Converting Kyosho ST-R, new to brushless conversions...

[pumpkinfish]

I have been lurking for a while now trying to educate my self on a brushless conversion as well as lipo technology. I need some help as I am ready to take my first steps towards starting a conversion. It seems that there are more people doing buggies than truggies, but after racing the two for the past year I am certain I want to convert the truggy unless there is some overwhelming reasons I should stick to the buggy.

I am going to use my Kyosho ST-R with BCE extended chassis for the conversion. I will be racing this at club races and will need at least 40 minutes run time on a pack. As for budget, I want to purchase quality electronics and do it properly. Please guide in me in making a best value choice and not just purchasing on price alone. I have learnt my lesson in the past taking shortcuts.

So far I know I was planning the following parts but don't know what I need exactly to compete effectively with nitro truggies: motor w/motor mount, esc, lipo, Kyosho plastic spur with mod1 pinions and battery tray. Am I missing anything? I have an ICE charger, will this work for a 4s 8000hv lipo (assuming this is the proper lipo for a truggy)? What lipo balancer is good to use?

Finally, how do setups differ with a brushless setup? Do I need to use thicker diff oil, lighter oils? Also, how long does it take to charge packs? If I only buy one lipo pack, would I be able to practice then have enough time to be able to charge up before the mains?

Thanks for the patience with a new guy :027:

[supralover72]

Well, I'm doing a buggy as buggies rule, but I'm pretty sure that an 8xl fegiao with mamba max for speed and a 9xl for tighter tracks would be great, but if you have the money, I say go quark 125b and neu. Ask around for which new to use as opinions vary.

For diff oil, you'll want thicker oil in the center as the sheer torque is ridiculous. I say start at 10 and work you way up.

Your going to need a UBEC/ External BEC no matter what however.

[jnev]

The best set up you can run with the parts available now would probably be the Quark 125b with a Neu motor. Many people wil get a lower KV motor and then run higher voltage battery like a 5s pack. But this is your choice.

For the battery tray, you can probably use a Kyosho twin force tray, or you can always make your own. For the motor mount, the rc-monster one is the one you should use probably: http://www.rc-monster.com/proddetail...rcmkyoshomount

You will want to use the Kyosho mod1 spur like you said and a mod1 pinion gear as well.

Going with the truggy is definitely the way to go. I have both, the truggy and buggy, and the truggy definitely gets more time on the track. It's just more fun.

For the setup. I'm only going to talk about what is available now and will not speculate about what may, or may not, be available tomorrow or next year.

For racing 4S is probably the best way to go in terms of weight, runtime and power on tap. The only problem that I see is the runtime that you require. I run an 8Ah pack and that's good for a solid 30 minutes on the track with my setup.

First the power train. Since you say that you want the best, I'd go with either the Neu 1515/1Y or the 1515 2.5D and Quark Monster Pro esc.

The 1Y is a 2200kv motor and the 2.5D is a 1700kv motor. Of course, the 1Y will be faster on like gearing than the 2.5D, but you can make up for some of that speed loss through gearing and the 2.5d will get better runtime. Most opt for the 1Y. The other benefit is that the 2.5d will be more 5S friendly, should you ever decide to go that route. Many run the 1Y on 5S, but it does get a bit hotter than the 2.5d on 5S. Although I've been teetering on what I like lately, if I had to make the choice now, I'd go for the 1Y. Under load it should deliver about 2000kv and I think that's about perfect.

As for the esc, the Quark is, unfortunately, the best going right now. It is smooth and runs the Neu motors very well. The problem is that many have had overheating problems with the Quark. This can be fixed with Mike's Quark heatsink and some thermal epoxy. If you have the internal heat transfer problem, you'll have to mod the Quark with the addition of an aluminum heatsink. It isn't hard to do, but some have found it necessary.

You could also consider the Compro controllers by MGM. They are very solidly built, but I've had nothing but trouble with mine and MGM is in the Czech Republic, so tech support and warranty repairs take forever. I bought my MGM a couple to a few months ago, and I haven't had it in my possession for more than a few days yet.

If Mike makes a motor mount for your vehicle, I'd jump all over it. It takes a lot of the pain out of doing the conversion.

You also want a ubec to power the radio and servo.

As for the battery, get the best that you can afford. I like the Kokam and Flightpower packs, although the Flightpower packs are widely used by those that can afford them. Very good batteries. Whatever you do get, just be sure the make note of the dimensions of the packs. They vary from manufacturer to manufacturer.

If you already have the ice, go for the Hyperion LBA10 balancer. It works well with the ice.

Back to the 40 minutes of runtime. You could go for a 12Ah pack, but it's going to be big and heavy. Whether you can run it will depend a lot on your track. For me, it's just too much and totally screws up my handling.

The best bang for the buck batteries around that deliver performance too, are the maxamps packs. They are good guys and will build you a pack to whatever specifications that you need, which is something that you can't do with the "better" brands of packs. I run the maxamps 4S2P 8000mAh packs and have never had any troubles with them.

[pumpkinfish]

Great replies. Thanks!

I guess I should qualify my run time concerns. We run three 5 minute quals and a 15 minute Amain and 10 min Bmain. How long does a pack take to charge? I would like to go, practice and run the quals, then race the mains. In case I make the Bmain and bump up, I want enough on tap to race tha A. I usually make the A but you never know if you have a bad day or brake something. So if a pack charges quickly, then I will have no problems charging between quals and mains. If it takes a while, I will need to budget two packs then pick the electronics after they are selected.

Does anyone know if the motor mount Mike makes if compatible with the Inferno 777? If so I am golden.

OK, you really don't want to be pushing things like that. A dead lipo battery takes an hour to charge, assuming that your charger can do a 1C charge rate. The ice can do 8A up to I believe 4S, if you have a power supply that can deliver the current. That's why we all go with the largest battery pack that is practical. No matter what capacity you get, it takes an hour to charge.

You also don't want to be running a bigger battery than you need, because it will be unnecessary weight. I'll go out on a limb and say that a typical race setup in a truggy will get you about 30 minutes on an 8000mAh pack and a good 20 minutes on a 5000mAh pack.

If you get two or three 5000mAh packs, you should be good. I go with the 8000mAh packs because they are not too much heavier and are good for practice. It's also good to try to standardize on a battery pack so that the handling will be consistent. If you had two of these, you should be able to easily run the qualifiers and get in a bit of warming up and then use the other pack for the main. Check out the maxamps packs. They aren't the very best that you can get, but the service is good and the products are usually solid for the money. The 4S2P 8000mAh packs should be able to keep up with your current demands too. If you don't go with the 8000mAh pack, I'd get the 5000mAh packs.

I don't know about the mount. I just got my first one from Mike. All of my others were home made.

[jollyjumper]

http://www.rc-monster.com/proddetail...rcmkyoshomount

there you go for the motormount.

[pumpkinfish]

Ok I am currently pricing some options and I have a question about the cells. I have decided on the 4S2P 8000mAh packs but need to know realistically how many cells should I show up with on race day ready to go? I was thinking two. If I had to recharge a pack at the track, it would be no problem, but I prefer less hassle if you know what I mean. Too many other things going on to distract me...lol!

[BrianG]

Depends how much time you have between heats/mains. Just remember it will take a little over an hour to charge a lipo pack at 1C if dumped - assuming your charger/power supply can supply a 1C charge rate.