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HPI RS4 PRO brushless upgrade

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HPI RS4 PRO brushless upgrade

Old 01-30-2009, 01:23 AM
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Default HPI RS4 PRO brushless upgrade

I recently dusted off my RS4 PRO (I know ) and would like to breathe some life into it. It has been sitting for years at a time only to be occasionally taken out to run a couple packs up and down the street when someone wants to see how fast it goes.
I plan on refreshing the car with a tear down and rebuild, shocks, diffs, new tires and belts. I recently saw some kids with a Traxxas truck with a brushless motor that was just crazy fast. Will my car be able to handle that power? If so I was thinking of one of the Castles Sidewinder packages http://www.castlecreations.com/products/sidewinder.html. How would the 4600kv on 3S compare to the 5700kv on 2S? I won't lie, I want speed that will make a Nun curse. This is just for fun, I don't plan on racing and don't necessarily want to break the bank. All my planes are brushless and lipo powered (I use Castle esc and Thunder Power lipos) so I am not new to the technology but I am not sure how it translates to cars. I'm used to props and watt meters.
The current setup in my car is: Trinity Speed Gem 12t Onyx, Trinity 1700(probably not in the best shape), Novak 610 HRV and Futaba Junior Tx. Right now I have the car geared as fast as possible, smallest spur gear, biggest pinion I could find. I'm looking to have something to tear around the parking lot between flights and when the wind picks up. Please offer any advice or guidance with this particular model or post a link to an RS4 PRO thread if there is one. Thanks.
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Old 01-30-2009, 10:46 AM
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I'm not familiar with the power handling capabilities of the RS4, but I can offer insight as far as sidewinder setups go. First off, to get the most out of brushless you will need to pick up new Nimh packs or go lipo. The 4600 on 2s geared up will break 45 mph and on 3s is capable of highway speeds. The 5700 on 2s won't have the power of the 4600 on 3s, but is still a beast. If you are doing speed runs in a "parking lot" then the 5700 on 2s is enough. The 4600 on 3s will need more room to show its full potential.
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Old 01-30-2009, 11:40 AM
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Originally Posted by Krio
I'm not familiar with the power handling capabilities of the RS4, but I can offer insight as far as sidewinder setups go. First off, to get the most out of brushless you will need to pick up new Nimh packs or go lipo. The 4600 on 2s geared up will break 45 mph and on 3s is capable of highway speeds. The 5700 on 2s won't have the power of the 4600 on 3s, but is still a beast. If you are doing speed runs in a "parking lot" then the 5700 on 2s is enough. The 4600 on 3s will need more room to show its full potential.
Thanks for the insight. It looks like the 4600 is the way to go. I can gear it on 2s and make the jump to 3s later, like in a week! I'm guessing even the brushless on nicad will make the Onyx feel slow.
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Old 06-04-2009, 04:51 PM
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Stumbled upon this thread...
I have a RS4 Sport, Sport 2 and Pro 2. I'm currently rebuilding the Pro 2 to use as a backup car. It should be noted that a lipo is too wide to fit in the battery tray, and might need to be taped in. A 3s in an RS4 would require you to remove the battery holders on the side because it will have to sit farther forward because it won't fit under the rear motor plate support. A 3s may also rub on the front belt since it will be taller, and a 2s/nimh is close to touching.
Let us know how it comes out.
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Old 06-05-2009, 10:35 AM
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the maxamps lipo will go right into it
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Old 06-05-2009, 04:16 PM
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Good to know, I'm using Orion Carbon hard case lipos and they are too wide.
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Old 06-05-2009, 04:33 PM
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I just cleaned up the car and have been running it in front of my house. I tried to take it to the parking lot I fly at and it is way too bumpy. Any sort of upgrade to the car without a better place to run would not be worthwhile. I've been looking at a truggy or something similar for the rough stuff. Clocked it in my street at 19mph with a hotwheels speed gun.
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Old 06-05-2009, 08:31 PM
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just go to maxamps.com and there is a link just for this car
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Old 01-02-2011, 05:29 PM
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Originally Posted by IH8VTEC
I recently dusted off my RS4 PRO (I know ) and would like to breathe some life into it....Will my car be able to handle that power?
Just to add a data point, I upgraded my RS4 Pro to brushless. If you are wondering if "it can take it". Of course. I just ran a Tekin 4.5 Brushless in it with the 2 speed transmission... It's the fastest RC car I have ever driven. I haven't had the chance to duct tape a GPS on to it yet - especially since there's snow on the ground.

My wife got me the TCX for Christmas, but I will still race the RS4 Pro as backup. It is significantly more sturdier than the TCX - read my rant in the TCX forum if you are interested.
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Old 01-10-2011, 11:27 AM
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Can you guys post some pics of your RS4 Pro? I've got a chassis that I got a few years ago and never did anything with. I am debating whether to get it running or not. I don't want to invest too much into so would like to use as much of what I have as possible. I'm very new to all this stuff.

I was thinking about making it brushless, can I use 3300Mah 6-cell batteries? Or, maybe brushless is not the best way to go given road clearance? Still debating.

I think it's missing the battery clamps so I'd love to see pictures if you guys have them.

Thanks.
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Old 01-10-2011, 05:55 PM
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I don't have any pics of mine, but I am running a 5000 lipo and I took the battery holders off and just taped the battery in using strapping tape.
I am running a 19 turn brushed motor and it is just as fast as my TC3 running brushless. It's not as "punchy" but is every bit as fast on the straight.
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Old 01-10-2011, 07:52 PM
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Originally Posted by Bossman429
I don't have any pics of mine, but I am running a 5000 lipo and I took the battery holders off and just taped the battery in using strapping tape.
I am running a 19 turn brushed motor and it is just as fast as my TC3 running brushless. It's not as "punchy" but is every bit as fast on the straight.

Great idea with the strapping tape...thanks!

With my 3300 NiMH batteries, does it make sense to go with a brushless setup?
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Old 01-10-2011, 08:06 PM
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You won't realize the potential of the brushless without a lipo battery, but either way is fine. Brushed systems are getting harder and harder to find. It may be simpler to go brushless, then you'll for sure have lipo cutoff when you go that way.
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Old 01-10-2011, 08:33 PM
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So if I get this thing setup with brushless and then get a lipo battery down the road, does it just plug right it? That is, can I just take out the NiMH and put in the Lipo or are there other things I need to do and worry about?
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Old 01-10-2011, 10:31 PM
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Originally Posted by miksnake
So if I get this thing setup with brushless and then get a lipo battery down the road, does it just plug right it? That is, can I just take out the NiMH and put in the Lipo or are there other things I need to do and worry about?
I assume you have all 6 cells of your NiMh in "side by side" configuration and is mounted perpendicular to the direction of the chassis (i.e. - you are not running saddle packs). If so, a 2s 5000 mah Lipo will tape to the same place. However, depending on the size of the Lipo hard casing, there may be some "belt rubbing" at the top of the battery. I'm not worried about it.

The bigger issue, as I found out, would be that you would need to file the chassis so that you can fit a brushless motor. BL's are a bit longer. This is no biggie so long as you have a file or Dremel.

I'll take a pic of my setup once I get home towards the end of the week.
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