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2015 - 2016 Rules Update

13K views 49 replies 28 participants last post by  CBear3 
#1 · (Edited)
As we head into the final year of our current 3 year rules package there are a few updates to be made; most as a result of technology changes or keeping up with racers' creativity. A complete update of the rules package will be done and posted shortly.

1) As announced last season, the truck class will switch to Novak Vulcan 17.5 handout motors.

2) There will be a minimum roof height for the truck class based on cutting the Protoform body on the molded in trim lines. The number will be published shortly. NEW MINIMUM ROOF HEIGHT WILL BE 4.50".

3) The SK class will switch from open ESC to blinky ESC.

4) The new SMC 4200 spec pack will be allowed along with the existing 4025 pack.

5) Receiver packs will not be allowed; internal or external electronic boosters only.

6) The 13.5 motor list will be updated a little closer to the start of the season.

7) No large capacity capacitor banks; ESC OEM equivalent capacitors only or 10,000 microfarad maximum for glitch busters type capacitors.

8) ESC’s must be configured so that they cannot be wirelessly updated when presented for technical inspection and as used in all competition (qualifying and mains). Some examples include removal from the car of any separate, external wireless modules; removal of any specific receiver used to enable wireless programming; and / or a locked software mode in the ESC which prevents wireless updating (locked mode must be indicated by a specific distinctive blink code or LED color).

9) the 17.5 open ESC stock class is officially removed from the class list

10) the Mudboss class will be run as a local track option class where there is interest. It will not be a points championship class.


Some comments on ESC voltage feedback and the reasons we are taking the approach of not allowing receiver packs.

At the conclusion of the 2013 – 2014 indoor carpet season some concerns were raised about a particular Hobbywing ESC regarding its ability to pass voltage from the receiver pack through the ESC, so called voltage feedback.

Immediately prior to the start of the 2014 – 2015 season; testing revealed that other ESC’s in common use in carpet oval racing also had this capability.
The main concern regarding this capability is the potential for the receiver pack to charge the main battery to a voltage higher than that allowed if the vehicle switch is left in the ON position or turned to the ON position after the vehicle has been through prerace technical inspection. A secondary concern is the ability of the receiver pack to provide power directly to the ESC and motor. However, because of the limited size of the wire from the receiver pack to the receiver and from the receiver to the ESC; this secondary effect provides little or no practical benefit in competition.

For the 2014-2015 season, the BRL addressed this issue by requiring vehicles be impounded after prerace tech with the switch turned off until immediately before a race heat. This minimized any possibility to use the “feedback” to charge the main battery.

Additional testing during the season showed that this feedback charging occurred to varying degrees with several different brands of ESC’s commonly used in oval competition. It also showed that at least for some ESC’S the degree of charging depended on the difference between the main pack voltage and the receiver voltage (lipo RX packs charged faster and to a higher voltage than LIFE packs). An apparently simple fix, removing the red wire between the ESC and the receiver, was tested but it was found that some common ESC’s either would not work at all without the red wire in place or had a voltage threshold where they stopped working that could be reached during a 4 minute race, especially in spec pack classes.

As we evaluated possible solutions to the problem we were looking for a single solution that could be applied across all known and future ESC’s. Allowing only ESC’s that did not feed RX voltage to the main pack was considered. However that would have meant continuous testing of ESC’s for this capability as new brands and models are introduced. That is not something any of the oval organizations, including the BRL, are equipped to do. It also would have meant a sizeable number of ESC’s in current use would have been banned. There is also the risk that enterprising racers could have modified an allowed ESC to provide the voltage feedback. We’ve seen racers be able to modify the BEC in a 2 cell ESC to make it work on 1 cell. It isn’t much of a leap to imagine modifying the BEC to allow voltage feedback. In some cases it could be as simple as eliminating a single diode.

For the same reasons; creating a matrix of ESC’s allowed with the red wire and those allowed only without the red wire was considered as a solution and rejected.

The only realistic solution that can be applied across the board in the same way for all ESC’s is to outlaw the use of receiver packs and require all power come from the main 1 cell battery. Racers will be allowed to use either an electronic voltage booster internal to the ESC or an external electronic voltage booster. The laws of physics mean that no electronic booster can create more power or energy from the main battery than was present in that battery to start with.
 
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#6 ·
Just one question though...if you eliminate receiver packs from competition....don't you eliminate Castle Creations from competition as well? After all their Mamba Max One cell requires a receiver pack to function? The booster deal works with speedos that have that type of circuit? But the Castle doesn't...
 
#8 ·
As John said, the Mamba Max Pro works fine with an external booster replacing the receiver pack. The input
side of the booster is connected to the main battery pack while the output side plugs into the receiver and supplies 5V for the servo and the ESC.
 
#10 ·
When you guys switch from receiver packs to boosters you will wonder why you messed around so long. Basicly they are the circuitry that companies like Hobbywing use internally to make their 1 cell esc's. The coolest is using one like the TQ on an esc that has a switch. Just plug the booster into the receiver and the esc plug into it. Hook the esc to the battery and flip the switch. One kicker is the esc must have its voltage cutoff turned off or down so low that 3.7v won't turn it off.
 
#19 ·
Sorry for the delay in publishing a number for truck roof height. The plan was to return from vacation, cut a fresh body on the lines, measure and establish the height.

Unfortunately my favorite hobbyshop didn't have any ORT bodies in stock. So I ordered 4 bodies. When they came in, they all had ORT labeling but the bodies inside were the Protoform Mazda 6. After a little thought, I decided against using the Mazda bodies to establish the truck roof height and re-ordered bodies from a different distributor. Hopefully Protoform hasn't placed Mazda bodies in all the ORT packages and when these new ones come in I'll have some truck bodies to use to establish roof height
 
#21 ·
HAHAHA on the Mazda 6 bodies, they would make GREAT "Truck" bodies!!

For those using boosters instead of Rec. packs -- While I don't agree w/ not allowing a rec. pack, I understand WHY (because racers are their own enemies and do dumb things) - but beyond that - who has the best price booster, the best working booster, and how are they correctly used? (I've been using rec. packs since about '85 at various times, and have never used a BOOSTER)
 
#22 ·
I like the Novak booster pn 5477. I have 3 of them along with some from wreckless abandon racing (local guy). I had 2 from tq who I think no longer sells them. Both the tq have now failed. One failed on burn in, the other had the wires come off the board after a few years. The Novak has nice silicone wires and a led showing its on.
I wire them to a jst style plug and wire the other end of the plug to the esc + and -. That allows quicker changes of esc since I don't have to remove the booster when changing esc. Just unplug. The booster then plugs into the rx just like a rx pack. I personally remove the switch and solder the switch wires together, so you just plug the battery in and the car works.
I know others like the switch and use it to turn the car on/off.
 
#24 ·
...so, If everthing I've been told about 'Boosters' is true... you have to WIRE THEM Into your system somewhere/somehow, where a rec. pack w/ a switch, can be plugged into the rec. pack location on a receiver and turned on and off w/ that switch?

How does that work when using a 2s powered system? (with a 1s ESC - like a Mamba 1c)?

...I pulled my Mamba 1c from my carpet oval car, and use it in my DIRT OVAL truck w/ a rec. pack. Can a "Booster" be used here in place of the rec. pack? (because I hate having to remember to re-charge the rec. pack...)
 
#25 ·
How does that work when using a 2s powered system? (with a 1s ESC - like a Mamba 1c)?

...I pulled my Mamba 1c from my carpet oval car, and use it in my DIRT OVAL truck w/ a rec. pack. Can a "Booster" be used here in place of the rec. pack? (because I hate having to remember to re-charge the rec. pack...)
To use an esc like a mamba 1 cell which has no bec circuit on 2s you would run an external bec, not a booster.

Most esc''s have a bec built in, so on 2s you don't need anything extra, just plug them in and go.
 
#28 ·
HW boosters are 6v 3a, 10 grams,no switch ,has led showing on,but like others can be wired into esc switch. No red wire from esc to receiver when using 2 cell esc's.
We've been using them for awhile now ,zero failures,guy's are super happy not having to charge receiver packs.
 
#29 ·
As previously announced we are increasing the minimum roof height for the truck class. The objective is to return to a configuration which keeps more of the front splitter on the body. In order to establish a height which could then be used on bodies with and without molded in trim lines; we cut and measured several Protoform bodies on the top of the molded trim line, the bottom of the trim line and as close to the center of the trim line as possible.

Without getting into establishing a roof height measured in 32nds of an inch, we have settled on 4.50" as the minimum roof height for the class for the 2015-2016 season. The initial post on this thread has been revised to show this number.

We realize this may still leave some wiggle room for guys to rake bodies and trim away some of the front splitter but we feel it is a reasonable number overall.

We also considered applying some sort of rule to eliminate scrapping of bodies (particularly for the truck class) but reached the conclusion that enforcement would be somewhere between difficult and impossible. We haven't been able to find a good way to nondestructively measure finished body thickness at a reasonable cost at trackside tech. A minimum weight which would prevent scrapping would be difficult to establish (given the different bodies allowed in the rules as well as differences in wheel well trim, differing spoiler lengths, etc). We can also think of ways to meet minimum weight while still scrapping to get a lower CG height from the body. In the end, we determined that we don't currently have a good way of enforcing a ban on scrapping. Absent a good way to enforce a ban, we decided to leave things as they are.
 
#31 ·
Nick, If you are ever in Kansas City, stop by and race at Chuck's track. He is always willing to let you voice your opinion and have a discussion on the pros and cons of any of the rules. We are lucky to have Him and his son care so much for the racing and the racers.
Randy
 
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