ran? because this car is a tank lol.. not weight wise, I just have abused this car to no end, and it keeps going.. Nothin like your deal.. but its a good car

cheers,

Patrick

hi patrick and thanks for the fast reply

i was running 37 rears and 40 fronts, my car was understeering alot, i guess i had way more rear traction, next race i'll try 37s all around or 40s all around/ harder rear springs (red) and increase front toe to 2 degrees. what do you think??

ok i didnt understand clearely what you said about the thrustbearing instalation, do you mean the small holes toward the 3mm allen bolt?? i guess yes since this is the stationary part!! right?

thanks

Ali

the front / rear compounds depend on the brand. With jaco I start with 38 front 40 rear unless the track has no grip or lots of grip.. I tried stiffening up the car, with mixed results.. give me an idea of the track and I can give you a better idea of where to go with spring.. somewhere in the short dark blue spring front and stock rear spring is a starting place unless the track is high bite. then pinks all around..

with the thrust bearing, there is one small Inner diameter hole, and one large.. make sure the small hole is closest to the flange on the holder..

Cheers,

Patrick

ok now i get it for the thrustbearing,

i use GRP tires, our track is a high traction one with 2 straight lines and wide corners, one tight U turn. over all, it's a nice big simple track, not very technical and not bumpy at all.

P.S. i live in Kuwait where we don't have Xray parts in our LHS, i order all my parts from HongKong, so i don't have anyother springs, i have the stock ones and the hard (red ones)

cheers,

Ali

Brass ring:



Use the normal 2 grooved discs, put some greese in the grooves.
In the middel is a brass ring, brass is a well used material as a bearing, it works very well, I am using it for years. These rings will cost you maybe 5 cent and will last way longer.
Currently I am waiting for ceramic rings which should give less friction as if it would be noticeable.....

Ceramic ballbearings will work to last longer but be sure you have quality stuff, cheap Asian ceramic bearings are just as crappy as cheap steel bearings......

thanks alot Roelof for all the info and details, i have a new thrust bearing, i'll give it a try once again, if it fails on me again, i'll try the brass ring.

am currently running stock gears, and i would like to shorten my 2nd speed, so shall i keep my 21 pinion gear and change the spur from 54 to 53?? will that help me ?? the 2nd speed ratio will be 4.97.
Now with the 54 spur, i get to the corner after the straigh line before getting to top speed.

thanks