what size wire should be run on bl speedo and why?

12 awg because it is the largest wire gauge wire that will not inhibit pod movement, if you do a good job routing it. Anything larger would also be hard to solder given the limited space on the speedo and motor. Anything smaller obviously has more resistance.

12 awg because it is the largest wire gauge wire that will not inhibit pod movement, if you do a good job routing it. Anything larger would also be hard to solder given the limited space on the speedo and motor. Anything smaller obviously has more resistance.

So... what's the lap time difference from the wires that Novak ships on the GTB vs. changing them to 12 ga wire ?

Thx.

It would be pretty tough to figure that out considering all the other factors that could affect your lap times as well as the difference being very small.

It would be pretty tough to figure that out considering all the other factors that could affect your lap times as well as the difference being very small.

That was kind of the point... switching the wires isn't going to make the car pick up 0.3 or 0.4 seconds I wouldn't think -- or even 0.1 ??

Agreed. But the person asked what he should run, which I read as "what is best". 12awg is best, if he doesn't bind the pod. This same subject got beaten to death in a thread maybe a year ago.

There are about a 100 different things that don't make much difference, but when you do them all it adds up.

You know, it never amazes me with the over abundant amount of intelligence that is among us on these forums!! The guy asked a question and Pat answers it. Why the sarcasm??

what I would like to know is if 12g is really the best then why do companies ship there speedo's with different wire.

2nd i'd like to see on track proof that 12g is better than 14g

The important part isnt the gauge but the resistance of the wire your using not all 12,14 gauge wires are created equally and have different resistances. Of course you need to keep flexibility in mind also, if all the powers not getting to the ground its a waste.

Easy way to calculate what resistance wire you would need would be to calculate your motors max amp draw. Then use ohms law. Heres a neat calculator I use at work.

http://www.the12volt.com/ohm/page2.asp

I think the biggest reason for the smaller wire on the speedo is cost.
Butch

12 wire is the best but when running a 21.5 motor you won't be able to tell the difference between 14 and 12 AWG except the 14 is a little more flexible and easy to work with. So pick a color you like and enjoy.

I run 12ga from the battery to ESC and some Orion Snake 14ga to the pod. I was able to use less total length of wire than using 12ga alone. 12ga just bound the pod up more and needed more distance to flex properly. If I added all the wire segments together it would total 21". On one of my cars I had a sub 20" install and I felt that the pod was getting stuck once and a while. The Novak GTB ships with 30" of wire

Below is an estimate. There are a few assumptions.

1. Total length of wire in the circuit is 12" (with brushless only 2 of the 3 are in the circuit)
2. The resistance values are accurate for the wire we are using (I haven't measured the actual wire)
3. Voltage is directly related to RPM and there are no additional losses caused by the additional RPM (This isn't extremely accurate as when the speed increases the loss also increases normally)
4. Average current of 45 amps (this is high but possible with 10.5 Velodrome racing)

Voltage Drop 16GA wire 0.1845 volts
Voltage Drop 12GA wire 0.0720 volts
Voltage Drop difference 0.1125 volts

If you are running a pack that discharges at 5 volts average ... how would like to race with someone running a 5.1125 pack? It is over a 2% difference. Depending on the track ... that could be a 5.00 second lap to 4.90 or less. On a velodrome ... that could be .2 seconds a lap.

But remember ... lots of assumptions in this calc.

I got my resistance values here:

http://www.stealth316.com/2-wire-resistance.htm

no thats info i was looking for. thanks.

You know, it never amazes me with the over abundant amount of intelligence that is among us on these forums!! The guy asked a question and Pat answers it. Why the sarcasm??

yup been wondering that for many years.......

ok all this technical mumbo jumbo is great. but it still shows me nothing you want to convince me show me proof on the track that you had a speedo with 14g wire on it and actually went faster by adding 12g wire.

how much wood would a wood chuck chuck if a wood chuck could chuck wood:freak:

a woodchuck would chuck as much wood as a woodchuck could chuck if a woodchuck could chuck wood

ok all this technical mumbo jumbo is great. but it still shows me nothing you want to convince me show me proof on the track that you had a speedo with 14g wire on it and actually went faster by adding 12g wire.

Alright you show me track proof that your car went faster when you replaced a gritty feeling front bearing.

I could throw out examples like that all day long, but you get the point.

I don't understand why everything on here has to be a debate. Post 1 was a simple question, post 2 was a simple and correct answer. Done, or it should have been.

there is way too much thought going into speedo wires!!! lol ...

Im no math magician here but :hat:..........change speedo wire & pick up .2 thruout a run or change a tire and pick up a lap!..

both!!

now your get'n greedy!!! :)

No debate from me that there are many things which are probably more important to lap times and overall race performance. But there should also be no doubt that lower resistance is better. I'm with Pat on that.

Will you find it in your lap times? I don't know. But I do know we did some dyno work (CE dyno) a while back with our motors. With brushless motors, you use the ESC when you're doing the dyno testing. We first ran some motors with a stock 4 cell GTB (16 ga wires). Then we replaced the wires with 12 ga. Power at 30 AMPS (these were 13.5's) jumped approximately 4 watts as a result (since you're powering through the ESC the CE keeps constant voltage and steps amperage into the ESC and not into the motor).

Now you can all debate whether a 4 watt difference matters on the track. But I know I'd rather have the 4 watts in the car than not.

I don't understand why everything on here has to be a debate. Post 1 was a simple question, post 2 was a simple and correct answer. Done, or it should have been.

Pat, not being a smart ass here but isn't that the whole point of forums like this? I read many forums on a variety of racing topics & series and they are all the same way... wonder if the sewing & cooking forums are like this.

Pat, not being a smart ass here but isn't that the whole point of forums like this? I read many forums on a variety of racing topics & series and they are all the same way... wonder if the sewing & cooking forums are like this.

You're right and all forums are like this it doesn't matter the topic.

Easy solution though. I'll do what about 84 of the 94 members I currently see signed on do. Not waste my time trying to help.

davepull,
I dont have the technical hows/whys but heres a quick story. Last year at the Triclone BRL Summer Nats ((banked asphalt/captires/5min races)) I was running dead shorted batteries and no matter where I geared I couldnt finish a run without dumping w/ 5-15 secs to go. The better my car got the more of a problem it became. Thinking it wouldnt make much a difference I had just left the 16awg wires on. I had some 14awg laying around so figured I'd try it. I went out and made a run and I made 5 mins with 30sec more battery to spare and it ran faster laptimes up front changing nothing else on the car and ended up TQing. I ended up going to 12awg and it picked up a little more.

For whatever reason it didnt seem to make as much of a diff when I went from 14-12 as it did when i went from 16-14. That was the best car I've had at that track so it was a good test and it was certainly noticable. I think under those circumstances it made a noticable difference, but for 4min carpet racing I cant see it mattering much though I would still put the 12 on.

I agree though, theres alot of thought on wire lol. Now Frank imagine if you rebuild the side shocks, add wire AND polish your kingpins!!! lol.

I am sure it all adds up, but with my current setup, the additional voltage loss of using 14ga to the motors is only about 0.01V for my 13.5motor. I am sure that having a freerange of movement in the pod action is well worth the loss of 0.01V.

I conceeded and went to 12ga completely and moved the speedo for a savings of 4" of wire over the last posistion. So now my motor should have .02V more to crank it faster.

My once 21"(10" 12ga and 11" 14ga) total wire install is now 17" of 12ga.

To do you calculations, don't add all three phases of the motor, just add two phases since only two are engergized at anyone time.

If you look at just voltage drop numbers, then you are missing out on a few other factors.

12 gauge will inhibit pod movement more than 14 or 16 gauge wire.
Difficult to bend consistently so there is no pod twist pressure to one side.
Scaling the car becomes a little more inconsistent.
More overall weight.
Higher center of gravity.


If you are racing velodrome sized tracks, the above items aren't an issue. But if you race carpet racing where your hitting a corner every 2 seconds, then they do factor in. With 13.5 speeds, I've run just as fast with 16 gauge wire as I do with 12 gauge. Mod classes might see a benefit from larger gauge wire.

I differ on opinion on the velodrome tracks, as yes the rear pod does alot of movment on the velo's tracks because of the high speeds and compression in the corners.. the velo here in indy has a quiet a few bumps and when your going 60mph, yes your suspention moves alot so I think your above items will work for both carpet and the velo very well..

Putting your ESC by the LR tire will require more wire flex. As the pod has more leverage at that point.

So in my last rewire job using 12ga wire, I moved the esc to route the wires right up the center of the pod and t-plate where they do not bind when the pod moves.

I believe the point that is trying to be made here is this. If you set your car up so that that the wire does not effect the performance of the car, and you let the bearings and the shocks, and yes polished shafts do their jobs. You can worrry about making your car carry the corner speed you need to make up the difference of the wire you are planning on saving weight or easy of routing with. Dave P is correct, we can all drive straight, but he who get's through the corner the best is the fastest. Infinate amount of setups for track, weather, temp, and chassis. Wire it up and find the best to get you through the corner with DaveP. Rumor has it he has found something.

Putting your ESC by the LR tire will require more wire flex. As the pod has more leverage at that point.

So in my last rewire job using 12ga wire, I moved the esc to route the wires right up the center of the pod and t-plate where they do not bind when the pod moves.
I have another approach for mounting my speedo. I'm willing to be told how stupid this might be, but listen to my reasoning before yelling.

I just got a Tekin RS speedo, hearing good things about it and wanting something that was a little easier to mount on the little "speedo" platform at the rear of my Custom Works car (replacing a GTB). So I get the RS and start trying to figure out what is the right orientation for the ESC so I can see the LEDs, get to the buttons, not have the sensor port and other wires at risk from crashes (our racing is kind if rough some time), and so on. Nothing really satisfies me. I look at that little RS, put it on a scale and it is only .9 ounces. I weigh the wire I am going to have to use to have enough so as to not bind the pod and that comes to about .4 ounces. So I think: Suppose I mount the speedo on top of the pod. Viola! No worry about flex for three wires and save about .4 ounces because now the wire only has to be about .5 inches long instead of 2-3 inches long. (true, the battery wires will be a little longer, but maybe not that much.)

So given that I'm pretty much a middle or back of the pack pan car driver, what's my real trade-off having a half an ounce extra of speedo weight on top of the pod instead of on the chassis? I guess PMSimkins will mention that this is one of those little things that will cost me, equivalent to that gritty front bearing (and I know that's probably valid) but I feel I'll be saving some weight at the same time I am moving that half ounce a little higher on the chassis. It turns out that the "A/B/C" posts on the Tekin are in the same order as the "A/B/C" posts on the Novak motor, so the wires are a straight shot for a half an inch or so with the ESC on the pod top plate. Oh yeah, that half ounce does move a little toward the center of the car from the left rear.

ok problem is that you don't want the weight that high. I have a cw I'll try to get some picks of how I have my rs pro mounted to run 17.5 lipo. when i ran 4 cell i just layed it down on the lr i never used the last cell location so I covered that tape slot up. i put the post in the back. then instead of looping the wire over the top like alot of people do what I did was loop it into the front of the pod right infront of the motor. looks very clean and bind free.

I have a thought on the size of speedo wire that you use. How much current are we actually pulling from the speedo to the motor? Not much. Another thing is, look at the speedo where the wire solders in. If you rolled that little peice of metal up that is on the circuit board, what size wire would that make? That is probably the most resistive part of the connection between the speedo and the motor. I noticed no performance difference runnin 12 ga versus 14 ga at the velo here in indy. And i certainly ran with the best of em here at the local tracks in indiana with 14ga. So my personal opinion is that there is not a noticable difference. certainly not enough to worry about.

ok problem is that you don't want the weight that high. I have a cw I'll try to get some picks of how I have my rs pro mounted to run 17.5 lipo. when i ran 4 cell i just layed it down on the lr i never used the last cell location so I covered that tape slot up. i put the post in the back. then instead of looping the wire over the top like alot of people do what I did was loop it into the front of the pod right infront of the motor. looks very clean and bind free.
I'd like to see that pic, but I do use the last cell location so I can't lay it flat. If it was a slider, I could lay it flat and move the tray up far enough to clear the tire, but I have a solid. I thought the RS would be small enough that I could lay it flat and clear the tape slot and the tire, but it isn't. (Unless I move the pod back - that this is a separate set of issues.) Another disappointment is that the receiver connection lead on the RS isn't long enough to make it from the speedo on the LR of the chassis to the RX mounted in front of the battery area. So I have to move the RX.

I don't mean to discount what you said, but as far as "weight up high" the body is 7 times the extra weight of the speedo (after I take away the weight of the wire I am saving) and is much higher. Running the wires forward and back instead of up and down seems like it would add even more wire (I've already got comments from people on how much wire I use) and add more weight. That is something I am trying to avoid on an already overweight car. The weight was one of my reasons for buying the RS.

i'll try to get a picture up.

in oval racing you want to keep the weight as low as possable. plus something else I just thought of is the fact that you add another once to pod. which leads to a big debate of sprong and un-sprong weight. put it this way if it was a good idea that would be where everybody ran it.

as for the servo lead you can either move the reciever to the center of the battery tray next to the center shock mount or just buy like a 3 inch servo extension.

got pic up in "my photo's" of the tekin rs pro 3400 lipo and the redline 17.5 installed in a custom works aggressor plus ton of good info on the rs and rs pro here

http://www.hobbytalk.com/bbs1/showthread.php?t=218288&page=10

Very nice. But the switch definitely needs to be someplace else. (At least for me.)

http://home.comcast.net/~robertgtourangeau/img2.jpg
If you want to mount the ESC to the pod, use the R3 Designs X2 pod.

The bottom pod plate has a battery slot by the LR wheel. I used this on my L30 when I was running Brushed. I bought the X2 Pod because it came with the Darkside Rear Steer option. R3 also just sells a non rear steer plate