09 handwarmer resistance

[TurboMatt]

Excellent work. I guess that means I be ordering the RSI's for sure then

 

[BLUEBALLER]

ruffyrider - thanks for confirming everything I assumed. 14Volt source & near 99% duty cycle at 10 bars.

I really didn't think it would be 50% duty cycle as previously stated, but didn't have the numbers to back it up (see, I told you, you we're pulling #'s outta your azz!!)



Arteex - get that aluminum outta there. it's not a matter of "if" its going to short out, but rather "when".

I know it's your sled, and it looks good, but is it worth the risk? At least fuse it if you're a stubborn old dog and refuse to take my advice.

 

[arteeex]

I ain't ascared.

If there was relative motion between the aluminum tape and the heaters I would be more worried. The foil may overkill, but given the short distance between the heater and the outer surface I wanted an efficient heat transfer agent to diffuse the output across a larger area and reduce the potential for hotspots. Normally, the handlebar will provide this function but I put the heaters on top of the rubber grips. I realize I may be sacrificing a set of heaters for the cause and in the name of science and I’m okay with that.

Choosing to leave the aluminum tape in place doesn’t make me stubborn. I am, but not because of this particular issue. My stubbornness is the result of a lifetime of effort.

A fuse is a good idea. I’ll buy into that one.

I also figured on adding about a ½ Ohm resistor to each side, especially now that we know the system is at 14V. This will bring the calculated current down to about 5.5A and still provide 38W per grip - vs. 27W for stock.

 

[TurboMatt]

Has anyone ever used the gel grip tape that RSI sells. I was thinking of using this stuff, but wasn't sure how it would hold up in the long run.
Any opinions?

 

[r0tax]

so, how many watts would the resistor need to be in this case?
and it should be safe to say, this resistor can go on either wire.
just unsure of what size (wattage rating to use).

heres some .5 ohm 25 watt
http://www.tedss.com/item.asp?id=2021007987

Radio Shack has a .47 ohm 5 watt resistor for $1.70 or so..

I ain't ascared.

If there was relative motion between the aluminum tape and the heaters I would be more worried. The foil may overkill, but given the short distance between the heater and the outer surface I wanted an efficient heat transfer agent to diffuse the output across a larger area and reduce the potential for hotspots. Normally, the handlebar will provide this function but I put the heaters on top of the rubber grips. I realize I may be sacrificing a set of heaters for the cause and in the name of science and I’m okay with that.

Choosing to leave the aluminum tape in place doesn’t make me stubborn. I am, but not because of this particular issue. My stubbornness is the result of a lifetime of effort.

A fuse is a good idea. I’ll buy into that one.

I also figured on adding about a ½ Ohm resistor to each side, especially now that we know the system is at 14V. This will bring the calculated current down to about 5.5A and still provide 38W per grip - vs. 27W for stock.

 

[ruffryder]

ruffyrider - thanks for confirming everything I assumed. 14Volt source & near 99% duty cycle at 10 bars.

I really didn't think it would be 50% duty cycle as previously stated, but didn't have the numbers to back it up (see, I told you, you we're pulling #'s outta your azz!!)

Yah, I was wrong on quite a bit of assumptions...... but that is what I get for armchair engineering....

Has anyone ever used the gel grip tape that RSI sells. I was thinking of using this stuff, but wasn't sure how it would hold up in the long run.
Any opinions?

I will be using them this year. I haven't had a chance to work on the sled much, except for last night...

 

[arteeex]

For this application I wanted to reduce the insulation between me and the heater, which is why I didn't use gel tape. There are cloth bar tapes that I would expect to work well - I do think you should avoid the vinyl tapes. Either way, the stuff is inexpensive and easy to replace as needed during the season. Give it a try.

I may change my setup and use tape if I find there’s a problem when the grips get wet.

 

[yamy07]

I also figured on adding about a ½ Ohm resistor to each side, especially now that we know the system is at 14V. This will bring the calculated current down to about 5.5A and still provide 38W per grip - vs. 27W for stock.

How does this compare to guys that are using the 06 bars wired in parallel? Any downside to 06 bars with -say 1 ohm added to each?

 

[glmf]

excellent job guys, the options are nice and thanks much for your hard work in picking up where yammi left off,

 

[justinator]

I also figured on adding about a ½ Ohm resistor to each side, especially now that we know the system is at 14V. This will bring the calculated current down to about 5.5A and still provide 38W per grip - vs. 27W for stock.

How does this compare to guys that are using the 06 bars wired in parallel? Any downside to 06 bars with -say 1 ohm added to each?

Looking for the same answer but I think you would need slightly larger than 1 ohm as the 06 bars measure 2.2 ohm vs the 3 ohm hot grips that blue balle used?? This is just a thought though, I am not an electrician

 

[arteeex]

 

[Timeline]

Finally got around to working on this. I have always wanted to keep the factory grips if I could. Controls didn't really matter. This is what I will be doing and preliminary tests looked pretty good.

The voltage in a parallel circuit remains the same regardless of resistance.
Current increases as resistance decreases.
My heating elements are 7ohms each. Wired from the factory in parallel the resistance is 3.5 ohms. I added a series parallel circuit to this. The series circuit is two 1 ohm resistors and one 5 ohm resistor totalling 7 ohms. 7/3= 2.3 ohms. I now have a circuit through my bars that is 2.3 ohms and draws 4 amps at about 3500 rpm. If I dare I could go lower by adding another 7 ohms to the circuit to make it 1.75 ohms. Or calculate it to be somewhere in between.
We now know that it is a steady 14 volts so,
Stock= 98 watts total......Resistors added= 112 watts
I realize that I have used some wattage by using this setup but bottom line is my grips are warmer.

I used three 25 watt resistors as these will definitely have a longer life span because they can dissipate the heat more efficiently. They are also a lot more accurate at 1% variance compared to 5- 10% for the ceramic resistors. Actual resistance is what is on the stamp. I have fabricated a small aluminum heat-sink to mount these on. These resistors are encased in aluminum and can be screwed down to the heat-sink. I will also apply thermal compound to the mating surface. I am using two 5 amp circuit breakers and will install one on both sides of the harness for the grips.

I will post the final installation when completed with pictures of the install, results and part numbers used.

 

[LJ 452]

I would exercise some restraint. At 5.2A the calculated output of 36W per grip (less that dissipated by the resistor) is about 30% greater than stock.

At 5.2 amps your current draw is 57% above stock at 3.2 amps!
At 6.2 amps your current draw is 87% above stock at 3.2 amps!

If you use 3.86 amps as max current it drops the percentages to 35% and 60%.

Use caution when doing any of these mods. You assume the risk, I can almost guarantee you Yamaha will not warranty, and will know you did something to the ECU or grips. When is the last time you said to yourself hey, I know this circuit is rated for 15 amps but I going to load it to 20 or 30 and not worry about it. The reason I make this statement is that there are some on here who don't fully understand the risk associated with any of these mods. All they hear is "warm hands", which we all want, but everyone should at least know the risk that they are taking. I'll be the first to admit I don't know the risks, but I'm sure that there are some. If it was as simple as reducing the resistance in the grips don't you think Yamaha would have just done that. Let’s give them a little credit, it's not rocket science. Do you really think they can design these motors and sleds but can't make a simple grip heating system. Make no mistake about it, there is some risk to changing this circuit. It may be a long term effect that no one will ever see as the sled will be recycled into pop cans by that time. Or it could be short term, ECU failures, or excessive demand on the charging system resulting in dead batteries, or damage to the charging system. Which brings me to a question, does anyone know if you can damage the charging system by overloading it. I would imagine you could but if someone that is familiar with these systems could chime in. Or better yet if someone from Yamaha would like to explain to us the reason for limiting the power, feel free.

I was able to scope my Phazer and Apex this weekend as well.

I don't have the 09' S.E. yet so maybe I'll get another reading once I get it.

Phazer: At idle with the control set to max the wave was <50%. As you rev the motor to 5K it would increase the wave to near 100%. Brake on/off had no effect. When the fan came on the pulse was zero at idle and again ramped up with the RPM. Tried the high beam lights on/off no change.

Apex: At idle with the control set to max the wave was <50%. As you rev the motor to 4K it would increase the wave to near 100%. Brake on/off also had no effect. When the fan came on also no effect, at idle or 4+k RPM. Tried high/low beam again no change.

The question still remains what the difference is. Why is it that if I use the Hot Grips PWM from a battery I get far more heat to the grips. Until winter comes we really won't know for sure what works and what doesn't as the temps will play a role in the grip heat. One thing I wonder is how much control the ECU has over the heater circuit. Will it cut power in any circumstance to maintain required power for the EFI. Thinking how I ride, on and off the throttle many times a mile, the fact that the ECU cuts the wave in half at anything less than 4K could be the sole reason for the cold hands. It would also explain why when cruising at 7-8K RPM's the grips get hot. It doesn't answer the fact that when WFO the grips as far as I can remember are cold. I didn't have the nuts to go WFO on the track stand as the sled was still in my trailer, I don't think I would do it anyway. I wonder if the sled again reduces power to the heater circuit when the throttle is up at the top of the range. I would think that the coil would produce enough power to maintain but maybe due to additional draw for ignition system and EFI it drops back down.

Another test that would be interesting would be to see if the ECU changes the wave due to the increased draw from the different heaters. I would think that it's just a pre-programmed curve that relates to engine RPM but you never know.

The funny thing is Yamaha is sitting back reading this and probably laughing as we try to understand what’s going on in that black box. I still believe that if they could, they would just up the power or would have gone with lower resistance grips. It's not like they aren't capable of figuring this out. There's something keeping them from upping the power, hopefully it's a long term/small risk issue.

My choice right now is to see what the stock grips are like, then if needed change to the Hot Grips PWM controller and give that a try. I figure this way I have not altered the stock components in any way and can always go back to stock. The only risks I see is not getting a full charge to the battery at idle, and there are many ways to work around that. Overall demand is only increased at idle, as it appears the duty cycle is +99% at >4000 RPM. So the change in over all power consumption is very low. Amperage and voltage remain the same as stock.

 

[ruffryder]

If it was as simple as reducing the resistance in the grips don't you think Yamaha would have just done that. Let’s give them a little credit, it's not rocket science. Do you really think they can design these motors and sleds but can't make a simple grip heating system.

Yes, completely, or the specs/temps they assumed were much higher or they factored in very large gloves, when most people now were smaller, thinner ones...

I would like to ask them why hydraulic rear shocks came stock on the nytro mtx.... I can call them dumb.... can't you?.... probably all marketing/economic decisions anyways...

Yah the worst thing that would happen from too much current is a toast ECU....

Which brings me to a question, does anyone know if you can damage the charging system by overloading it. I would imagine you could but if someone that is familiar with these systems could chime in. Or better yet if someone from Yamaha would like to explain to us the reason for limiting the power, feel free.

Nothing will happen to the overloaded charging system. It will only provide the power it was designed for... the extra power will come from the battery and additional draws if greater then the charging system will result in dead batteries.

I think the greatest problem with cold hands is the fact that they do not operate to the selected output using the switch until after 4500 rpm's on the Nytro. Since the stator/flywheel is rated at that rpm, it leads me to believe that the charging system does not provide enough power at idle to run the fuel pump, injectors, ignition coils, headlight and the rest. I think if they went to a better headlight (more efficient) the power savings could go to the handwarmers.

The question still remains what the difference is. Why is it that if I use the Hot Grips PWM from a battery I get far more heat to the grips.

The pwm signal on the nytro only really works above 4500. No matter what the setting, unless off, the nytro hand grips will have the same heat. It is only really past 4500 that the settings have an effect on the pwm signal. My hypothisis is that my hands would get cold when starting out or playing at really slow speeds....

The PWM from the battery is working regardless of rpm, you get full output at idle to redline when set at max, where the nytro only starts really working above 4500 rpm.

Thinking how I ride, on and off the throttle many times a mile, the fact that the ECU cuts the wave in half at anything less than 4K could be the sole reason for the cold hands.

My thoughts exactly..

 

[BLUEBALLER]

I would exercise some restraint. At 5.2A the calculated output of 36W per grip (less that dissipated by the resistor) is about 30% greater than stock.

At 5.2 amps your current draw is 63% above stock!
At 6.2 amps your current draw is 94% above stock!

.

this must be "new" math that I keep hearing about.

Actually - 5.2 amps is more like 35% higher, and 6.2 amps is 60% higher than the 3.86 amps which happens to be the stock heating element current draw.