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Old 08-05-2003, 09:58 PM   #1
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What is all of this one way Diff or CVD stuff? Also can someone clarify for me what the CVD and MIP are?


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Old 08-05-2003, 10:07 PM   #2
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1 way diffs use a 1 way bearing. Basically the bearing grabs 1 way, but slips the other. In this case, when power is transferred to it, it will grab, but if brakes are applied it will slip. They are good for larger sweeping tracks as they generally carry more cornerspeed, but not so good for tight tracks where you need to use more brakes.

MIP = Moores Ideal Products, they make CVD's which are Constant Velocity Drives, they replace the dogbones or universals that come stock with cars.
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Old 08-05-2003, 11:04 PM   #3
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So what I have in my totally stock car is a dogbone? How is this different from a CVD or is the same?
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Old 08-05-2003, 11:22 PM   #4
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What car do you have? Some cars come stock with CVD's.
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Old 08-06-2003, 09:49 AM   #5
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Losi xxxs, but it's the rtr version. Cause I was looking to upgrade to aluminum CVD's but then I wasn't even sure if my car had CVD's.
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Old 08-06-2003, 11:04 AM   #6
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I have a question about one ways and spools if ya dont miond real quick.
Can they increase my total top speed or acceleration? (in the straits)
Thanks.
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Old 08-06-2003, 11:08 AM   #7
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The Losi RTR has steal cvds front and rear. They are made by MIP.

A one-way or a spool will not increase your top speed nor will they help you accelerate faster. Only will help you to be faster in the corners.

Later,
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Old 08-06-2003, 11:09 AM   #8
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Quote:
Originally posted by zachzachz
Losi xxxs, but it's the rtr version. Cause I was looking to upgrade to aluminum CVD's but then I wasn't even sure if my car had CVD's.
I'm not sure what the RTR version would come with, but I'd be guessing it has the Losi slider shafts. Those actually arent bad at all, so you really dont need to upgrade them if that is what you have. If you dont believe me on that, Brian Kinwald was running the slider driveshafts over the weekend at the Hitec race...
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Old 08-06-2003, 11:11 AM   #9
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Quote:
Originally posted by DuffMan
I have a question about one ways and spools if ya dont miond real quick.
Can they increase my total top speed or acceleration? (in the straits)
Thanks.
The only way a 1 way would make you accelerate faster would be if your diffs were so loose they were slipping, so no, it wont offer any more top speed or acceleration, just holds more cornerspeed generally.
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Old 08-07-2003, 05:36 AM   #10
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Quote:
Originally posted by DuffMan
I have a question about one ways and spools if ya dont miond real quick.
Can they increase my total top speed or acceleration? (in the straits)
Thanks.
The advantage of a one-way, is that when your off throttle, the front wheels freewheel. That means all traction are avaible for turning. Without a one-way, the frotn wheels are always connected to the motor, thus the front wheels will both brake and turn while turning. Meaning the traction is shared between brake and turn.

When talking acceleration, the advantage of a one-way diff, is that you can turn and accelerate at same time. Also known as more on-power steering. In other words, you can accelerate ealier, when exiting corners - kind of virtual more acceleration.

The down side of a one-way, is that the car only brakes with the rear wheels. So they're only suited for a no-braking-driving-style (and track).
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Old 08-07-2003, 10:04 AM   #11
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So basically the one way just allows the front wheels to spin freely? And what if you put a one way in the front and back, would you not be able to brake at all? Or is this even possible?


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Old 08-07-2003, 10:11 AM   #12
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Quote:
Originally posted by Cole Trickle
The advantage of a one-way, is that when your off throttle, the front wheels freewheel. That means all traction are avaible for turning. Without a one-way, the frotn wheels are always connected to the motor, thus the front wheels will both brake and turn while turning. Meaning the traction is shared between brake and turn.

When talking acceleration, the advantage of a one-way diff, is that you can turn and accelerate at same time. Also known as more on-power steering. In other words, you can accelerate ealier, when exiting corners - kind of virtual more acceleration.

The down side of a one-way, is that the car only brakes with the rear wheels. So they're only suited for a no-braking-driving-style (and track).
So how about the solid front axle or spool? How does it work?
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Old 08-07-2003, 11:19 AM   #13
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spools and oneways are fun to play with. they really change the handling characteristics of the car.

regardless of whether or not you're using a spool, diff, or one way, the pulley is always rotating at a given speed, and it depends on many other factors. what changes among each of these devices is the ratio of inside axle to outside axle speed.

a spool is very elemental. as it's definition implies, it keeps the tires rotating at the same speed as the pulley. obviously in any arc or turn that the car makes the inside wheel carves a smaller path than the outside. thus, with a spool, you will get some slippage on both wheels as naturally the inside wants to roll slower than the outside due to the smaller distance it will travel over the course of the turn. the slippage occurs since the solid axle assembly will not permit a "differential velocity" across the axle.

a "differential" (humm..where did that name come from) was created to reduce this slip. what velocity is gained in the outside axle is taken away from the inside wheel, so as to average to the velocity of the center pulley/gear.

a one way bearing installed in the outdrive portion of the pulley/gear assembly is slightly different. it acts like a spool, locking up when there is any load in the reverse direction of the bearing. however, if the load is reversed, the bearing will freewheel in the same direction of that reversed load. the interesting result of all of this is that at worst the average velocity across the axles is that of the center pulley/gear. if there is any oneway action, or freewheeling, it must be faster than the center pulley/gear yielding an average velocity greater than the center is actually spinning. free speed!

how it all seems to translate to lap times is this.

using a diff as the control or average. a spool will typically only give better times if the traction is high and the turns are tight and on power (carpet). while it still allows 4w braking, it tends to give a push off power, when the weight is transferred forward on corner entry because the wheels insist on being the same speed, producing slip. on power it will produce good steering as the inside wheel will drive regardless of whether there is a load present (tire lifting = no load).

a oneway is often faster than running a diff because of the aforementioned quality of higher average speed (durring cornering). if the track conditions/driving skill will support braking with the rear end only, a oneway will almost always be faster. the inside wheel will be rotating at the speed of the center pulley/gear, while the outside will be freewheeling around at an even higher velocty. keep in mind that the inside front is already spinning faster than the inside of the rear since there is diff action in the rear. this is just the on power half.
off power the steering will be increased as a result of that being the only function of those wheels (no braking like cole said). all that being said, oneways are very common among high level racers and sweeping tracks, with medium to high grip. blistering cornerspeeds!

um yeah, so that's how a spool works

gotta go. lunch is over. that's funny, i'm still hungry. huh.
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Last edited by seaball; 08-07-2003 at 11:27 AM.
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Old 08-07-2003, 03:03 PM   #14
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Quote:
Originally posted by seaball
a one way bearing installed in the outdrive portion of the pulley/gear assembly is slightly different. it acts like a spool, locking up when there is any load in the reverse direction of the bearing....
Everything but this was great... on power, a one way does not act like a spool. Say for instance, that around a corner, with a one way installed, as the car is going through the corner, the extra steering of the one way, the rear end of this car begins to slide and lose a little traction, but as this occurs, the drivers begins to accelerate slightly. Where does the power go? To the front inside wheel (barring the chance of a bad setup, and the wheel no longer contacting the racing surface). And also of course, the rear wheels which are directly connected to the drive system. However, the outside front wheel is going faster than the inside front wheel (as it is travelling further) and it is subsequently traveling faster than the drive train is. So it is actually free-wheeling at this moment in time. Soon as the car straightens out, the amount of rear tire slippage and front inside tire slippage, along with the decreased difference in distance travelled by the two front wheels (because the car is straightening out), will cause the outside front wheel to now, drive the car as well.

There are a lot of strange situations encountered when using a a one-way, but this is just an example to show that saying a one way becomes a spool on-power isn't actually true, even if a one-way and a spool act similarly on-power.


Tell me if I got anything wrong there.
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Old 08-07-2003, 03:30 PM   #15
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Wow, great info, thanks alot.
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