A Few Questions Rolled Into One :)

[Malakite]

I'm building a couple of old Marui Ninjas which im really excited about! On the box it says that the car handles a 7.2 or an 8.4V. I only ever had a 7.2 in it when I was a kid, so i'm thinking of buying an 8.4V to see if it makes it quicker or rather at the very least last longer (being a 4WD it saps the battery like no mans business!). The bizarre thing is that if I look up the Motors online, it appears the basic 540 is for 7.2 only, so if that is the case, why would the box say you can use an 8.4V in it? Also whats the difference with makes of batteries that are exactly the same but just a lot more expensive than others?

I am looking at getting a super stock RZ as a few of you on here have said just how good they are. I am contemplating sticking this into the Ninja as I have plenty of gear spares etc should it take its toll on the gearbox. I do know that using an ESC really does make a difference in saving gears and good use of battery power etc, but I wonder if a normal Tamiya TEU-101BK is ok for 8.4V or would that blow it? Also would that one be ok for a 23 turn motor such as the RZ? The TEU-101BK says maximum 27 turns, so does that mean maximum as in no motor LOWER than 27 turns, or Maximum meaning no higher?! Also speaking of which, how many turns is a standard 540 motor, and were/are all standard 540 motors the same sort of speed/torque as each other?

Sorry to be a pain asking all the questions, but all of your advice is so helpful and I have been out of the hobby for so long, I really need to read up and get everything right before I pay lots to buy a few new parts and get it all wrong with everything blowing up!!

Thanks in advance for all of your help

[Yuley95]

Lucky you building a Ninja. I've always liked to look of that and been interested in building something by Marui. Can't justify the spend on a curiosity though...

I can't answer all of your questions because I am a bit of a novice myself but I can tell you that the TEU-101BK shouldn't really be used with anything UNDER 27 turn. It's a little counter-intuative but when they say the maximum is 27 turn they mean that the number of turns can't be lower than 27. Clear as mud?

You will find that some people on this site have sucessfully run lower turn motors with the TEU-101BK but it is not recommended.

I could make a guess at the rest of the questions but I will leave it to other who know more than me about these things to set you on the right path.

[RCH_Blackfoot]

Not all of the TEU-101BK's give me the same results. Of the 4 that I have, 1 can handle a Khosho 18t, another a 19t Orion, another will run a Orion 21t but nothing lower and the final doesnt even like to run the RS540 Black Can without givin me issues, but if I run the standard Johnson, it will work flawlessly. I have found them to be very finiky, worse then my ex-wife when it comes to being happy constiantly. Thats why for the same money, even less actually, I prefer the Dynamite Tazer 15t ESC, I can run a 15t and even some 13t on it without a worry, though I dont like to run anything lower then a 19t for runtime reasons. I will run the TEU-101BK only if it comes with the kit or the used runner I have aquired, but if I need to buy one, its the Dynamite for $24 at my LHS.

Your a lucky man to be able to build a Mauri kit, no matter what the version.

[WillyChang]

running 7c battery vs 6c usually reduces runtime for same mAh of battery, but it does go a little faster

you're also pumping a lot more wattage thru the ESC; back in MSC days it didn't matter that much

TEU101BK is only rated for 7.2V 60A, recommended motor no hotter than SportTuned

Also need to consider if your RX's BEC will live with 8.4V.

RS540s are usually spec'd for running off 12V DC for use in car vacuums etc so they won't be fussed

Your best bet is to get a ESC that is suitable for 7c+ like most Traxxas units

[Malakite]

running 7c battery vs 6c usually reduces runtime for same mAh of battery, but it does go a little faster

you're also pumping a lot more wattage thru the ESC; back in MSC days it didn't matter that much

TEU101BK is only rated for 7.2V 60A, recommended motor no hotter than SportTuned

Also need to consider if your RX's BEC will live with 8.4V.

RS540s are usually spec'd for running off 12V DC for use in car vacuums etc so they won't be fussed

Your best bet is to get a ESC that is suitable for 7c+ like most Traxxas units

So do you think I should not bother with an 8.4V i.e. they really dont make that much of a difference? I have sourced a Dynamite Tazer ESC that does 12T!! BUT it says for 4.8 - 7.2V, so am I risking it if I try and stick an 8.4V in?

Thanks for everyone's advice so far. I am so excited to be re-builing my childhood car its unreal. The kit has cost me more than I like to mention, but I just couldnt resist re-building a part of old Marui history

[Mad Ax]

Back "in the day" some cars were designed to allow 8.4v to give them an extra edge over the competition. The Tamiya Bigwig is an example. In those days most people used MSCs, which didn't cause problems if you put a bit more voltage through them. The extra 1.2v gave you a bit more punch, with the trade-off of a bit more weight, for just the cost of one more cell.

However, motor technology has come a long way since then. Modern tuned motors can give more power on 7.2v than the old ones would give on 8.4v; in my opinion, you're better off buying a modern tuned motor and powering it with 6 cells (unless you fancy spending extra on a 8.4-compatible ESC and motor combo).

Also remember with 7.2v you'll be a little lighter, so less chance of damage if you have a big crash.

The Super Stocks are a great range of motors - I have a few, and they perform better than my LRP 19t motor with longer run-times. The RZ will probably be a great choice for a 4wd buggy.

I use all my Super Stocks with the Tamiya TEU101 ESC and have never had a failure. Technically the 101 is not rated below 27 turns, but the 23 turn Super Stocks just seem to suit them. However, you will run this combo at your own risk - you could always source a cheap 21t limit speedo to be on the safe side.

In answer to your earlier question, almost all "silvercan" 540 motors will be 27turn. They are basic non-adjustable non-tuned motors that give basic, reliable performance with no maintenance and are a great starting point. Then there are "stock" motors which are usually 27turn but are tuned for performance. They require a little more maintenance (new brushes from time to time and periodic commutator regrind) but give better performance - and should work well on the TEU101 speedo.

I hope that helps

[Malakite]

Back "in the day" some cars were designed to allow 8.4v to give them an extra edge over the competition. The Tamiya Bigwig is an example. In those days most people used MSCs, which didn't cause problems if you put a bit more voltage through them. The extra 1.2v gave you a bit more punch, with the trade-off of a bit more weight, for just the cost of one more cell.

However, motor technology has come a long way since then. Modern tuned motors can give more power on 7.2v than the old ones would give on 8.4v; in my opinion, you're better off buying a modern tuned motor and powering it with 6 cells (unless you fancy spending extra on a 8.4-compatible ESC and motor combo).

Also remember with 7.2v you'll be a little lighter, so less chance of damage if you have a big crash.

The Super Stocks are a great range of motors - I have a few, and they perform better than my LRP 19t motor with longer run-times. The RZ will probably be a great choice for a 4wd buggy.

I use all my Super Stocks with the Tamiya TEU101 ESC and have never had a failure. Technically the 101 is not rated below 27 turns, but the 23 turn Super Stocks just seem to suit them. However, you will run this combo at your own risk - you could always source a cheap 21t limit speedo to be on the safe side.

In answer to your earlier question, almost all "silvercan" 540 motors will be 27turn. They are basic non-adjustable non-tuned motors that give basic, reliable performance with no maintenance and are a great starting point. Then there are "stock" motors which are usually 27turn but are tuned for performance. They require a little more maintenance (new brushes from time to time and periodic commutator regrind) but give better performance - and should work well on the TEU101 speedo.

I hope that helps

Brilliant, ok I won't bother with an 8.4V then, seems like a waste of time? Also Am I right to got for a Dynamite Tazer 12T Speed Controller instead of a Tamiya TEU101 ESC seeing as the Dynamite is for much lower turn spec motors, but believe it or not, no difference in price whatsoever!! OR do they not work as well with average motors?? I'm confused as to why they would be the same in price unless it is merely because it's not a 'Tamiya'??

Finally if I may ask, regarding the 'BEC' receivers. I have read concern that running a fast motor means it cannot cope with certain Receivers, can someone elaborate for me? Also I have 27mhz receivers and transmitters, but everyone appears to be going for 40mhz now - is there any real reason for this, or is it just because companies do not stock the 27mhz so easily? If not why not? Is it range or reliability or something?

Many thanks

[WillyChang]

27Mhz is shared with garagedoor beepers, CB radios and a whole lot of toys...

also more channels on 40Mhz to choose from vs 6 (or 12 if you believe in splits)

[Mad Ax]

Tamiya speedos are not usually "expensive" - they're just not the best performers. A dynamite 12t limit for the same as a TEU101 sounds like a great deal, so check a few things. Does it have reverse? Some ESCs don't. Non-reverse speedos are usually made for racing since they're more efficient (some race classes also ban reverse facility) and are slightly cheaper since they don't have to have different programs for reverse and brake.

I'm not familiar with the brand in the UK - it may simply be a cheap brand. Some brands are cheaper than others, some are very expensive. One would argue that you get what you pay for - it may not be as smooth as a more expensive one, but that doesn't mean it won't work properly - unless you're racing the difference probably won't be noticeable.

AFAIK, there's no reason why a 12t speedo won't operate a silvercan as well as any Tamiya speedo.

I've not heard of fast motors having an effect on receivers. Some receivers have BEC, some don't. Some ESCs have BEC, some don't. If you don't have a BEC at all, you may damage your radio (depending on what voltage it can handle and how much your voltage may spike during use). When you buy, check that your radio or ESC has BEC - if not, buy one seperately (they're not expensive).*

Again "back in the day" 27MHz was stocked more readily than 40MHz, at least in the UK and in my experience. Nowadays 40MHz is almost as widely spread. There seems to be a wider range of crystals for 40MHz. Since most toy RTRs use 27MHz, the frequency can be very busy in built-up areas with lots of band conflicts. Switching to 40MHz usually gives you more breathing space.

Out of choice I usually go for 40MHz just because I have less conflicts when I go to meets - however, if more and more of us switch to 40MHz, the problem will become just as bad on that frequency too. Then again, with more and more people opting for Spectrum-type radio sets, things will eventually get better, not worse

I don't know of any reason why 40MHz is technically better than 27MHz - but you might find it's less crowded.

*I learnt this just a few days ago on this very forum. I hope I'm not wrong (although it has been known)

[Malakite]

Mad Ax - great information thanks heaps! OK so at least I know im ok with this other ESC so long as it has reverse of course! I take it then without BEC on a receiver I still need it in the ESC or vise versa, so long as one of them has it

OK i'm off to order lots of parts now and keep it all hush hush from the wife of course! Seriously though she is very supportive and let me order the Marui Ninja as it was part of my childhood, what a wonderful wife I have

[GRIGGY]

OK i'm off to order lots of parts now and keep it all hush hush from the wife of course! Seriously though she is very supportive and let me order the Marui Ninja as it was part of my childhood, what a wonderful wife I have

Good for you dude. My missus doesn't mind me spending money on Tamiya stuff as she spends all her money on shoes! She has approx 50 pairs of shoes mostly NIB...They take up more space than my Tamiyas!

[Malakite]

Good for you dude. My missus doesn't mind me spending money on Tamiya stuff as she spends all her money on shoes! She has approx 50 pairs of shoes mostly NIB...They take up more space than my Tamiyas!

Haha I love it, 50 shoes NIB! haha classic!

[GRIGGY]

Haha I love it, 50 shoes NIB! haha classic!

She does have some that she uses for running / bashing but she prefers to keep them NIB. Then after a couple of years she'll sell them on the bay for less than half what she paid for them just to make space for some new ones!

Women...Don't you just love em...