R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 12-04-2009, 01:19 PM   #1
Tech Lord
 
syndr0me's Avatar
 
Join Date: Dec 2004
Location: 5280 Raceway
Posts: 13,140
Trader Rating: 32 (100%+)
Default 1S Mod Sedan

The way things are going with spec racing seems like the wrong direction, and has me questioning whether or not I want to continue down that road. The idea of open mod really does sound appealing, except that it's so fast many people are discouraged from running it. Since 1S has been so successful in pan cars, maybe it's time we revisit the idea for sedans. I'm going to start doing some testing, trying to figure things out, and see if there's something there. Anybody want to help?

I believe Rick Hohwart said he'd done some testing, perhaps he can share his findings with us. I'd love to hear from anybody else that's tried it as well. And, for the pros, and folks that typically run mod, what do you think of the idea of slowing it down somewhat with 1S? Is that blasphemy?

One of my concerns was run time, since we'd likely be pulling a lot more juice out of the packs. Perhaps, since the battery size for LiPo is already pretty well-established, we can keep the pack sizes the same (and weight rules), but wire the packs so they're 3.7v and double the capacity. My layman's understanding of electronics leads me to believe this is just a change in how the packs are wired internally, and perhaps how the balancing plugs are wired. Any battery manufacturers out there willing to wire a few up this way for testing? Maybe Thunderpower or someone?

The general opinion seems to be that two sedan classes ("stock" & mod) is enough. I tend to agree, though mod seems out of reach for a lot of guys at its current speeds, which is why I think you see the semi-pro folks tend to gravitate toward the middle ground of 13.5. Would the idea of a slower mod class appeal to those folks, or would they all drop back down to stock?

So what's the best way to get started testing right now? Grab a 1S pack for pan cars, add some weight, grab a booster and go?
syndr0me is offline   Reply With Quote
Old 12-04-2009, 01:26 PM   #2
Tech Elite
 
artwork's Avatar
 
Join Date: Sep 2004
Location: Thornton, CO
Posts: 3,112
Trader Rating: 62 (100%+)
Default

Quote:
Originally Posted by syndr0me View Post
The way things are going with spec racing seems like the wrong direction, and has me questioning whether or not I want to continue down that road. The idea of open mod really does sound appealing, except that it's so fast many people are discouraged from running it. Since 1S has been so successful in pan cars, maybe it's time we revisit the idea for sedans. I'm going to start doing some testing, trying to figure things out, and see if there's something there. Anybody want to help?

I believe Rick Hohwart said he'd done some testing, perhaps he can share his findings with us. I'd love to hear from anybody else that's tried it as well. And, for the pros, and folks that typically run mod, what do you think of the idea of slowing it down somewhat with 1S? Is that blasphemy?

One of my concerns was run time, since we'd likely be pulling a lot more juice out of the packs. Perhaps, since the battery size for LiPo is already pretty well-established, we can keep the pack sizes the same (and weight rules), but wire the packs so they're 3.7v and double the capacity. My layman's understanding of electronics leads me to believe this is just a change in how the packs are wired internally, and perhaps how the balancing plugs are wired. Any battery manufacturers out there willing to wire a few up this way for testing? Maybe Thunderpower or someone?

The general opinion seems to be that two sedan classes ("stock" & mod) is enough. I tend to agree, though mod seems out of reach for a lot of guys at its current speeds, which is why I think you see the semi-pro folks tend to gravitate toward the middle ground of 13.5. Would the idea of a slower mod class appeal to those folks, or would they all drop back down to stock?

So what's the best way to get started testing right now? Grab a 1S pack for pan cars, add some weight, grab a booster and go?
I would love to help, but all I can do is be a tester. I think this is a good idea and will help racing head in the right direction. Maybe Maxamps would be a good place to start they seem very eager to help. What about LiFE PO4 with the lower voltage?
__________________
Sanwa | R1 Wurks | Avid | 2mm Designs
artwork is offline   Reply With Quote
Old 12-04-2009, 01:30 PM   #3
Tech Addict
 
gubbs3's Avatar
 
Join Date: Aug 2006
Location: MN
Posts: 619
Trader Rating: 7 (100%+)
Default

That does sound like an interesting idea.

For a little perspective on the power side of things, I can tell you that on a smallish carpet track I am consistently pulling a little over 4000mah running a 3.5 in 1/12.
gubbs3 is offline   Reply With Quote
Old 12-04-2009, 01:40 PM   #4
Tech Addict
 
Join Date: Mar 2003
Posts: 645
Trader Rating: 1 (100%+)
Default

i think this would be great for all classes to be 1s lipo. i know that they could make 1s in the same configuration as a 2s lipo and it would not change much except you would need a receiver pack.

Mike
__________________
TEAM ASSOCIATED, SMC BATTERIES, REEDY MOTORS, JACO TIRES, RADIOPOST RADIOS, LRP ELECTRONICS, PROTOFORM BODIES, MAKITA POWER TOOLS, KICKER PEFORMANCE AUDIO, KOLORS BY KROPY, MUCH-, RSD
Mike Blackstock is offline   Reply With Quote
Old 12-04-2009, 01:58 PM   #5
Tech Champion
 
Davidka's Avatar
 
Join Date: Oct 2004
Posts: 9,931
Trader Rating: 77 (100%+)
Default

Lower voltage just doubles the amp draw and heat, the reason it works so well in 1/12 is that the cars don't weigh much. Nowadays the 21.5's in VTA cars are pretty fast.

All the rules need to be revisited, 13.5 was supposed to be a stock or superstock class but with the turbo equipped speed controls they're two winds worth faster so the class is pretty much busted, same w/ 17.5, which now seem as fast as 13.5's were in sedan.

The other day I heard two of the best ideas for stock/spec racing:

#1 no traction compounds. I know some will say "but the cars will be uncontrollable!", to which I answer true, with the current power packages, but when you limit traction, power comes into line until control is achieved.

#2 solder a fuse of a certain amperage in line with the battery. 15 amps? 30 amps? What better way to govern how much power will be used than an in-line ampreage limiter? This should probably be a re-settable circuit breaker...
__________________
"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 12-04-2009, 02:18 PM   #6
Tech Lord
 
syndr0me's Avatar
 
Join Date: Dec 2004
Location: 5280 Raceway
Posts: 13,140
Trader Rating: 32 (100%+)
Default

With 80C batteries, or whatever we've got now, amp draw really isn't an issue, right?

Your other ideas sound interesting, but I think maybe we're at the point where a more fundamental change is in order. The idea of going 1S in all classes intrigues me. With 17.5 sedan continuing to get faster, maybe making it 1S makes sense as well.

As for run time in 1S 1/12 mod, taking 4000mah out after 8 minutes isn't too bad. If sedans only run 6, and have room for double capacity packs, that would probably be a non-factor. Though it does take longer to charge them when you're putting 6Ah back in.
syndr0me is offline   Reply With Quote
Old 12-04-2009, 02:24 PM   #7
Tech Regular
 
Holmenkollen's Avatar
 
Join Date: Jan 2003
Location: Sweden
Posts: 444
Default

EFRA have allowed LiFe (6.6V) as of 15/2 next year. I think this is a great alternative for people that think modified is to fast. 6.6V is a little faster than a five cell setup but more controllable than Lipo. Itīs safer too.

I think anything below 6V puts too much stress on electronics and motors in touring (low voltage/heavy cars).
__________________
Xray - Hobbywing - Graupner
Holmenkollen is offline   Reply With Quote
Old 12-04-2009, 02:30 PM   #8
Tech Lord
 
syndr0me's Avatar
 
Join Date: Dec 2004
Location: 5280 Raceway
Posts: 13,140
Trader Rating: 32 (100%+)
Default

Certainly LiFe is an interesting option, but does that really slow things down enough?

The concern about putting too much strain on motors and electronics is definitely something to be mindful of, but I imagine we'd need to do further testing to know for certain. The same was said for 1S pan cars when people started testing that, and it ended up being pretty effective.
syndr0me is offline   Reply With Quote
Old 12-04-2009, 02:47 PM   #9
Tech Champion
 
robk's Avatar
 
Join Date: Aug 2001
Location: Macho Business Donkey Wrestler
Posts: 7,587
Trader Rating: 22 (100%+)
Default

Quote:
Originally Posted by syndr0me View Post
Certainly LiFe is an interesting option, but does that really slow things down enough?

The concern about putting too much strain on motors and electronics is definitely something to be mindful of, but I imagine we'd need to do further testing to know for certain. The same was said for 1S pan cars when people started testing that, and it ended up being pretty effective.
Life is going to give you a voltage around what GP3300s had a few years ago. Most 3300 packs went about a minute before they slipped under 7v.
__________________
A mutually re-enforcing cascade of failure

"Failior [sic] crowns enterprise." Robert Goddard

I-Lap Scoring Systems http://www.rclapcounter.com/
robk is offline   Reply With Quote
Old 12-04-2009, 02:51 PM   #10
Tech Master
 
Join Date: Nov 2003
Posts: 1,850
Trader Rating: 5 (100%+)
Default

Take a 2S saddle pack that's standardly used in 4wd offroad, cut the center jumper and wire both '1S' packs in parrallel. Same size, roughly, as a 2S existing pack, but with 10,000-12,000 mAh capacity. Then unleash the 1.5 mod motors Oh, u better use a 1/8th buggy ESC like an RX8 to handle the amp draw
__________________
Serpent SRX8 electric
Serpent Cobra 811TE-E
Serpent S120LTR 17.5 1/12th and S100LTR Pro-10
Serpent S411 Eryx 4.0 USGT
Team Serpent America and Desoto Racing
Stealth_RT is offline   Reply With Quote
Old 12-04-2009, 03:01 PM   #11
Tech Elite
 
SpraydbySprague's Avatar
 
Join Date: Jun 2008
Location: Conducting aggressive board meetings at my local track
Posts: 3,301
Trader Rating: 64 (100%+)
Default

So, we go to 3.7v LiPo to slow down the cars. Then strap in more motor, buy the latest ESC with whatever black magic software in it to because we need to once again go faster!?!

Am I the only one seeing this vicious cycle?

Keep it simple. Stock and open mod for touring (maybe 13.5 superstock). With open mod, ya can run whatever your skills can handle.
__________________
How would I describe my holeshots?

Three words...

Ready... Steady... Confetti!!!! (gonna need a new one of those)
SpraydbySprague is offline   Reply With Quote
Old 12-04-2009, 03:04 PM   #12
Tech Addict
 
Join Date: Mar 2008
Posts: 649
Trader Rating: 1 (100%+)
Default

Personally, I say run the same pack in both 12th and sedan. Limit the capacity and you'll limit the speeds by default.

For me, single cell 12th has braught two of the most important parts of mod racing back. Driving a pace and strategy. Limiting the capacity in mod has forced us to drive a pace. No more driving pretty much flat out for the entire run. And because you can dump you need to use strategy on when to save power and when to go for it. These two things were a huge part of 12th back in the day and I'm happy to see them come back. At least until the batteries improve enough to keep us from dumping.

Just my 2 cents but I think that adding driving and strategy are two things that would do sedan some good.
Fred_B is offline   Reply With Quote
Old 12-04-2009, 03:08 PM   #13
Tech Master
 
Join Date: Nov 2003
Posts: 1,850
Trader Rating: 5 (100%+)
Default

Quote:
Originally Posted by Fred_B View Post
Personally, I say run the same pack in both 12th and sedan. Limit the capacity and you'll limit the speeds by default.

For me, single cell 12th has braught two of the most important parts of mod racing back. Driving a pace and strategy. Limiting the capacity in mod has forced us to drive a pace. No more driving pretty much flat out for the entire run. And because you can dump you need to use strategy on when to save power and when to go for it. These two things were a huge part of 12th back in the day and I'm happy to see them come back. At least until the batteries improve enough to keep us from dumping.

Just my 2 cents but I think that adding driving and strategy are two things that would do sedan some good.
+1. I saw that at the Champs in 1/12 mod. Ppl had to start worrying about dumping again (sorry that happened to you Aaron) and it was cool to see the strategy again. If they limited the 1S capacity in mod sedan, the average joe racer might be able to compete in it again, instead of only a few pros with excellent reaction times.
__________________
Serpent SRX8 electric
Serpent Cobra 811TE-E
Serpent S120LTR 17.5 1/12th and S100LTR Pro-10
Serpent S411 Eryx 4.0 USGT
Team Serpent America and Desoto Racing
Stealth_RT is offline   Reply With Quote
Old 12-04-2009, 03:09 PM   #14
Registered User
 
UltegraSTI's Avatar
 
Join Date: Jul 2005
Posts: 7,171
Trader Rating: 20 (100%+)
Default

any1 remember the '4cell experiment'?

R
UltegraSTI is offline   Reply With Quote
Old 12-04-2009, 03:14 PM   #15
AE-Reedy
 
Join Date: May 2008
Posts: 780
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by robk View Post
Life is going to give you a voltage around what GP3300s had a few years ago. Most 3300 packs went about a minute before they slipped under 7v.
The LiFe batteries I have tested slip below 7v instantly when a load is applied.
The avg voltage during a discharge is below 6v @35 amps. LiFe is a definate alternative however the only way people are going to adopt them is if the rules change and make lipo illeagal.

Who will willing give up 7.4v for 6.6v?

I agree that something needs to change in order for TC to make a come back.
I also agree that all classes of TC need to be slower, this will accomplish 2 things.
1. It is easier for beginners to drive and hopefully keep in the class.
2. Force more advanced drivers to move up in class because they can't stand going slow.

I was/am in favor of 1s racing for all on-road but I also see the hurdles that have to be cleared to make this happen. LiFe might be a better alternative.

PS I have tested a mod 1s sedan and it works fine. Cars will need completely different set ups because it is so light. My car weighed in at 1230g with 1s.

It was fun to drive, just a little faster than current 13.5t speeds. The speed that most racers seem to want to run these days.
Sean Cochran is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
NORTHERN MINI RACERS, MINOT buttsy Minnesota and North/South Dakota Racing 2428 12-06-2017 07:04 PM
Tekin RS ESC sensored Jeff Cuffs Electric On-Road 23359 10-02-2016 06:57 AM
Associated RC12R5 Ferrarimk13 Electric On-Road 3811 05-08-2016 10:02 PM
Indoor Carpet Racing @ RC Performance in Madison Associated-08 Wisconsin & Illinois Racing 3426 11-25-2010 04:03 PM
WHAT CLASSES SHOULD RUN IN MAJOR RACES FOR 2010 beyondthepack Electric On-Road 52 12-05-2009 07:52 AM
1s LiPo Touring - the answer to clever ESCs? sosidge Electric On-Road 69 10-27-2009 06:14 PM
The reason for the lack of mod drivers... robk Electric On-Road 327 06-22-2009 05:23 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 02:17 PM.


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