Viper glider build

[grizztracks]

At least the YXZ uses Yamaha electronics. I've been looking at the sports shift version although I'm not dead set on sticking with Yamaha.

Dan, did you ever look at the secondary wrap to see if it could be backed off to drop rpm's and get it off the rev limit at takeoff ? If it's wrapped at 8-2 I'd back it off to 6-1 but if it's already at 6-1 I don't think you'll like a 3-3 wrap although you could try it before drilling out rivets to add more weight to the primary. If you need to add heel weight I'd call Call Chris Schmidt to see what he recommends for those Nytro fly weights.

 

[STAIN]

My Viper starts instantly every time now that I have added the UCAP. I actually just sold it to my neighbor and he loves it.

 

[yamakazie]

It was at 6-1. I backed it off to 3-3. Not sure I'll get to try it out this year

 

[Mills]

My Viper starts instantly every time now that I have added the UCAP. I actually just sold it to my neighbor and he loves it.

what is the UCAP? Why does it help starting?

 

[STAIN]

It is an ultra capacitor that sends 16volts to the battery when the battery is loaded
. Talking to a knowledgeable dealer a while back about the Viper starter problem. He agrees that it is poor ECU design and higher voltage to the starter is A cure. BUT he stated they updated the crank sensor pick up wheel in 17 to combat the cold start problem. They changed the spacing on the teeth to give a more accurate reading when the engine spins over slower during cold starts. The CAT ECU has a hard time telling top dead center when the engine is not spun over quick enough during cold starts. A lack of a cam sensor makes the problem worse as the ECU sometimes has to see a full revolution of the engine to determine TDC. Combine cold temps with a slower or inconsistent RPM when starting and the CAT ECU has a tough time getting the timing correct. I would like to see the difference between the 2 pick up wheels. He claimed you have to grind a little off the case away to make it fit in the older sleds.

 

[Ryno]

It is an ultra capacitor that sends 16volts to the battery when the battery is loaded
. Talking to a knowledgeable dealer a while back about the Viper starter problem. He agrees that it is poor ECU design and higher voltage to the starter is A cure. BUT he stated they updated the crank sensor pick up wheel in 17 to combat the cold start problem. They changed the spacing on the teeth to give a more accurate reading when the engine spins over slower during cold starts. The CAT ECU has a hard time telling top dead center when the engine is not spun over quick enough during cold starts. A lack of a cam sensor makes the problem worse as the ECU sometimes has to see a full revolution of the engine to determine TDC. Combine cold temps with a slower or inconsistent RPM when starting and the CAT ECU has a tough time getting the timing correct. I would like to see the difference between the 2 pick up wheels. He claimed you have to grind a little off the case away to make it fit in the older sleds.[/QUOTE

Are these for sale anywhere? Sounds like a good idea to have on these motors.

 

[STAIN]

There is a whole thread on these UCAPs

 

[grizztracks]

Great explanation. I will look for the thread.
Where can I get the capacitor as my '14 is degrading in its starting ability the more miles I put on it. The issue might be the battery being down on voltage so I think the first thing I am going to do is replace the battery. Having the UPCAP is a good belt and suspenders to this problem though.

Getting off topic here. Do a search for that info.

 

[rb2001srx700]

What an awesome project. I was wondering if there were any more updates on this. Also, there was a mention of using the sidewinder ECU? has this been done in a 2020 or newer Viper? Heading off to read about the UCAPS. Again, great read. Great job guys.