ECU

[4StrokeAddict]

Now this is entering my wheel house a bit. You guys haven't noticed any hardware differences between the ECUs have you? If not, flash on!

 

[cannondale27]

It's for the speedo. No big deal but speedo will be off depending on base flash

 

[NOS-PRO]

Now this is entering my wheel house a bit. You guys haven't noticed any hardware differences between the ECUs have you? If not, flash on!

No, all the ECu's look exaclty the same.

 

[NOS-PRO]

It's for the speedo. No big deal but speedo will be off depending on base flash

This will be interesting to see this year.

 

[cannondale27]

Yea. On the cats there is different number of magnets in some. Not as accurate as ours but option. If I remember right some had half what we have.

 

[Mtnviper]

Cannodale27 is correct. On the 7000's, they have a full set of magnets on the end of the drive shaft as well. The signal goes directly to the ECU and the pulses per mile is calculated out based on the base programming in the ECU. From there the speedo/odometer data is sent to the gauge via a data communication line. This is similar to how it works on other EFI Yamaha models as well!

The 2 stroke Cats use different amounts of magnets on the end of the drive axle. In this case the VSS signal is sent directly to the gauge for decoding and converted to speedo/odometer readings. 2 Stroke Yamaha's use a similar system, only instead of magnets on the end of the drive axle they use a reluctor wheel that has "teeth" for the VSS sensor to read.

 

[cannondale27]

Cannodale27 is correct. On the 7000's, they have a full set of magnets on the end of the drive shaft as well. The signal goes directly to the ECU and the pulses per mile is calculated out based on the base programming in the ECU. From there the speedo/odometer data is sent to the gauge via a data communication line. This is similar to how it works on other EFI Yamaha models as well!

The 2 stroke Cats use different amounts of magnets on the end of the drive axle. In this case the VSS signal is sent directly to the gauge for decoding and converted to speedo/odometer readings. 2 Stroke Yamaha's use a similar system, only instead of magnets on the end of the drive axle they use a reluctor wheel that has "teeth" for the VSS sensor to read.

I wonder if removing magnets would work to get a out of spec speedo closer? Or Evo can just use the base tune model specific.

 

[Mtnviper]

I looked into it, however the magnets are alternating north and south poles. Apparently when you remove them, the ECU detects the missing poles and sets a trouble code.
Probably the best option would be to have EVO program it base tune specific like you mentioned. Last fall when I swapped out my 8 toot driver's for 7 tooth's, I checked with the dealer to see if they had reprogramming available for driver swaps, however none was available at that time.

 

[cannondale27]

I looked into it, however the magnets are alternating north and south poles. Apparently when you remove them, the ECU detects the missing poles and sets a trouble code.
Probably the best option would be to have EVO program it base tune specific like you mentioned. Last fall when I swapped out my 8 toot driver's for 7 tooth's, I checked with the dealer to see if they had reprogramming available for driver swaps, however none was available at that time.

How far off was speedo after swap? In your case it would read faster than before I assume.

 

[Mtnviper]

How far off was speedo after swap? In your case it would read faster than before I assume.

Yeah, it's approx 12% faster if I remember correctly. I use to have a handy dandy interactive spread sheet where I could just plug in the different driver diameters and it would automatically do the calculations for you. I think I lost it when my old lap top crashed though. I posted it in this thread http://www.snowest.com/forum/showthread.php?t=381426&highlight=driver on SW but I can't seem to open it with my new computer I guess I'll have to do some digging!

I'm not to concerned about the speedo reading fast because I don't use it much mountain riding. I would like the odometer to be accurate though, mainly so it doesn't clock up more miles then what the sled actually has and effecting the re-sale value.

 

[4StrokeAddict]

Seamed to me like my speedo was pretty much spot on last year to my GPS. I think I was within a 1-2mph across the range. How far off are you guys?

 

[NOS-PRO]

My turn to chime in.... When I setup for asphalt last year (2014) I ordered a new Cat drive axle from a 2012 XF because it had the 2.52 pitch drivers I needed for the asphalt track. The axle came with only 2 magnets in, 180° from another. I tried it and my speedo said 25mph when I went thru the finish line and my timeslip said 107mph. This year I bought the extra magnets and put them in the same way (which I thought by checking the original shaft) but still, the speedo reads 30mph at the finish line.

Shagman popped out his plastic end with the magnets and switched it over to his drag axle for asphalt and was reading good numbers.

So, yes....I think we have a ton of room to adjust the speedo with magnet polarity.

 

[picasso]

My 2015 viper is reading around 6 mph slower than my Gps and our other 2015 viper. Odometer and both trips are also 25-30 miles less than other sled. I've zeroed them at the same time. Any ideas? Other sled yesterday read 110 miles, mine red 82. Zeroed them at the trail head side by side.

 

[cannondale27]

My 2015 viper is reading around 6 mph slower than my Gps and our other 2015 viper. Odometer and both trips are also 25-30 miles less than other sled. I've zeroed them at the same time. Any ideas? Other sled yesterday read 110 miles, mine red 82. Zeroed them at the trail head side by side.

Get it flashed again

 

[Happyhours]

Mine speedometer reads 5mph faster than gps. It has never been flashed and is a 2016 xtx.