R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 03-06-2010, 10:58 AM   #31
JQ
Tech Master
 
Join Date: Jan 2008
Posts: 1,588
Default

Have you ever heard of someone making a dirt bike heavier? No? And rally cars? No?

Downforce is not the reason cars can and should be light.

am: Thats what I mean, I just said it abit differently. And even with the current designs, just set up changes, a lighter car will be faster. The problem is tyres, as new compounds may be needed. For example in electric. For PL 1:8th scales use M3, just like 10th. The 10th boys need something new.
JQ is offline   Reply With Quote
Old 03-06-2010, 11:24 PM   #32
Tech Initiate
 
turner2's Avatar
 
Join Date: Mar 2009
Location: Kingman, AZ
Posts: 44
Trader Rating: 2 (100%+)
Default

you are also talking about full scale racing. these are 6 pound cars. not saying anyones opionions are wrong. a light car is fast to an extent. make the car 3lbs put a .21 in it and go win all the races. oh and dont wreck.

downforce is the reason full scale can be light. ex:sprint cars. 850hp in a 1300lb car. and they have more power to weight ratio than an indy car. do indy cars rely on downforce?
__________________
TLR 22 2.0
TLR 22SCT
Powered by Visa
Pike Motorsports RC
turner2 is offline   Reply With Quote
Old 03-07-2010, 01:28 AM   #33
JQ
Tech Master
 
Join Date: Jan 2008
Posts: 1,588
Default

Then why do they make dirtbikes or rally cars light? Its not downforce!

The laws of physics are the same for real racing cars or bikes, and for RC vehicles.

F=ma Force = mass x acceleration, or rather a= F/m
JQ is offline   Reply With Quote
Old 03-07-2010, 02:01 AM   #34
am
Tech Master
 
Join Date: Jul 2004
Location: Norway
Posts: 1,602
Default

So we agree, Joseph :-)

Soemtimes i just do not get english good enough, lol.

Will THE news be released soon?
am is offline   Reply With Quote
Old 03-07-2010, 04:50 AM   #35
JQ
Tech Master
 
Join Date: Jan 2008
Posts: 1,588
Default

I dont know what you are talking about :-D
JQ is offline   Reply With Quote
Old 03-07-2010, 08:23 AM   #36
Tech Lord
 
Integra's Avatar
 
Join Date: Dec 2006
Posts: 12,482
Trader Rating: 8 (100%+)
Send a message via MSN to Integra
Default

Quote:
Originally Posted by turner2 View Post
do indy cars rely on downforce?


lol i hope your kidding.
__________________
TNS Driver - Radio Post - Blue Groove Apparel - Team Panther - Hitec - Losi - W.E.D. Paint - Clockwork Fuel - Competition Heat - SUMO Racing - Tekin - Team Terribles - M2C Racing - Matrix Concepts - Kal Gard - BuKu Power - DE Racing -
Integra is offline   Reply With Quote
Old 03-07-2010, 09:01 AM   #37
Tech Elite
 
madweazl's Avatar
 
Join Date: Oct 2002
Location: Woodbridge, VA
Posts: 2,578
Trader Rating: 11 (100%+)
Default

How does weight change geometry?
__________________
RadioPost
Mugen MBX7r | CRE Picco 5TR/2120 | Hitec 7950/7940
Tekno NB48 | B6 Pro/2058 | Hitec 7950/7940
Kyosho RB6 | Viper VTX10r/Reedy Mach 3 9.5 | Hitec 7940
Schumacher SX3 Pro | Viper VTX10r/Reedy Mach 2 8.5 | Hitec 7940
madweazl is offline   Reply With Quote
Old 03-07-2010, 10:09 AM   #38
Tech Initiate
 
turner2's Avatar
 
Join Date: Mar 2009
Location: Kingman, AZ
Posts: 44
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by Integra View Post
lol i hope your kidding.
explain. id love to learn something today.

Quote:
Then why do they make dirtbikes or rally cars light? Its not downforce!
they also get airborne. so downforce is irreleavant. a 2700lb car of that size is heavy. compared to the horsepower they put out.
__________________
TLR 22 2.0
TLR 22SCT
Powered by Visa
Pike Motorsports RC
turner2 is offline   Reply With Quote
Old 03-07-2010, 10:27 AM   #39
Tech Lord
 
Integra's Avatar
 
Join Date: Dec 2006
Posts: 12,482
Trader Rating: 8 (100%+)
Send a message via MSN to Integra
Default

Quote:
Originally Posted by turner2 View Post
explain. id love to learn something today.


quick quote off an automotive site.


"Downforce is the Holy Grail of auto racing because it
dramatically increases traction by forcing the tires against the pavement. Increasing the vertical force on the tires with aerodynamic loads increases the amount of lateral force they can produce. More grip means faster cornering speeds and quicker lap times. An Indy car produces so much downforce at speed that it could literally drive upside down on the ceiling of a tunnel."


so to answer your question Yes Indy does rely on downforce.



here's another quick quote from a physics site


"Every time a wing generates lift (or a spoiler generates down force) it also generates drag. Drag is the natural reaction of the fluid (air) to resist motion through it (the car). Drag is bad, because it slows down the car. So, more down force is good... but too much down force = too much drag, which is bad. Very very high performance sports cars, like Le Mans or F1, have a ratio called the 'lift/drag' ratio. The car designers try and maximize this so that the car has just enough force to get around the corners, but not so much that they are too slow. Indy cars, and ones that are designed like that can have down force on the order of 3G's, at 200mph. That means they could hang completely upside down on the track, and as long as they kept going fast enough, they would still stick to the road. "
__________________
TNS Driver - Radio Post - Blue Groove Apparel - Team Panther - Hitec - Losi - W.E.D. Paint - Clockwork Fuel - Competition Heat - SUMO Racing - Tekin - Team Terribles - M2C Racing - Matrix Concepts - Kal Gard - BuKu Power - DE Racing -
Integra is offline   Reply With Quote
Old 03-07-2010, 12:54 PM   #40
JQ
Tech Master
 
Join Date: Jan 2008
Posts: 1,588
Default

Quote:
Originally Posted by madweazl View Post
How does weight change geometry?
I dont think anyone here has intended to say weight changes geometry, rather less weight may require geometry changes in order for the car to perform better than it performed when it was heavy.
JQ is offline   Reply With Quote
Old 03-07-2010, 05:50 PM   #41
Tech Adept
 
el Bourlando's Avatar
 
Join Date: Sep 2008
Location: Indianapolis
Posts: 218
Default

Dirt Bikes and Rally Cars are driven by people in or on them.
R/C cars are driven from a drivers stand.
Full scale racing does not 100% translate into r/c racing.
Lighter is better to a point, and for the situation.
Removing rotating mass has a bigger effect than sprung weight. IMO
Removing weight to put it where you want is probably good. Some pro drivers run their batteries up front.
Ultimatlely we are tuning the chassis's we have to work with to get the most out of the design.
The wieght rules are designed for safety and to keep costs "reasonable".
__________________
Brian Bourland

I69 Raceway Head of Track Operations- RC Enthusiast Extraordinaire
KYOSHO Privateer Inferno Tki3 & MP9e
el Bourlando is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Lowering the weight of Touring Cars that use lipo TheCoolCanFanMan Electric On-Road 141 02-27-2016 10:48 PM
ROAR 1/12 weight limit miller tyme Electric On-Road 171 01-09-2009 03:14 PM
Lipo vs Nimh Racing and Minimum Weight yyhayyim Electric On-Road 91 09-20-2007 04:56 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 05:12 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net