Dutch Phi-nomenon – Corally RDX Phi 09
Track test
We tested Corally’s RDX Phi 09 on a large, and very fast track. We geared the Speed Passion motor 22/78 at first which proved a bit too long as LRP’s SXX TC Spec speedo generates a lot of RPM so we went down to 20/78 which gave an overall ratio of 7.8 which was ok. Our tyre choice was Much More Racing’s 28 deg Sweep rubber that was a good and consistent choice for the warm asphalt track.
Next thing was to set-up the SXX TC Spec speedo according to LRP’s new SXX setting guide for large tracks to 1/5/1/1 but after the first couple of laps we switched to 1/4/2/2 as the level of grip available did not allow for the aggressive ADPC mode ‘5’. We also gave the suspension one millimetre more droop at the rear to make for a more stable back end coming out of the tighter turns. We also lowered the suspension 0.5 millimetres to 5.5 mm in front and 6 mm up rear. Now the ‘09’ felt even better. Thanks to the front one-way, turn in at the beginning of corner was very good, the chassis felt very precise with good grip. It’s hard to compare the new Phi 09 versus the old ‘NiMH’ type car as we drove, both with different set-ups and overall weight, but we had the feeling that the Phi 09 feels a bit more precise.
To generate a touch more grip we moved the front shocks one hole in and now the car felt absolutely dialled. The chassis had a very good balance and was a pleasure to drive. With the 7.4V LiPo battery and 5.5T motor top-speed was insane but although traction was quite high the rear differential held up very well. After five packs we very slightly sanded the diff washers with 1000 grit paper and a few drops of WD40, then cleaned everything, reassembled all parts and the differential felt like new again although it is non-sealed and we ran it outdoors.
Conclusion
Corally’s RDX Phi 09 is a sensible evolution of the previous RDX with a future-ready chassis technology making it easy to run powerful LiPo batteries. Performance as usual is top-notch but we do not understand why the car (still) has such sloppy wishbones that wobble on the inner hingepins. In our understanding of a good performing high-tech car at least the rear suspension has to be rock solid to guarantee maximum performance and drivability. Good thing is that this is the only real negative point and that it does not seem to hurts the car’s overall performance too much (see Performance Tips section).
Specifications
Scale: 1/10
Chassis: 2.4 mm carbon fibre
Upperdeck: 2.4 mm carbon fibre
Drivetrain: fulltime 4WD
Differentials: one-way/ball differential
Suspension: independent double wishbone
Shocks: alloy/oil filled/coil over spring
Dimensions
Length: 380 mm
Width: 187 mm
Wheelbase: 250 – 262 mm
Track – front: 162 mm
Track – rear: 162 mm
Weight: 1260 gr
*Stock set-up with wheels as tested
Equipment
Car: Corally RDX Phi 09 Rubber Spec [corally.com]
Motor: Speed Passion 5.5T Competition 2.0 [speedpassion.net]
Speedo: LRP SXX TC Spec [lrp.cc]
Battery: Team Orion Race Spec 3800mAh [teamorion.com]
Body: Mon-Tech Nazda 6 [mon-techracing.net]
Performance Tips
Suspension – The first and probably most important tip: get rid of the slop in the rear wishbones. We hate to say it but from the box the suspension arms show radial play on the hingepins. You can overcome this a bit by adding very thin spacers (thicker Delrin style ones are supplied) on the hingepins to stop the also possible axial play. By shimming the wishbones correctly the wobbly feel can be reduced. You can go as far as dripping some CA glue into the opening of the wishbones and scrub with a reamer after drying to do a near perfect job. We only added some washers while testing the Phi 09 and noticed a slightly more precise back end of the car but laptimes where not affected so we think reducing the amount of play in the arms is mainly to please the drivers/mechanics.
Battery connectors – When soldering male connectors to the speed control please make sure you use plugs with the lowest possible height. On the negative pole you see a current connector with some sort of additional ring to solder the wire on. For the positive pole we used one of Corally’s ‘Corally Plugs’ (#1634) that is of a lower height so the wire is nicely routed between the battery and the upper bulkhead. If you would use the taller connectors the wire and plug would interfere with the bulkhead.
Pinion gear – When choosing your pinion make sure you use items with a low as possible, or hidden, grub screw otherwise the screw can catch the belt.
C-Hubs/Castor blocks – The new blocks come with steel inserts for the fasteners and additionally offer the possibility to adjust the steering block height with the help of three nylon washers. As a rule of thumb it can be said that running the steering block high means a more aggressive steering and running the steering block low means a less aggressive steering. Please beware that you change the bumpsteer setting as you move the blocks up and down so you may need to add a washer or two under the outer steering ball stud to keep bump steer at a consistent level.
