What gearing with a 44t spur? - RC-Monster Forums

jordan... · 06:49 AM

hey everyone,

I'm getting a Neu 1527/1D motor (hopefully before i die

) and am going to be running with a center differential unit. I've got the Kyosho 44t spur on it at the moment, but can't decide on what a good # pinion would be to start with. What do you guys run with the 44t spur and your motors?

I was thinking of running 18/44, yes it will be geard for 100mph, but it gives a good amount of clearence between the driveshaft and motor. Also was considering 14/44.

As you can see, if i can find a good starting point i should be able to fine tune from there, but i have no idea right now. I'm not going to be racing, just general bashing and some speed passes.

thanks in advance

jordan

P.S i know i know, i might have just gone overkill the motor a little

suicideneil · 06.19.2008, 06:02 PM

Just a tad, just a tad...

I dont know why it didnt occur to me earlier:

http://www.rc-monster.com/forum/showthread.php?t=2332

You should find a whole shed load of useful info & ideas in that thread, and Dafni is still active, just a bit quiet, lol.

lutach · 06.19.2008, 06:27 PM

Wow. This is going to be fun. Why just 100mph

. The 44T plastic spur+1527/1D= Melted plastic

. Are you only going to do speed runs? Do you plan on having this nice

crazy powerful set up for normal running? Just make sure your drive train is up for it

. I would go hard steel on the spur and pinion.

jordan... · 11:35 PM

thanks Neil, that threads exactly what i'm looking for

@Lutach: I'm not actually planning to hit 100mph, i just thought if i geared it that high it would run really efficient, and hopefully tame down a little torque. The melted plastic is what im afraid of, do you know anywhere i can get a steel 44t mod1 spur? i have been looking.

I'm not to worried about my drivetrain at the moment, HB Lightning CD, hardened steel dogbones, UE 8 Spider diffs, UE steel 8mm cvds. I think this setup will put them to the test

thanks
jordan

Patrick · 06.20.2008, 05:10 AM

I'd start with the smallest pinion you can get to fit. Even with a 12t you'll be geared for ~70mph. Even if your not driving that speed the motor's still going to have a fair bit of load from the gearing, so I think it's going to draw a lot of power.

jordan... · 06.20.2008, 05:37 AM

Thanks Patrick, thats exactly the type of anwser i was looking for. Would using a larger pinion make the motor pull more or less amps?

Patrick · 06.20.2008, 05:45 AM

Hard acceleration off the line the bigger pinion will put more load on things and draw more amps.
At top speed the bigger pinion will draw more amps, because your cars needs more power to go faster.
I don't really know what will draw more when cruising at a set speed (say 40mph or whatever)

jordan... · 06.20.2008, 05:52 AM

ok, thanks mate, i can never get my head around that

One thing that i was kinda wondering about... even though a 12t pinion will gear it for 70mph, because of the size of the motor and the size of the tires etc..., could that mean it is still undergeared??

Patrick · 06.20.2008, 06:52 AM

I don't really know much about 1527's, since I only know cars, and they don't get used in cars too often, but I doubt 70mph would be undergeared.

jordan... · 07:41 AM

Quote:

Originally Posted by Patrick

I don't really know much about 1527's, since I only know cars, and they don't get used in cars too often, but I doubt 70mph would be undergeared.

True, can anyone with experience with 'big' motors chime in... Lutach maybe

thanks Patrick
jordan

lutach · 06.20.2008, 09:23 AM

suicideneil · 06.20.2008, 11:52 AM

One thing that did occur to me is that using truggy ratio diffs instead of buggy would lower the gearing a fair bit- I'd say plumb the numbers into the calculator and see what it says. In theory, the truggy ring gear & pinion is all you should need to make the change, so you can keep the rest of the UE 8spider diff (a bit of shimming perhaps, but little more)...

lutach · 06.20.2008, 11:56 AM

Quote:

Originally Posted by suicideneil

One thing that did occur to me is that using truggy ratio diffs instead of buggy would lower the gearing a fair bit- I'd say plumb the numbers into the calculator and see what it says. In theory, the truggy ring gear & pinion is all you should need to make the change, so you can keep the rest of the UE 8spider diff (a bit of shimming perhaps, but little more)...

You are right. The RC8 for example uses 4.3 diff ratio. I used the HB buggy diffs to do my speed runs and now the truggy diffs are back in for some fun times

. My MBX5T had the buggy diffs as well and now it has the truggy diffs for again some fun times

. Shimming is a must with the 4.3 truggy ring gear and pinion.

TDC57 · 06.20.2008, 11:59 AM

Hay Jordan!,
I've got a 47T mod 1 steel Spur I can send you?. It's off my XRay. If you want it (no $) just pm me with your address and I'll get it out in the mail to you today / this weekend.

Shaun...

jordan... · 06.20.2008, 11:07 PM

@Shaun: thanks for the offer, i really appreciate it

, but i think i'll have to pass because i would have to cut the Gmaxx frame rails quite alot to get it to fit. Thanks again though

@Lutach: Thanks for the list, really helpful, i might go for that 42t spur for some better clearence, didn't know they made anything that small. Can't wait to see your truck running on that 1527. I was actually thinking of getting a LMT 22xx series, but i think they work out close to $400-450 US

Any reason you would fit the largest pinion? I would imagine since the rpms would be lower the engine would run cooler?

@Neil: Thats a good point about the diff gearing, never considered that. I'll have a play around with BrianG's calc and see what i can come up with.

thanks for all your help guys

jordan