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Old 06-15-2011, 09:47 AM   #1
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Default RS-4 help on 90-100 mph

i was thinking of puting a bigger engine. its got an o.s. .15 cv-r and hit about 65mph i would like to get up 90- 100 mph. and can i put some wider tires in the back like the 1/8 scale have. are will it be better to upgrade to a new version car.
iv got pics of car at rchotspot.blogspot. COM
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Old 06-21-2011, 02:58 PM   #2
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How did you know you went 65 mph?

I once had a Super Nitro RS4, 33R ruber tires, .21 engine, a really tall set of single speed gears, a super slipery GT-One body, and managed 85 mph...clocked with a radar gun.

At that speed we were having issues with the tires ballooning so bad they would rub the body and start to melt it or they would rip in half from the centrificul force. Anything above this speed and you're going to want to go with foam tires.

RCCA did a 100 mph Super Nitro and they had to use custom pullies and other one off parts to get it to hit that speed with a .21.

This is why I wonder what you used to measure your speed because 60 mph with an RC car looks a hell of a lot faster than it is. Also, to achieve 90-100 with the car you have isn't going to be cheap and as speed climbs, durability falls fast.
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Old 06-22-2011, 07:29 AM   #3
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Originally Posted by Robotech View Post
How did you know you went 65 mph?

I once had a Super Nitro RS4, 33R ruber tires, .21 engine, a really tall set of single speed gears, a super slipery GT-One body, and managed 85 mph...clocked with a radar gun.

At that speed we were having issues with the tires ballooning so bad they would rub the body and start to melt it or they would rip in half from the centrificul force. Anything above this speed and you're going to want to go with foam tires.

RCCA did a 100 mph Super Nitro and they had to use custom pullies and other one off parts to get it to hit that speed with a .21.

This is why I wonder what you used to measure your speed because 60 mph with an RC car looks a hell of a lot faster than it is. Also, to achieve 90-100 with the car you have isn't going to be cheap and as speed climbs, durability falls fast.
The car Robotech is talking about was featured on the cover of RC Car Action several years ago (I have that issue in a box somewhere in storage). There were a ton of custom-made parts (spur gear, clutch bell gear, pulleys like Robotech said, HPI Corvette Super Nitro body, etc.) to make that Super Nitro break the 100mph barrier (101.667 to be exact). Those guys made a big investment (a lot to get those custom-made parts which weren't cheap) in getting that car to that speed. Are you sure you want to go this route?
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Old 06-22-2011, 09:35 AM   #4
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Wolf Pack Radiculs




http://www.wolfpackradicals.com/home.html
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Old 06-22-2011, 09:52 AM   #5
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Wolf Pack Radiculs




wolfpackradicals.com
That's the company that made the 21 conversion kits that both Steve Pond at RCCA and I used on our .21 Supers. It wasn't that one, that's their newer one that actually address chassis weight and layout issues that come with bolting in a .21 to a Super Nitro. At that point though it's no longer a nitro sedan...It's an 1/8th scale nitro car like a Serpent or Proceed...just not as good.

In addition, that conversion kit still doesn't address the issues of gearing. When I did the 85 mph car I was trying to replicate what RCCA had done but with all off the shelf parts. I was running a RS4 Nitro 3 2-speed clutchbell because the pinion gears could be screwed on and off. I would run the two speed clutch but had the clutch locked down so I could use the much smaller 2nd gear spurs. Then on the two speed clutchbell I'd use the largest 2nd gear pinion I could find. I think we were running something like a 37/22 combo (the 23 tooth gear wasn't out yet and later we went to a completely different clutchbell but I never got a chance to run it with that setup). The belt pulleys were stock size but the HPI steel pullies.

While the rubber tires caused their own issues, their size and their tendancy to balloon probably helped since it increased their diameter and shrunk the contact patch thus producing less friction. No evidence of this and obviously the rubber tires wouldn't have carried us to 100 but I wonder if our gearing setup would have let us get to 85 had we been running foams.

Lastly is a matter of where do you run it. RCCA used an airstrip...I had a very long, very flat, very unused section of asphault. a 70+ MPH needs a lot of room to get to that speed and even more room to shut down.
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Old 06-22-2011, 10:51 AM   #6
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this really was interesting that time.. remember Steve's project well like many seem to do.. I think I also remember them saying that they should have chosen something else for the chassis than Super Nitro

I also bought some part from wolfpackradicals to my super and even got some extra parts for free. nice guy, dunno if he's into R/c anymore, do you know?

and oh yeah, I also had this superten FW04 with all the tuning parts and Novarossi .12 5-port. I run it one evening and the windshield was covered with smashed flies/mosquitos ;D sure fast but far from 90 mph
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Old 06-22-2011, 12:33 PM   #7
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wolfpack isnt making parts anymore.

The guys in miami have been going 100+ with RS4-2's for a while now. Just takes money and time...
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Old 06-22-2011, 02:39 PM   #8
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wolfpack isnt making parts anymore.

The guys in miami have been going 100+ with RS4-2's for a while now. Just takes money and time...

+1 I would PM a member here on RCTech his nick is MiamizFinest he has been running those speeds for a while now

Cool dude too, I met him last year and talked Speed for a while, he has alot of knowledge
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Old 06-22-2011, 04:26 PM   #9
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wolfpack isnt making parts anymore.

The guys in miami have been going 100+ with RS4-2's for a while now. Just takes money and time...
Like the old saying goes...

How fast can it go? How much money do you have?
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Old 06-22-2011, 09:10 PM   #10
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^^^ what he said u can only go as fast as your pockets can take you, shoot me a pm with ur number I'll help you out
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