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Old 07-22-2008, 05:52 PM   #46
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There has to be more going on, otherwise where are these "ramps"?

"The locking is enabled by internal ramps which act like a wedge, with the throttle and brake torque being applied to it. The rate of lock is in direct reaction and in direct proportion to the torque input- the more torque, the harder it locks. The angles of the ramps can be changed with optional parts to achieve various handling characteristics."
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Old 07-22-2008, 06:01 PM   #47
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Ok, I think I figured it out but need to do a little more research before I look like an even bigger idiot. Be right back.

Those round things with the grooves are what they call ramps and different ones are available so they obviously play a role.
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Old 07-22-2008, 06:07 PM   #48
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Quote:
Originally Posted by wingracer View Post
Ok, I think I figured it out but need to do a little more research before I look like an even bigger idiot. Be right back.

Those round things with the grooves are what they call ramps and different ones are available so they obviously play a role.
and how about the concave spider gear on the spur gear in pic 11? or am I looking at the picture wrong.

It also doesnt show those 4 tiny gears as having o rings and washers on the back.. maybe its just because its a poor drawing.
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Old 07-22-2008, 06:14 PM   #49
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Somehow those "ramps" (the round pieces that go over the spider gears) can apply load to lock up the diff under power. Here is an article on the real thing.

In an effort to solve the problem of the open differential gear train designers have come up with a number of solutions over the decades. One of these uses several clutch plates coupling the axles to the bevel gears. It was made famous by General Motors during the muscle car era as the "Posi-Trac,' but the proper name for this type is the 'Salisbury Differential.' In the early Salisbury units like the Posi-Trac, the amount of wheel spin allowed is controlled by the preload on the clutches. The theory was great, but in practice the preload was difficult to get right and changed as the plates wore. Many refinements to the Salisbury differential have been added by other manufacturers over the years, including one by Xtrac, the Hewland Powerflow and a new diff called the Variloc introduced by Taylor Race Engineering. Although there are differences among them, all use ramps splined to the inside of the housing which load the clutch discs through the end gears when power is applied. The loading of the discs is therefore controlled by the ramp angle employed.

Since we want differential action entering a turn and need to reduce wheel spin when the throttle is applied, the ramp angles are different between the coast and power sides. The coast ramps are usually 80, 83 or 90 degrees to load the clutch plates little, if at all, allowing speed differentiation under braking. The drive ramps can be anywhere between 30 and 60 degrees depending on how much lock-up is needed out of the corners. Additional adjustments can be made by the type and stacking order of clutch plates used and by preload on the plates. These units can be set up anywhere between an open differential to something approaching fully locked, both entering and exiting turns. Although they are very effective when properly set up, some power is lost as heat when the plates are slipping.
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Old 07-22-2008, 06:16 PM   #50
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Here are the ramps:

http://www.amainhobbies.com/product_...ducts_id/26341

And I guess these act as the clutches:

http://www.amainhobbies.com/product_...ducts_id/26356
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Old 07-22-2008, 06:18 PM   #51
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damn, thats crazy.

I would like to try those. one day maybe.
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Old 07-22-2008, 06:19 PM   #52
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I admit that I am curious. Price is definitely a drawback but if they work the why I think they do there could be something to it. Then again, maybe not.
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Old 07-22-2008, 06:29 PM   #53
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The blue can is nothing more than that, a blue anodized, machined can with through holes for 4 screws...

The part you are missing, which IMO is a mistake by the CAD guy...he forgot to show that step. Anyway, there are different outdrive assemblies shown in the instructions. One half (the one without the Spur gear) is "locked" onto the blue can, than the other half (the spur gear and "gear set") is installed with four screws sandwiching the entire assembly.

Xray makes a similar diff...which is here and is explained pretty well....this should end the questions:

http://www.teamxray.com/teamxray/new...7ddf9d61696042

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Old 07-22-2008, 06:40 PM   #54
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Yeah I figured it out after posting all that. That's why I said I needed to do more research before looking like even more of an idiot . So now the question is, do Xray guys use it and like it? If so this may give all the other brands a similar option.
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Old 07-22-2008, 06:43 PM   #55
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...this was in the link

"The Active Differential has been long-term tested with great success in all different racing conditions, (including the European Championship and World Championship) by factory team drivers including Yannick Aigoin, Jon Hazlewood, and Josh Wheeler. Yannick Aigoin won the 2006 Euros and Oliver Simon won the 2007 Euros B, both of them with the Active Differential aboard their winning cars."
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Old 07-22-2008, 06:54 PM   #56
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And Xray can make it for half the price.
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Old 08-10-2008, 01:15 AM   #57
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this would be a limited slip of sorts not a thorenson(sp) diff very cool
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Old 08-11-2008, 03:17 PM   #58
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I run these diffs in my RC 8. They are different that the Xray diffs in several ways, so they don't compare. I have not ru the Xray, but I hear they are great. The Xray diffs are filled with silicone, the Fioroni diffs run grease only. Why? I'm not sure, but thats how Fioroni designed them so thats how I run them. It is recommended to rebuild and re-grease every 3 races. The diffs have amazing foward bite. I run OS Speeds and the new Trinity EB Extech and the more power you throw at em, the better they work. I have run all 3 front, center and rear. The car has a off power push in the turns, so I am going to run the center only, then tune the car with the front/rear diff. The diffs are very durable, I have never had one grenade or wear down yet. I've run two complete sets and I really like em so far. As far as the cost, thats part doesn't concern me so I don't figure that into my decision to run them. I don't mean to sound like a snob at all. I believe you get what you pay for.

I will continue to tune with them and I will report back after this weekends racing. Fioroni make amazing parts and yes they are expensive. I just like their stuff alot and I have had very good luck with the diffs and their clutches. To me, the low maintance of the diff's and the fact they conform to each track takes the part out of my race day maintenance and allows me to work on others way to improve/tune the car.

P.S. I don't work, nor am I sonsored by Fioroni. Again, I just like their stuff.
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Old 08-11-2008, 05:18 PM   #59
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Well for me I look at what I'll call "diminished returns"..What your talking about here is $675..I am an expert club level racer..I dont care to travel or really race at the "BIG" races anymore..been their done that....I'm looking at how much my lap times will improve (I have tried the torsen diffs..and I know that the Fioroni is not the same but the way it puts the power down is close) versus how much I'm spending..as far as low maintenance goes..how did you figure that..when Fioroni tells you NOT to go over 3 races without a tear down..and they recommend that you do this after every race..when it comes to Fioroni..I'm of the opinion you over pay for what you get..it's nice stuff..but so is king headz..and all the other cottage parts makers stuff..Fioroni was the "shit" back in the day..good luck on the diffs..
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Old 08-11-2008, 05:57 PM   #60
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Im not an "Expert Club Racer", but I think the main question asked if anyone had tried these diffs and are they worth it. I answered the question with my experience with the diffs, since I actually have them and use them. I like them and I will continue to use them. I dont care if you use them or not. Also, not here to get in a pissing match on price etc. or play the usaul ford/chevy thing. I will keep those interested up to date after this weekend.
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