percy-RCU

Ok have heard a lot about these miniaturized pieces of mechanical wonders, but in our RC world, how much do they really make a difference ? I have seen and heard claims about 40% and 70% increase in traction but has anybody really experienced a considerable difference in traction and overall driving experience as a whole with torsens ? Are they worth it ?

kyokai2

If you have a top end buggy they already very strong dependable diffs and can be dialed in to give the traction and diff action required by changing diff fluid. Torsen diffs are a waist of money IMO, especially at over 100$ each. Stick with your stock diffs and learn how to dial them in.

percy-RCU

Is it true that your driving style needs to dial-in to the concept of torsen diffs ?

For instance, it appears that for the torsen to work effectively, there needs to be torque flowing constantly from the power source(engine) to the diff and thereby the axle, then it can transfer that torque to the non-slipping wheel so if there was no power flowing (like as in a turn you would instinctively cut the throttle to as low as maybe idle). Now that doesnt help. The diff needs to "see" torque in order to transfer it to the proper wheel or axle.

Any other things to keep in mind when using torsens ??

P.S:- you need to break them in properly too - a few easy(not fast) figure eights should do it.

i8tweety

My Feedback: (11)

You can tune a regular gear differential to work well in high or low traction conditions (or a compromise of the two). A torsen differential provides near maximum traction for all track conditions. During the course of a race weekend, track conditions are continuously changing. This makes it extremely difficult to have conditional differentials set for current track conditions (it changes drastically between the start and finish of a 45 minute main).

Do they really help with lap times? If you are a serious racer (and consistently run clean laps), you will see faster laps (how much faster depends on the track you run on). Are they worth the money? If you're not on a tight budget and already have titanium turnbuckles, spare parts (or complete back-up/parts car), rigid chassis braces, selection of tires (suited to various track conditions), full compliment of spring tensions, sway bars, shock oils, etc. I say go for it.

DSA.308

My Feedback: (6)

100.00 each? WHERE? Try $200+ EACH. Do they make a difference? yes. I installed the front and center Torsen diffs from Nuova Faor, and I would highly recommend them. If they were just the same as conical gear diffs, they wouldnt sell a single unit at $200+ each.

percy-RCU

Ofna's are about that much. Duratrax are even less.

kyokai2

Todd, if you paid 200$ or more for a Diff you got screwed. For the weekend racer Torsen Diffs are a waist of money, if you race professionally and are sponsered by Mugen or Kyosho(which I seriously doubt you are) and run with the best racers in the world then you might benefit. Glad to hear that you like them, everyone I race with think they suck and are way overpriced, so Im not alone.

DSA.308

My Feedback: (6)

I paid $270 for 4 complete units (2centers/2fronts/& a box of extra drive cups, O-rings, etc.). So I bought about $800+ worth of diffs for $270. I will probably sell my second set for $250(1/2 of the retail cost), and then my set will be essentially free. Or I might just put them in my second buggy, so both my rigs have torsens. I would have bought 1 set at retail if I hadn't found them used for cheap, and not felt screwed. I think they function far and beyond the ability of a conical gear diff, and besides I can appreciate the technical advantage, and the complexity of the inner workings. Having the wheels with grip getting the power has a certain appeal to me, beyond the advantage you pointed out which was to get screwed by buying them. Do you and your racing buddies think they suck because you don't want to shell out $200 each, or do you think they serve no purpose other than looking nice and being expensive, and all the hype about increased traction is crap? I might believe they aren't any better then the conical diffs, except I understand how they work, and the billion dollar automotive companies promoting and engineering "torsens" (Subaru, GM, Hummer, ETC,ETC,ETC) have enough real world testing and applications to just discount their ability to increase traction. I think they work great, and I think I will just keep my second set of TORSENS for my back up 1/8 buggy that I probably shouldn't have- since I am not a National or factory sponsored racer.

kyokai2

If you got 4 working torsens for 270 then thats a good deal, the way you made it sound is you paid 200$per diff. For the price of 1 torsen I could have 6 to 8 factory diffs with different weight fluids to get the diff action I need or desire and the amount of traction. I have run a few Hyper 7's with the torsens and didnt notice any traction improvments at all over my K2, I actually thought it had worse traction and pushed more in the corners especially coming off throttle. I would like to see you get your backup buggy with the standard diffs and compare it to your race buggy with the torsens and do a comparison, run the same track with an equal setup. If your lap times are faster with the torsens I will be very surprised, more than likely they will be slower! Why do you think Mugen and Kyosho dont use them on their high end factory buggies like the K2 or the XR or the MBX5? It could be that they dont want to make money for selling someone else's product but if they were that much better they would use them. My K2 comes with LSD diffs and I really like them although most people I know that run the 7.5 take them out in favor of the stock diffs, not torsens. Can you explain this? I am a firm believer in the saying "you get what you pay for" but with the torsens I dont believe for a weekend racer this is the case. Like I said, if you like them and feel they can make you faster COOL!

DSA.308

My Feedback: (6)

I dont believe for a second that the $100 OFNA torsens perform anything like the Fioronis or Nuova Faor diffs. Thats like comparing the transmission in a Dodge Colt to a 6 speed Getrag in a VR-4. Im sure you can tune 6-8 diffs to perform like my 1 torsen will, but it requires changing the diffs!

By the way the BBF diffs that are pictured below work is with conical gears, but the insides are all machined tool steel! Best made regular diffs I have seen. What do you think about these? Also these dont use silicone....they use the same special grease as do the Fioronis. They feel about twice as smooth as a stock diff. I looked on BBF site and these are more around $180 each.

solo racer

I agree with Todd. In theory a torsen diff should be superior to the others, but it will require some getting used to.

I can definitely vouch that a Torsen works excellent in a full scale automobile. My race car used a Quaife Torsen diff that replaced the standard Clutch style diff and I must say it did make a difference, especially on slippery surfaces or when each drive wheel is on a different surface. It does require a different driving style too but allows faster corner entry and exit and a much more stable mid-turn.

However, I agree that for the average weekend racer they are not worth it. Unless you have the money to burn and like to have the best of the best. For professional level racing every little bit counts so you may as well have them.

kyokai2

I think you misunderstood what I meant about having 8 diffs, I can vary the fluid viscosity to get the amount of diff action I want. That cant be done with torsens. Are you saying they make cheaper torsen diffs for the hyper 7 or that they are different then what you have? I guess they could make a different model of diffs I dont know much about them because like I said I dont use them. Im sure there are pluses and minuses using either style of diffs but like I said for me Id rather be able to vary the amount of diff action for my driving style. Changing diffs in my car is like 10 minutes so its not bad. You must really be into racing todd, thats a crap load of money to throw out the window just for diffs but like to know how they hold up and how they would compare back to back in your race buggy and back up buggy. Anyway, hope you have good luck with them and give you faster lap times since thats what we all want.

i8tweety

My Feedback: (11)

With a torsen differential, you don't need to tune it like you do with a convential gear differential. The amount of diff action varied depending on the track conditions. Therefore, there is no need to "tune" a torsen differential.


The ofna torsen diffs are not as nice as those from nuova faor or fironi. I will ge getting my hands on an ofna unit this week-end and will be posting pictures of the internals.

BTW: different torsen differential designs provide a different degree of power transfer. The old nuova faor 4 gear wasn't as good as the 6 gear hyper japan traction.

DSA.308

My Feedback: (6)

Is the 6 gear hyper japan the OFNA you are going to be posting pictures of?

i8tweety

My Feedback: (11)

Todd,

Don't insult the hyper japan traction diff like that . The hyper diff is the one you posted a pic of to show some of the gears are supported on pins. You'll see the difference when the pics are posted.

DSA.308

My Feedback: (6)

heres the BBF insides.....

Olly_Webb

Hi DSA.308,

I just wanted to make sure that you realised that the BBF differetials are not TORSEN diffs, as far as I'm aware they are in fact Limited Slip differentials.

Im sure you know the important differences between these diffs, I just wanted to make sure there was no confusion.

Have any of you guys run different TORSEN diffs back to back, say from different manufacturers?

Cheers,

Ol.

AKasasin

dang man it sounds like you need a nap or something, grumpy[] i run the ofna center torsen diff in my kyosho st-r up here in alaska & man i love it, how can you go wrong with just a center? if your front is getting more traction then the power goes there, if the back is getting more traction then the power goes there. very simple so if you have the money get the center torsen diff, if you are like this guy then take a nap or two, & get laid.

Nitro Fumes

Although I don't have one, they don't even make one for the Losi XXX-NT I believe it should help. A torsen diff uses worm gears inside as spider gears and because they will only rotate in one direction they will prevent your differential from unloading. Power only goes to the side where the traction is. An open gear differential unloads. You ever notice on the 4WD truggies when they accelerate and pull up the front (or the front inside wheel comes up in a turn) how the tires just grow? Its because the open gear (even a limited slip) will unload and send the power to the side with the least resistance. Well, not on a Torsen. The power goes to where the traction is because the worm spider gears will lock and prevent the no traction side from unloading.

Here is a link showing a full scale torsen:
http://flashoffroad.com/features/Tor...rsen_works.htm

http://flashoffroad.com/features/Tor...RealTorsen.jpg

Pedsaktix

It would be nice to see them manufacturers create miniture Active Center Diff, Active Yaw Control, Anti Skid Control and Super All Wheel Control.. you might have to add electronics to control it but it'll be mad cool to say the least.

gubbs3

My Feedback: (1)

Torsen diffs are really just a tuning option. Yes, they can be beneficial, but most often they are not the fastest way around the track. Answer this, how many drivers at the worlds ran torsen diffs? That will give you a good clue to how to get around the track the fastest.

hands without shadows

Just so the last 5 posters know................this thread is 4 years old

Pedsaktix

Interesting.

I didn't even notice that until you point it out!

Nitro Fumes

I hadn't noticed that. But 4 yrs ago I wasn't doing R/C and didn't know about this website either.

buttmonkey1969

I'm toying with the idea of installing a torsen in a modified 1/18th Vendetta ST ....the powerful 380 size brushless motors (ammo/permax etc) have so much torque that traction from stop is in need of such mechanical aid...