GEAR diff or BALL diff ?
 

GEAR diff or BALL diff ?
Which one is better ?
Under what conditions is one better or worse then the other ?

I've heard so many conflicting onions at the track last couple weeks...
"They finally figured out Gear diffs now, and all the pros use them"
"Ball diffs are less drag , you only want to use Gear diffs on carpet with mod motor"

I'm so confused....

Seems like preference to me...I like 2 gear diffs, but that may be the way I drive. I have had a fast guy tell me he's always faster with a spool and ball diff, but he said he's driving hard enough to pick tires up and the gear diffs unload on him. At the same time, one of the local fast guy's car looks like a 1/12 on rubber tires on asphalt and he has 2 gear diffs. ???:weird:???

You might just have to try it and see if you like it.

I do prefer the way my car drives with a ball diff but it only last a few races before it feels rough, probably the way I build/run it so I use a gear diff just because it's pretty much maintenance free.

If I could build a ball diff well that lasts I'd use that :p

I like the feel of a gear diff in the front, it's possible to adjust the viscosity of the oil which is impossible with a spool :P Try it out, everyone say different about what's the best choice :)

For me, a geardiff in the front have always been slower so far. The car is a lot easier to drive, and can hide poor handling. With my previous Xray, I made a (quite big) mistake during a routine clean of the car, making the handling very uneven. I couldn't feel a thing with the geardiff in the front, but when I tried putting in the spool again, I could immediately feel that something was wrong.

The next couple of days I will spent on testing the geardiff in the front on asphalt. All my tests so far have been on carpet.

Charles, testing at CAL, with less traction conditions, the gear diffs had less rear traction than the ball diffs did. It seems the gear diff marvel at high traction situations like carpet, but less grip tracks like P-Lot tracks, the ball diffs work much better in our testing.

So basically there is no advantage using a Gear diff on most asphalt surfaces... except maybe to make the car easier to drive , but not faster...

My feeling is that a gear diff in the back gives you more on power steering on high traction surfaces. On low traction the car can be loose or light up the inside wheel.

At the RROC this year the biggest single improvement I made to my car was installing a gear diff in the front. I used cleaning putty so it was very tight which I don't think you could duplicate with fluid. Hebert, Levanen and I used this setup. Not only was the car easier to drive, but it was faster. This took me from a guy just off the pace to a contender.

FYI easier to drive makes you faster even if the lap times are not faster. Fewer mistakes will be made and your overall time will improve.

Let's not forget a gear diff can be tuned using different oil weight.

http://www.spec-r.com/default/images...my_install.jpg

Geardiff for sure...

well I'm not sure it faster ,but it is quicker than the ball diff because the gear diff doesn't slip ;)

I ran with the gear diff in the front and sure make it's easy to drive but not faster than spool ..Some how the spool can break down the speed into the corner better than gear diff...( unless you put puddy in the front gear diff..)

I vote for Gear in the rear only..my 02 cent

There are definitely an advantages Charles. For one, you get much better turn in with a gear diff up front. You couldn't do that too easily with a Spool set up. And tuning plays a factor as well with the different oils, etc. Again, the disadvantage to the gear diff is running in less traction situations where you just can't STAB the throttle with our spinning out. It is different for everyone..i like running a gear diff up front but not in the rear. Reinhardt ran DOUBLE diffs at the Reedy race..but then again...he can run double spool and still lap me.

..he can run double spool and still lap me.[/QUOTE]

that's funny....:cool:

Can you give some details about what cleaning putty is and where I might be able to find some. I'm pretty dirty and might be able to use some cleaning putty. Seriously, I would love to try some in my diff.

This is the stuff he means and you can buy them at Kamikaze Hobbies.

http://www.tqhobbies.com/tqhobbies/i.../XCE103233.jpg

KAMIKAZE HOBBIES

someone cant really tell you which ones better. your gonna have people who like the gear diff , and the people who like ball diffs. try them both . its a personal preference.

I haven't built a gear diff with putty yet, but I have with 500k oil. If the putty is thicker than the oil does the diff actually get "worked" when running the car? Has any of the team ever tried a steel, or weighted, spool? I'm wondering how much, if any, of the difference in handling between the front spool/gear diff is due to rotational weight?

Thanks

That's cause Reinhardt knows how to tune a ball diff...

this thing inside the diff...!? they are move...? :eek:

Doesn't look like the gears would give at all... stuff looks pretty dense... Looks like it would be almost the same as a spool... but I guess not... As far as what you said Charlie " you just can't STAB the throttle " ... I don't drive that way so maybe I might like the gear diff ???

How much power do you loose say with a 21.5 or a 17.5 motor compared to a Ball diff ?

You don't lose any power at all unless the wheels spin and lose traction. Personally, i think you will be fine because you drive that 2wd sedan pretty damn good.
Bigdog...i mean Double GEAR diffs btw.:weird:

He Ran Gear diffs at reedy:sweat:

Gear diffs are faster, theres a reason why pro's ALL use them now. The car is harder to drive? Learn to drive it like that or you will be going backwards at a rate of nots:nod:

My 2c

Do you pack the front gear diff with putty as much as possible? Or just put like a big chuck inside?

I like gear diffs, but then I have such limited experience with ball diffs, guys who have been tuning balls for years seem able to get 'that' much more from them, but I think for someone newer to electric maybe gears are a much friendly option.

Just based off some stuff I noticed, the gear diff seems to stay exactly the same during a heat, or even during a whole meet or more (without being touched), the last ball diff I built you could feel it change/alter throughout a heat. :confused:

Also I tried a front gear diff, and yeah you loose some drive out of the corners, but I was surprised how much easier it was to drive with, the spool seems to fight the turn in, diff just glides in, I can see spool cars pull out a bit harder than me, but then I'm able to come in a lot quicker.

It's all playing with oil weights as well, I had like 100k up front and it lost a lot of drive (compared to spool), but 200k and it's not bad now (300-500k and I recon it would be golden), as for the rear I just kind of love it so much I can't imagine putting the ball back in.

For me, I don't gain as much on entry with a gear diff in front as I do on exit with a spool. Yes it makes the car smoother but it just doesn't have the rip out of the corner. Also, what about the extra rotating mass up front?? JMO

good thread,one question. when you say 300-500k what oil is that
i am used to ball diffs or off road running up to about 10,000 weight oil
is 300k same as 3,000 weight :confused:

300.000-500.000 (in the front diff).
1:8 off road use much lighter oil

Yep, I'm talking up to 500.000cst rated silicone oil, I'll likely have to get some Kyosho though as most brands stop around the 100-200k mark.

Keep in mind for me this is a 4 gear TOP micro gear diff up front right now, and they need heavier oil to feel the same as a 6 gear full sized diff, same micro in the rear uses 10k when the bigger ones use like around 1k.

Which also brings up what people do run in the rears, for the SpecR's etc, people run anything from 250cst shock oil (seems extreme to me), up to say 1500cst, my Yokomo came with a bottle of 700cst, I think the new Serpent comes with 1200cst, no idea what the factory fill spec is on the SpecR, though I plan on buying a SpecR soon...

I am in the process of fitting front and rear gear diffs in my TA05v2 and am just not sure if I should be now running a center oneway or not bother. Anyone have experience with this?
the advice would be much appreciated :)

I ran the double gear diff setup on my v2 with 100k front and 1k rear oils, you don't need a center one way for this setup but I would suggest around 300k for the front I just didn't have 300k to use up front.

cleaning gum
 

IMO the reason guys are having more success with things like cleaning gum in the front rather than heavier oil is due to the fact that with oil, once you get boss of it and it starts rotating in a certain direction, it will continue to gain speed regarless of how heavy the oil is and the tension becomes lighter, whereas, with something like cleaning gum, regardless of the rotation speed, the tension on the diff remains the same throughout.

Again, this is only my opinion, but all the top guys are using this instead of oil, and there must be some reason for this???

it was hard to drive front gear if used to front spool... it will take some times to drive front gear smoothly... compare to spool, gear tend to spin the car... frankly say, untill now i still not get the max speed for some corners... but at overall infield, gear is faster than spool... of course out of corner, spool is more on power (very obvious)...

for now i am comfort with 300k oil compare 500k... although 500k better at on power... 300k give me more steering (easier to turn the car)

if u want an easy n relax driving... spool is the answer...

The Xceed stuff mentioned is what I use. I have no idea if different brands of the putty are different.

Juho instructed me to pack the diff as full as possible. After one or two runs you might need to add a little more but once it is set it should not change much. You can play with the amount to change the feeling as you would do with oil.

With the TC6, we use the slipper spool which is essentially a diff so the difference between a gear diff and out spool is not as much as it might be with other cars.

The diff is tight enough where there is probably not a lot of diff action. With a spool you have to fight the car into the turn where with the putty diff the car enters the corner more smoothly and faster.

Other cars may react differently but with the TC6 gear diffs are a big improvement.

That's enough for me to give it a go, I've kinda been holding out in hopes the well known rumored TC6.1 updates that may include a gear diff show up. I know you can't really say what, or when, or much of anything, but I have a riddle. If the kit showed up with gear diff option in 2-3 months I'd wait for it, longer then I'd mod the Spec-R....so should I wait? :sneaky:

im of the same opinion, id like to try one and give my honest thoughts, but then id rather wait for a associated one to come one with a swag of update parts

ed

I would say that it could be around that time frame so I would wait.

thats all the info i need

thanks Rick 8)

So with the putty in a front gear diff, why not just run a really tight ball diff up front?

I'm speculating here (lack of tuning with ball diffs myself), but I know my TOP ball diff at full lock up, is still a little bit more free than my micro gear diff with 100k fluid in it, and a full 6 gear diff would be a fair bit stiffer with 100k.

Awesome Rick thank you...I really like the associated diffs and will hold out for their version...the slipper spool works pretty well now that they hard anodized the outdrives. :)

I was thinking of trying that myself. But as I understand it, cranking down the ball diff and trying to run it hard that way will reduce the life you get out of it. Not sure just where, but at some point you reach a point of diminishing return when your replacing parts too often.