EXUP Removal

[john10toe]

Keep in mind that article about woody's sled had been modified in order to see those hp gains,this was not a show room stock sled,if you read dyno techs article,you see where they had to open up the pipe dia. from 35 to 38mm and in other areas plus advance the cam timing 5* to show those gains.

The 35mm head pipe to 38mm head pipe change is a OEM change that comes on all 2011 and newer Apex models. Also the 5* advanced cam timing is stock on the 2011 and newer Apex models too. Those were just references to items that have changed from the 2006 to 2010 models compared to the 2011 and newer models.

That is absolutely correct......the 2011 Apex was manufactured with those upgrades. At the beginning of the Dyno article it doesn't say it was a modified Apex it simply says it was "a preproduction 2011 Apex that Yamaha asked him to bring to DTR for evaluation." Continues to say "assuming that Woody's preproduction 2011 Apex is typical of production, the power numbers are amazing...." Regardless of peak horsepower I thought the most interesting graph was comparing the 2011 Apex to itself, with and without a functioning EXUP valve. Significant midrange horsepower gains with it working. I still say it is worth while keeping providing it is functioning correctly.

Below is a link to an article by Snowmobile.com describing Yamaha's EXUP.

http://www.snowmobile.com/products/insi ... -1178.html

 

[Millinocket Rocket]

Keep in mind that article about woody's sled had been modified in order to see those hp gains,this was not a show room stock sled,if you read dyno techs article,you see where they had to open up the pipe dia. from 35 to 38mm and in other areas plus advance the cam timing 5* to show those gains.

The 35mm head pipe to 38mm head pipe change is a OEM change that comes on all 2011 and newer Apex models. Also the 5* advanced cam timing is stock on the 2011 and newer Apex models too. Those were just references to items that have changed from the 2006 to 2010 models compared to the 2011 and newer models.

Yes, the way I understand it is, Woody came up with and did the mods to the new 11 Apex, and Yamaha took and built them all like that for the added HP....

 

[snowbeast]

Keep in mind that article about woody's sled had been modified in order to see those hp gains,this was not a show room stock sled,if you read dyno techs article,you see where they had to open up the pipe dia. from 35 to 38mm and in other areas plus advance the cam timing 5* to show those gains.

The 35mm head pipe to 38mm head pipe change is a OEM change that comes on all 2011 and newer Apex models. Also the 5* advanced cam timing is stock on the 2011 and newer Apex models too. Those were just references to items that have changed from the 2006 to 2010 models compared to the 2011 and newer models.

So Allen are you saying the 2011 -2015 models with esup exhaust now really do make 163 hp stock,that is show room stock? After reading AM snowshoot dyno reports on brand new ones right out of the crate they are all close to 150 hp according to them.

 

[Srxspec]

No, I'm not saying they make 163 hp stock, as they are very lean from the factory and this leaves HP on the table. Woody did not come up the modifications for the 2011 and newer Apex models, he simply drove the truck to the dyno.

 

[Millinocket Rocket]

Ok, must just be with his power up kit then. I know he adds fuel with a resistor in the airbox as part of his kit, geared down one and speed sheave, might be forgetting some other things too.