Dynotech Reseach has the # on the 2011 Apex

[kviper]

I would say that most of the bike guys are indeed just squids and want to believe the pipe builders dyno charts.

I have got zero interest in looking at the pipe builders dyno charts as I have seen about ten different Supersport, Superstock and Superbike motorcycles (two with full World Championship factory support) on the dyno. In every single case, a well calculated and optimized exhaust system without EXUP (or similar device from other manufacturer) have out-dynoed any exhaust system with EXUP (or similar device from other manufacturer) at every rpm of interest (basically every rpm above idling) and in every possible load case, static as well as dynamic lap simulations. This is the reason why none of the race kit ECUs from any of the motorcycle manufacturers are equipped with connectors for the EXUP valve...
Then again, I am not saying that disconnecting the EXUP valve of the new Apex is going to be a success. Except for being obnoxiously loud and likely creating the all familiar "tach tango", the changed tune is likely going to mess up the fuelling and destroy the power band. But give any of the good exhaust system manufacturers like Akrapovic, Termignoni or Arrows a chance to calculate and optimize something, and I am damn sure they will out-dyno the stock exhaust by quite some margin - at every rpm and in every load case of interest. But what the hell do I know, I am just a squid...

One more time!!!! We are talking SNOWMOBILE'S, Totally different state of tune than a bike. Why do you think Yamaha had to retune the first RX motor from the bike world,Because it needed a very broad power band more than high end power or horse power as most would call it. I guess Yamaha didn't know what they were doing then either, we could have had 170 HP back in 03. You guy's will never get that a sled needs low and mid range torque way more than a bike. The 2011 Apex has been in the hand's of the after market people for a while now. Any one heard of a delete kit available yet?

 

[Carver]

The 2011 Apex has been in the hand's of the after market people for a while now. Any one heard of a delete kit available yet?

I'd say kviper has a good point

 

[KnappAttack]

But give any of the good exhaust system manufacturers like Akrapovic, Termignoni or Arrows a chance to calculate and optimize something, and I am damn sure they will out-dyno the stock exhaust by quite some margin - at every rpm and in every load case of interest. But what the hell do I know, I am just a squid...

When they get it done take it to Dynotech so it can be proven. To date, nothing has been done with the old 150 HP injected engine that improves power 1-2 HP over stock. Till then, its all a pipe dream!

 

[Rash]

In my opinion, the most of the hp gains on the new 2011 is due to bigger header, and advanced timing (5 deg) than the valves...

so new exhaust won't get more thant 2-3 hp more and will be too loud..

we'll see..

 

[Macheater]

ecopter I'm with ya on that one! Ok so everyone want's to debate the value of EXUP. EVERYBODY got what they wanted more horsepower.

BUT, if Yamaha REALLY wants to impress, they need to take the sled off of the Krispy Creme diet program. Get its weight down to somewhere even CLOSE to what the competition is then I'll be impressed. Notice I didn't say the same as, I said close. :exc:

 

[kviper]

I have seen light and it is not always better! I will keep what i have.

 

[kviper]

But give any of the good exhaust system manufacturers like Akrapovic, Termignoni or Arrows a chance to calculate and optimize something, and I am damn sure they will out-dyno the stock exhaust by quite some margin - at every rpm and in every load case of interest. But what the hell do I know, I am just a squid...

When they get it done take it to Dynotech so it can be proven. To date, nothing has been done with the old 150 HP injected engine that improves power 1-2 HP over stock. Till then, its all a pipe dream!

Exactly, A lot of people complained about 2 G'S for a Yam-Charger that gives 20 hp yet they will pay 6 to 7 hundred for an obnoxious sounding exhaust that may (benefit of the doubt) give 4 hp and close our trail's.

 

[SuperStroker!]

You are 100% correct Mike! Any one who has the train of thought that with a cvt transmission you don't need the low and mid torque that a bike needs is lost in the snowmobile performance world. The torque band of the four stroke is the reason a four stroke competes so well in the drag racing world!!!!!

Again, at WOT...where the DYNO graphs are done....YOUR APEX cvt does not stay at any given RPM other than 10500 for any period of time....like a bike would.

In order to "shift the clutches" (torque feed back) and provide the capability for the engine to reach 10500 RPM, the more torque the engine makes at the "low ratio curve" (remember, ground speed begins before the motor RPM reaches 10500 RPM, in other words the sled is moving, the clutches are engaged to the belt and the "tuneup" in the clutches is already under load converting static mass to moving mass) the more shift force (belt squeeze) can be applied to pull against the torque peak WHICH IS NOT 10500 RPM! The HP peak may be at 10500 RPM but this is where torque and RPM cross over to HP, based upon the constant 5252 and at that point and only that point do you want to see 10500 RPM...thats deep in the ground speed (velocity of the sled in MPH) against HP RPM at the top of the pull.

The reason Mike is faster than everyone else, with the same power, is because he understands that he needs to pull against and follow the torque peak RPM as it DYNAMICALLY MOVES and the heat changes the torque RPM DURING THE PULL. The torque and HP peak changes based on the load. The more agressive the 'tune up" and the harder the tune up pulls against the available torque the more combustion heat is generated and the TORQUE PEAK UNDER PULL rises during actual field acceleration against ground speed.

Torque at low RPM is just as important in acceleration run on a snowmobile CVT slipper as it is in a motorcycle gear slipper and/or a hand gear shifter.

Mike is correct IMO regarding the importance of torque and the value of torque in CVT clutching and he is also correct regarding the exhaust IMO. change the cam to provide more duration and the bottom suffers...like any other racing vehicle which needs to accelerate from a dead stop or is droping RPM significantly...torque, wider torque band at lower RPM will beat you every time!

 

[87gtNOS]

The reason Mike is faster than everyone else, with the same power, is because he understands that he needs to pull against and follow the torque peak RPM as it DYNAMICALLY MOVES and the heat changes the torque RPM DURING THE PULL. The torque and HP peak changes based on the load. The more agressive the 'tune up" and the harder the tune up pulls against the available torque the more combustion heat is generated and the TORQUE PEAK UNDER PULL rises during actual field acceleration against ground speed.

Torque at low RPM is just as important in acceleration run on a snowmobile CVT slipper as it is in a motorcycle gear slipper and/or a hand gear shifter.

Mike is correct IMO regarding the importance of torque and the value of torque in CVT clutching and he is also correct regarding the exhaust IMO. change the cam to provide more duration and the bottom suffers...like any other racing vehicle which needs to accelerate from a dead stop or is droping RPM significantly...torque, wider torque band at lower RPM will beat you every time!

This is correct and wrong.....

Mike (we'll use Mike for the example!) does not hold his Apex at 7000rpm and let it gain rpm at WOT as he is drag racing. That would be ridiculous.
I can however see him revving it to 9800 rpm and letting it shift to 10600 or so during the run.
In doing so, torque at 5000rpm is useless.

 

[SuperStroker!]

The reason Mike is faster than everyone else, with the same power, is because he understands that he needs to pull against and follow the torque peak RPM as it DYNAMICALLY MOVES and the heat changes the torque RPM DURING THE PULL. The torque and HP peak changes based on the load. The more agressive the 'tune up" and the harder the tune up pulls against the available torque the more combustion heat is generated and the TORQUE PEAK UNDER PULL rises during actual field acceleration against ground speed.

Torque at low RPM is just as important in acceleration run on a snowmobile CVT slipper as it is in a motorcycle gear slipper and/or a hand gear shifter.

Mike is correct IMO regarding the importance of torque and the value of torque in CVT clutching and he is also correct regarding the exhaust IMO. change the cam to provide more duration and the bottom suffers...like any other racing vehicle which needs to accelerate from a dead stop or is droping RPM significantly...torque, wider torque band at lower RPM will beat you every time!

This is correct and wrong.....

Mike (we'll use Mike for the example!) does not hold his Apex at 7000rpm and let it gain rpm at WOT as he is drag racing. That would be ridiculous.
I can however see him revving it to 9800 rpm and letting it shift to 10600 or so during the run.
In doing so, torque at 5000rpm is useless.

Of course not, he finds and follows and pulls against the torque (and that may be as low as 8500RPM at launch, not sure as I have not seen the dyno sheets) with the throttle wide open, as long as it continues to generate velocity (ground speed/acceleration). I guarantee he finds the the peak torque RPM out of the hole (which may peak at 8500 for example) and he pulls against the torque and follows it upward (allows the RPM to increase at the proper rate vs ground speed, attempting to follow the torque with the engines RPM and does this with the tune-up in the clutches) to the HP peak and if he's smart and I know damn well he is...he'll even over-run his 4 stroke past 10600 rpm (if the power is still capable of pulling the RPM up at full shift>>>two strokes are generally poor at this because the power drops like a rock past the peak) in the last 100- 200 feet (depending on the run distance).