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I'm about to start on my frame (finally) once the new garage slab is poured Monday morning and I get the shop moved back in. My short list was 'Busa/GSXR1000 but I saw an old V-max 1200 the other day, and engines are available for next to free.

It's got a drive shaft flange pointing rearward, though I know not which way it turns yet. I'd like to be able to use a Miata or RX7 IRS. The induction stuff may be a bit tall.

With the right exhaust, a V-Max is about the best sounding motorcycle ever.

Has this been done yet?

The driveshaft is on the left side of the bike. By looking at the entry point of the shaft into the final drive, and the contours of the final drive housing, it's obvious the shaft turns opposite the direction of an automotive driveshaft. Sorry.

You will have to run a flipped diff. Meaning the gears in the diff will be running in reverse. You'll notice a whine. You will also have to have a pump to circulate the diff oil sence the gears won't be able to sling it around. If I remember correctly Yamaha had a chain drive version of that motor so you may be able to turn it sideways like anyother BEC and run a prop adapter. Now you got to worry about a dry sump. No matter how you look at it there are problems. Robert W. did a shaft drive fzr1300 Locost with a flipped diff. Look at his posts. Russ

Wonder if you could find a Honda differential off a S2000, or maybe one of their 4WD's?

I don't know about their AWD rear diffs, but since it's coming off a FWD tranny there is no reason it couldn't spin the normal way either. I do know the Honda S2000 spins the normal way though.

It would add a little to the cost of the build, but you could also make some sort of "driveshaft rotation conversion box". Quick-Change gear sets are relatively inexpensive, and would not only allow you to have the output from there spin the correct direction, but also center the output on the car more.

Build the worlds only FWD Locost?!

I looked into reverse rotation differentials for my build which also has a reverse rotating yamaha engine. The only ones I coul find were front diffs from 4WD's and they seemed oversized for a bike engined car and the ratios were not great for my motor. You may be luckier in your search, or the ratio may suit you better.

If you have access to machining some parts, it is possible on the Vmax to remove the middle gear assembly and mount the engine sideways to how it ws in the bike. There are some chain drive conversion kits out there for that bike.

I ended up just flipping my toyota axle and added a little electric pump to flood the pinion bearing.

I too have, and am currently, looking into how to do a shaft drive mc engine in a true LOCOST way.

Spending money is the easy way. A custom small reverse rotation gearbox is very simple and can be built with any gear reduction you may want to work with whatever diff ratio you have. But unless you have access to the gears and shafts required it will get expensive fast. Once you add the desire to have reverse gear also though, the complexity goes way, way up, as does the cost of course.

You can go with Quaife or Nova Racing Transmissions but both are well over $1,000 delivered. Nova sent me a nice drawing of a reverse rotation gear box that does include reverse built just for this purpose. I think Quaife can build one also but at even higher cost.

The Reverse rotation Ring & Pinion gears available for the Toyota 7.5" is one way. Although probably not the best way as robertwa said.

I am leaning towards just running an inverted rear end and see how much the whine bothers me while looking for another alternative.

Grassroots Motorsports magazine built a custom reverse rotation gearbox with reverse gear for their Bezerkely project and it is very instructional to read how it self destructed the first autocross run. The article on the gearbox explained how many hours were involved in the design and construction of it.

I plan an electric reverse to keep the cost down as I already have the starter motor to use for it.

James

You could consider a hybird, take the rear end from the motorcycle. Don't use the rear wheel though, bolt on a sprocket and then run a chain to the rear diff, no ring and pinion. It's a little odd, but you'll be up and running and be able to adjust your final drive ratio and get IRS. Look for other solutions once the car is running. There a pictures on this site of people with chain drives to their differential with no ring and pinion...

Not ideal but getting going at all is a huge hurdle.

Very short answer:

NO.


I'm a realist. I've got an ex-road race MKII Sprite which has thousands of hours in restoration, so I've pushed the rock up the hill before. I have zero, no, strike that; less than zero desire to reinvent the car. I'll build a chassis based around a Miata/RX7 IRS, and pick a powertrain based on whether I intend to do SCCA class based autocross as a serious objective.

If that happens it'll be the smallest, most powerful non-bike engine I can find within reasonable cost. Otherwise I'll just tap my connections in the local sportbike/road race oriented shops and have the mad stuntaz rustle me up a 'Busa mill.

I make stuff out of mitered and mig-ed mild steel very frequently. A 7 chassis isn't a challenging undertaking except for restructuring my very small (11x22') garage to accomodate a working project as well as the Sprite, DRZ400 and KTM950 supermotos, an RD400, a Yamaha Zuma, 60 gallon compressor, air dryer, blast cab, parts washer, 40" base and top cabinets, a bench, a flamables cabinet, a 20 ton press, tig, mig and gas welding and a plasma cutter....I forgot. Theres a 21'6" rowing shell, but it hangs from the ceiling.

I intend to get the table placed, and to move a small horizontal bandsaw from the machine shop in the basement up to the garage. Once I'm cutting and tacking tubes in I expect I can get the basic chassis together in a couple weeks tops.All the suspension bits will be done in SolidWorks from which sheet drawings are very quickly extrapolated. The objective is to waste as little work time as possible. It's designing parts, drawing parts, cutting, machining, or welding parts.

I'll buy the IRS, front hubs, rack, shocks, Heim joints and bushings, brakes, M/Cs, steering shaft/hub/wheel, wheels+rubber, engine+ancilleries, fuel cell, and bodywork pretty much all at once. I've got the steel already, and plenty of wire, tips, gas, blades, and grinding/cutting consumables.

So. Ix-nay on the E-max-vay. Gotta get this thing underway.