Stage 4 Evo

[canuck5]

With my CAI, flash and resonator I'm seeing 16psi at elevation pulling 9200+ rpm in max loaded snow conditions I finally went through a belt after 1400km of deep riding.

 

[06yamahaapex]

I have a cr resonater and I'm a little worried about it running lean after reading this. I know cr says it's safe but how safe.

 

[Lund]

If your tricking it and it's adding air that it doesn't see that's where potential lean conditions will exist?

That is 100% correct
But the SW runs very much on the heavier side of the scale for lambda values.
This is much more of an issue with guy's back east, flatlander's, not so much mountain riders. This is why i alway recommend an O2 gauge mounted on your bar.
Eastern rider's are not recommended to use both pipe and cold air intake on the SW for that reason.

 

[Lund]

I have a cr resonater and I'm a little worried about it running lean after reading this. I know cr says it's safe but how safe.

You are safe, i have personally seen the number's my self. 13.4-13.5 on a wideband with CR's resonator pipe.

 

[06yamahaapex]

You are safe, i have personally seen the number's my self. 13.4-13.5 on a wideband with CR's resonator pipe.

13.5 at wot isn't that great? I like 12s on the viper?

 

[Lund]

13.5 at wot isn't that great? I like 12s on the viper?

Anything above 14.7 is considered lean. 12 is rich, the magic number is anything around 13-14 in the rough. If your racing or competing then you want to get as close as possible to 14.7 with out burning down. I have seen on my Nytro number's as high as 16+ and it lived, because i had it tuned on the margin.
Having your Viper at 12 you were actually losing power.

 

[06yamahaapex]

The viper always pulled better at 12 it seemed

 

[canuck5]

These 4 strokes have always seemed to like extra fuel and rpm Nytros were the same way.

 

[Lund]

The koso gauge is new to me , I will have to read the manual. It does not read vacuum , not sure if that has something to do with it

BTW, i personally don't recommend Koso to monitor your motor. They are ok, but you get what you paid for. Cheap or economical is not a good way to monitor such an expensive motor.
We use AEM professional performance gauges or Redline.
If that is not an option, Digitron make's a high quality gauge also but they also make an lower, economical gauge that i would avoid. You need to inform your self and what you pay generally will reflect the quality of the gauge with Digitron.

 

[DRD]

14.7 will produce the lowest emissions, not the best power, at least on anything I've ever had the luxury of tuning via wideband.

 

[Lund]

The viper always pulled better at 12 it seemed

These 4 strokes have always seemed to like extra fuel and rpm Nytros were the same way.

That could be, a lot has to do with real world condition's vs dyno run's. Either way, i just wanted to emphasize that your safe.

 

[roughriders]

BTW, i personally don't recommend Koso to monitor your motor. They are ok, but you get what you paid for. Cheap or economical is not a good way to monitor such an expensive motor.
We use AEM professional performance gauges or Redline.
If that is not an option, Digitron make's a high quality gauge also but they also make an lower, economical gauge that i would avoid. You need to inform your self and what you pay generally will reflect the quality of the gauge with Digitron.

should have added earlier this was with cr straight pipe. Air to fuel was 12.5 on wide open pulls. Gauge didn't seem cheap when I payed for it lol

 

[Lund]

14.7 will produce the lowest emissions, not the best power, at least on anything I've ever had the luxury of tuning via wideband.

That is true, most efficient is 14.7 anything above is dangerously lean, that is why 13-14 is safe yet efficient. You have to remember these are dyno runs done in shop and not at elevation. At 6,000ft i would expect to see richer numbers like 12 or high 12.
This is the reason we don't recommend pipe and cool air set up for low elevation riders.

 

[roughriders]

With my CAI, flash and resonator I'm seeing 16psi at elevation pulling 9200+ rpm in max loaded snow conditions I finally went through a belt after 1400km of deep riding.

Canuck is yours a 17 or 18. I was seeing 9050 rpm at 15psi. This on 18 with cr pipe. I was debating the Evo flash to

 

[canuck5]

17 and I'd highly recommend it

 

[skegpro]

You are safe, i have personally seen the number's my self. 13.4-13.5 on a wideband with CR's resonator pipe.

With a CAI?

 

[Lund]

With a CAI?

Winder
LOL, sorry misread that, don't have my glasses on.
Pipe and CAI.

 

[Tuesday]

Rode my sled for the first time with CR CAI and evo stage 4, loved it. Revy with 3+ft of fresh snow and it was rocking. Redline also helped me out with clutching seems to be right on the money. Pulling around 16-16.3lbs boost at 9300 ish RPMs. Also running CR straight pipe. Probably switch out to a redline pipe as the straight pipe is pretty loud on the trail. Up top in the deep it sounds awesome IMO.