Why does the 1985 VMAX has so much HP?

[corkman]

Why does the 1985 VMAX has so much HP, as opposed to the later models, like the 1999 model that I have for example?
Is there anything I can do to my 1999 model to increase the HP to closer to the 1985 model?

Thanks,
Bill

 

[blaxmax]

No difference. It has all been compensated for through the years.
As far as trying to make faster try a stage 7 kit.

 

[Traumahawk]

1st...Have you ever dyno'd yours to see how much HP yours makes? 2nd.....do you know the story BEHIND dynojet using a 1985 Vmax to calibrate their dyno?

One of the biggest headaches of Dynojet's go-it-alone chassis-dyno project was figuring out how to assign meaningful power numbers in the face of unknown inertia from the moving parts of the hundreds or thousands of engine, drivetrain, and tire combinations. Wrestling to fully understand inertia and powertrain losses, Dobeck and his team quickly realized that the standard physics formula of weight, time, and distance for converting acceleration into horsepower simply didn't work-the derived number was always lower than accepted numbers. They poured on resources and burned up time and money investigating it, but no matter what they did, the math never added up.
Dynojet's final number-fudge was arbitrarily based on a number from the most powerful road-going motorcycle of the time, the '85 1,200cc Yamaha VMax. The VMax had 145 advertised factory horsepower, which was far above the raw 90hp number spit out by the formula. Meanwhile, existing aftermarket torque-cell engine dynamometers delivered numbers that clustered around 120. Always a pragmatist, Dobeck finally ordered his Chief Engineer to doctor the math so that the Dynojet 100 measured 120 hp for a stock VMax. And that was that: For once and forever, the power of everything else in the world would be relative to the '85 Yamaha VMax

http://www.hotrod.com/how-to/engine/113-0603-dynojet-chassis-dyno/#ixzz2MhR1YRCm

To make good HP out of a stock Vmax, it has to be tuned well, and set just right. The floats need to be at 17mm. (Which is on the lean side)....and the Vmax likes to run lean. Really as close at 14.0-1 as you can get for an A/F ratio.

A member on here....Jim, has an original 1985 Vmax that he bought brand new, and I believe that it dynod at 115 hp all stock. Dmann (Dennis) has an 03, that all stock dynod at 119, on 3 different dynos. My 07 stock....was 104. When I sent my carbs to Dannymax for a rebuild, he said that my flaot levels were probably around 12 mm.....and thats from the factory, the carbs had never been gotten into.

So, make certain that the floats are set at 17 mm.....make certain that everything else is in good tune, and it should be good enough. People on here have taken stock Vmax's.....and the usual hp is between 105 and 115. A lean float setting will really help you out though.

 

[blaxmax]

(To make good HP out of a stock Vmax, it has to be tuned well, and set just right. The floats need to be at 17mm. (Which is on the lean side)....and the Vmax likes to run lean. Really as close at 14.0-1 as you can get for an A/F ratio. )LEAN? How about right on?
(So, make certain that the floats are set at 17 mm.....make certain that everything else is in good tune, and it should be good enough. People on here have taken stock Vmax's.....and the usual hp is between 105 and 115. A lean float setting will really help you out though). LEAN? How about right on?

 

[CaptainKyle]

It is always fun hearing about the 1985 Myth. I love the stories I here:rofl_200:

 

[rusty]

It is always fun hearing about eh 1985 Myth. I love the stories I here:rofl_200:

Yep, total myth :rofl_200:

 

[blaxmax]

A total myth ---BUT---- a better start than most---
Why? Because the '85 is like no other.
If you add the larger vboost manifold from later manifolds (2mm larger) will more gas flow? Larger venturi's-----HUH?:ummm:
The exhaust was changed in '86 why? It did not meet the standards- hell give me one of those '85's please!!! Too loud---ahhhhhh.:rofl_200:
Some manuals even state the carbs from the '85's were 34mm and others were 35mm.
I have yet to find a 34mm set from a Vmax (many from a venture though) (wouldn't interchange them) but if '85's had 34mm and you added 35mm
well what can I say.:clapping:
Myth but well just my observation and my own experience.

 

[Traumahawk]

(To make good HP out of a stock Vmax, it has to be tuned well, and set just right. The floats need to be at 17mm. (Which is on the lean side)....and the Vmax likes to run lean. Really as close at 14.0-1 as you can get for an A/F ratio. )LEAN? How about right on?
(So, make certain that the floats are set at 17 mm.....make certain that everything else is in good tune, and it should be good enough. People on here have taken stock Vmax's.....and the usual hp is between 105 and 115. A lean float setting will really help you out though). LEAN? How about right on?

Well "right on" by Yamaha standards is 15-17 mm, as per the book, with 15 mm being rich, and 17 mm being lean. So 15, 16, or 17 is acceptable....but the Vmax for most hp likes 17.

 

[blaxmax]

Right on by me would not be lean. IMPO

 

[Traumahawk]

Right on by me would not be lean. IMPO

Look at this thread by Mark.

http://www.vmaxforum.net/showthread.php?t=17274

 

[blaxmax]

Look at this thread by Mark.

http://www.vmaxforum.net/showthread.php?t=17274

I could care less ---
I have stock pipes (drilled) and larger than stock mains,larger paj1 & paj2- shorten springs, hand sanded stock needles, my own risers under my needles, degreed my own cams with my hand turned slotted sprockets with my own cops I built and It runs to MY own SATISFACTION---
Forgot to mention the larger vboost.

 

[Traumahawk]

I could care less ---
I have stock pipes (drilled) and larger than stock mains,larger paj1 & paj2- shorten springs, hand sanded stock needles, my own risers under my needles, degreed my own cams with my hand turned slotted sprockets and It runs to MY own SATISFACTION---

And thats ok.

 

[blaxmax]

I have yet to own a slower motorcycle than a vmax. And that's ok.

 

[Bill Seward]

The best way to get a really powerful '85 is to get a red one..

 

[blaxmax]

That's it----I'm off to the paint store.

 

[schudaddie]

The best way to get a really powerful '85 is to get a red one..

glad I got my red one. first one in town. #874 :eusa_dance:
later, bill

 

[jinks]

I owned a bone stock 1985 , and now I own a bone stock 1998. The 85 pulled harder on the

top end by far. Why..who knows. Nothing done to either one. RED 1985 GREEN 1998

 

[DMAN999]

My stock 2000 pulled 118-119 RWHP on 2 different dyno's and Leecifer's stock 2000 pulled 118-121.
So as far as which year has the most HP I'd have to say they are all capable of good numbers but so far the stock 2000's have put out the best numbers I have seen.


And I may be slightly Biased But IMHO Green is the fastest color because Red means Stop, Yellow means slow down and Green means Go.......... !!!!!!!!
unk: :biglaugh: unk:

 

[The Beekeeper]

Maybe the fact that Lees 2000 was a Canadian bike says somthing, those Krazy Knooks got those long hard winters to get their **** right!.........:biglaugh:.........Tom.

 

[blaxmax]

Fastest one I've ridden was Dragmaxster's stock '87 canadian -----red.:clapping: