Monday, 24 August 2015

Sakura D4 Build and Review

My friend and fellow drifter Matt from GHz Hobbies gave me a 3Racing Sakura D4 to build and review. This is quite exciting as there has been a lot of hype on this chassis, both the AWD and RWD. I am going to be building the AWD version; each bag will be briefly explained and points made where required. If you would like just the conclusion, scroll to the bottom of the page.

(Image source: 3Racing)

First things first, what do we get in the box? You are greeted with a selection of bagged components all numbered and match up to the instructions that are also very well put. Nice clear images with minimal text is what we all like to see. In the back on the manual, you'll find a couple of blank setup sheets and a pre-configured setup from 3Racing; one that I will be referring to many times. You also get a list of spare parts and options parts with serial numbers. Also included in the box is a bag of tools and a 3Racing/D4 sticker set.



Enough waffle, lets get to it.

Bag 1: Bottom deck, front and rear lower suspension arms


A nice touch from 3Racing, multiple options of suspension mounts allow different settings for (inbound) front and rear toe. They have also included 0.5mm shims; another tunable item for those with the know how. The front arms look like they are universal for AWD and RWD so could convert to RWD in future. There are also different damper hole options in the rear arms again future-proofing for RWD.


Here's a little build tip. Instead of rounding off grub screws when trying to cut threads, use a button head or countersunk screw instead. Being 2mm, they will transfer the torque easier. It's gotten to the point where I just leave this in where I can.

Bag 2: Front and rear bulkheads, motor mount, front gear diff and rear spool

Pretty straight forwards here, a lot of the components are the same or similar to the D3; same bearing holders for the diffs that can be flipped to get more adjustment. I don't have a lot of experience with gear diffs but I'll build it as per instructions however, seeing as it's plastic, it would be best to swap it out for a one-way diff from the D3 if there isn't one for the D4.

Bag 3: Drivetrain (belts, pulleys etc), bulkhead covers, shock towers and upper deck


Bando belts, nice touch! A not a spring pin insight! YAY!  Although we do have a very clever design, changing pulleys will still be easy but you'll need 3 Racing ones to keep it 100%. They've supplied a plastic and a metal spur adapter, of course I'm going for the metal one as there's less chance of it getting damaged or threaded.


Shock towers.. What can I say? There is a known flaw in manufacturing with both the front and rear towers. You may have noticed that some shock towers have two lines of positions available for the upper damper position, well these are supposed to have this option but the upper holes have ended up small and thus not usable. Having said that, unless you know what to do with them, they're pointless anyway.


Bag 4: Steering linkages, turnbuckles, rear uprights and shafts



Standard D3 rear uprights and shafts, a little grease and they were fitted. High improvement on the steering setup; good leverage, good swing in both directions, definite improvement from the D3 setup.

Bag 5: Front knuckles, shafts and turnbuckle tool (yay!)




The front arm setup on this AWD is very interesting. I can only assume the RWD arms are different as these don't have caster adjustment.
Double A arm is also an old suspension setup so I am intrigued with this design.The knuckles have been redesigned; no C hubs and still quite sturdy although I do feel that (approximately) 15-20° SAI might be a little too much.
Another nice touch with the ball ends is having a slight curve, a design implemented to clear the wheels at full lock for the RWD chassis'.
The shaft outer joint pins that used to come loose are now designed to sit in the bearing so no more locking up. The shafts also look like they have been upgraded to allow for more angle, a little grease and they went straight in.

Bag 6: Servo mount and battery tray (and 3M double-sided tape)


There are two options for mounting the servo depending on whether you fit a standard or shallow type servo and which way you decide to face it. Whoever gets ownership of this chassis will most likely fit his/her own servo and horn/saver so that will be left untouched. The battery tray however, due to the holes 3Racing have drilled on the chassis, this battery tray will take any size battery! The battery sits across in the chassis in front of the motor but the RWD version does have a diffuser battery option should you want to go that way.

Bag 7: Shock absorbers


The shocks have to be fully built up, standard D3 shocks but there are 2 pairs of springs - make sure you get them the right way round. You also get 350 oil which is my go to oil so straight in with that.

HERE is a good video by Ultimate RC on how to build shocks. I'm not going to go through the process as there are loads of videos and website/forums explaining how to do this.

Bag 8: Front bumper, body posts and body post cushions

All straight forward here

Bag 9: Rear diffuser, antenna mast, wheels and tyres


The diffuser is pretty cool, smaller than the D3 one but has the option to screw on weights to it again future-proofing the design.

Tool bag (lol):

Handy pair of pliers
Selection on socket wrenches
Turnbuckle tool

Conclusion:

So there you have it. The chassis is based on the D3 but of course it would be as it is the successor. This AWD version of the D4 has RWD capabilities on it and as a budget chassis, a very competitive chassis. There are plenty of tuning aspects available on the chassis but you could always opt for the RWD counterparts so get more adjustment.

This AWD version has also been future-proofed as mentioned above but also follows current trends with the midship-rear motor position and the option for a diffuser battery. The diffuser on the AWD version has been cleverly designed to accept weights to be fitted to it should the owner want to or need to.

All in all, a very competitive chassis for the price and with 3Racing and third-party companies offering upgrades, this chassis will last a long time just like it's predecessor.