Xanavi_R34

iTrader: (7)

Hmmm... I get the both sides but the inner and outer, not really... But i did shaved off the raised plastic rings... all of it, including where you put the bearing in the circle...

Xanavi_R34

iTrader: (7)

Sir cruisaaja, No worries anymore sir about the 16 balls ball diff... I got it working smoothly now and there is no problem... What is bothering me right now about the diff is that when I turn the diff at one side, it is smooth then suddenly for 1 sec, there would be a sound like there is something stuck inside but not that often, only for sometimes... Opened and checked it, remove some dirts and plastic that I scraped of then tried it again, for a long time, I thought it was gone but then suddenly it came back... So do you guys think it is only a dirt or anything that I shouldnt worry about??? I just noticed it is kinda half open (the balls) so it is really prone to getting dirt inside the diff balls and diff... Am I right???

Pics will follow, just charging my digicams batteries... Hehehe...

Tek Nickal

I don't see why you can't just use both the inner and outer holes for a total of 16 diff balls. Whats the reason for having the balls riding on the outer edge of the diff plate? And why do you need to shave off the rings around the holes where the balls go?

Xanavi_R34

iTrader: (7)

Now I get what the outer and inner holes are... Hehehe... Anyway, that I do not know... Was wondering also but what the heck, I have just drilled the holes already for a total of 16 diff holes (outer) so might as well just do the tuts...

And why shave off the raised plastic diff holes??? It is because if you do not shave the raised diff holes, it wont spin freely... Like what I did the first time building it... And I read the tut carefully, then just I noticed that I need to shave them off... Then after that, it spins freely now... Nike a normal ball diff but smoother...

5tylez

iTrader: (5)

has anyone seen this?

rampal

iTrader: (4)

old news... check last couple of pages...

Toughbeard

iTrader: (2)

I tought you said the horse was dead

but to put it this way I want to go down to lower FDR for running stock and with lower IR I can do that.

For the increased friction, the outcome of the modification suits my needs there for I can live with the added surface resistance, but by using a larger pulley you reduce stress in the belts. (unfortunately there is no best of two worlds) the minimum recomemded teeth for a pulley is around 20 for 3mm pitch belts. it is a give or take thing you can go lower but you have the accept the penalty of the belt abuse.

Cruisaaja

I though that same when i did that diff, but if Marc and rest of the TRF guys use that way i`ll do sameway

Xanavi_R34

iTrader: (7)

yeah, trust those guys who use it with experience...

Andyg01

see tryhard's posts and look at his website, look for carpetwars

jinsc

Yeah, I was just kicking it to make sure it was dead. That and it was kinda funny to see you contradicting yourself. Anyway for others that might like a good explanation as to the point of using an 18 tooth center pulley read on.

There are so many things that affect the efficiency of our touring cars drive train. Here are just the key ones:

Required Preload (to handle drive train load)
Pulley diameters (belt wrap & tooth count)
Tooth profile (mesh and un-mesh of the teeth)
Material (Aramid or glass fiber and Rubber compounds)

The required preload of a drive train probably has the most affect on the drive train efficiency if all else is equal. For high load situations such as modified or off-road, you of course need more preload to avoid the belt from climbing/jumping teeth. Lower load conditions like stock, you can run much less preload. So yes, tension/pressure in general does increase resistance/drag. However going from a 16 tooth center pulley to an 18 tooth (adding 2 teeth) is not adding more tension or pressure unless you increase preload. In fact, this is one of the primary reasons why it’s LESS friction/pressure/drag because with the 18 tooth pulley, you can run less preload and maintain the same amount of load capability as the 16 tooth pulley had. Or you can maintain the same preload and increase your load capability. Either way, you get an increase. Think of it like stage diving. You don’t want to stage dive into a crowd of only a couple people. The more people you have to catch you, the less force is applied to each person. This is actually a similar reason the TRF guys make the modifications to the diffs. More on that later.

The increase in pulley diameter also reduces the amount of bending the belt must do so this further reduces friction.

The tooth profile doesn’t really benefit much from pulley size but it was on the list because it has to do with general drive train efficiency do to the meshing and un-meshing.

The material is very important because of the flexing the belt must do. Aramid fiber (aka Kevlar) is a great material but it has good and bad tendencies. It is stronger than glass fiber and heat resistant but it can expand slightly depending on humidity. Glass fiber is not as strong but is very stable. Then there is the rubber compound, softer compound will have less resistance to flex compared to harder compounds. How important is this? It’s why Tamiya Low Friction option belts are low friction, because of the fiber material and softer belt compound. It’s not because it has less surface area (they are all the same width). The softer rubber compounds of course don’t last as long and break down much quicker. The also are a little less efficient at high speed because they begin to flutter more.

Back to the TRF diff mod, using the 501 diff rings and the outer diff holes puts the diff balls in a better position of leverage over the load they must sustain. This allows a big reduction in diff tension in itself for the same holding force as it would compared to stock. So, less tension, less wear. Adding more diff balls is similar to adding more teeth to the center pulley. The additional balls distribute/share the load which further allow less diff tension for the same holding force (like stage diving). This is why your diff will last much longer and stay more consistent with this diff set-up. Again, this is also why going from a 16 tooth center pulley to an 18 tooth will do one of two things, REDUCE friction/increase efficiency (less preload requirement) or increase load capability if you maintain the same preload.

Tek Nickal

Thanks, thats exactly what I needed to know about the diff.

jinsc

Speaking of diffs, it’s VERY important to use the right diff lube. Good diff lube has a very specific characteristic to it and that is it’s ability to allow rotation of the diff balls but resist sliding/slip. My personal favorite is Associated silicone diff lube (red label) or Schumacher diff lube. The Associated is thinner and creates a slightly free feeling diff as the Schumacher lube is much thicker and seems to have better griping ability. Both are very good but if you run stock, the Associated is probably good for most conditions and for mod, the Schumacher is your best bet. If you do the TRF diff mod, it is VERY VERY important to use the right diff lube between the 501 diff rings and the outdrive surface because if you don’t, your diff will likely slip (especially if you run mod). This is because the 501 rings aren’t keyed like the stock ones are. So don’t put in wheel bearing grease from Pep Boys because a you got a quart for the same price of real diff lube. Don't laugh, I've seen people do that and wonder why they have to tighten the diff so much to keep it from slipping and the diff is so stiff from being tightened so much.

Besercoe

iTrader: (9)

I have been waiting for ages for a company to release a big diff ring diff.

It makes so much sense with the horsepower we have nowadays, it happened in 12th scale years ago, and is long overdue in TC. Although it is disapointing to hear the 501 rings are not keyed

Now i am just trying to work out how i can incorporate this into a Cyclone.

Tek Nickal

So you have to apply grease between where the diff plate sits onto the outdrive?