R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road

Reply
 
Thread Tools Search this Thread
Old 11-24-2007, 10:23 PM   #61
Tech Fanatic
 
Serpentd's Avatar
 
Join Date: Jul 2004
Location: Evans, CO. USA
Posts: 798
Default

Quote:
Originally Posted by 8lackflagracing View Post
I may need parts again I am a racer 13 years ontrack do you have a wed sight for this car
Best thing to do is look at the Motonica thread here on RCTech. But here is the Main website for the car http://www.motonica.com/english/index.htm. If you need personal assisitance let me know. I will help all I can. Also, if you need a car or parts, let me know that as well. I want all the 301 crew to drive the Motonica. Although getting Vincent to change might be difficult. Check it out dude, you will drool I promise. Garen just posted some Great Pics of the car on the Motonica thread.
__________________
Blessed are the SIC
Serpentd is offline   Reply With Quote
Old 11-25-2007, 08:10 AM   #62
Tech Elite
 
squarehead's Avatar
R/C Tech Charter Subscriber
 
Join Date: Nov 2003
Location: Wheaton, Illinois
Posts: 4,211
Trader Rating: 75 (100%+)
Send a message via AIM to squarehead Send a message via MSN to squarehead Send a message via Yahoo to squarehead Send a message via Skype™ to squarehead
Default

Wow, great answer on the tire questions. Most helpful, for sure.

My only question with the rear camber issue is, why aren't the cars designed so that the rears don't camber and wear so unevenly? I don't think I have ever seen a real or R/C race car that was designed with so much rear camber, then forced more camber into it with coned tires. It seems like a terrible solution to a design flaw, yet all of the manufacturers do the same thing. I don't get it.


Fantastic thread.
__________________
Everything depends.
Nothing is always.
Everything is sometimes.
squarehead is offline   Reply With Quote
Old 11-25-2007, 08:28 AM   #63
Tech Adept
 
Join Date: Feb 2004
Location: colorado springs
Posts: 225
Default

Darint - great reply. very informative.

As Darin said, each track is a bit different. The track me and SerpentD run on actually prefers bigger tires due to the track surface.

BlackFlag - All the major cars (Mugen, Kyosho, Serpent, Motonica) are all great cars. Each one will drive into the corners differently based on the suspension geometry. If you have been racing with the RRR, you may want to start with the Evolva (either 05, 07, or the M3 when it comes out) as the two cars will have a similar feeling when driving it and you'll be already be familiar with how the cars are built.

SerpentD - Please stop hyping up the Motonica . Just joking, I know how excited you are about the car. I'll see ya next year.

ApexSpeed - no car wears all the tires the same, not even Formula 1. You're seeing larger camber angles on these cars due to the amount of suspension travel and the g-forces (you won't find many vehicles that endure higher forces) acting on the car while cornering. The amount of cornering force these cars go through is incredible, so these geometry's (especially in the newer cars) work very well.
darkangel is offline   Reply With Quote
Old 11-25-2007, 11:35 AM   #64
Tech Regular
 
ESWLFSE's Avatar
 
Join Date: Nov 2007
Location: Terra Ceia, FL
Posts: 326
Trader Rating: 7 (100%+)
Send a message via Yahoo to ESWLFSE
Default

DarinT - when cutting a set of tires for a proper F-R diameter stagger where do you measure the rear diameter once they are cambered?

Last edited by ESWLFSE; 11-25-2007 at 12:57 PM.
ESWLFSE is offline   Reply With Quote
Old 11-25-2007, 12:19 PM   #65
Tech Master
 
garen's Avatar
 
Join Date: Jan 2006
Location: GLENDALE
Posts: 1,730
Trader Rating: 7 (100%+)
Default

always measure the outside of the tire
__________________
bpengines-usa.com fioroni-usa.com motonica-usa.com

Airtronics Avid RC Byron Fuels VOX Engines

VMR Tires - available at http://motonica.ipower.com/store
garen is offline   Reply With Quote
Old 11-25-2007, 01:33 PM   #66
Tech Fanatic
 
Serpentd's Avatar
 
Join Date: Jul 2004
Location: Evans, CO. USA
Posts: 798
Default

Quote:
Originally Posted by darkangel View Post
Darint - great reply. very informative.

As Darin said, each track is a bit different. The track me and SerpentD run on actually prefers bigger tires due to the track surface.

BlackFlag - All the major cars (Mugen, Kyosho, Serpent, Motonica) are all great cars. Each one will drive into the corners differently based on the suspension geometry. If you have been racing with the RRR, you may want to start with the Evolva (either 05, 07, or the M3 when it comes out) as the two cars will have a similar feeling when driving it and you'll be already be familiar with how the cars are built.

SerpentD - Please stop hyping up the Motonica . Just joking, I know how excited you are about the car. I'll see ya next year.

ApexSpeed - no car wears all the tires the same, not even Formula 1. You're seeing larger camber angles on these cars due to the amount of suspension travel and the g-forces (you won't find many vehicles that endure higher forces) acting on the car while cornering. The amount of cornering force these cars go through is incredible, so these geometry's (especially in the newer cars) work very well.
Darkangel my friend!! Yeah dude. I'm stoked for next year. I hope Sal races with us, How is his wife...have you heard? Sorry for off subject guys. But MOTONICA ROCKS dude, it ROCKS!!!

As far as the camber issue, I see what Apexspeed is trying to say, but just like Darkangel said, the G-force is incredible with these cars. I ran accross a few "action" photos and it really shows the rear camber in action. let me see if I can find them again and post a few. This will show you first hand.
__________________
Blessed are the SIC
Serpentd is offline   Reply With Quote
Old 11-25-2007, 01:59 PM   #67
Tech Fanatic
 
Serpentd's Avatar
 
Join Date: Jul 2004
Location: Evans, CO. USA
Posts: 798
Default

K guys, here are the "rear camber action" shots. I did not take these photos. The dude that did I think his name is on the picture. So just to give him due credit, he took some excellent pics for sure. Also, look at the difference in tire diameter on each car going around the corner (looks like same corner). You can see the HUGE amounts of camber gain on these shots. Just imagine the forces on the other back tire that you can't see. The tires you can't see is where you need these larger camber angles.
Attached Thumbnails
General 1/8th Scale On-Road Thread-img_0599.jpg   General 1/8th Scale On-Road Thread-img_0613.jpg   General 1/8th Scale On-Road Thread-img_0639.jpg   General 1/8th Scale On-Road Thread-img_0673.jpg  
__________________
Blessed are the SIC
Serpentd is offline   Reply With Quote
Old 11-25-2007, 02:13 PM   #68
Tech Regular
 
ESWLFSE's Avatar
 
Join Date: Nov 2007
Location: Terra Ceia, FL
Posts: 326
Trader Rating: 7 (100%+)
Send a message via Yahoo to ESWLFSE
Default

Great pics thanks Darren!

Next topic 2-speed shift points. Is this something that is adjusted to match powerband and gearing only or might it change specific to a track even with the same engine/gearing and why?
ESWLFSE is offline   Reply With Quote
Old 11-25-2007, 02:40 PM   #69
Tech Elite
 
squarehead's Avatar
R/C Tech Charter Subscriber
 
Join Date: Nov 2003
Location: Wheaton, Illinois
Posts: 4,211
Trader Rating: 75 (100%+)
Send a message via AIM to squarehead Send a message via MSN to squarehead Send a message via Yahoo to squarehead Send a message via Skype™ to squarehead
Default

Quote:
Originally Posted by Serpentd View Post
K guys, here are the "rear camber action" shots. I did not take these photos. The dude that did I think his name is on the picture. So just to give him due credit, he took some excellent pics for sure. Also, look at the difference in tire diameter on each car going around the corner (looks like same corner). You can see the HUGE amounts of camber gain on these shots. Just imagine the forces on the other back tire that you can't see. The tires you can't see is where you need these larger camber angles.
Great photos and a legitimate explanation, however, all those photos show me is the gross camber gain in a corner of a severely unloaded inside tire. As I look at these pictures, and try to figure the geometry out, I'm thinking about F1 and LeMans cars with massive corner G-loads (and using ground effects). There are no cars that design THAT much rear camber and change into the suspension. That amount of camber gain in race cars is never something that can be considered advantageous. Granted, the whole of an 1/8th scale gas car is unlike anything else, but it doesn't make sense to me--no matter how many Gs these cars pull in the corners.

Now that I am looking at those photos, I'm wondering if the suspension was designed around a live rear axle that will never allow the inside tire to turn less than the outside tire. So the solution would be to lift a majority of the inside tire off of the ground in the corner with stupid camber gain. An odd solution to a problem to me, as I would think a car with the most contact patch on the ground through a corner would perform at a greater level than one scrubbing and lifting tires off the ground.

So a side question is, why the live rear axle without a differential? Wouldn't a car with a suspension design that allowed for more tire on the ground through the corner using at least a rear differential behave more consistently?



Just wondering out loud... nothing more than questions to a fairly foreign concept to me.


doug
__________________
Everything depends.
Nothing is always.
Everything is sometimes.
squarehead is offline   Reply With Quote
Old 11-25-2007, 02:51 PM   #70
Tech Fanatic
 
Serpentd's Avatar
 
Join Date: Jul 2004
Location: Evans, CO. USA
Posts: 798
Default

Well, I posted those photos just to show you the G-force. If I showed you pics of the other side of the car, all you will see is the tire being flat on the asphault using the entire contact patch of the tire. If I found a rear pic of a car going around a corner like this, then it would be easier to see. So yeah, the pics didn't entirely explaing camber since those are the tires that or Unloading, but just wanted to give you the sence of what Darkangel was talking about with the high G-forces. I don't think that a diff would hold up to the power these cars give. Plus honestly, these cars are stupid fast with this solid rear axel design. So, no issues there. I see the gears turning in you brain, and you are making some good points. I need to leave right now, so sorry for the fast incomplete post Apex and everyone. Back soon. Later.
__________________
Blessed are the SIC
Serpentd is offline   Reply With Quote
Old 11-25-2007, 04:35 PM   #71
Tech Adept
 
Join Date: Feb 2004
Location: colorado springs
Posts: 225
Default

SerpentD - I'll send you a pm about Carol and Sal DiFazio

ApexSpeed - I understand your thoughts, I had them as well trying to figure out why certain things are what they are and still work. The scale difference and the incredible differences in forces (they are probably 2 to 3 times that of a F1 car in relation to each other) is where the suspension theories kinda break down. There are probably certain F1 tracks that requires 2+ degrees of camber on a F1 car to provide enough camber gain. Also remember F1 cars suspension only moves a few inches at most in relation to the car, where 1/8 cars suspension moves a great deal more in comparison.

SerpentD is probably right about the gears in a diff not being able to withstand the torque these engines produce. Also remember a rear diff = understeer (to a point) in these cars. 1/8 cars almost demand you use your throttle finger to steer the car as much as the front steering does. With a diff you will never get that unless you put some extra thick oil in (at which point you might as well have a solid in). You will have a lot of grip from the tires to overcome to get the car to turn.
darkangel is offline   Reply With Quote
Old 11-25-2007, 06:05 PM   #72
Tech Adept
 
flack's Avatar
 
Join Date: Mar 2005
Posts: 240
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by ApexSpeed View Post
My only question with the rear camber issue is, why aren't the cars designed so that the rears don't camber and wear so unevenly? I don't think I have ever seen a real or R/C race car that was designed with so much rear camber, then forced more camber into it with coned tires.
Something to think about...the rear tires on 1/8th scale are REALLY wide. When you put a few degrees of camber in them, the outside of the tire no longer is touching the ground. By "coning" the tire, you allow the whole tire to contact the ground. I don't think any other full scale car runs with tires that are as wide as they are "scale" wise on 1/8th.

You don't "cone" the fronts and they are at least half the width if not smaller than the rears.

Doug
__________________
www.TSRCAR.com
flack is offline   Reply With Quote
Old 11-25-2007, 07:08 PM   #73
Tech Master
 
JFCJ's Avatar
 
Join Date: Mar 2004
Location: Cincinnati Area
Posts: 1,024
Trader Rating: 31 (100%+)
Default

Great write-up Darin!

Thanks for taking time to write it up!

J
__________________
* www.tsrcar.com * John's BSR Racing Tires * Serpent America * BOCA Bearings *
JFCJ is offline   Reply With Quote
Old 11-25-2007, 08:20 PM   #74
Tech Master
 
Join Date: Nov 2004
Posts: 1,085
Trader Rating: 14 (100%+)
Default

One thing ive heard from a racer about coning the wheel is that the outside wheel will alway have a larger diameter than the inside wheel. when power is applied the same power is sent to both the rear wheels. So lets say the point of contact is a single point. As the car rolls more, the point of contact moves towards the larger diameter for the outside tire......towards the smaller diameter for the inside tire.

When power is applied, the larger diameter of the outside wheel "pushes" the car more than the smaller diameter of the inside wheel. This puts a torque on the outside of car making it turn in the corner a little better, in theory.

Sorry if I confused anyone
__________________
Speedpassion : Speedpower : East Coast Bodies
thunderbt3 is offline   Reply With Quote
Old 11-25-2007, 08:59 PM   #75
Tech Regular
 
P2gee's Avatar
 
Join Date: Jul 2004
Location: TX
Posts: 378
Default

Quote:
Originally Posted by flack View Post
Something to think about...the rear tires on 1/8th scale are REALLY wide. When you put a few degrees of camber in them, the outside of the tire no longer is touching the ground. By "coning" the tire, you allow the whole tire to contact the ground. I don't think any other full scale car runs with tires that are as wide as they are "scale" wise on 1/8th.

You don't "cone" the fronts and they are at least half the width if not smaller than the rears.

Doug
Very good point here. You know, I have played around with power/weight and power /displacement numbers for our 1/8 cars compared to some of the state of the art 1:1 cars. In 1:1 cars we are driving a mid 70's Can Am chassis with almost John Force funny car HP in the engine bay. Kinda hard to compare to current F1 cars because none of them are making 3-4 thousand HP that I know of and if they did the chassis, tires ect would have to be alot different to maintain their current state of handling. The pics above are an excellent dipiction of why 1/8 tires cone to the inside. With a spool real end both tires are turning the same speed but the inside tire is scrubbing due to running a shorter arc........call this race truing your tires.
__________________
Airtronics M-12
BYRONS Gen2 fuel
Capricorn C802
www.motorists.org
P2gee is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Micro On Road & 1/18 Off Road Nats Thread RCMadness Micro and Mini Scales 1168 11-23-2017 08:19 AM
OFNA 1/8 Scale Thread Lost Racer Electric Off-Road 9 07-01-2011 05:32 AM
Northwest Racers General Discussion Thread Desolas Northwest Racers 23 02-14-2008 03:17 PM
‘Official’ On-Road racing of 1/18 scale Off-Road Vehicles Thread imjonah Micro and Mini Scales 13 10-10-2007 08:45 AM
1/12 scale thread highwayman Electric On-Road 2 04-19-2003 05:30 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 04:58 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net