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Posted

1st pics of the VBoost mounted on motor, concerned about air box and mounting. This setup increases top of carb heighth 1" above original. Makes ya wanna go----hmmmmmm.

 

Dan

Try this a gain

Posted

Looks good. I've been looking for the same setup. I thought about the 1" problem. How about an airbox and cut down the sides. Then put a flat panel automotive filter in. Probably need to put a couple crossbars under the filter to support the panel. As long as you keep a couple inches between the filter and the bottom the air flow should be good. Then mpd the original box top by opening it up and putting an air scoop on the lid that goes the entire top. This should enable you to keep the original false tank configuration. How about the carbs fitting between the upper frame bars? Any widening needed?

 

JB

Posted

Haven't got that far yet, as you can see it's still on the bench. Should have forks by this weekend so I can get 2 wheels back on her to get the motor in. Only got a couple of weeks left, so it may have to wait till after maintenance day. But we'll see.

 

Dan

Posted

Nice Dan, very nice ...

 

Open the Fake Tank Cover and let the Airbox stick outside. Don't tinker with the Airbox, as it will hurt the Airflow through the Intake and you loose Torque. Best would be, you mount the smaller Battery Box from a Vmax, a 17 AH Battery and the Vmax Airbox for better Airflow. But as a 1st Step the Venture Parts will do well.

 

How do you plan to operate the V-Boost Valves ? With a Vmax Servo Motor and the Vmax Blackbox ?

Posted

Hey Squeeze-

With the modifications, is the original design and airflow of the box still valid. I like the idea of the V-Max box. I studied this and have found a lot of V-Max hot rodders going to individual filters etc. Makes me wonder about the effect at anything but WOT. If he has a spare airbox it would be a good time to tinker. I have a link someplace from the V-Max Outlaw page that outlines the airflow from stock box to open carbs. It seems to me that there is a definate difference with the filter exposed on a stock 1st Gen. My 1986 runs poorly until the lid is put on. That tells me the carbs are running restricted. It may very well take a lot of tuning and re-jetting to get the air/fuel ratio correct if the box is modified.

 

JB

Posted

My 1986 runs poorly until the lid is put on. That tells me the carbs are running restricted. It may very well take a lot of tuning and re-jetting to get the air/fuel ratio correct if the box is modified.

 

 

 

Ditto for my 87. I don't think the carbs are restricted per se, but calibrated to the restrictive airbox. Recalibration would be a simple matter of jets and needles - simple - yeah, right. The potential's there but would take a lot of tinkering, esp hard without a dyno and EGA meter.

 

Jeremy

Posted
Hey Squeeze-

With the modifications, is the original design and airflow of the box still valid. I like the idea of the V-Max box. I studied this and have found a lot of V-Max hot rodders going to individual filters etc. Makes me wonder about the effect at anything but WOT. If he has a spare airbox it would be a good time to tinker. I have a link someplace from the V-Max Outlaw page that outlines the airflow from stock box to open carbs. It seems to me that there is a definate difference with the filter exposed on a stock 1st Gen. My 1986 runs poorly until the lid is put on. That tells me the carbs are running restricted. It may very well take a lot of tuning and re-jetting to get the air/fuel ratio correct if the box is modified.

 

JB

 

JB, were going into Philosophy here.

 

I for one wouldn't go to individual Filters on a VR. Yes with a complete Carb Kit, like the Dyno Stage7 Kit, you could gain some Horses over the complete RpM Range, at a respective and respectable Fuel Consumption. But this is valid for a complete Vmax Setup and i'm pretty much sure the Stage7 wouldn't work with a complete VR Setup. Vmax Setup means 35mm Carbs, always open V-Boost Butterfly Valve and the Vmax Spark Timing, which is a bit different to the VR Timing. Not to mention different Cams and Valve Diameters. But the most Gain is in the upper third of the RpM Range, where we VR Riders are not that often, at least when thinking about Speed Limits, of Course.

 

For long Distance Riding is a Setup with an Airbox better, because you gain more Torque than hp and keep the best working Range where we ride, in the middle of the Bandwidth. This isn't hurting the Consumption necessarily.

 

The Carbs are not restricted by the Airbox, the Carbs in Fact are restricting the whole Intake System. If you mount larger Carbs, you will gain a Lot of Power, just because the Engine takes everything what your able to deliver at a good adjusted Mixture and transfers it to Power and Torque. On a Vmax, you can wake 15 to 20 Horses just by mounting 39 mm Carbs.

 

An open Lid on the Airbox hurts in two Way the Response of the Carbs and the Intake System. One Thing is due to the open Lid, there is too much Air on the Intake and the System is not calibrated for this. The other Thing is, the Lenght of the Intake System is a Lot shorter than with the Lid mounted. Because of too much Air AND a less 'ducted' Air System, the Throttle Response is very poor or the Motor isn't even able to hold Idle RpM.

 

As you might know, tinkering with the Carbs on the V4 Setup is a major PITA, getting it on a Dyno would need to find a somehow basic working System, sort of a educated Guess, before let it run on the Dyno, at least if you wouldn't spend Money on 20 or 25 Dyno Runs. I think a very educated Guy with a huge Cabinet full of Jets and Needles could work it out in 15 Runs or so. Seeing six Runs per Day as possible, this would make it at least 2.5 Days on the Dyno ... Not to mention the Tire would be be new at the Beginning and ruined afterwards.

 

All this being said, i recommend to keep the Airbox in Place or convert to a Vmax Airbox. Because the Vmax has a slightly larger Airbox and a clearer Setup inside the Box.

 

 

 

btw .. if you think about how much Gain is possible ... I had my Max on the Dyno, first Run without V-Boost activated at 80kw on the rear Wheel, second Run was with V-Boost activated at 6k RpM @ 88kw. Gain on Torque was 3 Percent by active V-Boost.

Posted

Wow. I'm gonna try it when I get the motor in (do carbs clear the frame?). Maybe leave false cover off. WIll operate manually for now with cable and thumb switch (pegscraper idea). Most likely will wait till after maintenance day to really screw with it and talk theory and possibilities.

 

But you gotta admit------ IT LOOKS AWESOME!!!!!!!!

 

Dan

 

Just think-- at night with red leds under the airbox shining out the sides highlighting the vboost and carbs------SCHWEEEETTTT!!!!

Posted

I agree on the filters. When setting up our stock cars, we have to work the RPM range. This means things like velocity stacks and carb spacers are out. I didn't realize that the carbs on the VR were restricting the motor that much. For the street on our touring bikes an open box would not work well. With your information in mind, the V-Max box seems to be the best idea. I would suspect in this case, that the intake vaccum would be altered by the different air box. That would also me changing the spark advance mechanism to match!! Yack!!! To much messing around for a touring bike. Now, if I find a spare VR things would be different. V-Max driveline grafted into a Venture Royale.

Posted

Here goes; the 2nd situation that i have found. Intakes are oval, vboost is round. As far as I can tell, the bottom matches up well for the oring, but the top is too short. I don't think it will seat. Was the intake design changed from oval to round? just on the maxxes or the ventures, too? Bolt pattern matches up, seems like the base angle and the vboost angle are just slightly different, but it bolted up tight.

Posted

Dan, i don't see antything that wouldn't fit togehter. If you're in Doubt about the Sealing of the Vmax bottom, carefully apply some Grease to the O-Ring and mount the Manifold to your Motor. AFter you hve undone it, the Grease will show you where the O-Ring found a Seat or not. Watch for the Bolts which go into the upper Hole near the Intake Valves, they are shorter than the others.

Posted

I wouldn't mess with cutting a hole in the cover. Attached is a pic of daveg90's VR and it has a V-Boost sitting under the hood. I bet if you contacted him he'd supply you with pics and some friendly advice on how to shoehorn the whole setup in there. If remember correctly he has a switch that allows him to switch the Boost on and off..... BTW his VR is one of the cleanest I've ever seen... :thumbsup2:

Posted
something like this ??

 

Very interesting read. I was wondering right from the beginning of this thread why not go completely with the V-max heads and TCI or even a complete V-max engine swap instead of just the carburation. It was answered in the last paragraph though. I just feel that my bike has plenty enough power for a touring bike but if I wanted to soup it up into something special then I would have to go all the way.

 

Dick :):):)

Posted
Very interesting read. I was wondering right from the beginning of this thread why not go completely with the V-max heads and TCI or even a complete V-max engine swap instead of just the carburation. It was answered in the last paragraph though. I just feel that my bike has plenty enough power for a touring bike but if I wanted to soup it up into something special then I would have to go all the way.

 

Dick :):):)

 

enough Power ??

 

Is it a Rolls Royce ??

 

:rotf::rotf::rotf::rotf:

 

Sorry, just kidding

 

Sincerly, i don't think enough is enough.

 

When i ride my Max and then the Venture, i allways feel there's missing something. Maybe the 40 hp ?? I've ridden a Lot of real powerful Maxxes and i can tell you, there's nothing like a 1500cc with EFI. You just can't hold on to the Handlebars. These Motors will pull the Arms out of you. Now, the Costs are another Story but i can feel my Mouth getting wet and the Dribble running down every Time i think of it.

 

If i ever take out my VR Engine, i sure wouldn't bring it back in. I'd mount my '99 Vmax spare Engine and save the 1300 cc for an Update and mount it in my Max afterwards. The Vmax Engine in the Venture has also a downside. The Vmax gearing isn't perfect for the Venture and for my Purpose. But i'm sure i'd come over that.

 

For me, and for some others, it's not only a Question about more Power, it's an Attitude to tinker around and find some of the lost Horses inside the Casing. It's a 'Hey, i can do it' Thought and the wonderful Feeling of winding out these V4's in second and third Gear and really feel the Power. A Lot of Power is there, we just need to shake the Horses a bit and awake them. The Satisfaction of that is more than just more Power or more Torque. It's a wonderful Reimbursement and a good Way to get rid of the daily Stress some of us suffer from.

Posted
Hey Squeeze,

 

What 39mm carbs are you talking about that give a V Max 15 - 20 hp?

 

These are Mikuni or Keihin Flat Slide Carbs. You even can get them in 41 mm Boring. But they are expensive, very very hard to adjust and most of them are very poor in Throttle Response in lower RpM. Power on top End is awesome. The flat Slides are connected direct to the Throttle Cables and you need to adjust the Accelerator Pumps about every Month to the varying Weather Conditions. Because of the bigger Boring, the Mixture Buildup on low Revs is poor and therefore it ends up in very poor Mileage at most Cases. Better to mount a Hitch and trailer your own Barrel of Gas.

 

They are not the Way to go today. If you want to spend a Lot of Money, better go for a EFI. Easier to adjust to our Needs and way better Mileage.

Posted
that battery mod. got my attention , do you know what size battery he used?

Thom

 

PC 680 as far as i can read the Label in the Picture

Posted

Once again, WOW. At this time, I have made a decision to go with standard carburetion till after maintenance day. Then I'll have more time to put this thing together correctly. And, I'm ashamed to say, I did not have time to polish the cases. I may have a little bit of time before I put the motor back in, but I sincerely doubt it. My side jobs (pays for this stuff), boys baseball, meetings about government issues have gobbled up my time since I tore it apart. That and actually SLEEPING sometime (down to 5 hrs a night, not good). Just got my solid engine mounts in from Blue Mountain, Delprins, also found out that the wrong slides (bushings) for the lower fork tubes were ordered wrong (now have an extra set of uppers if somebody wants to buy them, my cost), will set my fork job back to at least next Wednesday or so till they come in. I'm starting to get frustrated with this, would rather just spend my time on the bike, but,,,,,,,,,,,,,,,,,,,,

 

Dan

Posted

Hi,

My chopped 83 has a manual vboost and straight intakes with individual filters. Had some trouble with tuning initially until I finally discovered the problem. As everyone has noted, removing the airbox cover causes problems - but not for the reasons that I have heard explained. Decreasing the pressure drop on the intakes effectively increases the overall operating pressure inside the carbs. The float bowls are vented to the atmosphere so the increased pressure inside the carb venturi effectively decreases the gas flow into the venturi. The increased overall air pressure inside the carbs mean that gas pickup tubes have less of a pressure difference to move the gas into the carb. You can change to other filter schemes but you do need to keep the filter pressure drop similar to the stock airbox to prevent the engine running too lean. Another aspect which gave me problems for quite awhile is the routing of the carb vent/overflow lines. The air pressure at the ends of these lines has a HUGE effect on the gas flow into the carbs. My chopped venture was running too lean until I realized that the vent tube location (the stock routing) was effectively reducing the air pressure inside the float bowl. The tubes were terminated down low behind the engine but the lack of fairings (my guess) meant that this area was at a slightly reduced pressure when moving at 60mph or so. I changed the vent tube locations and found that the fuel air mixture went from lean to perfect. If you don't believe this, simply try blowing (rich) or sucking (lean) on the vent tube when the engine is running. You will find that very little pressure change makes a huge difference. I now have an Innovate wide band air/fuel gauge so I now know exactly what is happening and can see these effects easily. If you want some more details on converting to individual filters, just PM me.

zag

Posted

Dan,

 

I was part of a group that started the Venture Super Sport project back in 2000, where Dave Getsfried actually completed his. Actually I completed mine on my 93 w/V-Max heads but totaled it in Arkansas 4 months after I completed it. Dave had just bought his bike in Sommerset and I worked with him getting his completed. However he went a different avenue that I on the crossovers and kept the butterflies.

 

I am attaching the write-up that he sent me, FYI. Also, the V-Max junction rubbers for the carbs is an almost possibility to get installed. You will probably pull all of your hair out before you get all 4 of these in. The reason is that 1" that you loose with the V-Max intakes and puts the carbs right up close on the frame. What I did was use the junction rubbers from the crossovers for the carb juctions. You will need to chamfer off the taper (1/16") from bottom of the carbs to make them fit the grooves in the junctions.

 

You will also need to fabricate a new mount and tube for the pull throttle cable. The one that is there will not fit with the bike's frame.

 

Oh, and you can make your stock air box work by installing a flat top on it. I took a K&N Venture filter and cut 1" off of the bottom with a dremel and cutoff wheel. Then I took the rubber base I just cut off and cleaned the filter material letft on it. Then I laid down a big heavy bead of black RTV silicon and then set the top of the filter down into and let it dry good. Now I had a K&N filter that would fit in the bottom of the OEM air box. But with this you will need to drill a bunch of 1/2" holes. The exact number will depend on which size main jets you install.

 

Good luck,

 

Rick

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