Just a brief look at my B4 before it loses its NiMHs for good… and probably the brushed stuff as well, although I don’t have any brushless electrics for this one yet!
A couple of things have impressed me about the B4 over a few months of owning and racing it.
First is how incredibly durable it is. I am effectively learning 2wd from scratch, racing on a pretty unforgiving multisurface indoor track, and I haven’t broken a single thing. The only part I have had to replace is the rear bulkhead, which was my fault for mistakenly threading a 5-40 screw into it (instead of a 4-40).
Second is how astonishingly well sorted the car is out of the box. After trying almost every alternative part Associated do, and trying various ballast arrangements, I keep coming back to an unballasted car, with springs, 30 degree caster blocks and black steering rack ballstuds being the only parts that are not in the box. Considering the B4 was released 6 years ago and developed on clay tracks, that is just amazing.
Associated B4
Still running the simple white body on my car. Easy to see, easy to paint. Tamiya PS1 cans if you were wondering. I’m running the JConcepts 7″ V-wing (#0109) which is brilliant. Super durable and looks a lot better than the tiny little kit wing – which cracked at the first race meeting. This JConcepts wing is still rock solid. Does it make the car faster and better handling? No idea.
Associated B4 electrics
Under the shell at present is the following…
- Futaba S9451 servo – this will stay.
- Futaba R133F reciever – also staying – I see no need to go to 2.4GHz when 40MHz works so well and there are fewer crystal clashes nowadays!
- Keyence Rapida Pro ESC – such a good speedo, no capacitors or diodes hanging off it, full on-board programming – perhaps one day the brushless speedos will be this good?
- Orion V2 12×1 motor – I don’t like these at all – no power and a nuisance to work on. Only put it in because my 19×1 needed new brushes.
- East Power 4200 NiMH cells – I’m amazed that these survived 2 years of infrequent use and misuse. During that time at least two cells dropped to zero in storage but came back to life. They are totally shot now though.
Not that it is particularly relevant now since so few people use NiMH, but to get the pack to fit neatly in the B4 tray (which was designed around earlier, smaller cells), I had to rebuild it using the Trickbits economy battery bars, which are flat and thin (#TB2001). Stepped bars make the pack too wide.
B4 steering ballstud
You may just be able to make out in this photo that I have drilled out the top of the Associated ballcup. I have also replaced the ballstuds on the car (at great expense!) with Associated’s socket-head versions from the GT2 and B44. This allows me to undo the ballstuds without unpopping the ball ends. Frankly this wasn’t worth doing. If you want to copy me, use a 2.4mm (3/32″) drill bit to clear the 2mm (5/64″) hex wrench.
What is worth doing is replacing the silver ballstuds that are standard on the steering rack, with the black ones (#3981). These are 30thou lower than the silver ones, and remove the bumpsteer that you get if you use the 30deg caster blocks (an essential in my book – #9593). On the topic of caster blocks, have a 2.8mm (7/64″) reamer or drill bit handy to open out the hinge pin hole – the moulding on these has got incredibly tight since Thunder Tiger took over. My Dremel saw a lot of service during the build!
Associated B4 axle pins and nyloc nuts
The only other change I have made to the car is a few parts from Nortech Racing. These axle pins are very simple but well worth having in my opinion. The standard B4 axle pin is a rough roll-pin that isn’t as big as the slot in the wheel. Stripped wheels seem likely – thankfully it did not happen to me. These Nortech pins are slightly longer for a better fit in the wheels, and are smooth and solid too which should make them stronger. I was hoping that the longer pins would stop the wheel nuts from working loose, however that has not really been the case. They need checking after each run. It’s a shame Associated don’t supply flanged or serrated nuts like the Japanese cars have.
The other Nortech part is the 4-40 nyloc nuts to hold the camber link ballstuds in place. The plain nuts in the kit can work loose, I lost one myself. I suppose a little threadlock would help but that doesn’t help assembly and disassembly. Nyloc is the way to go. Associated also make a few different kinds of nyloc nut if you prefer.
So, that is the car, all that remains is the setup. As I said earlier, I have tried most things, but kept coming back to the same settings. A few observations…
- The 30 degree caster blocks get the balance of the car spot on.
- Moving the camber links in one hole at the wheel tightened the car up nicely and stopped its tendency to roll deep into the corner.
- Since I run on a mostly carpet track, I found that the stiffer I went on the rear springs, the better the car got. More precision and greater corner speed. Generally I’m running silvers or greys in the outside hole on the wishbone (truck blues are a step too far and make the rear lose grip).
- Front springing is in balance with the rear (generally blues or silvers in the outside hole). I also prefer #1 pistons as the #2′s seemed to make the front end a little unpredictable.
- Anti-roll bar has never been better than running a slightly stiffer spring rate. It upsets the balance between roll and pitch stiffness
- I could barely tell the difference between wheelbase settings
- I tried putting more ballast on the front bulkhead to keep the nose down in fast corners. It failed to do that and just made the car feel a little more sluggish on the steering. Stiffer rear springs and shorter links did more to keep the nose down than.
Associated B4 indoor setup – b4_caldicot_19x1v2_DA.pdf
That’s it for now! 
