Rhino Racing C-LDS - Active Differential. An In-depth Look
April 13, 2022
Rhino Racing, the makers of the RhinoMax and RhinoMax II chassis have been making a name for themselves over the past few years with their out of the box thinking and designs. We here at Super-G have been fortunate enough to be closely working with them and are always excited to see what they come up with next. The Rhino Racing C-LSD was no exception, and we have been anxiously waiting to put it to the test. Being without a track for the past 4 months has been torture to put it lightly, and with the prototypes in our possession and no way to test, well it was really a test in patience.
To really appreciate what Rhino Racing has accomplished, one must have a firm grasp of tuning with a diff. Many overlook this aspect of tuning and just build them per the manufacturers suggestion and just accept it as set and done. For many others, they view the diff tuning as one of the core tuning tools, I know I do.
There are 2 types of differentials (Ball and Gear) and also a Solid Spool, used to connect the rear wheels on the modern day RWD R/C Drift Chassis.
Ball - A Ball Diff has been very popular in On-Road R/C since forever. It allows tuning by tightening the pressure between the balls and the plates to create more or less resistance to the diffing action between the two rear wheels. At the loosest setting, the wheels will freely spin at different speeds from each other, giving the most traction on low throttle and also allowing the chassis to change directions quickly and easily. With more tension added, it starts to act more like a limited slip differential, trying to keep both tires rotating in the same direction. If it’s tightened up enough, it will act as a Solid Spool.
Solid Spool - A Solid Spool is exactly what it sounds like, solid. It does not allow any differential in speed between the two rear wheels. This typically will provide more speed and stability while in mid-drift, but at the sacrifice of exit speeds and acceleration and also less traction over all.
Gear - A Gear Diff functions as an open diff and uses Diff Fluid (Thick Silicone Oil) to tune the resistance between the two wheels. The thicker the fluid, the closer to a Solid Spool it becomes.
SO WHAT’S THE DIFF-ERENCE?
Solid Spool is self-explanatory
The wheels are locked together, there is no tuning involved. The main benefit is speed and stability mid-drift.
Ball Diff - The resistance is constant
The tighter you adjust it the resistance will be the same throughout the different throttle positions and rev range.
Gear Diff - The resistance varies
The quicker the throttle comes up, the more resistance will be applied to the wheels. Imagine moving a paddle slowly through a pool of water, it will have a very slight amount of resistance. Now imagine moving that same paddle at 10 times that speed. It will be very difficult. That is how a gear diff works. It will have roughly the same amount of resistance at all throttle positions, but when you quickly apply throttle, it will create more resistance between the wheels, and make it react more like a Solid Spool. Not quite, but it’s been the closest we have had.
How I personally tune my diff
I always choose a Gear Diff when it’s an option. I give it a quick throttle burst when I want less traction for a quick direction change. I roll on the boost/turbo mid drift when I want that added acceleration. Since our track is very low traction, I have actually been tuning for maximum traction by having a fully open differential. I have been using a light coat of grease instead of Diff Fluid, and have removed the o-rings to have the most free moving diff possible. I sacrifice a bit of speed mid-drift, but it rarely affects what I am doing.
Ok ok, so what about the Rhino Racing C-LSD?
I will start by saying Rhino Racing has done an amazing job with this diff! For anyone who has not really ventured into diff tuning, be prepared to have your mind blown! For those who rely on diff turning, your prayers have been answered.
Rhino Racing has given us the best of both worlds, and has provided a lot of adjustment. It can be dropped in and used as it ships with some really good results, (4 pinion gears with the soft spring set) but with the ability to fine tune, it really is next level.
Essentially, the C-LSD is a precision Gear Diff with an adjustable clutch system that will lock the diff at a given RPM.
Springs
The C-LSD is supplied with 2 spring sets, Soft and Hard. These are used to set the Engagement Point of the diff. The Soft set will engage the lock at a lower RPM, where as the Hard set will cause the lock to engage at a higher RPM. The higher up in the RPM range the lock engages, the larger range of open diff it provides, which translates to more traction for a longer duration. There is a byproduct of the springs in regard to the type of engagement. The softer springs will provide a slightly “snappier” engagement than the harder springs.
Pinions
The design allows for the use of 4 or 8 pinions. This dictates “how” the lock engages. 4 pinions will slightly ramp up before fully locking, so the feel is a “softer” engagement. 8 pinions provides a more positive lock, feeling almost instantaneous for a “harder” engagement feel. A byproduct of the number of pinions is the effect on the amount of resistance in the C-LSDs open state. 4 provides the most free spinning diff, where as 8 adds a slight, but noticeable amount of resistance. Both are amazingly smooth due to the inline gear setup when compared to the bevel gear types.
Tuning the “Open” Diff State
Rhino Racing has also provided the seals and gaskets to run Diff Fluid to further tune the C-LSD just as you would any other gear diff. I see this as a valuable tuning option that I’m glad to see Rhino Racing has included in this design. No matter how you tune your Gear Diff, you should be able to obtain a very similar setup with the Rhino Racing C-LSD, but with the added feature of locking the diff in the higher RPMs.
My personal setup After testing all the different combinations
I have settled on 8 pinions with the hard spring set. Our track surface is polished concrete and very low traction. This setup gives me the widest RPM range with a fully open gear diff, but when I get into drift, it locks up quickly and gives the benefit of a Solid Spool. The Rhino Racing C-LSD provides the feeling and performance I have become accustom to with my Gear Diff setup, but now with the benefit of a Solid Spool at the most ideal time. Truly the best of both worlds.
Why 8 pinions instead of 4?
I found with 4 I have a bit too much traction under low throttle and forces me to drive faster than desired. Possibly causing issues chasing slower setups. 8 pinions gives a little more resistance, which in return allows more control over speed and angle.
Side Note: There is such thing as too much traction. Recently it seems many just want to tune for maximum traction and speed, but the reality is, a good balance is ideal. A chassis which has so much traction it cannot chase a slower car and maintain angle is not a better tuned chassis. In fact it is the complete opposite.
The quality of the components appears to be very good. The fact Rhino Racing has used inline gears rather than the more common bevel gear setup, I have found it to be one of the most free spinning gear diffs I have used. Time will tell if the components will hold up, but I can say it’s looking very promising.
If I had to say anything I feel is not favorable about this product, it would have to be the weight of the unit. In my preferred configuration it is considerably heavier than my previous diff. Tamiya with upgraded drive cups - 19g vs. Rhino Racing C-LSD 8 gear config - 30.8g. That is a considerable increase in weight and rotating mass. That being said, the benefits far outweigh (pun intended) any negative effects of the added weight and rotating mass.
Is the C-LSD a game changer? It depends where you are coming from in the tuning realm. Like anything else, it’s not going to make the beginner into a champion. It is however the best performing diff I have used. I guess a better way to put it is, it is the best differential I have used to date. HIGHLY RECOMMENDED.
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