My Race Revo

[BP-Revo]

I'm not exactly sure how Brian's calculator takes KV. It may take unloaded KV, which would result in less estimated speed if a loaded KV value was entered, or vice versa.

I think the calculator is a compensation of both, because when I enter Castle's unloaded KV ratings, speed ends up off the charts. However, when I enter in a LMT motor, speeds are quite low (and users on here with the same setup as I entered have gotten much more speed).

[jhautz]

Originally Posted by captain harlock

Hey, Jeff.
If I use the speed calculator of Brian's with all the data I have, the speed it estimated was 47.91mph..

Is there a possibility it could be faster?

Not sure what data you entered Cap'n. Can you use the data output feature on brians calculator and post it so I can see your inputs vs my assumptions. Like I said before... I am only guessing at what setup he might be using and yes by pushing higher motor rpms you can get it up there, but in generall it seems that 1/8 diffs and the slipperential it has a pretty low gear ratio.

[BrianG]

I use whatever KV values are published, loaded whenever possible. In a way I like using loaded kv values and then other ways I'd prefer an unloaded kv value.

Using loaded values helps the result be closer to the real thing. However, it seems like a "fudge factor". I highly doubt we load our motors the same way as whatever method they use to measure "loaded". IMO, the calculated result in the right range, but not as accurate.

IMO, using unloaded values is better.... as long as the motor resistance and amperage drawn is known, both of which causes the kv to drop. This kv drop is more accurate because it is specific to the application you are using it in.

[captain harlock]

You mean that the 1950/10 unloaded is rated for 1307rpm and loaded 1254?

[RideIcon]

i just read this whole thread and i think my head is going to explode, that is the sexiest revo i have ever seen. I'm working on building an electric revo and have been looking at ideas for a while and i think im going to be dreaming about your truck, lol

[BP-Revo]

"I'm too sexy for my shirt...too sexy for my..."

that popped into my head after I read your post RideIcon LOL

[Dafni]

Jeff, the slipperential allows perfect gearing range in my opinion. I aim for 30K rpm motors (1950/6 on 4S or 1950/8 on 5S or something like that) and gear for app 35mph. I was able to get this with the revo slippy done without probs...but I can't remember what gears are on there at the moment. It works, though. Mike and me did the math when we designed it, should work for almost all combos. Not far from an E-Maxx tranny.

I remember when I had the 1950/8 on only 4S, I had to run a 38/20 or something like that, but it worked.

Yes, I have the buggy diffs, not truggy.

If you need any more info, just let me know. Okay, jeff?


All others, thank you for the kind words! Pics are still on page 14, just in case you're wondering :)

Cheers guys
Daf

[jhautz]

Its not really the slipperential that lowers the gearing to much, its the combination of the 1/8 diffs and the slipperential that add up to forcing gearing up in the 20T pinion range. The ratio reduction caused by the slipperential by itself or the 1/8 buggy diffs by themselves isnt a big deal, but when you combine these together it really starts to push the pinion size up to the limits of whats available.

I see what you are saying, and I agree, for a 35 mph setup the gearing is no problem really. I tend to use mine for both bashing and track, and I like to gear mine up a bit for bashing. I guess that the slipperential isn't really intended for that anyway. Its is more of a racing setup anyway.

I was just curious what you were running because I was having a hard time figuring out how to gear it for more than 40mph without having to push the motor to higher RPM than I typically like.

[Dafni]

Yeah, gotcha. Mike and me designed it with 1/8 scale diffs in mind.
I can check what I run at the moment tonight. But you got it, usually I don't go for 40+.

I guess if you have a motor spinning at 30-35K you should be fine.

Laters, and thank you
Daf

[BrianG]

Use bigger tires? :)

[Serum]

I would say smaller? the stock diff has a 37/13 ratio over the 43/13 or 43/10 ratio of the buggy diffs.

so, when and where can i buy a kit? :D1!!!!!!!!

i need one!!!!! why to sway bars up front? and why the off to the side motor mount? after all this i need one now!

[Dafni]

Originally Posted by E-MAXX Rock's

... why to sway bars up front? ...

Because I want as much on-power steereing as I can get.

On my buggy I like the front sway bar very very thin, and alot of guys I know with truggies take the front one completly off too.

What did you use to make the swaybars? Are the parts off a different truck or are they custom bent metal.

[Serum]

a rod of spring steel.