R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 01-09-2008, 09:54 AM   #16
Tech Elite
 
glassdoctor's Avatar
 
Join Date: Aug 2006
Posts: 2,250
Trader Rating: 4 (100%+)
Default

I don't know which is better... all I can say is that it seems many have tried lighter cars (gone lipo...) and messed with the setup, etc... but they end up adding weight to be at least close to what a "nickel" car is.

I'm not saying a light car won't work or is a bad idea... maybe more r&d is needed to find the right setups.

But for now I'm adding weight to my lipo 1/10 car.
glassdoctor is offline   Reply With Quote
Old 01-09-2008, 09:58 AM   #17
Company Representative
 
ballisticsart's Avatar
 
Join Date: Jan 2007
Location: Northern California
Posts: 428
Trader Rating: 20 (100%+)
Default

So are you saying that the cars we have now are to easily breakable??? our whole program are brushless 1/10 scales and out of 42 drivers last weekend we only had 2 not finish due to breakage. also the way a track is built will save cars. Poles that hold the building up and blunt objects break things. if you want to reduce price run the lrp ai brushless set up or the novak evx. Who said it has to have a gagillion profiles to be fast!! both speedo esc combos for around $160 they both do the job well and have plenty of power for 2wd. I think that beats putting all the money into redesigning the cars for different electronics. my .02 not trying to offend anyone or downplay anything thats been said.
__________________
CFO - P1hobbies.com
P1raceway.com
Mercenary
ballisticsart is offline   Reply With Quote
Old 01-09-2008, 10:01 AM   #18
Tech Fanatic
 
Scrubb's Avatar
 
Join Date: Jun 2003
Posts: 834
Default

It would be nice to see the weight rules remain the same and the manufacturers use the lightweight properties of lipo technology to make up the difference and beef up some parts and lexan bodies.
__________________
Mark Westerfield

Last edited by Scrubb; 01-09-2008 at 10:19 AM.
Scrubb is offline   Reply With Quote
Old 01-09-2008, 10:14 AM   #19
Tech Elite
 
Join Date: Jun 2005
Posts: 2,570
Trader Rating: 26 (96%+)
Default

If you run a lighter buggy then there would be less stress on the parts. There are tracks where people do have trouble finishing though.
party_wagon is offline   Reply With Quote
Old 01-09-2008, 10:50 AM   #20
Tech Champion
 
Davidka's Avatar
 
Join Date: Oct 2004
Posts: 9,937
Trader Rating: 77 (100%+)
Default

Thereis one reason and one reason only that 1:1 racers reduce weight at all costs and model racers don't: horsepower limitations. They have it and for the most part, we don't. If all racing were say, stock class, every racer would try to keep his vehicle as close to the weight limit as possible. In modified, we have so much more power than we can use that extra weight does not translate into the disadvantage that it would if horsepower were a real limitation to performance.
__________________
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."

In mind and body, we're all heading towards old age. It is slower to go by bike.
Davidka is offline   Reply With Quote
Old 01-09-2008, 10:51 AM   #21
Tech Legend
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 29,555
Trader Rating: 240 (100%+)
Default

Quote:
Originally Posted by Scrubb View Post
It would be nice to see the weight rules remain the same and the manufacturers use the lightweight properties of lipo technology to make up the difference and beef up some parts and lexan bodies.
I don't dissagree with you Mark, but I still say that manufacturers will still shoot to have there vehicle be right at that minimum and we still end up adding in weight.

Again, the idea has merit, just don't see it happening.
__________________
Member - Red River Radio/Control Car Club
< Tekno EB48SL / SCT410.3 | Tekno EB410 x 2 | Yokomo YZ-2 DTM x 2 | LC Racing EMB-1 Buggies and Truggies >
Cain is offline   Reply With Quote
Old 01-09-2008, 11:26 AM   #22
Tech Master
 
sim600's Avatar
 
Join Date: Dec 2003
Posts: 1,624
Trader Rating: 15 (100%+)
Send a message via ICQ to sim600
Default

You cannot keep getting more and more grip by just going to softer and softer tires. On many surfaces, you still need the weight to push the tire patterns into the ground. On asphalt, you this limitation is not so obvious because the rough road surface can dig into the softer tire. On loose dirt, softer tires will just grip the loose top soil better but harder ones can dig deeper. So softer isn't always the answer.
sim600 is offline   Reply With Quote
Old 01-09-2008, 12:16 PM   #23
Tech Addict
 
foolio's Avatar
 
Join Date: Jan 2006
Location: Indianapolis, IN
Posts: 732
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by Davidka View Post
Thereis one reason and one reason only that 1:1 racers reduce weight at all costs and model racers don't: horsepower limitations. They have it and for the most part, we don't. If all racing were say, stock class, every racer would try to keep his vehicle as close to the weight limit as possible. In modified, we have so much more power than we can use that extra weight does not translate into the disadvantage that it would if horsepower were a real limitation to performance.
We're going to have to agree to disagree here. Not all 1:1 classes have HP limitations. Personally, I can't think of any. Yes there are limits on displacement, fuel delivery, and other things. In F1, there is as much as a 50HP difference between MF's cars and they all strive to meet the absolute minimum weight requirement to get that edge. I agree, the shear amount of power available in Mod racing is sometimes a crutch more than an asset. However, lighter cars will accelerate, brake, and change direction faster.

Of course, this whole argument is difficult to prove for anyone. We are just sharing opinions here...we know it's mostly going to come down to the driver...not a few grams here and there...
foolio is offline   Reply With Quote
Old 01-09-2008, 12:21 PM   #24
Tech Addict
 
foolio's Avatar
 
Join Date: Jan 2006
Location: Indianapolis, IN
Posts: 732
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by sim600 View Post
You cannot keep getting more and more grip by just going to softer and softer tires. On many surfaces, you still need the weight to push the tire patterns into the ground. On asphalt, you this limitation is not so obvious because the rough road surface can dig into the softer tire. On loose dirt, softer tires will just grip the loose top soil better but harder ones can dig deeper. So softer isn't always the answer.
Yes, but to a certain degree we have aero to help us with that on the high speed sections of the track. On the low speed sections, less mass is easier to turn, brake, and accelerate so you can go with less grip and overall less energy expended which can turn into longer runs and less heat generated as waste. Which leads us back to the original point of this post; you can use less battery and less motor to save on weight and mass in motion to get the same result.
foolio is offline   Reply With Quote
Old 01-09-2008, 12:49 PM   #25
Tech Champion
 
Davidka's Avatar
 
Join Date: Oct 2004
Posts: 9,937
Trader Rating: 77 (100%+)
Default

Quote:
Originally Posted by foolio View Post
We're going to have to agree to disagree here. Not all 1:1 classes have HP limitations. Personally, I can't think of any. Yes there are limits on displacement, fuel delivery, and other things. In F1, there is as much as a 50HP difference between MF's cars and they all strive to meet the absolute minimum weight requirement to get that edge. I agree, the shear amount of power available in Mod racing is sometimes a crutch more than an asset. However, lighter cars will accelerate, brake, and change direction faster.

Of course, this whole argument is difficult to prove for anyone. We are just sharing opinions here...we know it's mostly going to come down to the driver...not a few grams here and there...
By power limitations I do not mean that they are limited within the rules, simply the vehicle's potential to accelerate. With a 1/10 mod offroad car it is very easy to power so that the vehicle's acceleration limited only by the car's traction and ability to stay on the ground. In F1, the car's with a 50hp disadvantage can't get that back with weight reduction because they are already and minimum weight within the rules, while an RC a car can be 6-8oz heavier than another and have no acceleration disadvantage whatsoever because there is more power than the traction can handle in the first place.

A lighter car should do all of those things but until we can find spring rates that accomodate the weight change it is a challenge to come up with a setup that has as much traction and stability to match the heavier car with no power/acceleration disadvantage.
__________________
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."

In mind and body, we're all heading towards old age. It is slower to go by bike.
Davidka is offline   Reply With Quote
Old 01-09-2008, 01:20 PM   #26
Tech Master
 
Ed237's Avatar
 
Join Date: Mar 2007
Location: Dudley PA
Posts: 1,431
Trader Rating: 10 (100%+)
Default

If you havent already, I suggest that you weigh your stadium truck. You will discover that its already 250-500 grams over the ROAR weight limit.

Moreover, the T4/B4 set ups posted on the AE website suggest adding weight thus disproving that a lighter car is a faster car.
Ed237 is offline   Reply With Quote
Old 01-09-2008, 01:38 PM   #27
Tech Addict
 
foolio's Avatar
 
Join Date: Jan 2006
Location: Indianapolis, IN
Posts: 732
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by Ed237 View Post
If you havent already, I suggest that you weigh your stadium truck. You will discover that its already 250-500 grams over the ROAR weight limit.

Moreover, the T4/B4 set ups posted on the AE website suggest adding weight thus disproving that a lighter car is a faster car.
Are they saying that adding weight is how to make your car faster? Or, are they saying that is makes it easier to drive? Wait, maybe they say to add weight to make the car handle better?

Or, maybe they don't say why at all. I wouldn't use that bit of info as a way of "disproving that a lighter car is a faster car". It just doesn't make sense.
foolio is offline   Reply With Quote
Old 01-09-2008, 02:21 PM   #28
Tech Master
 
Ed237's Avatar
 
Join Date: Mar 2007
Location: Dudley PA
Posts: 1,431
Trader Rating: 10 (100%+)
Default

Yeah, your right, Cavalieri, Tebo, Maifield have no idea what they are doing!

Sorry to use the sarcasm, but, to put it in perspective, AE designed the T4 to be heavier than ROAR rules and their drivers are adding weight to it. The people who design and race the cars for a living are advising you to add a few grams to your car to make it easier to drive.

I don't know why. Maybe motors and batteries have improved over the last 10 years to the point where they have exceeded a reasonable power to weight ratio that makes driving them too unpredictable unless they have some strategically placed ballast.
Ed237 is offline   Reply With Quote
Old 01-09-2008, 02:25 PM   #29
Tech Regular
 
NJA82's Avatar
 
Join Date: Apr 2007
Location: Cairns, QLD
Posts: 430
Trader Rating: 33 (100%+)
Send a message via MSN to NJA82
Default

Quote:
Originally Posted by foolio View Post
We're going to have to agree to disagree here. Not all 1:1 classes have HP limitations. Personally, I can't think of any. Yes there are limits on displacement, fuel delivery, and other things. In F1, there is as much as a 50HP difference between MF's cars and they all strive to meet the absolute minimum weight requirement to get that edge. I agree, the shear amount of power available in Mod racing is sometimes a crutch more than an asset. However, lighter cars will accelerate, brake, and change direction faster.

Of course, this whole argument is difficult to prove for anyone. We are just sharing opinions here...we know it's mostly going to come down to the driver...not a few grams here and there...
There is HP limitations in lots of forms of motorsports, it comes in many different ways though, WRC rally cars have a minumum wieght limit and a 300HP limit, they use an air intake restrictor to limit the HP, you will find that every other motorsports on the same scale have limitations that will also affect HP in some way or another, might not be a direct HP limit but the other rules will still keep the cars limited in some way, types of fuel, engine size/displacement, chassis weight etc. are enough rules to keep a hold on power levels as the engines cannot mathmatically produce much more power than they already do per cc of displacement using a certain type of limited race fuel.
Nitro R/C is about the closest thing to real world racing in the fact that the engine size limitations and the fact that any internal combustion engine can only produce as much power as the air it is flowing ( which is about the same HP level most .21 off road engines have been making for over 5 years now )
so HP is limited in theory combine that with a minumum weight limit and you have controlled HP cars that are all about the same speed on the track. Then compare this to electric modified which has battery tech that is constantly evolving and the batteries are the real producer of the power in electric, motors and ESC`s are merely portals for the electricity to spin the wheels, so therefore once again the idea of running less voltage batteries etc. comes into play, 5 cell etc. because unlike nitro which is pretty much always going to be limited by the engines displacement for HP, electric can constantly add cubic inches to its engine basically by having greater power batteries.
NJA82 is offline   Reply With Quote
Old 01-09-2008, 02:30 PM   #30
Tech Champion
 
Davidka's Avatar
 
Join Date: Oct 2004
Posts: 9,937
Trader Rating: 77 (100%+)
Default

I don't think AE and Losi designed their cars around any specific weight. Remember, both the XXX and the B4 designs came out when we were running 2400mah NiCds and 3000 Nimh's. These batteries were 3-4 oz lighter than the current 6 cell packs people are using. The added weight in those setups are not to make the car heavier, they are a balance adjustment. If heavier was truly faster the weight addition would be greater. I have not heard of Cavaleri, Tebo strapping lead everywhere they could in the chassis.

For what it's worth, the only driver that could stay in sight of Cav at the Midwest champs (in Mod Stadium truck) was Brian Kinwald running BL and Lipo with just enough weight to be legal.
__________________
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."

In mind and body, we're all heading towards old age. It is slower to go by bike.
Davidka is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
500 Gram Mini Scales. bmr R/C Items: For Sale/Trade 1 07-08-2008 07:31 AM
US Balance 500 Gram Scales Bruce53 R/C Items: For Sale/Trade 3 07-05-2008 08:22 AM
$1000.00 TOP END NITRO CHALLENGE $1000.00 ocrraceway Indonesia Racing 2 08-12-2005 11:24 PM
$1000.00 Top End Nitro Challenge $1000.00 ocrraceway Australian Racing 13 07-27-2005 05:06 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 12:36 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