Mach929

iTrader: (3)

lol, joe i know these bikes have integral transmissions, i've logged quite a few miles on my kawasaki and my cbr. I was pretty much getting at the problem of reverse...unless this thing would be so light you'd be doing fred flintstone style. a completely separate electric reverse may be the way to go.

Ben

iTrader: (33)

My dad's wing, which you so despise, has a separate electric reverse that works off the starter motor--it pulls double duty. Really neat system.

Starsky

iTrader: (1)

Not sure how difficult it would be to retrofit, but snowmobiles these days do reverse by reversing the direction that the engine turns. When you select reverse, the engine stops and then restarts spinning the other way. Pretty slick to use.

hustler

iTrader: (6)

my step brother has a 700whp 1500cc suzuki motor turbo drag bike that leaves harder than anything on earth.

jasonrobo02

iTrader: (13)

Joe,
That quaife diff that you linked to that can accept a sprocket is a good piece. I used that while building a FSAE car and liked it a lot. One of the main benefits is being able to use a wide array of cheap sprockets to get a proper rear end ratio for your intended use.

When I used it, it was able to accept honda axles, but it seems now they offer stub shafts which should bring the cost of your axles down.

cardriverx

iTrader: (12)

that is actually pretty cool.

ZX-Tex

iTrader: (15)

I was going to say before that the Quaife sprocket driven differential setup is similar to what we did on our FSAE car as well. I think a lot of teams did this IIRC. We built our own using a Torsen but the idea is the same. A diff in its own case (to hold lubricant), a sprocket in place of the ring gear, and two pillow block bearings. That approach does have the added hassle of having to adjust for chain wear.

jasonrobo02

iTrader: (13)

ZX, When I was involved in SAE, a bunch of teams used the Quaife ATB diff because they almost gave it away to teams with a heavy discount. I think the team went to a different tosen setup the year after I left because the Quaife is a heavy bitch!

ZX-Tex

iTrader: (15)

Interesting... IIRC the deal was the other way around when I was in it (back in 94-95). We got the Torsen cheap so we went with that. We were so poor we scrounged whatever we could. Less than 6 of us built that whole damn car from scratch in less than a year (while going to school AND working part time) and took it to competition with less than $12K total budget. It was ******* insane.

But I digress... thread jack over

You know, I understand the confusion about the integral transmission. With all of the Harley based custom cruiser madness in the media the last few years, I think many may have the misconception that the transmission is always separate from the engine. I mean, that is the way it works on all of OCCs and West Coast Choppers bikes, so the sport bikes must be that way too right?

Yeah figuring out how to handle reverse is one of the big PIAs with the bike engine adaptation. Not sure the reverse running engine would work with a 4-stroke, at least not easily. Though I am not a snowmobile guy, I would guess that scheme is exclusive to two-stroke motors.

Joe Perez

iTrader: (8)

Yup, that's definitely one of the primary motivators. There is simply no other sound like a big inline 4 turning 13,000+ RPM. For that matter, have you heard the Stratosphere engine? I wish like hell I could find the sound clip from the Tokyo motor show, it is simply amazing.

Two of the boxes I pictured above provide reverse. With the standalone diff however I'd have to invent something electrical, and I suspect the performance and complexity of such a system would be undesireable.

On a 2 cycle, it's achievable. With a 4 cycle, you couldn't do it without having some means to decouple the cams and rephase them, along with an oil pump capable of pumping in reverse.

One of the benefits of the first box I linked to, the PowerTec, is that behind that side cover is the quick-change reduction gear. Same concept as a quick-change automotive diff- pop the cover, replace the gears, put the cover back on.

This is true. Harleys use a separate gearbox with a belt-drive intermediate. Many of the BMWs are the same as well, and from the layout, I expect that Honda's opposed engine bikes ('Wing, Valkyrie, etc) do too, though I've never serviced one.

Pretty much all the other modern motorcycles out there use a single case containing both the engine and transmission. And not just sportbikes, but everything from 125cc dirtbikes and Honda Nighthawks all the way to the big superbikes. The transmission and clutch are both lubricated with the same oil that's pumping through the engine. The primary benefits to this approach are obvious- smaller size and lower weight.

silentbob343

Busa powered smart car?

Zarniwoop42

iTrader: (1)

not realy on topic, but

I saw some **** on the history channel about the stunt cars that they use for a disneyworld show. I think they are stripped down fwd opels that weigh in just over 1000 pounds. They are powered by some kind of large mc engine, and they have modified sequential transmissions that have four speeds forward, four speeds reverse. They also have buttons that bring them to preset speeds for jumps that have to be repeated many times per day without crashing, or ******* up the suspension so bad the car cant finish the show.


fukin cool

PAT!

iTrader: (1)

Part of the reason for the expense of motorcycle turbo kits is the very limited market.

The Power Commander has been around for years and was reverse engineered by a company a few years back and sold into the Automotive community.

I planned on making a tube-frame bike powered car a few years back, until the killer deal I had going on a wrecked ZX12R fell through. I was toying with using a starter motor for reverse. Cheap and has plenty of power to move a sub 1000lb car about. It would take a bit of work to make the engagement smooth but the price was very attractive...

Joe Perez

iTrader: (8)

Kneeslider has an old article on some of the various M/C engined cars out there. Your SmartCar is there. Some of the vehicle are interesting, but none approach the configuration that I lust after. http://thekneeslider.com/motorcycle-powered-cars/

Truthfully, once I'm in a position to actually begin the project, I'll pay retail for a new M/C donor if that's what it takes. The ZX14 is only $12k new, and figure on recouping a lot of that off the sale of the frame, bodywork and suspension components afterwards.

What did you have in mind for the reverser? I see two possibilities. One, arrange a ring gear (like the flywheel gear) around the diff on the side opposite the sprocket, and mount a starter motor as normal to engage it. Two, arrange the motor such that it drives a sprocket which can be raised and lowered to engage the chain.

Neither appeals to me.

Honestly, once I was into a project with a budget of that magnitude, I'd probably just bite the bullet and buy the PowerTec. It's £2,858 as compared to £525.00 for the regular diff, but I think it would be worth it.

PAT!

iTrader: (1)

I never settled on how I was going to arrange the powertrain, which to an extent dictates how I would achieve reverse, so I kicked around quite a few ideas. Both of what you mentioned. Also various ways to engage the front wheels for reverse; both wheels connected to a minuscule diff with the starter driving it directly, a single wheel driven by a half-shaft that would decouple from the stater.

I also toyed with making either a front engined reardrive set-up or a mid engined reardrive setup using a driveshaft. With these I though of simply adding a gear to the shaft that the starter would drive.

Joe Perez

iTrader: (8)

Hmmm. No, for me it's transverse mid-engine rear drive. No driveshafts. The idea of finding a way to drive the front wheels however is quite interesting, and something that I'd not considered. Perhaps rather than a diff, simply two motors, one each mounted just at the inboard side of the A-arms, with a tiny, ultra-light little halfshaft. Hmmm.

However, it seems I've been beaten to the punch (and quite soundly) on the whole "Atom-esque vehicle powered by a M/C engine" concept.

Link: http://forum.atomclub.com/index.php/topic,3848.180.html

Pix:





It kinda looks in that first pic like the reverse motor is engaging the drive sprocket?

Joe Perez

iTrader: (8)

Yup, here we are. Details on the electric reverse at the bottom of this page: http://forum.atomclub.com/index.php/topic,3848.195.html

That's pretty much what I was thinking about, except I hadn't considered having the motor engage the drive sprocket. Schweet.

The_Pipefather

iTrader: (5)

I dont know the whole thing about the atom. yes its a fast car no doubt, but I think it could have been lighter had it not been for the fact that the frame rails also serve a cosmetic purpose. Those curved rails make that whole process of jig-making a royal pain to someone who wants to replicate it. I'd go with a much simpler frame design, or, look into laminated composites. They're not as expensive or tough to work with as everyone thinks.

eunos1800

Yea agree 100% bike tuning stuff is ridiculously expensive.

Even things like exhausts, your talking around £1000 for a Yoshimura or Akrapovic exhaust system for most bikes.
Thing to take into consideration with most though is weight and engineering.

5kg is a hell of a lot on most sportsbikes that's partly why those exhaust systems are expensive they're titanium

Moving between bikes and cars daily i would have to say, generally sportsbikes are far superior engineering wise than the vast majority of non supercars.


Joe,
The power commander is more comparable with the EMB than a PC.
Depending on the model you have you can adjust the fuelling via laptop on a TPS v RPM table.
On the better versions for the newer bikes you can also adjust timing and have a type of Autotune feature via the stock O2.

Not standalone standards granted but then they start at around $300 so they're not bad VFM compared to everything else (MS aside).


Cheers
Mark

messiahx

iTrader: (2)

I can't imagine riding that gt42r Hayabusa; I've only ever rode a 125cc 11hp enduro bike and it seems to me that 721hp on a bike would only mean insta-backflips.