Superchargers

[TopCatGr58]

Addendum

One thing I'll mention is that my pulley IS just a standard "V" type, and requires a little bit of lateral tension to keep the pulley engage to run the ALT.

The above photos show using pulleys with TEETH, which could possibly allow LESS lateral tension since the TEETH will help in transferring the rotation energy without the need for so much lateral tension to keep a regular "V" belt from slipping!

T.C.

[Eveready1100]

I believe that if you show all those little air ports the same same pressure the tuning should not change much as long as fuel is not blown back out of the bowl. One of those ports on the carbs goes right into the slide diaphragm chamber

Just looking at your reply as quoted here, and I'm wondering how you're going to get the slide diaphrams (Vacuum operated ) to work with the pressurised air feed from the blower?

[natemoen]

Just looking at your reply as quoted here, and I'm wondering how you're going to get the slide diaphrams (Vacuum operated ) to work with the pressurised air feed from the blower?

I had kind of been wondering that too. CV carbs will not work with a supercharger. Your slides will always be 100% open.

[shane007]

I had kind of been wondering that too. CV carbs will not work with a supercharger. Your slides will always be 100% open.

I disagree. All ports and passages of the carb will see pressure. It's not so much about vacuum as a pressure differential before and after the slide. Thats why it works great for altitude changes. The air on the intake side of the slide is always a higher pressure than the engine side. Say I put 1 psi into the carb... Now the slide is also pushing down with that much more force being closed even when the pressure in the carb is the same. It's the airflow that opens the slide imo. The air will always be flowing toward the engine and the slide should still operate due to less pressure on the engine side.
But I may be wrong as that's just my theory, I will try to do some research to back myself up. Off to look for articles!

[shane007]

Alright guys, I could really find any proof on why or how it would work under pressure but I did find a build up of a blow through turbo Harley cv40 carb on a samurai on the Zuwharrie forums. On the keihin cv40 the bowl vent is external like our 70s xs carbs but still needs to see same pressure as rest of carb. Also the samurai engine size is 1300 cc's BTW.
http://bbs.zuwharrie.com/content/topic,127127.0.html
May be a little long but he fully tunes it to where he wanted eventually.

[natemoen]

I too really have no concrete proof as to the workings of a cv carb with a supercharger either, just my thoughts on physics ans such.

My thoughts on your air pressure theory. You are sort of correct, but I would say that you are looking at it upside down. Yes the pressure on the outside of the carbs is higher, but that is not what matters. What really matters is that there is a vacuum on the engine side of the carbs. That is what makes the carbs do what they need to do. With the suercharger you are forcing it though rather than sucking it through. The air pressure outside the carbs is at 0psi and the engine side is at -10 psi.

As to the thread you posted about the blow through turbo cv carb setup....good luck! That in my mind is not worth the effort. Seems like it would be easier to do a megasquirt efi setup with just throttle bodies and a supercharger.

[Eveready1100]

The air on the intake side of the slide is always a higher pressure than the engine side

compounded when you have a supercharger ramming air in from the outside!

and:

Now the slide is also pushing down with that much more force being closed even when the pressure in the carb is the same. It's the airflow that opens the slide imo

Shane, the side doesn't push down as such. It is sucked up by the diaphram that has the vacuum applied to it from above. It is not the airflow under the slide that opens it up. By applying air pressure to the diaphram chamber the slide will be forced shut and stay there. It will not run like that!

Here's a link to a youtube video that might help you understand what I'm talking about - https://www.youtube.com/watch?v=wyspAHrMbb8

[Orange4]

Another supercharger option is one from a Toyota Previa. I'm pretty sure it's draw through. Also, bonus silly factor would be the minivan supercharged XS11.

[MPittma100]

Supercharged

This might be an alternative. It would save you a lot of time and effort.

The rear brake is mechanical and therefore may be limited. But this could be overcome by adding a parachute. You can get any color that you desire as long as it's red.

MTT Turbine Superbike Y2K

Machine: Rolls-Royce 250-C20 turbo shaft

Top Limit: 227 miles/hour (365 km/h)

Power output: 320 horsepower (239 kW) @ 52,000 rpm

Transmission system: 2-speed automatic

MTT Turbine Superbike which is also called Y2K Turbine Superbike, is known as 2nd wheel driven motorbike powered by a turbine engine in the world after Suzuki GSX-R750. It was created by Ted McIntyre of Marine Turbine Technologies Inc and the machine is featured with a Rolls Royce Allison 250 series turboshaft engine that can produce 238kW (320hp) output. Each unit is sold for $150,000 and according to Guinness World records, MTT Turbine Superbike is the most powerful and most expensive production motorcycle. In many races, it is also the fastest production motorcycle on the road.

[shane007]

Nate and Eveready: hopefully I can make it work with the carbs as I've heard of it done on other CV carbs. If it doesn't work for me I won't be upset as I've only spent 150.00 on the charger, and if I can't get it to work I have always wanted to do microsquirt 3 with gsxr throttle bodies. I would just be more stoked initially if I could make it all work without going efi.
Orange4: If I can't fit this eaton m45 into my bike I might look into that one.
Problem is I forgot just how wide the engine is and the charger pulley may be in the way of my leg lol. Will hopefully be able to recess the pulley into one of the sides for a bit more room. Will post pics when It stops raining... And after I find a place to upload too.
Mpittma100: would save me time and effort if I didn't have to work for many years to afford it lol. I'd be scared ****less on that. I don't usually even go over 90 or so.
Almost forgot to mention... I've been researching how to optimize boosting the engine and I am thinking of going down a step in the plugs to a colder plug to prevent preignition along with cutting back the ground strap. Right now I cut off a good chunk of the ground strap and side gapped my plugs to .040 I tested my spark and if I pull a wire off it will jump at least another 1/2 inch to complete the circuit. I have the green dyna coils and am hoping this will help keep consistant ignition and cutting back the ground strap will reduce hotspots.

[3Phase]

CV Carburetors Will Supercharge

Shane, I had to think about it, then look it up but CV carburetors will work with a supercharger or a turbo.

The '80s style Mikuni carburetors might be slightly easier to Supercharge than the earlier '70s carburetors because the float bowl vent is run from external tees between the carburetors, then up to the airbox. The '80s style have the vents cast into the carburetor inlet so the float bowls will be easier to pressurize.

The throttle shaft seals on all XS/XJ carburetors are directional and they're installed for vacuum in the throttle bore, not pressure, so they'll leak if they're not replaced and turned around.

However you do this you'll have your work cut out for you but here's a Victory site with some decent information:-

Supercharger Installation on Older Motorcycles | Supercharger Installation, Part 6

Carburetor and intake manifold modifications
I make the assumption here that all prospective applications will use a carburetor, which may be placed either before (upstream of) the supercharger, as a “draw-through” system, or after (downstream of) the supercharger, as a “blow-through” system. Any supercharger will require considerable fabrication for either method. With the exception of some draw-through models that originally used an Amal or S.U. carburetor, all supercharger inlets will need some work, in some cases only a minor change in flange pattern, in others a complete re-location.

Blow-through
Here the carburetor remains at or near its original position between the intake manifold and the supercharger, and only pressurized air enters it from the supercharger’s discharge port. The carburetor’s position simplifies that part of the construction somewhat (throttle & choke linkage, fuel lines, &c.), but also poses some problems:

1. the carburetor must be sealed to prevent boost from escaping. Potential air leaks include the throttle
and choke shafts, air slides, air correction openings, float bowl vents, throttle cables, etc. The
leakage is harmless since it’ only air, but it will reduce boost and cause an irritating noise.
2. the float bowl must be pressurized as well.
3. the air cleaner must be re-located to the supercharger’s inlet port.
4. re-jetting is needed not only for the extra air, but because a carburetor cannot “see” and react
to a change in density (boost), but only to a change in velocity.
5. an intercooler between the supercharger and the engine will help suppress detonation and provide
more power in high boost applications.
6. the connection between the supercharger discharge and the intake manifold may be at any angle,
even straight up.

Blow-through carburetor selection should take into account how well sealed the throttle shaft and float bowl are, and how easy it is to apply supercharger discharge pressure to the float bowl vent.

The carburetor’s venturi (throat) size should be about the same as the original carburetor, and no larger than the largest factory high-performance carburetor. Since flow is already pressurized as it enters the venturi, a slight reduction in size does not reduce power significantly. If response is bad, use a smaller venturi (beginning with smaller primaries). A carburetor larger than needed frequently results in lean mixture that will not respond to normal jetting changes. A Keihin CV (“constant velocity”, the same principle as the S.U.) carburetor is available in different venturi sizes with the same basic body, so if response is bad, use a smaller venturi, if boost is limited (or mixture is too rich on top) use a larger venturi, etc. without complete new fabrication of cable, hoses, etc.

CV carburetors such as the S.U., Stromberg CD175, Keihin, Mikuni, &c. must have boost applied to both sides of the air valve or diaphragm.

A method of enriching mixture in closer proportion to rising boost pressure is to apply dynamic pressure (rather than static boost pressure) to the float bowl using a pitot tube, as explained: Modifying carburetors for blow-through use.

Carburetors with air correction jets must have boost pressure applied to the jet. Sizing should begin with the smallest number. For the Mikuni VM (part # BS30/97) this is the .5, or .50mm (.020”). In some cases a blank jet will produce better results. Carburetors with drilled passages such as Amal Monobloc and Concentric Mk I·, Linkert, S.U., &c. should explore drilling and tapping the passage for a common jet to make adjustments easier to perform and evaluate.

Have fun!

.

[shane007]

3phase: awesome man, thanks for helping me confirm my thoughts on CV carbs under pressure! Many of those points I have already thought out but there are many very good points in there. About the leaking shaft seals on the choke and throttle... I talked to my welding buddy about enclosing all the carbs and he agreed that it would be difficult due to space constraints. I will not worry too much about the seals until I can get it running but will think of a solution.

Topcat: your pulley ideas are good. I agree with you that I shouldn't use a design which requires lots of tension. I looked back at your pic of that supercharged bike on page 2 and I really like how the charger is tucked so close to the engine. I don't think mine will fit there and I may not be able to use the charger I have because of interference with my leg. Also realized I have to reverse the direction of the blower to put it on the alt. Side
Thanks guys! I am finally making one of my crazy ideas happen and its all because of this forum!

[3Phase]

You shouldn't have to enclose the carbs. The throttle shaft seals will leak but there's no reason to put 'em in a box or anything weird.

.

[TopCatGr58]

Hey Shane,

With regards to the pulley location, you might also think about putting in a jackshaft so that you could route the energy to the other side if you want it there?? JAT.

T.C.

[shane007]

Jackshaft

Topcat: The jackshaft idea is pretty good. It would allow me to tuck the charger more out of the way while also allowing me to run off the alt. Side. I could put the jackshaft right over the starter and have plenty of leg room.

Only issue I see is bearing issues at near 10k rpms. I am trying to run a 1:1 ratio to start and I'm afraid bearings without an oil supply will dry and burn up. Maybe I can enclose parts of the shaft and fill with oil.

I disassembled the charger last night to see how hard it would be to reverse the rotation and I would have to machine parts of the front housing to get it all to line up and bolt together.

On the other hand my welder buddy said if he takes his time and all we can make all mounts and get all 3 shafts within 15/1000 tolerance. I think I will use a toothed belt to transfer power so there will be some give to reduce shock loads.