Converting my CRT .5

First off, hi. I am Eric. This place seems to be full of knowledgeable people and I hope to learn a lot here.

With that out of the way let's move on to what I came here for. I'm going to convert my CRT .5 since I'm tired of nitro. I'm going to be using the RCBros conversion kit, a Mamba Max, and a Medusa MR-036-050-3300V2-5. I got most of it sorted out. Except for one thing, gearing. I know I'll be using the stock spur so I'm going to need to know what pinion I should use. The truck will be run on 3S LiPos and use the stock 2.2 wheels.

[BrianG]

Welcome! Your setup sounds almost exactly like mine, except for the conversion kit used (I made my own mount, ESC/rx tray, and batt tray) and I stuck with stock size tires. I think you'll be very happy with your proposed combo. As far as gearing goes, I have mine using a 14T pinion, which sets the top speed at around 35mph. Seeing as you are using 2.2" wheels, you may want to gear down a little more, probably 12T or 13T because the larger tires will have a higher roll-out; that will keep you in the ~35mph range.

BTW: There are some R/C calculators (link in my signature) that may help in choosing the right gearing.

Thanks for the reply. I've already ordered the kit and it should be here in a few days. Is there anything I've missed that I should know about the conversion?

[BrianG]

I assume you're gonna stay with the steel spur? If so, a hardened pinion is a must (Mod1 pitch).

Not related specifically to the conversion, but you might want to check the diffs. In stock form they come pretty much empty. Some people have also upgraded the shocks; Revo shocks with jato springs in the front, and front 8th scale buggy shocks in the rear. Makes for a better ride from what I noticed.

I was looking into the shocks. And I heard that with brushless you should run a higher weight fluid in the centre differential. Is this true?

[BrianG]

I do. There is so much torque that the fronts balloon like crazy otherwise. Personally, I like 120k, but most people think that is wayyy too thick. But, I mostly bash so the extra snap is nice. 120k is just enough so you can wheelie when you want to, but more controllable than a locked center diff. For racing, you'd want more control, so thinner fluid would be better (probably around 30k).

[E-Revonut]

I only have 10k in my center diff and I can still wheelie from a stop, sometimes it flips right on its lid. I run a RC-Monster motor mount, homemade aluminum battery tray to hold the lipo on it's side. I run a Medusa 36-50-4800 on 2s 5000mah 25C, Mamba Max esc, still have the stock shocks with 50weight, and 10th scale buggy rear tires(essentially stock, same size, just have differest tread). I gear for no more than 35MPH to keep it sane but have geared it for over 40MPH, esc gets a bit warm though. I have also run 10th scale truck tires but I like it better with the stock size.

[magman]

In both my crt.5 I run 5-15-7 and I bash so this set up works well for me. I also have 1/8 ofna front buggy shocks in the rear and Revo in the front w/blue jato springs

[Arct1k]

Mag do you mean 7 (f) 15 (c) 5 (r) - normally its is lighter oil in the rear I thought...

[magman]

Originally Posted by Arct1k

Mag do you mean 7 (f) 15 (c) 5 (r) - normally its is lighter oil in the rear I thought...

Yup....another example of my 40 yr. old mind working backwards!

What size screws do I need to use to mount the motor?

[nitrostarter]

m3X8's work fine, just check the depth before locking it down and running it.

Thanks.

Also, what 1/8th shocks wrok best on the rear? Anything extra I have to buy does it just bolt on?

[magman]

I use 1/8 buggy front shocks from Ofna .......http://www.amainhobbies.com/product_...ed-Shock-Set-2 just assemble and go!

Also, the Revo shocks on the front work great as well so much stronger and smoother than the stock ones....here is a thread on them....http://www.rc-monster.com/forum/show...t=crt.5+shocks