'Splain me this! (Vboost)

[coffee_brake]

Would someone out there who knows better, please explain to me about the Vboost? What I understand:

The Vboost is a system that allows more air to enter the carb system at 6k rpms by opening more butterfly valves that are closed the rest of the time.

Now, how does it work? Is there a sensor hooked to the tach? Is it manual or electric-assist? What opens those butterflies in the carbs? I saw some folks installing an electric switch to make it a manual system, and I saw some others installing friction cables to do the same thing.

If there's a succinct explanation that I missed while searching, please just point me there....

 

[82ndCowboy]

The Vboost is a tube with butterflies between the manifolds on each bank.
When you hit 6000 rpms, the butterflies are opened via a servo motor that is electronically controlled.
When the butterflies are opened each cylinder is pulling air/fuel mixture from both carbs instead of just one when the butterflies are closed.

 

[coffee_brake]

So...each cylinder gets a carb, but at 6k rpm, each cylinder gets two carbs' worth of fuel and air?

How does that not foul the plugs? The jetting must be a nightmare.

Is the servo motor prone to failure?
Are the mods for putting a switch or cable on the Vboost hard on that motor?
Is there a downside (other than bad fuel economy and speeding tickets) to controlling the Vboost manually?

Why doesn't this system exist elsewhere on other models?

 

[richwrench]

At 6000 + rpm's the engine is flowing enough air that the mixture is right on - nothing but a rush of power similar in feeling to a turbo. The kits that kick v-boost in at 3000 rpm acually make the bike run too rich & you loose horsepower if you check it on a dyno. Some people like it anyway because of the "seat of the pants" feeling you get at that rpm. I tried it & didn't like it so I removed it. Others have tried it & love it so they keep it. To each his own I say. I haven't seen a huge number of posts where people have problems with servos or what-not. Probably too much slack in the cable is the biggest problem - no big deal - easy to adjust if the carbs are off. I believe Yamaha has a patent on Vboost, but I'm just relying on memory - don't quote me on that. What I DO know is that my VMAX is waayyyy faster than my buddies V65 Sabre with no boost...:biglaugh:

 

[82ndCowboy]

Rich is right.
It's a personal choice.
I personally think Yammy got it right when they designed the vboost the way it is and works the best as stock.
There is the Tboost Switch mod that allows you to change the rpms from 6000 to 3000 and off completely with a small toggle switch.
Then there also is a sassy vboost controller that allows you to set it at a lot more settings, including always on.
And then there are some that just unplug it when it is in the open position and leave it open all the time.
I tried that just to see what it was like. It was fun, but millage suffered just a little and I kept spinning the rear tire on corners, which was kinda nerve racking when I wasn't ready for it. Plus I ride in all kinds of weather, so wet roads and vboost always on = increased risks.
So now I'm happy with the stock setting.
But that's me. I'm not out to push the limits. I just love riding, any where and just about any time. As long as the temp is above 50 degrees.

 

[coffee_brake]

OK so basically...don't mess with it.

I've hit 6k rpm several times within the first few days on mine, a few times I didn't realize it and I was not in a good place to have lots of extra speed piled on, like leaned over in a curve or scooting through heavy traffic. I love the all-rpm-torque on this bike, but there are times I can see the benefit of turning off that feature so there are no surprises.
Granted, most of my commuting and curvy roads riding has been on inline-fours, where if you want power you rev it high-high-high...so it may just be my learned riding style. Maybe I need to learn what 5.5k feels like and keep it there in the city and on the tight twisties.

Thanks!

 

[maxcruiser]

So...each cylinder gets a carb, but at 6k rpm, each cylinder gets two carbs' worth of fuel and air?

How does that not foul the plugs? The jetting must be a nightmare.

Is the servo motor prone to failure?
Are the mods for putting a switch or cable on the Vboost hard on that motor?
Is there a downside (other than bad fuel economy and speeding tickets) to controlling the Vboost manually?

Why doesn't this system exist elsewhere on other models?

You have the vboost concept down now.

As far as plug fouling, etc... the carbs are actually smaller in size than a standard 1200cc 4 cylinder bike motor , but makes up for it and then some with the vboost system.

I have had a manual vboost system on mine maxs for years and I like being able to control when and how much boost it has.

As far as why it is the only bike with vboost is mainly because of the v4 configuration and how the intake tracks are set up.

Servo motor rarely fails - main failure part on the vboost system is the electronic vboost control box (located under the left air scoop)

A switch or manual boost systems are not hard on the motor anymore than how hard you are on the throttle.


Mike

 

[naughtyG]

I'm actually considering installing this T-Boost:
http://cgi.ebay.com/ebaymotors/ws/e...3217&ih=007&sspagename=STRK:MEWA:IT&viewitem=

Two reasons:

1, I'm just curious to see how it feels kicking in a 3000rpm for a laugh.

2, I heard that switching it off altogether helps gas mileage when touring.

Since my commute is 90 miles of I-4, having it off may help on mpg, maybe.. Also, I think it could be a good thing to have it off when it rains. Having said that, it's easy enough to wire a switch to the V-boost controller to switch it off manually, but I like the idea of having the T-boost option. :eusa_dance:

Anyway, for $40 I think it's a cool gadget, so when I have a little spare cash I'll do that mod.

Other than that, make sure your V-boost cable is adjusted properly and that your butterflies cycle properly when you switch the ignition on, and you're golden. unk:unk:

 

[Frosty72]

I put the Tboost switch in not long after I got the bike in 04'. When I first got it, I was switching it between the three settings all the time, and it was hard to tell the difference between the settings since there seems to be a natural kick at 6k anyway. I eventually decided to leave it in the off positition for fuel savings, and only flip it on if I think I might need the extra kick.

One day last summer after washing the bike I went for a ride and after I got out of the neighborhood I started noticing that the bike seemed to be running extra strong that day, it kept lurching forward harder than normal at the 3k mark. After a couple of those surprise sprints I figured out what had happened, I had bumped the switch down while washing.

So after getting used to riding my bike for a few years I am able to easily notice the difference in the settings on the Tboost, and like you said It's only $40!

 

[gamorg02]

I'm actually considering installing this T-Boost:
http://cgi.ebay.com/ebaymotors/ws/e...3217&ih=007&sspagename=STRK:MEWA:IT&viewitem=

Two reasons:

1, I'm just curious to see how it feels kicking in a 3000rpm for a laugh.

2, I heard that switching it off altogether helps gas mileage when touring.

Since my commute is 90 miles of I-4, having it off may help on mpg, maybe.. Also, I think it could be a good thing to have it off when it rains. Having said that, it's easy enough to wire a switch to the V-boost controller to switch it off manually, but I like the idea of having the T-boost option. :eusa_dance:

Anyway, for $40 I think it's a cool gadget, so when I have a little spare cash I'll do that mod.

Other than that, make sure your V-boost cable is adjusted properly and that your butterflies cycle properly when you switch the ignition on, and you're golden. unk:unk:

NG..

yea, for $40 i may pick one up as well... anyone know if for touring its better with it off? i often commute with it in the summer and cruise around 80 - 90 mph so its always close to kicking in vboost.....

not sure if its actually something useful tho... still thinkin about it

 

[Lew L]

I love my "T-Boost" :biglaugh: I don't have it on all the time and I think 4K would have been better but it's not possible with the standard ( and affordable) T-boost.
Lew

 

[gamorg02]

I'm actually considering installing this T-Boost:
http://cgi.ebay.com/ebaymotors/ws/e...3217&ih=007&sspagename=STRK:MEWA:IT&viewitem=

Two reasons:

1, I'm just curious to see how it feels kicking in a 3000rpm for a laugh.

2, I heard that switching it off altogether helps gas mileage when touring.

Since my commute is 90 miles of I-4, having it off may help on mpg, maybe.. Also, I think it could be a good thing to have it off when it rains. Having said that, it's easy enough to wire a switch to the V-boost controller to switch it off manually, but I like the idea of having the T-boost option. :eusa_dance:

Anyway, for $40 I think it's a cool gadget, so when I have a little spare cash I'll do that mod.

Other than that, make sure your V-boost cable is adjusted properly and that your butterflies cycle properly when you switch the ignition on, and you're golden. unk:unk:

hey NG, i'm thinking of ordering, is this the legit version? would u order from that specific store?

thanks man.

-g

 

[KJShover]

I bought one from that guy a few months back. he's good to deal with, fast shipping.

I got mine to play with, the 3k opening is kinda seat of the pants cool. but I bought it to easily turn the Vboost off.

While on a red cross ride I noticed my light didn't come on untill about 100 -105 miles and it normally comes on in the low 90's while touring.

 

[naughtyG]

hey NG, i'm thinking of ordering, is this the legit version? would u order from that specific store?

thanks man.

-g

I don't think there's such a thing a 'legit' for this, but for all the places I've looked at this is the only one that offers the 3-way switch and the easiest installation.

So when I buy mine, I'll definitely buy it from this guy. He's also good at replying to emails, and if you don't feel like giving fleabay more $, you can order directly from his own website for the same price.

http://www.qualitypartsonline.com/

 

[gamorg02]

I don't think there's such a thing a 'legit' for this, but for all the places I've looked at this is the only one that offers the 3-way switch and the easiest installation.

So when I buy mine, I'll definitely buy it from this guy. He's also good at replying to emails, and if you don't feel like giving fleabay more $, you can order directly from his own website for the same price.

http://www.qualitypartsonline.com/

thanks NG. i understand the "legitimacy" of the t-boost, but i also dont' want something that will fry my electronics or anything. I'm going to order tomorrow.

 

[gamorg02]

just ordered via their non ebay site.

can't wait to feel the rush @ 3k rpm and also looking forward to the 10%?ish gas mileage at touring...

anyways thanks everyone for the help, and also sorry about the: :hijacked:

 

[naughtyG]

Lol I ordered mine too now - early xmas yay - I wanna check it out as well I've been looking at it for too long!!

 

[dave741]

google " vboost " and you will find pics

 

[gamorg02]

not meaning to hijack the thread again...

but so i finally got around to installing the t-boost and i drilled the hole a bit too far down so when I went to put the throttle body cover back on the switch was pressed to hard on it and broke! :bang head:

oh well.. looks like i gotta goto radioshack or servicestar and find a new switch. i'm also going to email the guy and find out which wire goes to 3k openings and which one is stock opening.....

guess i'll be putting a new hole in the plastic too, plugging the hole thats there.... just an FYI for anyone doing it double check the clearance on the throttle cable cover...

 

[vmax_virgin]

I recently bought an 1988 vmax and was told that the vboost had been removed. I don't notice any kick at 6k. The bike has great power. Does anyone know about this and would I get an improvement in performance if I were to reinstall the Vboost? Do I have to have the factory air box? I currently have K&N type individual filters for each carb. Thanks.