Dyno proof of v-boost?

[steamer97]

From specs I figure v-boost may gain 45-50 horsepower over non-v-boost (Ero vs. usa/Canada bikes). Does anyone have dyno results showing the different torque and HP of the same bike with v boost off, then on again (ran to redline) ?

 

[dmax1]

I am also wondering if changing the smaller v-boost on an 85 with the larger v-boost units from later years would net you any horsepower gains?

From specs I figure v-boost may gain 45-50 horsepower over non-v-boost (Ero vs. usa/Canada bikes). Does anyone have dyno results showing the different torque and HP of the same bike with v boost off, then on again (ran to redline) ?

 

[one2dmax]

Don't expect that kind of gain but it will be noticeable. I haven't tried to dyno verify the amount (never crossed my mind to try) but will do when we have our next event. My guess is around 10-15 HP on the upper RPM range (no change on the lower range).

 

[alorio1]

From specs I figure v-boost may gain 45-50 horsepower over non-v-boost (Ero vs. usa/Canada bikes). Does anyone have dyno results showing the different torque and HP of the same bike with v boost off, then on again (ran to redline) ?

No dyno but just a write up on the subject on this link;

http://www.vmaxoutlaw.com/tech/vmaxstory/vmaxhist.html

 

[dingy]

I dynoed my Venture with & without V-boost operating on same run setup and difference was 10 hp.

Gary

 

[thor_eyerdhal]

EU Vmax give 103 HP, (99 for later ones) at crank.
But this not only lack of Vboost :

-No vboost
-spacers on diaprhagms (cannot open more than 3/4)
-ignition curve with less total advance
-Small diameter exhausts

 

[steamer97]

Yes, I too have wondered what the later/larger tubes would do with the 1mm larger carbs. Prob. not much gain I suspect. With that thought, what year did the V-max start using larger carbs and tubes? And the Venture carbs, larger in some years than other years? I'm looking forward to real dyno readings, thanks all!

 

[alorio1]

Larger tubes on the 86, smaller exhaust ports on the muffler ends in 86 also. I have an 85 with stock exhaust and the exit port hole is 32MM. I have a set of 86 exhaust and the port holes are 31MM. theoretically someone with a 86 or later bike should just have to do the exhaust (drill 3/8" holes) mod and have more HP than the 85. As I understand it, the exit exhaust ports was the only thing that was modified on the exhaust and larger tubes for the intake manifold for the change. All tis was done to decrease the DB level (noise) to pass the emission test in US models. I could be mistaken on some of this info.....

 

[88Vmax]

theoretically someone with a 86 or later bike should just have to do the exhaust (drill 3/8" holes) mod and have more HP than the 85.

Wait.... wait... wait. I thought the 85 more horsepower thing was a myth??? Lol. Does the 85 have more hp?
And are the venture carbs bigger than the 86 vmax? I wonder if one would benefit from making slightly bigger vboost tubes with exhaust and carb upgrades to match?

 

[Traumahawk]

Its my understanding that the venture carbs are 1mm smaller than the Vmax carbs. All of the official literature says that the hp did not change from 85 on up.

 

[DMAN999]

The 1985 Yamaha Vmax had non-DOT approved exhaust canisters. This was corrected on the 1986 model and at the same time, (1986 model) the diameter of the VBoost tubes were increased from 30 mm to 32 mm. Allegedly, this was done in an attempt to make up the difference in the “loss” of horse power from the exhaust “correction”. I think it’s important to note right here and now that the rumor of the 1985 Vmax being the fastest model year ever made, is simply not true.

From here:
http://vmax.lvlhead.com/tips/vmaxhistory2.htm

 

[one2dmax]

83-85 venture carbs are 1mm smaller and will make more torque with a slight loss in hp. 86-93 are same size as the vmax so no power gain or loss with them (they don't have a standard choke provision though).

 

[jfeagins]

Wait.... wait... wait. I thought the 85 more horsepower thing was a myth??? Lol. Does the 85 have more hp?

Not sure about the HP numbers between different years, but I can say, unequivocally, the 85 color red is the fastest color ever produced! :biglaugh:

 

[marsmax85]

And the Bestest of color too ! :biglaugh:

 

[invalidsession]

My big bore, (1420cc) stage 7 and Kerker equipped 2007 Gen 1 has no noticeable vboost effect despite the fact it's enabled. However, it will light the rear tire in 3rd at 70mph and the oil light is lit all the way to well over 100mph at full throttle. Is there any real point to having the boost connected on my bike ?


Chris.

 

[marsmax85]

^^^ I want one !!

 

[one2dmax]

It's doing it's job but you are just accelerating through the transition so fast you won't feel it engage lol.

 

[AP76ita]

Hi I have a '91 EU 102hp
De-restricted by my mechanic. Carbs full open now huge increase of high end power and all band response.
Recently I tested a 145hp
It amazed me how fast and smooth reaches 9.5k rpm and lights oil light up, but in low rpm torque and throttle response it really disappointed me compared to mine

As far as you know is 102hp more optimized for low end torque?

EU Vmax give 103 HP, (99 for later ones) at crank.
But this not only lack of Vboost :

-No vboost
-spacers on diaprhagms (cannot open more than 3/4)
-ignition curve with less total advance
-Small diameter exhausts

 

[Parminio]

We get it. You have the most powerful Vmax on earth even though it's down 40 horsepower. It's the best by far. You win.

You can stop necroing 6 year old threads now.