It had to have a thread of its own.

I recently acquired a YRF brand new and set about building it. Couldn't resist and made a few mods I am going to detail if interest warrants it.

One paramount rule I follow (with all my mods) is that no original part can be modified, so if the need may be, the car can revert to complete originality.

First thing I did was to collect all the annoying hopeless philips head screws and replace them with allen head screws of equal length if possible. The long screws at the back presented me with the first problem because high tensile allen head countersunk screws don't come threaded all the way, and some lenghts are not available (40mm) or not easy to come by anyway. I decided to replace then the threaded spacers with straight drilled ones I made on my lathe and used locknuts at the top to hold everything down.

Looking at the tall screws the rear CF plates slide against at the rear, I didn't like the arrangement so I made a couple of neat little aluminium sliders to guide the plates up and down.

I replaced all the front suspension and steering straight rods with titanium turnbuckles to make adjustments easier.

I built the diff with ceramic balls, and replaced the spring washer with a diff spring I made form a spring I had lying around. the diff is smooth but I have some problems with it coming loose. The screw might need some threadlock. There is also a question about the inboard end of the driveshaft touching the screw head and casuing it to come loose. I am looking at the moment into the possibility of replacing the driveshafts with Tamiya universals with 42mm swing shafts and 53499 axles. They're on their way.

Looking into the possibility of replacing the diff joints I found the joints from an HPI RS4 Mini will fit straight in. I have one on standby for now. There may be some issues with clearance to the inboard end of the driveshafts but I'll look at it when I get there.

I have replaced the spur with a 64pitch 105 tooth form Kawada and the pinion with a 29 tooth (Kawada again, they're the smoothest on the market and good quality dural), and the car is silent at full chat as a ghost. This pair gives the closest ratio to the kit stock (7.81 vs 7.80), but I found the spur was very close to the top front suspension plate. I replaced then the spur with a 103 tooth which gives a tad more clearance. This should be used with a smaller pinion but the adjusting slot on the motor support does not allow for proper mesh, so I went instead to a larger one at 30 tooth for the moment. Enlargin the adjusting slot in the motor support is not an option either because the motor would hit the belt pulley. I ended up with a slightly higher FDR (7.7) this way, but that shouldn't be a problem for a silvercan. Perhaps the adjsuting slot should have been at the bottom instead of at the top of the motor plate but that's an issue I will look into later if I decide to up the power a bit.

I moved the spur a little bit further out by grinding the spur shaft locking key all the way to the end (the only original part that was modified) to allow the holder to come out a few mm, and used a spacer between the holder and the bearing in the bulkhead. This mod is needed to give a perfect alignment between spur and pinion (originals were offset by a good three mm, because the pinion was sticking out too far even when pushed all the way to the motor bushing, so it wasn't a problem introduced by my replacing of the box parts with the 64 pitch gears) whilst at the same time allowing a better fit ont he motor shaft because you don't have to push the pinion all the way on the shaft to the motor bushing to get as much contact as possible between spur and pinion.

Next I looked into using Lipos. I thought about modifying the chassis slots which are spaced for Nicd so are closer together than the high capacity Nimh (or dimpled bottom Lipos) would require. I decided against it for reasons I have explained above as well as an idea I will elaborate on further down. An orion 3800mAh will squeeze in but it will force its way a bit. I removed the rear post from the bottom chassis plate and made a custom plate from blank PCB that sits at the top, under the top deck, floating on the two rear top deck supports (these have a collar machined at the top) and has a stopper coming down at the back. The stopper is a screw with a long nut machined from brass hex spacer as used in electronic equipment. This was positioned to give a couple more mm of battery space, enough for the Lipo to sit comfortably in its cradle. Of course the original battery strap didn't fit anymore because this is meant to rest on the rear posts above the collars where I have now the custom made plate. I had then to make a new strap which I made again from PCB blank and I machined another four brass hex spacers to allo foe the slightly wider lipo to fit snuggly. It worked a treat.

Some pictures will happen soon, I hope.

Next on the tuning list are dampers and I am looking at some good quality dampers if the kit ones don't work satisfactorily. The rear shouldn't be a problem, but the front might require some smart work to squeeze in.

A nice low profile servo is needed too, I don't like the sight of the standard servo hanging off the plate, waiting for a t-bone whack to wreck it.

As it stands the car is 200grams below weight. I expected this and this is the other reason I decided not to bother modifying the chassis battery slots. I will make a custom lead tray for the lipo and the slots will end up full of lead anyway.

Hope to hear from anyone who has worked on these cars and am interested in your solutions to these or other problems.