R/C model car guys out there? Question

[aschen]

Originally Posted by BE911SC

Guess what? I found this same seller on Amazon, ordered the battery-charger combo, then got a refund a few days later when they said that they did not in fact have it in stock. That's when I came here and asked.

Thanks though!

Ok i have a new option for you above if you are willing to solder or use butt connectors. Im about 75 percent sure the common and cheap team associatex rc 18 battery will work as well. I dont believe your model to be 1/10th scale

[mikester]

Do you have the Tamiya kit number this thing is?

[Ayles]

With a Tamiya plug...
NiMH Battery Pack: 7.2V 4500mAh for RC-10 Cars and Sumo Robots

[mikester]

I think it's this one: Tamiya America Item #56708 | RC TT-Gear Porsche Turbo RSR - GT01 Jagermeister (Finished)

Which is actually 1/12 scale and not 1/10. 500mah is ridiculously small...

Let me check the details - maybe with some minor modifications to the setup you could do a lipo. Otherwise getting a nimh in that size isn't a problem. Go to the hobby store that carries stuff for 1/16 cars and they should have something about the size you need in the 5-1100 mah range. The 1100 mah batteries for the 1/16 cars are pretty small actually.

Can you give us the measurements of the compartment too? Depth, length and width.

Last question - can you soldier or not? You might need to change the connectors.

[aschen]

Originally Posted by Ayles

With a Tamiya plug...
NiMH Battery Pack: 7.2V 4500mAh for RC-10 Cars and Sumo Robots

That won't work. It is not a full sized battery and has a smaller connector than standard tamiya

[aschen]

Originally Posted by mikester

I think it's this one: Tamiya America Item #56708 | RC TT-Gear Porsche Turbo RSR - GT01 Jagermeister (Finished)

Which is actually 1/12 scale and not 1/10. 500mah is ridiculously small...

Let me check the details - maybe with some minor modifications to the setup you could do a lipo. Otherwise getting a nimh in that size isn't a problem. Go to the hobby store that carries stuff for 1/16 cars and they should have something about the size you need in the 5-1100 mah range. The 1100 mah batteries for the 1/16 cars are pretty small actually.

Can you give us the measurements of the compartment too? Depth, length and width.

Last question - can you soldier or not? You might need to change the connectors.

Tower has the connectors as I posted they look very similar to team associated 1/18 the scale. I am guessing it is 6 series 1/2 AA cells but he didn't give a depth

You could prob run 2 series lipo but I wouldent bother

[BE911SC]

Originally Posted by mikester

I think it's this one: Tamiya America Item #56708 | RC TT-Gear Porsche Turbo RSR - GT01 Jagermeister (Finished)

Yes, it is that one. 1/12th. Let me check all options before I solder on a new connector for a compatible battery.

Someone asked the dimensions of the battery box in the car chassis. 4 inches by 1.25 inches by about 1 inch deep, maybe a tad deeper.

[mikester]

Bottom line is that you just need to find an after market battery that fits those dimensions and matches the chemistry of your charger.

Now, if you want to upgrade it to a lipo battery you will need to upgrade your charger and either also update your electronic speed control to one that supports a lipo low voltage cutoff or buy a separate low voltage cut off thing that fits between the ESC and Battery in the car.

Non of that is terribly expensive and in fact if you search google for Tamiya GT-01 upgrades you'll find quite a few brushless conversions which will totally support going lipo.

Don't worry about sticking to the factory battery of 500mah as that is simply a measure of how much energy is in the pack. If it is the same size and same voltage (7.2v) but has a higher mah rating it will simply last longer.

nimh batteries are pretty lame and if you aren't going to drive if very often I do not recommend them. When they rest they lose charge and if they rest too long (sitting for months with no usage) they pretty much die. They are not resilient like NiCds were back in the day.

Lipos if stored with 80% charge will last a long time. They don't lose while resting and they have excellent discharge capacities. You do have to monitor them closely while charging and you do need to make sure you're not discharging them at a higher amp rating than they can withstand. Doing anything wrong with them basically results in a puffed up battery (puffing up means it is releasing energy the wrong way) and if you take that too far they simply ignite and can do so quite dramatically. I have been using them for years now and have only had one light up on me and it was a very small battery for a micro-plane where the connector became dislodged from the pack (no wires between) and the pack's leads connected (positive to negative) and it puffed up very quickly and caught fire quickly too. Luckily it was a very small single cell (3.7v 120mah) battery.

To replace your 7.2v battery you will want a 2cell lipo which will bring you to 7.4v. It is a minor increase in voltage but the battery will likely have 2 - 3 times the mahs (discharge capacity) and so when you're running the car the draw will actually get 7.4 volts instead of a lower voltage due to high draw rates. With Nimh and NiCds, they typically have lowish draw rates and so when you draw them past what they can support their voltage output drops. Lipos are lighter so a battery of the same size has a higher capacity to be drawn from and so you're less likely to experience a voltage drop. Basically that means that car will scream compared to a car powered with a nickle battery. The down side is if you do over draw it instead of just a voltage drop you'll also likely ruin the battery.

[BE911SC]

Thanks Mikester for the help and the tutorial! Thanks everyone! I'll get back to you when I have a solution.

[mikester]

Let me know if you want me to see if I can find a good power system to put in it. I just need to know what sort of performance you want. Are you just looking to toy around so you don't want it so powerful when you hit full throttle it flips over backwards (I have a short course truck that will do this on asphalt or pavement) or do you want something sporty, fast and good run time?

[scottmandue]

I have been out of the R/C car thing for over a decade.

But I remember my Tamiya used to get HOT after a few runs... longer run times may mean higher temperature.

YMMV

[aschen]

They sell a brushed upgrade motor for it. It is stamped 370 so assume a 380 sized motor amd/or brushless system would fit. gain dont think it is the right car to do anything fancy on. I think it will just end up broken or beat up.

TowerHobbies.com | Tamiya TamTech-Gear Sport-Tuned Motor SPT

My bet is 2S lipo would probably fry the stock controller. As you said the voltage is about the same as 6s nimhy but the output impedence of lithum polymer is so low it will maintain that voltage into high loads. My guess is it would fry. Ive fried a couple older scs when lithium polymer came out doing the same thing.

[mikester]

I was going to suggest replacing the stock 370 with a mild Kv brushless (something to make it more efficient but not a lot faster) as well as a Brushless and Lipo friendly ESC.

The heat buildup on a light setup like that would likely be less than the stock setup.

The platform is a quality platform and while I wouldn't put something over the top in it Tamiya themselves have a brushless setup they sell for the GT-01 chassis (and the AWD TT-01).

Just adding a lipo isn't a terrible idea but the extended run time and the higher capacity will increase the wear and tear on the power system. The motor will be going faster for longer and the ESC will also be sustaining higher outputs than it is likely designed for. Eventually it will cause a failure somewhere but that's just an excuse to upgrade.

[aschen]

as an ironic aside, I got one of the first series tamtech cars when they came out. I think it was about 89, it was a mirical of modern technology to have a hobby grade car in 1/24 th. Regretably mine was an f40 not a 956 or similar. I really enjoyed that car, we made race tracks by taping garden hose to the concrete.

[David McLaughlin]

Ashen, I still have an old Tamtech too, a Lotus F1. I think it's 1/14 scale; wonder if it still runs?

[aschen]

probably needs a new battery but it should be good to go. If its of 80s vintage it is likely 1/24th scale.

Fire that bad boy up and have a good time with it!

[jyl]

I have a Tamiya Porsche 959 RC, built but not run, unpainted. Where might be a good RC website to sell it? I'm looking for an alternative to eBay.

[David McLaughlin]

How much do you want for it? I'm interested.

[jyl]

I'll PM you, David.

[mikester]

Originally Posted by aschen

as an ironic aside, I got one of the first series tamtech cars when they came out. I think it was about 89, it was a mirical of modern technology to have a hobby grade car in 1/24 th. Regretably mine was an f40 not a 956 or similar. I really enjoyed that car, we made race tracks by taping garden hose to the concrete.

They make a lot of smaller scale high quality cars now. All the way down to 1/36 scale.