I want to build a crosskart, not a race one but one I would drive through forest dirt roads, old cubic stone roads and such. Which kind of differential would do better? The crosskart would be rwd only, and have double A arm rear suspension.
I want to build a crosskart, not a race one but one I would drive through forest dirt roads, old cubic stone roads and such. Which kind of differential would do better? The crosskart would be rwd only, and have double A arm rear suspension.
Welded diffs work well for offroading and would be a good choice for a dedicated offroad vehicle. The only real downsides with them for offroad use is the ability to get stuck more easily (since you're going into everything using a high-traction drive mode, you can't "activate more traction" to get out) and tearing up grass where you might not want to.
A torsen is just a bit less slippery than an open diff, good for track use (where you only want to keep the one-wheel-peeling under control) but very mild for offroad use, where I would only consider recommending a torsen for the front of a 4x4.
Do quads have diffs?
I thought most ATVs other than the top of the line ones just ran spools or even solid axles.
Ps I want to see this crosscart build.
ATVs are usually locked in the back, but it's not such a problem because the rear usually has very high roll stiffness so it just unweights the inside tire. Plus, they're narrow. I'm not sure about side by sides.
The trucks I've been in with spools always seemed to just push the front tires if you were trying to turn slowly on a loose surface. You HAD to slide it to turn, which was mostly fun and sometimes very annoying.
I forget, I think one of the SxSes has some kind of actual diff, but basically all of them are locked rear and viscous or open front (I'm talking the performance models, no idea about the utility versions but that doesn't seem super relevant here). You definitely notice it and it does generally require a bit of sliding to turn (you're on dirt...you're probably sliding anyway) but works pretty well. If I was building one I don't think I'd bother with anything other than locked or some kind of clutch diff. A torsen seems like it would basically just be a less predictable open diff in off road conditions. But I've never tried it so maybe I'm wrong.
gearheadE30 said:ATVs are usually locked in the back, but it's not such a problem because the rear usually has very high roll stiffness so it just unweights the inside tire. Plus, they're narrow. I'm not sure about side by sides.
I don't think any SxSes come with locked diffs, they're more like street-based 4x4s in that they have manually lockable diffs at the most from the factory.
On a light enough vehicle, having no diff works about as well.
What are your plans for track width and wheelbase? Aggressive driving style or just putting around on trails like it was a golf cart?
In reply to Robbie (Forum Supporter) :
It's gonna take a long while until I start building it, I have just started designing the frame and it will take some time to finish up because I want it to be perfect:)
In reply to Pete. (l33t FS) :
The wheelbase is 2300 mm, I haven't decided yet on track width but I guess around 1600mm. I would drive it mostly aggressively.
gearheadE30 said:
The trucks I've been in with spools always seemed to just push the front tires if you were trying to turn slowly on a loose surface. You HAD to slide it to turn, which was mostly fun and sometimes very annoying.
I once watched a Jeep drive over the sidewalk while trying to do a left turn on pavement, going ook ook ook the whole time. Someone forgot to unlock the rear locker :)
Clutch pack diffs are the all-around solution, but for forest road hoon use I'd think a spool would work. The helical would go open with major traction differentials and if you break an axle you're done.
noslynx said:In reply to Pete. (l33t FS) :
The wheelbase is 2300 mm, I haven't decided yet on track width but I guess around 1600mm. I would drive it mostly aggressively.
Definitely a solid spool would be best. The wheelbase and track being far from square will help a lot, and years of running an RX-7 with all sorts of different diffs suggests that a welded diff handles the same on loose surfaces as a decent clutch diff, and an open diff is not nearly as predictable. Torsen diffs are just fancy open diffs IMO, there is no slip limiting, just torque biasing.
Any time you will be on power the tires will be spinning anyway, any time you are cornering the tires will be sliding, any time you are off power then the clutches generally overpower the tires' traction and don't slip. So a spool is simplest and most predictable in its function.
The only downside to a spool or welded diff is that it is hard on the axles on the street, especially when towing a trailer. Issues it does not sound like you will have.
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