09 handwarmer resistance

[arteeex]

LJ -

I agree with most of your post. And, not to get all philosophical, there is obviously some risk of letting the smoke out of the box given we really don't know the limits of the ECU or the impact of stealing watts from the system. This is why I am suggesting we not push the system too hard. It’s only my opinion that 5 – 6A is a reasonable level for these aftermarket heaters.

In my tests I measured both RSI heaters and stock grips in parallel. The RSI heater circuit indicated 1.7 Ohms and the stock grips indicated 3.64 Ohms. At 12.3V from the battery I saw 6.6A and 3.27A for the RSI and stock, respectively. The difference here in both current (amps) and power (watts) is a 100% increase over stock.

Switching to calculated values and using 14V, the anticipated output of the stock grips would be about 3.9A and 55W for the pair at a 100% duty cycle. In the same conditions (and adding a resistor to bring the system to 2.7 Ohms (which I didn’t specify in my earlier example), the RSI heaters will draw 5.2A and deliver about 72W at a 100% duty cycle. This is how I arrived at the approximate 30% increase in output of the RSI over stock heater elements. ((72-55)/55)*100 = 31%.

There are many ways to parse this out, but the point for me is to keep the total heater circuit resistance, as seen by the ECU, to something in the range of 2.3 to 2.7 Ohms. I’ll accept the risk of a 30 – 40% increase in load– not so much a 100+% increase.

 

[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 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.

Your right in trying to figure it out quickly I worked it the wrong way. With that when I measured my grips I had 3.2-3.3 amps at full power.
A simple "hey check your math" would have been fine. No need to bash

At any rate the increase as measured on my grips would be 57% and 87% respectfully.

Yes at 3.86 amps stock the increase is 35% and 60%. The point I was making is that it is substantially above the assumed (known to be safe) rating.

 

[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.

Your right in trying to figure it out quickly I worked it the wrong way. With that when I measured my grips I had 3.2-3.3 amps at full power.
A simple "hey check your math" would have been fine. No need to bash

At any rate the increase as measured on my grips would be 57% and 87% respectfully.

Yes at 3.86 amps stock the increase is 35% and 60%. The point I was making is that it is substantially above the assumed (known to be safe) rating.

While we're on the topic, do you happen to know how many amps are currently running through your ECU?

I'll give you hint. It's 310% higher than the current flow for the hotgrips.

do you feel better now?

I've already posted this info before. The injectors run almost 12 amps through the ECU.

That's the main reason I'm not too concerned running 6 amps for the hotgrips.

What you decide to be acceptable however may be a lower/safer value.

 

[Timeline]

Hey we all know we are taking a risk at doing these mods. No it's not rocket science. Some have had the 06 bars on for a while though and are comfortable with that. I just like it to be a little calculated then to simply plug something in and go. I'm sure Yamaha has a reason for it. Probably making it bullet proof. Unmodified these ECU's may last forever. Maybe we shorten it a little. I think anyone trying any of these modifications knows that it won't be covered under warranty. It's no different than adding a turbo, NOS or a supercharger. It's all a gamble.

For me adding 1.2 amps to the system to gain 10-15 degrees of heat and using a fuse to add a little safety factor is good. All this for twelve dollars and a little tinkering in the garage. If it ends up costing me an ECU so be it. I think I'm still playing it on the safe side.
After all I've spent more in one night on Sushi and cocktails with the boys then that ECU costs.

What ever you chose, all the power to you.
Do it for the moderators, lets keep it sane and constructive.

Peace Out!!!

 

[arteeex]

As promised, here's a cartoon to show how I wired in the RSI grip heaters. The image shows ONLY ONE GRIP HEATER - you'll need to do this for each side (each grip).

The additional power resistor will let you dial in the amount of current (amps) that you feel comfortable pulling from the ECU. The greater the resistance the lower your current draw. I would not recommend installing more than a 2-Ohm resistor because you'll get close to giving up more watts to the resistors than the heaters and be close to the stock system again. The fuse is just an additional safety factor.

Please exercise your own best judgment here. Obviously, there's been no real-world testing of this setup. Once you cut the wires, you're on your own.

 

[yamy07]

This thread started out with "09 handwarmer resistance" 14 pages later - has anyone answered this question? If so, I must have missed it. So if someone has measured their 09 - please post the info again.

 

[Bamboo]

This thread started out with "09 handwarmer resistance" 14 pages later - has anyone answered this question? If so, I must have missed it. So if someone has measured their 09 - please post the info again.

There has to be someone out there with the new 09 in his/her garage. Lets see some numbers.

 

[kkraus]

For what its worth, I was told by the Yami guys at the Wausau Yamaha demo tent that they didn't change a thing for 09. NICE!

 

[BLUEBALLER]

This thread started out with "09 handwarmer resistance" 14 pages later - has anyone answered this question? If so, I must have missed it. So if someone has measured their 09 - please post the info again.

There has to be someone out there with the new 09 in his/her garage. Lets see some numbers.

All 09 owners are still in denial..........give 'em a couple of months.

 

[Bamboo]

As promised, here's a cartoon to show how I wired in the RSI grip heaters. The image shows ONLY ONE GRIP HEATER - you'll need to do this for each side (each grip).

The additional power resistor will let you dial in the amount of current (amps) that you feel comfortable pulling from the ECU. The greater the resistance the lower your current draw. I would not recommend installing more than a 2-Ohm resistor because you'll get close to giving up more watts to the resistors than the heaters and be close to the stock system again. The fuse is just an additional safety factor.

Please exercise your own best judgment here. Obviously, there's been no real-world testing of this setup. Once you cut the wires, you're on your own.

Is there a specific brand of resistor that is better?? Or is the radio shack stuff good enough? Is there a specific make and model you recommend?

 

[LJ 452]

The key to the resistor working is that it is rated for the wattage required, go to low and well....it toast. the higher wattage resistors you will likely find ill be ceramic and tend to have a 10% +/- precision so you may want to have the guy measure the two your buying to match them up.

 

[arteeex]

For my science experiment I used generic 1-ohm Radio Shack power resistors. These are the bigger ceramic jobs that can dissipate more heat than the little ones you typically see in electronic systems.

http://www.radioshack.com/product/index ... age=family

I have two 1-Ohm (1.1 actual on the 4 I bought) resistors in parallel to give me about 0.6-Ohms additional resistance for each grip. This setup provides a system of about 4-Ohms per grip. At 14V this will draw about 6.5A for both grips, which is nearly twice what I measured for the stock grips. Because I'm still a little paranoid about this additional current draw, I may go to a single 1-Ohm resistor on each grip circuit to pull the current draw down just a bit before the snow hits.

If I get time this week, I’ll drag out the IR camera and see what the difference in temp is between the two configurations. I know the grip temp on my REV is about 120F and I think this would be a good target for the RSI setup Nytro.

 

[Timeline]

These are by far the best resistors you can use. They are able to disapate the heat much easier, are much more durable and can be screwed down to a heatsink of some kind. I have used them in many tough applications to upgrade systems that have failed their engingeering specs. They are also much more accurate at a variance of only 1%. Most of the time the value you buy is the value that can be measured with a meter. The leads that come off them are very strong and should fit our application nicely.
Don't be fooled in thinking that the higher wattage uses more power like a light bulb. ( I think I read that somewhere on here before ) The higher wattage light bulb uses more power because of the resistance in it. A 100 watt light bulb has a resistance of 10 ohms and a 60 watt bulb has a resistance of 17 ohms.
In a resistor it's wattage rating is it's ability to disapate heat that is a by-product of resistance.
I will be using 25 watt resistors in my mod to lower the total resistance of the grip heater circuit.

http://www.sayal.com/ActionIndexP.asp?ID=28190

 

[Timeline]

Here is a better picture of those resistors. These are the ones I am using.

 

[arteeex]

Yep. These are better. Do they come in Blue?