JBS & Hunterworks sheave testing tuned by Dynojet.

[InfidelMT]

Finally got around to installing the JBS extreme sheave Version 2 and tuned by Dynojet locally at headquarters. I will be testing both sheaves and reporting results from both. The YXZ and my X2 are the first to be tuned by Dynojet.

Initial conditions:
1. JBS extreme sheave version 2 with 18 gram weights with shim installed.
2. Hard pack dirt road.
3. 10 PSI in all 4 tires 27x10x14 which are not light at 38lbs each.
4. >4000ft elevation.
5. ECU tuned by Dynojet locally with Power Vision.
6. Full cab and windshield.
7. Top speed 64mph

My first impression of the JBS sheave. The bottom end through mid range is wicked fast. Pulls very very strong. Low range and mid the RPM's are noticeably higher then stock just cruising around at low mph. Not a big deal but it is somewhat louder. I think I could have easily pulled a few more MPH airing my tires up to 18psi and fine tuning it at Dynojet on the Dyno. So I'm guessing top end of 66-67mph could be attainable very easily.

Now that it is installed I will take it back to Dynojet have them run it on the Dyno and fine tune to post final results. I have purchased a Hunterworks sheave as well with 20 gram weights and will be doing the exact same testing and will post the results of both. I'm not biased to either JBS or Hunterworks. Both make an outstanding sheave which is way better then stock. It all is going to depend on my riding style which sheave I end up with.

Just some of the features of Dynojet's Power Vision. Coming soon.. It is not released yet to the general public.

Speed limiter is gone

Fan activation is 10 degrees cooler

Injector pulse width is kept through the range

All monitoring of everything on the Yamaha BUS (injector pulse width, RPM, Vehicle speed, accelerator position, throttle position, ignition timing, coolant temp, air temp, intake air pressure and gear (H,L, N and R).)

Full ignition and fuel maps through the whole rev and speed range (can also set a target air fuel ratio based on stock wide band O2 sensor in the exhaust for these tables)

Rev limit increased by 500 RPM

O2 sensor monitoring

Drive by wire mapping through whole rev and speed range

All of these are user configurable too through power vision. RPM, Speed Air fuel ratio, fan engagement temps, etc. All plug and play. This is going to be a game changer with the ability of fine tuning our X2/X4's. Dynojet has and will be the leaders in tuning when it comes to powersports. Wide band with O2 will also be available in the near future with autotune.

https://youtu.be/YTvPYQaAlfI





Sent from my iPhone using Tapatalk

[InfidelMT]

James you need to send me some 20 gram weights so I can test both sheaves equally on the dyno. As I believe 20 gram weights I'd have a little better cruising speeds with lower RPM's rolling the dirt roads swerving like I'm George Jones. lol In any regards impressive clutch. 64 mph wasn't bad. Pulls like a rocket off the bottom end. I think airing my tires up from 10 to 18 and some more tuning with 20 gram weights I believe 68-70mph is possible.

[Timmi]

James has tested with 26, 28, 29, and 30 inch tires but not 27. He showed 7900 rpm with 28's at 63 mph. I have 27 on mine but no adventure pro to show rpm.

[InfidelMT]

James has tested with 26, 28, 29, and 30 inch tires but not 27. He showed 7900 rpm with 28's at 63 mph. I have 27 on mine but no adventure pro to show rpm.

Yeah in my case I believe 20gram is the ticket. RPM's are too high.

[Timmi]

My goal is 29" Bighorns on my X2. I don't ride much road so I will go lighter than 20.

[InfidelMT]

My goal is 29" Bighorns on my X2. I don't ride much road so I will go lighter than 20.

Yeah in your case you should be fine. However with mine running 64mph @ 8600 RPM's is way too high. My only thought is running 20 gram weights and having it tuned on the dyno. I'd like to see more like 7800-8000 at 64mph.

[Timmi]

you need larger diameter tires

[InfidelMT]

well larger tires isn't happening. I'm already running way larger then stock with 27x10x14's. It feels like I'm in low gear when in high. So running 20 grams maybe the ticket?

[Timmi]

the weights won't matter when they are run all the way out, the only way to change gearing ratio is in the sheaves, the tires or new diff gears

[InfidelMT]

Yes I understand the weights won't matter on full shift out and top speed. However just cruise speed say 30 or 45mph it does matter. Heavier the weight the lower RPM's you have. NO disputing that. I'm fully aware the gear ratio is what it is.. I'm also not putting on 28"-30" tires. I'm running with what I have.