Dynoed a stock Attack today!

[ReX]

One question I've always had is why not correct the hp to riding temperatures (freezing or slightly below).

In reality our sleds are making more than the dyno numbers in the real world because the power goes up as the temperature goes down (assuming it's jetted correctly).

I seem to remember looking up the correction factors and finding 137 hp turns into a real 145 hp a little below freezing.

 

[Roadrunner]

One question I've always had is why not correct the hp to riding temperatures (freezing or slightly below).

In reality our sleds are making more than the dyno numbers in the real world because the power goes up as the temperature goes down (assuming it's jetted correctly).

I seem to remember looking up the correction factors and finding 137 hp turns into a real 145 hp a little below freezing.

Good point, but the other thing to remember is that the temperature under the hood is higher than the outside temperature.

 

[Mighty]

One question I've always had is why not correct the hp to riding temperatures (freezing or slightly below).

In reality our sleds are making more than the dyno numbers in the real world because the power goes up as the temperature goes down (assuming it's jetted correctly).

I seem to remember looking up the correction factors and finding 137 hp turns into a real 145 hp a little below freezing.

Good point, but the other thing to remember is that the temperature under the hood is higher than the outside temperature.

Not if you run some type of ram air. With this, fresh cold air is shot straight into the throttle bodies

 

[87gtNOS]

Listen guys, lets not get caught up in correction factors.
I have been through this on HCS a million times...seems some SHOPS like to overcorrect their dyno numbers or manipulate them. I have about 6 long threads on HCS and Dootalk I could reference, but TY is not about all that crap.

Believe Freddie. He is not trying to sell overinflated HP figures.

Freddie, I hope, is here to show us GAINS...who cares what the base HP was. Let's see the gains!

Thank you freddie for helping us here in TY.

Jonathon
aka...HCS dynosheet sh it disturber.

 

[dirkdiggler]

Not sure if any of you had your title or Ship document from Yamaha on your old RX-1 but mine showed 138hp. My Attack Title showed 149.5.

Dyno tech has dynoed the Apex at 150 hp and they use a Super Flow which is one of the best dynos on the market. They also Dynoed Excel Motor Sprots Attack with his exhaust and showed over 150 HP.

Just becuase freddies Dyno shows 139 or what doesn't mean it's not 150. Maybe Freddies Dyno reads low!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Don't get caught up in the numbers. A well tuned Apex drills a well setup RX-1 from what I've seen on the lakes so far. That includeds Filtered RX-1's

 

[yammiman]

That is all I need to know - the two dynos I seen were the ones dirk is refering to - now I get!

 

[QCRider]

The fact that the Apex is significantly faster than the RX-1 is due to a few things, not just a little more hp. If hp were the only key then an Apex could NEVER hang with a Mach Z, and many people here have said that they do. Don't forget the 2.2 lb lighter crank in this discussion.

Also, if you look at what Freddie said, his Dyno is quite accurate and he is not saying that others are not. What he IS saying is that they use a "Correction Factor" which can be anything that they want to enter. It's all about who is doing the testing and what it is that they are trying to sell you. Freddie is doing this to see what improvements he can make, so he doesn't care about some adjusted hp number.

 

[dirkdiggler]

The fact that the Apex is significantly faster than the RX-1 is due to a few things, not just a little more hp. If hp were the only key then an Apex could NEVER hang with a Mach Z, and many people here have said that they do. Don't forget the 2.2 lb lighter crank in this discussion.

Also, if you look at what Freddie said, his Dyno is quite accurate and he is not saying that others are not. What he IS saying is that they use a "Correction Factor" which can be anything that they want to enter. It's all about who is doing the testing and what it is that they are trying to sell you. Freddie is doing this to see what improvements he can make, so he doesn't care about some adjusted hp number.

Do you know anything about Dyno tech? They publish a Magazine and have a web site dedicated to Dynoing. They have been Dynoing the Amsnow and now the Snow week shoot out sleds for years. they are very reputable.

Like I said earlier maybe Freddie's Dyno shows lower numbers.

As far as the Theory of lighter crank being the reason the Apex is faster I'd have to disagree. One of the reason the RX-1 shows higher torque number s down lower is directly related to this. Torque is what moves you out of the hole. The trade off of a quicker reving sled is that it will make less torque on the bottom.

 

[ReX]

Or the particular Attack that was run on the dyno could make a little less power than some of the others. I don't know what the hp variations are from sled to sled but there must be some variation.

As far as the Apex being significantly faster than RX-1's, my experience shows they are pretty close. With only a clutch kit my RX-1 beats a friends Apex ER more than half the time (and so far always beats the Apex in high traction conditions). The sleds are so close, even on top, that they can be considered identical. We've stayed side by side for miles running WOT. Maybe his is a little slower than others? I don't know. It's 100% stock (except for 144 gold diggers).

My sled has over 14,000 kms on it; his has just under 3000 kms on it.

 

[fourload]

Freddie, I have the first Dynotech test of the Apex in front of me.The motor had 0 miles and was run on 87 octane pump gas.The air temp was 59 degrees and they don't state much about baro or humidity. They got 148.1 corrected horsepower at 10700rpm with a fuel flow of 67.9 lbs/hr and a BSFC of .49.If you divide the fuel flow by the BSFC you get the actual hp.Am I correct in saying this??If so they got a actual hp of 138.57.This is right in line with what you got.Thanks for your no BS hp figures.I would also like to see what the mach z and firecat would do on your dyno.Bet their heads would be deflated too.

 

[TT670]

One question I've always had is why not correct the hp to riding temperatures (freezing or slightly below).

In reality our sleds are making more than the dyno numbers in the real world because the power goes up as the temperature goes down (assuming it's jetted correctly).

I seem to remember looking up the correction factors and finding 137 hp turns into a real 145 hp a little below freezing.

This is where the "correction factor" thats being discussed is used, Freddies numbers are after the math is done. HP is HP, it dont matter if its 10 deg or 100 degrees or at sea level or 10,000 feet, once corrected it all washes out.

 

[dirkdiggler]

One more question for Freddie. Did you know the gear reduction Ratio is different in the Apex then the RX-1??

 

[ReX]

This is where the "correction factor" thats being discussed is used, Freddies numbers are after the math is done. HP is HP, it dont matter if its 10 deg or 100 degrees or at sea level or 10,000 feet, once corrected it all washes out.

But it does matter to the rider. Since the actual output HP changes with temperature, the sled is quicker in colder weather. If we are riding a machine that produces 140 hp at 70°F, but we always ride it in conditions where it makes 145 hp we've actually got 145 hp on tap when we want it not 140 hp.

We still need to correct the hp to a certain condition so we can compare sled to sled in a standard set of conditions - all I'm saying is why not correct it to 20 or 30°F for sleds instead of 70°F or whatever is typically used.

 

[87gtNOS]

Freddie, I have the first Dynotech test of the Apex in front of me.The motor had 0 miles and was run on 87 octane pump gas.The air temp was 59 degrees and they don't state much about baro or humidity. They got 148.1 corrected horsepower at 10700rpm with a fuel flow of 67.9 lbs/hr and a BSFC of .49.If you divide the fuel flow by the BSFC you get the actual hp.Am I correct in saying this??If so they got a actual hp of 138.57.This is right in line with what you got.Thanks for your no BS hp figures.I would also like to see what the mach z and firecat would do on your dyno.Bet their heads would be deflated too.

LOL!, so many Dynotech runs are corrected like this!! 200hp MachZ's when uncorrected it's only 190hp!! That's only 5%, which may be ok, but it's actually the fact that 200 sounds better than 190!!!

F7's making 153hp, but when uncorrected are 144hp, etc....

It's all about selling HP. HP=$$$

Yes, If you divide the fuel flow by the BSFC you get the actual "observed" hp.

Correction factors should only equate to around 2% on average.

 

[dirkdiggler]

I was just looking at the Amsnow Dyno Sheet on the Apex. They claim it made 149.8 at 10100 RPM. If you take 149.8 * 5252 /10100 you get 77.8 which is exactly what they show for Torque.

So there numbers are correct by the calculation as well!!!!!!!!!!!!!!!!!!!!!!!!