CRT Conversion Questions

[Steve182]

I am planning on converting a CRT to BL and have been doing some homework by reading past builds etc.

Here are my remaining questions:

I have the stock spur right now and its huge. Are there smaller spurs that will fit on the stock center diff so I dont have to buy a whole new one?

And if I ran the Castle 2200kv motor, would it make more sense to go with a 5s vs. the 4s? Im not racing so that isnt an issue. I'd probably like to gear for around 40-45 mph tops.

Thanks in advance guys

[lincpimp]

The stock spur is huge cause the crt uses buggy ratio, 43/13, diffs. Most truggies use a 10/43 diff ratio, and can get away with a smaller spur and still have a similar overall rollout with the taller tires that truggies run compared to buggies.

You can swap the ring and pinion on the crt for hot bodies lsp parts to get the 10/43 ratio. Then you can run a 46t or similar spur. I did this with my old crt as I wanted to use the kyosho plastic spurs.

the CC motor would be better with 5s and lower gearing than with 4s and taller gearing. It will also open up battery choices a bit, as 4s in a truggy will require really good lipos, like polyquest 6000 packs. You can drop dowm to 4500-5000 mah packs with 5s and that opens up your choices quite a bit. 4s in heavy vehicles is not really a good idea, in my opinion...

[Steve182]

Hey thanks for the reply man. I shot you a PM with a few more questions.

My CRT build is done and I used the stock 62t spur with a 13t pinion, 2200kv cc motor with 5s, radar at 43 MPH with loose traction, proved to be enough for me if it wasn't I would use a 15t pinion.

[Steve182]

Thanks fsracer, good to know I could still use the stocker.

What kind of temps are you getting?

[ssspconcepts]

Mike also sells the Kyosho plastic spurs for a few dollars...and they hold up well. I have a couple of extra center diffs with a 44T and 46T spurs for my CRT. This offers a lot of options for gearing.

[Steve182]

Well the Kyosho spurs bolt right up to the stock diff? Im on a pretty strict budget right now, so I wanna keep my costs down as much as I can.

[ssspconcepts]

Originally Posted by Steve182

Well the Kyosho spurs bolt right up to the stock diff? Im on a pretty strict budget right now, so I wanna keep my costs down as much as I can.

Yes, the Kyosho spurs are a direct fit to the CR and CRT X1 and X2 diffs.

[Steve182]

Sweet! Just what I wanted to hear. Looks like I will have to take a look at them.

Here is the link to my buildhttp://www.rc-monster.com/forum/showthread.php?t=17637, after 20 minutes of hard driving I still can't get the Monster fan to turn on which is factory set to 150f although the ambiant temp up here is cool 50f.

[sweetride4me]

I went with the ofna hyper st truggy diff in my build with 14t pinion I'm around 40ish and temps are perfect, plus it's an 8 spyder center diff versus a 6 spyder and it's 52t versus the stock 62, makes a huge difference in room...

[Steve182]

Awesome, thank you for your replys guys.

I think I might take a look at those Kyosho spurs. That will be the cheapest alternative, and give me some more room for the battery placement.

[ssspconcepts]

you won't be disappointed with the kyosho spurs on stock CRT diffs. Spider 8s look cool and they are robust but they are also high maintenance because they are prone to leaking. After owning several spider 8 sets, I have grown to prefer the Jammin and/or HB diffs...especially the spiral cut ring and pinion versions.

[Steve182]

Sweet, that definatley seems like the smartest thing to do. Now I need to sell some stuff to fund my MMM Combo!

[sweetride4me]

I can attest I am very very very happy with the MMM combo in my BL CRT just watch my vid in my build thread