Dynotech Reseach has the # on the 2011 Apex

[Ike]

http://snowmobiles.yamahablogs.ca/

Ike

 

[2001srx=fast]

most hp made at 9000 rpm?

 

[grader]

the 9000 rpm refers to clutch rpm after the gear reduction. engine rpm would be aprx. 20% higher at 10800 rpm.

 

[kviper]

kviper, do we have a 2011? No, so who really cares...let them guys figure it out.

But on a motorcycle, at 7000 rpm, and you go WOT, it STAYS at 7000rpm....and these guys are removing the EXUP....I guess they don't know what they're doing!!

7000 on a bike may be a bad example...because in most applications, the valves are fully open above 6000 rpm.
I am betting that the valve is open on the sleds above 6 or 7000 rpm too.

I must add, I do have a Yamacharger.

I guess if you don't care you should not post on this topic because it is in reference to 2011 hp number's and i am very aware of the difference's between bikes and sled's and the history. Bottom line here is the valve makes a much broader power band and that is big in the centrifugal clutching world like it or not.

 

[sx7001]

kviper, do we have a 2011? No, so who really cares...let them guys figure it out.

But on a motorcycle, at 7000 rpm, and you go WOT, it STAYS at 7000rpm....and these guys are removing the EXUP....I guess they don't know what they're doing!!

7000 on a bike may be a bad example...because in most applications, the valves are fully open above 6000 rpm.
I am betting that the valve is open on the sleds above 6 or 7000 rpm too.


I must add, I do have a Yamacharger.

I guess if you don't care you should not post on this topic because it is in reference to 2011 hp number's and i am very aware of the difference's between bikes and sled's and the history. Bottom line here is the valve makes a much broader power band and that is big in the centrifugal clutching world like it or not.

The 2011 Apex has different primary clutching than previous. Heavier weights and less spring that will keep the rpm down longer. This is the purpose of EXUP,it produces a stronger and broader power curve. If you take out the EXUP the stock clutching will not work and the sled will slow down. Engagement on my 2011 is 3000 rpm, very low. Don't waste your money on the aftermarket crap that will promise more power. Your wallet will be lighter and your sled slower.

Larry

 

[cacsrx1]

Wow, somebody better get Yamaha on the horn and see if they will put a catalytic converter in there somewhere, it complements the EXUP nicely.....when hung on the wall.

 

[kviper]

DynoTec did the unbiased testing, Call them and tell them they are full of shi$$. This is not the same motor as the bike's and it is not a bike. LOL! I have wasted enough time on this.

 

[cacsrx1]

DynoTec did the unbiased testing, Call them and tell them they are full of shi$$. This is not the same motor as the bike's and it is not a bike. LOL! I have wasted enough time on this.

I dont think anybody is disputing the numbers. It is however, retarded to think the newfound power is a direct result of the EXUP and not the redesigned head, altered cam timing, and longer Vstacks.

 

[tomanytoyz]

The torque is like a diesel engine compared to those 2-smokes! YAMAHA #1

 

[kviper]

DynoTec did the unbiased testing, Call them and tell them they are full of shi$$. This is not the same motor as the bike's and it is not a bike. LOL! I have wasted enough time on this.

I dont think anybody is disputing the numbers. It is however, retarded to think the newfound power is a direct result of the EXUP and not the redesigned head, altered cam timing, and longer Vstacks.

I don't recall any one saying all of the new found power was from EXUP but it would be retarded to look at the dyno sheet's and say the low end and mid range Gaines are not largely due to EXUP, And please don't tell me that a snowmobile is run at WOT 100% of the time, If you believe that than you are leaving a lot of your sleds performance on the table.

 

[kinger]

I dont know what your trying to argue, thing thing has a ton of changes and it makes better power that is what we want right?

Let the aftermarket dyno guys see if they make more power with eliminating the EXUP.

 

[dynotechjim]

you guys who have not read the tech sidebar by Kevin Cameron in my article don't understand Exup. It's only designed to add torque and hp at low-midrange RPM--when it opens it's straight through like an open collector. When it's closed, choked down at low-mid RPMs airflow CFM is INCREASED, and power is higher.

 

[kviper]

Safe to say the head, cam timing and intake runner change is responsible for the high end HP but you usually loose low to mid torque from these changes and with the EXUP you get the low and mid back in a very healthy manner. Thanks for your in put dynotechjim, Nice to hear from someone who understands what is going on.

 

[**sj**]

exup is the real deal for the 4holer...what that sled was missing is bottom end.....and this is the equivalent of rave valves for a 2smoke doo...anyone trying to convince you on the improvements of removing is selling you snake oil..big difference between a bike with a gearbox and a sled with a cvt boys!

 

[87gtNOS]

l..big difference between a bike with a gearbox and a sled with a cvt boys!

Yeah...you whack the throttle at low rpm on the bike and what happens??..it stays at LOW rpm!!

Whack the throttle at low rpm on your sled....and instant HIGH rpm!

Where would the EXUP valve be most helpful????