Hello,
Just wanted to get an opinion from everyone, for our series next year they just opened some options so if you had the choice to run a standard 4 cell brushed motor, 21.5bl with a 7.4v lipo, or a 17.5bl with a 4cell which would you choose? I currently run a GTB with a 13.5 and a 4800 pack in my touring car and love the simplicity of not having to mess with everything but for my oval stock cars there already set up with brushed 4 cell systems. I think if I'm going to do something it would be with a super sport novak that I have and the 4 cells I already have and just buy a 17.5bl motor that way I'm only buying a motor and the motor is worthy of running the next class up just add lipo's. What do you guys think?
Thanks for your help.

From our testing with those systems, you can get away with mixing the 4 cell Brushed STOCK motors with the 17.5 4 cell combo...so that option can give you mulitple choices..

The 21.5 will make a AWESOME class - but so far it's shown to be a little faster than the other two.

I think the 21.5/Lipo is an awesome class. It is good on speed without all the maint. of 4 cell brushed. When your done with your race just plug in the batteries and make any chassis adjustments you want. Like SW said in another thread, is all about momentum, which means chassis setup, and driver skill. Oh did we mention buy one battery for the whole year. That's what I'm talkin about!!!

We are going to do some extensive testing of the 21.5 Novak Brushless motor/Lipo combo this afternoon and this evening. I also have my own personal opinion on mixing 17.5 lipo/10.5 4 cell running in the same class from what I have seen over the past three weeks. We own the track so we have access for testing things at anytime and I think the oval community is very interested in Lipo oval racing. I have been watching the Lipo battery for almost two years and have always thought it could be a good thing with oval. We just never had a motor Lipo combo to compare as close as possible to stock 4 cell class until possibly now with the 21.5.

I will post what I see later this evening if anyone is interested.

Bill Murdock

Bill,

Our mixing of the classes on Asphalt and the Velodrome have been really close (17.5 & 10.5) but on the carpet, the 10.5 has had a pretty good advantage so far.

I'm not sure if the advantage is in Power or due to better fine tuned setups...but so far the 10.5's on carpet (for the FAST guys) have about a 2 lap advantage. (Granted that's over a 5 minute period and we're looking at sub 4 second laps...so we're probably talking what .03 or .04 seconds a lap.

So for local club racing, this is probably close enough to let the guys who want to run 17.5 LIPO run with the 10.5 guys...so long as they know and understand the 10.5 guys have a performance advantage.

Joe,

We are seeing the same thing in regards to 17.5/Lipo v 10.5/ 4 cell on carpet.


Our carpet has approx. 175' run line. 48' wide track. We had two drivers with almost identical cars. One 17.5/lipo and the other 10.5/ 4 cell. Drivers have about as similiar skills as you can get. No doubt about it the 10.5 had the advantage. I have also been seeing this over the past 3 weeks during our weekly races. I was pretty convinced last week during our race program but today I have no doubt.

Now the 21.5 Lipo combo. Imo it has just a little over a brushed 4 cell stock. Time difference was about .5 per lap less then 17.5/lipo. But I feel it would be an excellent combo for racers that want about as close a stock brushed speed as you can get. I used to run stock and I think I would like to run this combo as a class. Seemed nice and smooth for our track. Now granted, I am going to play around with roleouts over time. Today I ran a 3.25 roleout and the motor came off the track at 150 degrees on a consistant basis.

Around here the majority of the oval crowd is wanting to go Lipo but we have to have a class for the Brushless 4 cell guys. My thoughts at this time after the first of the year I would like to see 21.5/Lipo, 13.5/4 cell, 17.5/Lipo as classes at our track. That way the NiMH guys still have a class that is very challenging.

We are still at the track and continuing some testing but so far this is how things are looking.

If we have time Rob is going to try another roleout tonight with the 21.5 however we will do more testing with the 21.5 until it becomes more readily available and popular as a class.

Later,

Bill Murdock

Bill,

The "I would like to see 21.5/Lipo, 13.5/4 cell, 17.5/Lipo" structure would be pretty good...as would the 17.5 4 cell / 21.5 LIPO / 17.5 LIPO which would give 3 speeds...and only 2 motors.

Joe,

I agree. That looks good also.

Bill

thy say 17.5 is faster then brush.I run brsh and i make the a main just about every week .and doing the same laps.but I do spend aboult ! hour on the motor every week I am going to try a 17.5 this week to see if its faster.

thy say 17.5 is faster then brush.I run brsh and i make the a main just about every week .and doing the same laps.but I do spend aboult ! hour on the motor every week I am going to try a 17.5 this week to see if its faster.

Don't expect it to feel like a 19T.. the difference is very minor.
You can't go by just feel when comparing the two, you need to look
at lap times, and your heat times.
What you will notice, is a LOT more time to keep up with your car,
when you don't have to spend so much time on your motor..
The times are faster now, granted some of that may be the new rug,
but what you'll see more than anything is consistency from run to run.
It just doesn't change, unless YOU make a change to the car...
That is what I see to be the major difference.
I think they hit it pretty good on the 17.5 vs. stock..
from what I have seen, anyway.
Good luck with it, Ed.... there are a plenty of guys that will be happy
to give you a hand, I expect....
You've certainly helped guys your share over the years! :thumbsup:

A 17.5 is not any faster then a good brushed motor. My findings are that at the start of a run a good brushed motor(like the ones you build Ed) are faster but not by much. It's after a couple of minutes when the brushless is about equal to a good brushed and toward the end of a run the 17.5 is a bit faster. The biggest difference is the amount of work and tuning involved with getting that good brushed motor you dont have that with brushless but dont be fooled I dont care how good your motor is it wont help at all if the chassis isnt right...and thats where drivers now can spend more on along with more pratice because of the time they now have due to not having to rebuild and tune motors..

Another note is that you will see a difference in your good packs and the realy good packs along with the duds LOL becuase there will not be as much of a difference in motor performance between runs and you can actualy tell whitch packs are better a whole lot easier

Ed you need help just stop by Ill be glad to help to get you going....

I tried this past week the 21.5 with 4 cell and it ran about .2 tenths slower then 17.5 4 cell which is so close to 27 t brushed it isn't funny both turning 95 laps at the track.. What i think we will do if the sportsman class goes brushless is use the 17.5 with a rollout rule ,(that way when they move up to next class they already have the motor just have to buy different gears.)

Well I 'm glad I started this topic, I'm not sure I really got a solid answer but alot of good true tested information thats for sure! It seems like the best set up for everyone is the one with the most parts to roll into the next class?! It doesnt really sound like one is WAY more dominant than the other but like jmcormic say the fact that you can spend all your time making your CAR go faster instead of cleaning and messing with a brushed motor says it all. I think I am going to go with the 21.5 and a lipo since I am just getting my feet wet in oval then I can spend more time driving and tuning the car instead of working on an old brushed motor! Just my thoughts

Hi
Been reading this with much anticipation. Our track is tarting to loose some #s. last year spent about $300 on motor stuff.
this year going to go 13.5 brushless. Class is loaded (Pete Dagnolo)
Trying to get our stock intermidiate to see the advantage of brushless. Which in my opinion will save the guys money and time!!! Which will let them focus on the set and driving. So far guys are curious.
What I am looking for is hard data to prsent to the track so we can build up our classes again
Thanks
Dan Murn :confused:

I have read alot of good info on this thread about the difference in performance between the various configurations. One question I have is what car setup changes are seen between say running a 13.5/4 cell and 21.5 lipo. Just changing the motor battery combo may not be the whole answer.

With the LIPO (in all classes) you wind up with less Left Side weight, so getting the proper balance is probably going to be your biggest deal.

I'm figuring this is why some of the LIPO based configurations are running just a little slower than some of the 4 cell guys...

I really haven't heard if guys think the lighter car makes them PUSH or if it makes them LOOSE. (I really haven't noticed much difference myself...other than to me the LIPO car has been a little easier to drive) which might mean it's tighter and I need to loosen it up.

I don't have a 'regular' track that I'm running on enough to be able to FINE TUNE my adjustments at the moment...(Which is where a nice CARPET track can be fun...to really dial in fine tuning.)

X - Man: The best way to generate 'Hard Data' for your track owner would be to grab a 17.5 and stick it in a car..and get it dialed...then run against the 27t stock guys. Those two combos have shown to be very very close so far on most of the tracks we've tried it on. (Don't be afraid to GEAR that 17.5 TALL... search the threads for suggested RollOuts)

I have read alot of good info on this thread about the difference in performance between the various configurations. One question I have is what car setup changes are seen between say running a 13.5/4 cell and 21.5 lipo. Just changing the motor battery combo may not be the whole answer.

Softer front springs have been one of the main things I have changed when running the Lipo combo cause the car has a whole bunch more push to it when you make the weight change from 4cell to Lipo.

Joes is right, the car doesn't unload the back of the car when you cut into the corner with a lipo like it did with 4cell so it is easier to drive!

I realize there are currently no "rules" that are being and widely used for 10h scale lipo racing. But what car weight is being used, are you allowing the weight to be whatever it is or are you adding weight to get the car back to it's total weight when it was a brushless 4 cell car?


I am starting to see local tracks developing there own "local rules" relative to 21.5 lipos, I see that as a problem, every track different, some using modified BRL rules about body and keeping the weights the same as 4 cell. This could hinder the growth of lipo racing without some common ground.

Ron,

My series has been kind of 'off the dirt road' when it comes to weight rules for a long time.

Back about 10 years ago when we made the switch to 4 cell (At that time I was working for NORRCA) the weight rule dropped to 38oz.

I believe the 6 cell weights were 42oz and 44 oz (Expert and Sportsman)

We went to just one weight with the 4 cell.

Most other organizations and clubs have since kept creeping the weight UP as the cells got heavier. (Which SUCKED those those of us who tried to use old cells whenever possible)

We stayed at 38oz.

I plan to keep the weight at 38oz. with LIPOs as well. (I had thought about jumping upto 40, but decided against it.)

Some of the other clubs and tracks have kicked the weight to 40oz.

My arguement against the HEAVY cars are the same arguement we had when switching to 4 cell in the first place... "Lighter Cars Don't wear tires QUITE as much"

Not that this is that valid of an arguement..cause FAST cars Do wear tires...LOL

38oz w/ LIPO woohoo!

I hope most will go with 38 oz for carpet and 39 for caps or both 38 that way no extra weight would be needed for most cars!

..............

Scott,

How big of a spoiler can you run?

I recently did my car on the asphalt using a SPOILER ONLY at ROAR Spoiler height (2 inches)

Car drove VERY well - I was real happy with it - so I tried it again on our local track 2 weekends ago - this track is close to 300 ft with SQUARE corners. The spoiler car worked well there too.

................

Hi
Been reading this with much anticipation. Our track is tarting to loose some #s. last year spent about $300 on motor stuff.
this year going to go 13.5 brushless. Class is loaded (Pete Dagnolo)
Trying to get our stock intermidiate to see the advantage of brushless. Which in my opinion will save the guys money and time!!! Which will let them focus on the set and driving. So far guys are curious.
What I am looking for is hard data to prsent to the track so we can build up our classes again
Thanks
Dan Murn :confused:Dan- If you want hard data to see the difference between a 13.5 & a Stock motor,the best thing to do is to run a 13.5- loaded car in a couple of timed races (or run the whole raceday) with the Stockers. Compare the laptimes between the two motors afterwards w/ the group. All the data you'll need will be on the time sheets. If you let the field know in advance that you're running a 13.5 motor for testing purposes,I'm sure they won't mind.

Another piece of data you can use is what you said you spent on motor stuff last year.
$300 would have gotten you a nice BL setup. The initial cost to "convert over" to BL is kinda pricey for most racers at first,but it'll be cheaper in the long run. Also,you won't have to lug around stuff like spare motors,loads of motor brushes and springs,comm lathes & dynos. You won't need them w/ the BL motors.

This is what we did at our track when the BL question first came up & it was a huge success. We're going to be running our first LiPo oval class this Friday night. Later on,if & when you decide to make the jump to LiPo,do the same thing as above and race it w/the NiMh cars-then look at the lap times.

Good luck & let us know how it went!
-George
Race Director
Hobby World- Jacksonville,FL
www.racewayathobbyworld.tk (http://www.racewayathobbyworld.tk)

What GEORGE Said is exactly what we did for our testing. My feelings are it doesn't really do any good to put a product on the track 'by itself', the best testing is under RACE conditions and looking at lap times. (End run times don't always show the whole picture but LAP times can tell a LOT of Truth)...especially if the scoring system is set to show them into the .01 range or lower.

The easiest and more accurate way to get an apples to apples comparison is to just look at race results from around the country.

Oval Masters
http://thunder.rcresults.com/2007OvalMasters/
(Flat carpet Snowbirds sized)

ROAR Nats
www.carolinarc.com
(Paved oval, caps)

This will give you an idea of how the best in stock run versus the best at 13.5. If you just throw a 13.5 in and try to compare odds are they will look a lot closer than they really are since your gearing and setup will most likely be off.

We are starting to mix some as well. One very successful class is NASTRUCK. We use touring cars with rubber tires. You can run 19turn or 10.5 brushless. Six cell NIMH or Lipo. I run a Komodo Dragon 19turn and an Orion 3200 Lipo. I ran 3800 NIMH prior to Lipo. All of us are very competitive. Our track limits Lipo to either Orion or Peak with the hard shell.

.........

Yes Scott, that combo wasn't designed to mix. Novak's goal was this:
21.5 / LiPo = 13.5 / 4-cell
17.5 / LiPo = 10.5 / 4-cell

James,

Close, but the 21.5 / LiPo was supposed to be SLOWER than the 13.5/4 cell. We were hoping it would be close to 27t Brushed/4 cell.

However, it's not bad...although it's faster...it has kind of a flat feel and is pretty easy to drive. (Some say easier than 27t Stock)

The 10.5/4 cell and the 17.5/LIPO we have been mixing all year long during testing...on MOST tracks they run nearly identical. (On carpet the 10.5's have still been a little faster) We think that may be because the 17.5 just doesn't seem to pull/draw the amperage (no matter how you gear it)

I was aware of Novak's design. But, we have some very fast 13.5 guys up here. And our 10.5 guys are currently faster than the 17.5/LiPo combo. Incidentally, they are the same guys. LOL!

I would rather hunt with Dick Cheney than drive with Ted Kennedy.


hmm Can you HUNT Ted Kennedy while DRIVING with Dick Cheney? LOL

Our guys who are running the 17.5 are gaining on their 10.5 times each time they run it...I think it's just a matter of time and the 17.5 will be FASTER...once guys get the weight change and chassis setups DIALED.

...........

We did a little more testing of the 21.5/Lipo again this weekend. Was hoping to run it against some 13.5/4 cell cars but weather here was bad and turnout was low. So I ran it alone for four heats. Will try again next weekend.

We took the same car with BRL 13.5 specs ( no wing and no rear end cutout) put the lipo and 21.5 in it and put it on the track. We had to make very few adjustments to the setup.

The 21.5 is a little sluggish but once you get the car up to speed it handles really well. Keep in mind our track has wide sweeping turns and approx 170 -175' run line. In traffic I don't believe you will have the same power as a sintered 13.5/4 cell. But I did find that it was more similiar to a non-sintered 13.5/ 4 cell in speed. Now I did manage to get the lap times faster this week over a week ago. We cut the lap times by a tenth. But last time we used a different car. One that was set up for 10.5 racing.

IMO the 13.5/4 cell on a short track will probably beat a 21.5 Lipo car. On a larger track ( one where you can keep up the momentum on a 21.5/lipo) the cars could be close in speed. If the 13.5 motor was non-sintered the two would be much closer.

But, I still feel that the 21.5/Lipo is as close as you can get to stock brushed/ 4 cell racing. In stock brushed 4/ cell racing you had to keep up the momentum also as part of your race strategy.

Now another thing we did was to see how long you could race without charging the Lipo battery( 4800 ) used with a 21.5 motor. Answer--- about 13 mins.
We ran one five min. heat then 45 min later ran another and 45 min later ran another without charging. The first two heats there was no drop off of lap times. Lap times stayed the same for three minutes into the third heat, then drop-off in lap times was pretty quick. The car finshed the third heat but just barely. Cut off did not occur and there was no problems with the lipo battery.

We are going to run this car against some 13.5/ 4 cell cars next weekend on a track similiar to ours. We shall see how it does.

Later

Bill Murdock

Bill -- it seems that the SWT guys have decided to run the Orion 3200 carbon LiPo pack with the 21.5, and I think ARCOR has that pack in its rules too.

So is running these tests with a 4800 pack a representative test if we are going to end up with the 3200 being the pack that we ultimately run ? It seems that the battery is still a big question mark with the LiPo oval group. I'm going to start testing the 3200 this coming weekend with a 21.5.

I guess worst case, we'd have to carry around 1 4800 pack and 1 3200 pack in our boxes -- so we'd be covered as far as what the track we are running at decides on.

Thx.

TeamGodwrench,

With the amp draw the 21.5 motor pulls, I don't think you would have to have the 4800 pack if the races were 5 minutes or less even if the rules allow for them.

That would be a totally different story with the 10.5/LIPO class, and possibly even with the 17.5/LIPO class...but were only pulling about 1800 - 2000 mah's from the 3200 pack with 17.5's.

The 4 cell configuration of the 4800 packs do give them a lot deeper amp pull, but I haven't seen the 21.5 being able to actually pull that many amps to need it.

Now, over 13 minutes of FULL Up-to-Speed racing on a short little carpet track... What's that work out too? 200 laps? NOW that's racing... Take the TIME out of it..and run 200 lap mains. WOOHOOO - that'll make you WARM on a Cold winter day.

(Funny, the guy who won our STOCK Championship in '06 at our final event last year ran his STOCK Car for the 5 minute race...and since it was the last race of the day/year he continued to run after the time expired and I kept his laps counting... In RACE TRIM MODE - his car ran for 13 minutes before his times started to fall off...that was with 4200 nimh batteries.)

Thanks for that info !

A 200-lap main... now THAT would be fun !! It would sure take the "gotta win it in the first corner" mentality out of the racing :-)

So it sounds like the 3200 pack is plenty for 21.5 motors... plus they are about $50 less than the price of the 4800. I just got a new 3200 Orion Carbon from Tower with a $10 off deal it was only $75.

Jeff,

I also think that the battery size for the 21.5 should be limited also. I know Rob wants to limit it also for 21.5. There does need to be a limit on all classes of Lipo. Something like 3200 for 21.5 and 4800 for 17.5. But I don't know if that will fly. We will watch and see what the racers want.

Now one thing I don't agree with is limiting a specific Company battery. Why? Because the distribution of Lipo's is not like the sub C cells. You are going to see many company names on Lipo's including Windtunnel. As a matter of fact the Windtunnel Lipos have been selling for weeks now. Competition brings lower price. And one companies Lipo will be no different than another except in price.

Bill M.

Thanks Bill -- it seems like no matter whose name is on the case, inside most of them are made by Kokam -- at least the ones I've seen so far.

Are the Windtunnel LiPos on the website yet ? Curious to get some info on them.

Thx.

Now one thing I don't agree with is limiting a specific Company battery. Why? Because the distribution of Lipo's is not like the sub C cells.

Bill,

Do you understand why we are limiting the batteries though?

The biggest problem with lipos (Not in a case) are they come in lots of different sizes, and configurations... How much TECH do you want to do..and allow companies who have not proven their safety record?

Just as the 3200 is a two cell pack, the 4800 is a 4 cell pack...by limiting to one source it allows racers to concentrate on RACING and not worrying about who's got a better motor or battery.

Joe,

Teching a Lipo is very simple. There is a meter available to do it.

Lipo's should be encased. But even that does not protect them. I saw this at our track. Driver wrecks his car and the Lipo then fails to power the motor. Another driver had this meter at the track and put it on the lipo and found that one cell was dead. It was an Orion battery. It can happen to any of them. Even encased. But like I said many companies will be out with there Lipos. Some are very well known. Be ready for it.

Anyway I will continue to test Lipos with brushless motors.

Bill M.

Joe,

Teching a Lipo is very simple. There is a meter available to do it.



This meter tells you the "C" rating and the average voltage and the capacity and the IR?

Good or bad maybe but teching for equality?

Ballistic bill thanks for all your testing on this, I ordered a 21.5 and a 4800mah lipo for mine. The only rule for our class this year on the lipo is 7.4v so I figured I would go for the 4800mah. I run a 13.5 in touring car and I have a little more top speed on the straights with the 4800 versus the 3200 so we'll see if it makes any difference on the 21.5.

The 3200 should be better all around if your running stock type speeds. The 4800 pack is a 15c and 3200 is a 20c and the new 3600 is 25c higher the C ratting the more voltage pack will have:)

21.5 Brushless Motor News

Well, in anticipation of the 21.5 Brushless / Lipo class in '08 we ran 2 cars today mixed in with our field of STOCK 4 cell cars.

Simply put - NO COMPETITON. Granted I think some of the NiMh guys batteries may have been getting old this time of the year...'cause they were off their regular pace (Which is usually a FAST 25 lap run) but, right out of the gate with the first run, the first ratio, etc. the 21.5/LIPO combination ran a qualifying time in the fast 26 lap range. Donn Natale was able to grab laps running his 21.5/LIPO as quick as 10.66 seconds. (2 years ago, 1/2 the Sportsman 4 cell MOD guys would have been happy running those times)

FAST 27t. Stock 4 cell times are usually in the 11.7 range up front and fall off to the 12.4-12.5 area.

The 21.5/LIPO for my car started a little slower than Donn's times @ 11.0 and fell only to 11.8, running a fairly fast 27 lap run too.

So long and short - the 21.5/LIPO ran 2 laps quicker than the BEST 27t/4 cell record time...on it's first day.

I assume you were running a a velo. I was hoping that the speed might be just about the same as a 13.5 and I'm guessing on most of the carpet tracks it might be. I'll be testing as soon as the weather cooperates here in Iowa. LOL

Joe,

Ran the same 21.5/Lipo car today as last weekend. We worked with setups a little more and we got the car to go faster. We were turning in the range of 4.1 last weekend we now got the car to do alot of 3.9 along with about the same number of 4.0 laps. The car was a little pushy so I think we have faster lap times coming in the future.

I once felt that the 21.5/Lipo was slightly faster than 27 turn stock. I am now going to have to use the term moderately faster than a 27 turn. I would now have to compare it more to a sintered 13.5 rather than a non-sintered 13.5 like I did last weekend.

The 17.5/lipo cars today were turning 3.8 to 3.9 with some 3.7 lap times thrown in.

I had wished that the 21.5/lipo would have been a little slower than it is.

Also keep in mind that the car I am using is my 13.5 BRL rules car. No wing and the back is not cut out. If I shave another tenth off my lap times then this car with a 21.5/Lipo could put up a pretty good race with some 17.5/lipo cars.

That's what I have found for this week.

Later,

Bill M.

Joe, I finally had a oporttunity tpo run my 21.5 lipo in comp.

the track was a low banked 330 run line asphalt track.

below is what the various class ran for lap times:

27t 4 cell came out with 7.3 finished with 7.7's 4min.
10.5 4 cell 5.9 6.3 "
13.5 4 cell 6.4 6.7 "
21.5 lipo 6.6 7.0 5 min.

This was the second week for the 21.5.

I had a smile on my face all day, no motor hassle, no battery to solder in and out, peak, discharge and baby. Life is good!!!!

Ron - Awesome...and just about where it should be in the Speed spectrum, all in all still a little quicker than what I had hoped the 21.5 would be...but it's EASY to get on the throttle isn't it? (Personally, I still think the 25.5 was the "MORE" perfect motor...it had room to grow as we learned about it...)

The down side to a 25.5 is we'd be running OVERDRIVE gear ratios even on SHORT tracks.

(Can we put a SLIPPER CLUTCH on a Motor Shaft...and run PINION gears on the Axle?)