First off, we want to apologize to all the faithful HDBlower fans for keeping you in the dark for so many months. Some of you have wondered if we were still around or if the project was still moving forward. The answer is a resounding YES!
After the input we received from our participation at the VTwin Dealer show in February, the decision was made to make some final revisions. Some of the revisions were quite substantial and required more time than we expected, but in the end we are happier with the product and we are sure our customers will appreciate the changes in spite of the delays. The key changes we made are as follows:
De-Coupled Blower Drivetrain:
The original HDBlower kit that we displayed at the VTwin show in February was driven off a gear connected directly to the crankshaft. On our original test bikes, the crankshaft runouts were all within 0.005″ and we did not see any issues with blower drivetrain. However, as many of you may well know by now, the latest HD twin cam engines can have acceptable crank (TIR) runout as high as 0.014″; ridiculous we know. We found that as the crank runout increased, the bolt holding the blower drive gear would begin to loosen from all the bending forces and eventually the gear would start back itself off. This forced us to go back to the drawing board and design a blower drivetrain that would not be affected by the runout of the crankshaft. Our solution was to completely decouple the blower drivetrain from the engine crankshaft using a specially designed floating coupling that would be completely unaffected by crank runout. Thus far, this new design has been performing flawlessly. Another benefit of decoupling the blower drivetrain from the crank is that it also made the kit much more easy to install as most the kit can now come pre-assembled.
NEW VS OLD SUPERCHARGER DRIVE GEAR COMPARISON
DISASSEMBLED SUPERCHARGER DRIVE GEAR COUPLING
Metal Football Basket with Integrated Plenum and Blow-Off Valve:
Taking cues from the original factory component, our initial football mounting basket design was made from injection molding glass-reinforced nylon-66. However at the VTwin show, several people requested that we offer a metal version of the football basket because they ultimately wanted to chrome it it. When we came back from the show, the design team met and decided that we would redesign the football basket so it would be made out of metal. In addition to now having the option to chrome the basket, this was design change had numerous other benefits. The main benefit of making the basket out of aluminum was that the part became structural and allowed us to integrate the intake plenum directly into the design which resulted in a larger plenum volume and also less parts. The new design also allowed us to integrate a larger more efficient blow off valve directly into the plenum cover.
Adjustments to Height and Thickness of the HD Blower Mounting Assembly:
In order to clear the latest drive-by-wire throttle body equipped bikes, we had to shorten and add some additional thickness to the overall assembly as well as modify the compressor housing design to allow adequate throttle body and pushrod tube assembly clearance. We also massaged the lower case to sit in tighter to the bike thus reducing the chances that the stock exhaust pipes would need to be modified or replaced on certain models.
NEW MAIN MOUNTING BRACKET AND PLENUM DESIGN
Keep a look out for these new 4×6 cards we’ll be passing out when we are out riding the HDBlower test bikes.
Here are some shots of the final design. We will soon be finishing all of our testing and transitioning from the pre-production phase to the production phase of the project. The HDBlower should be available for sale by April or May 2014.
The rendered 3D CAD models are great in helping us visualize what the kit will look like, but nothing compares to seeing the actual production pieces. Recently we received the first pre-production footballs for inspection. These pictures should give you a better idea of what kind of quality and finish you can expect from the HD Blower kit.
first article for inspection
Here is a recent dyno graph of a the kit on a stock 103 engine.
1)The 103 motor is completely stock!…stock exhaust, stock cams.
2) We still have not finalized the last few parts of the design for this kit…for example the ‘football’ is only a prototype design, we expect better results from the new/final football design and air cleaner set-up.
3) We can still spin the charger faster for greater gains, but this will require lowering the bikes redline.
4) We estimate the addition of cams and exhaust to yield atleast an additional 25-35 hp
Here are a few things to note when watching the video:
THE SOUND: The blower kit is virtually silent. The whirring sound you hear is the sound of the dyno rollers and not the supercharger. Except for sounding more powerful, the classic potato-potato Harley sound remains unchanged.
LEG POSITION: The riders leg position is the same as on a factory bike with plenty of leg to supercharger clearance.
Riders foot on the brake and in normal riding position with HD Blower prototype installed
The HD Blower football sits slightly higher than the stock air cleaner cover and only sticks out an additional 1/4″ from the stock position. The final production units will be heat insulated and aircooled so cant burn your thigh on the football.
The main unit below the football sticks out from the side of the bike by less than 1″, allowing the riders leg to remain in the stock riding position.
Mule bike being tested on our Superflow motorcycle dyno.
People have been asking us how much power the kit makes and in all honesty we really don’t know at this point because we are still in the middle of trying different configurations to come up with the most rideable power curve. In its unrestricted configuration, we estimate the kit should be able to make over 135hp to the wheels (at approximately 13psi of boost) but will probably require certain supporting mods. As a point of reference a stock 103ci makes about 65hp and a stock 96ci makes about 57hp to the wheels. Now before you go busting out your imaginary rulers and start measuring the horsepower of your fantasy blower/turbo set-ups, let us just say…we are not interested in chasing after the title of making the most horsepower. If we wanted to cater to the peak-horsepower-chasing dyno-weenies, we would have built a refrigerator sized blower kit large enough to house the biggest possible supercharger, 2 nitrous bottles, a case of beer, and a pint of nitro. Continue reading
First Magazine Ad Ever…lets get the party started.
Can you believe the main picture of the supercharger kit is a computer generated rendering? Don’t worry, this blower kit is in pre-production functional prototype testing phase, and isn’t just some fantasy digital graphics art project. HDBlower is only made possible with the right blend of old school mechnical know-how and new school wiz-bang computer technologies. We’ll show you more of the tools of our trade in later posts.