11-03-2001, 02:54 AM
Join Date: Aug 2001
Location: Malta. G.C.
Hi all. Greetings from Malta.
THE SHOCK SAGA.
May I add my little bit to this one too, since my set up is pretty controversial and has caused quite a bit of discussion in these columns in the past. Whilst Speedo has a point, I have to agree more with Dave in general. Certainly suspension tuning is one hell of a black art.
Just as a background, I have been playing with real race cars for almost 40 years and built my own championship winning car in the 80s. I stopped racing due to heart problems some years ago and am back racing now with a much quicker car than I have ever raced before.
My brother who also races his own 2 litre single seater, bought the car ready built some months ago. It has a great engine Ė 180 bhp from 1380cc, great brakes, but handles like a pig. Just a look at it and you notice immediately that it is all wrong. I have raced it a few times, including a championship hill climb last Sunday, and it is presently on blocks where I am applying some RC technology to it, in the suspension department.
The car is way too hard sprung, way too hard damped and has far too much rubber on the road (10 inch slicks when it doesnít need more than 8 inch) Ė it bounces off all the undulations in the road and spends more time in the air. Apart from this the suspension arm angles are all wrong but this is going to need major surgery so it will have to wait a bit as we are hill climbing again in a couple of weeks.
Now letís look at RC. We donít have the problem of having too much rubber as we all run 24mm wheels and tyres, but we have such a vast choice of springs and damper settings that we can so easily get lost.
My RC car is a Yoke special basically, but with lots of subtle changes Ė such as a top deck that encourages flex and is therefore more forgiving over the kerbs. Remember I am 55, my reflexes are not what they used to be, and nor is my eyesight, so this set up whilst being all right for me, may be totally wrong for someone with lightening reflexes. My son Ė 18 - admits it handles well but prefers the more twitchy and quick reacting set up he runs on his cars.
I run 30 oil all round on TC3 shocks with No 2 pistons, and soft yellow Tamiya springs. The reason for the TC3 shocks is that they are longer and therefore give more droop. The shocks are set on the innermost top hole and the outermost bottom hole, both front and rear, thus making the shock work less for a given amount of travel. Most other settings are fairly standard Ė bottom arm pivots on lower holes all round, 1 degree rear toe, zero up front, 1 degree negative front and 2 degrees rear, and 5 degrees front caster.
Yes the car may be lazy in itís response but it suits my slow reactions. Certainly that amount of droop and the soft springing and damping ensures that the wheels are always in contact with the road. Also because our track is bumpy the soft springing helps there too.
Now I said I am applying this to the real car too. I have softened up the shocks and springs and already it feels much better Ė still in the garage of course. When I put it on the ground at least the springs compressed by about 1/6th of their uncompressed length. Before it just used to land with the springs not reacting at all. Iíll have to wait till next week before I can try it again, but it certainly looks more reasonably sprung.
Clearly real race car technology and RC technology go hand in hand. I built RC cars using my knowledge from real cars, and I also apply that RC technology to the real thing. Just as an example I built an RC car last year using the efficient TC3 drive train, but MR4 wishbones and hubs Ė all on a flat 3mm carbon fibre chassis. It handles so well.
Weíre supposed to be RC racing tomorrow but itís raining at present. Letís hope itís dry.
Joe from sunny Malta.