Question for someone with a tach (1500)

[schoeney]

I was wondering if someone with a tach can tell me how may RPM's a 1500 FI is turning at 70 mph in 5th gear? 80mph?

Thanks

You can figure all that with the patented Gadget RPM & Speed calculator.

http://www.gadgetjq.com/vulcan_speed_rpmcheck.htm

The answers would be: 2863 @ 70 MPH & 3272 @ 80 MPH

[dhelfritz]

I have an 06 nomad and CaddmannQs are real close to what my tach reads. I have the Kawasaki fire and steel tach.

[misunderstood]

I have a 1500 and was going to say that from memory you'd be in the 3000 range, so CadQ is right on target. http://s2.images.proboards.com/cool.gif

Remember that the calculations are based on everybody having the same size tire and that it's pumped up to the same diameter. Aside from that wrinkle, it's all based on gear ratios, which are mathamatically invariable. As my old math professor used to say: "You just plug in the numbers and turn the crank."

(That was back in the day when adding machines, calculators, and cash registers all had a physical crank you had to work. ;) )

[schoeney]

Thanks Caddman...your depth of knowledge never ceases to amaze me!

Well, just don't ask me about football or baseball. I couldn't even tell you who won the series. ::)

[markw]

I have an 04 1500 and installed a tach and tire sizes are stock. I run about what Cad said around 2800 @ 70 mph and 31-32 @ 80 mph. Not that I ever go that fast on the 55 mph roads I take to work... :)

[moenko]

A (kind of) related question to tach owners - is the Nomad a single fire or dual fire ignition (i.o.w. - do I need a single fire adapter)? Thanks - Moe

[lomax]

Moe ....I have done quite a bit of looking into your question of whether the Nomads are single or dual fire ignition. It seems there has been quite a bit of discussion on this on other forums. From what I can gather, the 800, 1500 and 1600 are dual fire and the 900 and 2000 are single fire. Gadget has posted on several occasions that the Nomads are dual fire. The basis of dual fire (also called "wasted spark") is that as one cylinder is firing on the compression stroke, its also fireing the other cylinder at the same time on its exhaust stroke, as opposed to single fire firing only on the cylinder on compression stroke. The number of plugs per cylinder has no bearing on which system it is. With dual fire systems, no adaptor is required for the tach. All the info I have read has me somewhat confused , but I usually will go along with what Gadget says on most topics. There may be others with their own opinions and I would be interested in hearing them and corrected if I'm wrong......
Mike
....It was also suggested by others that because we have 2 coils on our bikes, the idea of dual fire didn't apply as each coil supplies one cylinder which would make it single fire.....sheesh!!!!! ???

With two pickups and two coils, and two cylinders and a computer, there would be no reason in my mind for a Nomad to be dual fire. In fact, dual fire seems truly only applicible to engines with a balanced firing order like my old KZ900. The Nomad fires the first cylinder then rotates 310^o and fires the second cylinder. Then it rotates 50^oand exhausts the first cylinder, then 310^o and exhausts the second cylinder, then 50^o and fires the first again. Maybe that would work OK as a lost spark ignition depending on the valve timing, but when it fires the second cylinder the first is 50^o from TDC on the exhaust stroke, which is a fair bit, but I guess as long as the valves are open the firing of any unburned gasses couldn't create any reverse pressure on the piston, right? I don't have the valve timing specs handy though, so no telling.

[moenko]

Friends, thank you both for your input. I really appreciate the research, lomax. I have done similar and there is no indication that the VN1600 needs a single fire adapter, and therefore IS a dual fire ignition system ( I think you're mistaken here, Caddy).

THIS (http://www.meancycles.com/Home.asp?PartID=211502&AccCategoryID=2250&AccCategoryTypeID=0&BikeModelID=5749&ManufacturerID=0&BikeType=Cruiser&CompanyID=0) site sells the adapter and only the VN2000 is listed, confirming lomax's research. I guess one could just use alligator clips to see if the RMPs are correctly displayed - that would give the ultimate answer.

Thanks again, truly appreciate it!!!

[lomax]

...for what its worth, the Barons tach on my 1500 required no adaptor.. :)

...there is no indication that the VN1600 needs a single fire adapter, and therefore IS a dual fire ignition system ( I think you're mistaken here, Caddy)...

Oh, I was convinced that it was a "wasted spark" system. I just cannot understand why it was made so. After a good night's sleep, I can see that with two coils and an offset firing order, that my description of the firing sequence was wrong. Each cylinder will fire independently, but on both strokes.

Can anybody postulate some reason for this?

[moenko]

Cadd, I'm no pro in engines but from what I heard on my former site from people who seemed to know: The firing order etc. has nothing to do with "single" or "dual" fire. The reason for the "wasted spark" is (or so I understand) to lower emissions, it burns any residual mixture just before the exhaust stroke. So, since we seems to have a "dual fire" system, we DO have the "wasted spark". I could be terribly wrong here, but that is how I understood it when it was explained before. Hopefully someone with real knowledge about of the subject will chime in - I like to understand this whole setup better myself.

I heard that same rumor about the emissions reduction, and perhaps there's some truth to it, but I'll tell you this: The wasted spark system was invented way before the days of smog laws.

It was done so a 2 cylinder bike would be lighter & cheaper because it only needed one coil, one set of points, and one condenser. A four cyl. bike needed only two of each. Of course a car with any number of cylinders had only one of each, but it needed a heavy and expensive distributor to make it work. Notice that modern cars have no distributor, but instead multiple coils like a motorcycle. My V-6 Pontiac happens to have lost spark ignition as well (and I'd forgot all about that) because it's a very accurate and high performance system. Really accurate distributors are really expensive to make. My V-6 Toyota does not have Lost spark. It has a coil for each plug.

Now here's the part where emissions might be an issue involved:

If you trigger the ignition from the cam, like my old Honda 350 twin, you need two points and two condensors, and two coils, because it fires at half engine speed (and was not a "twingle"). If the points were triggered from the crank (which makes it Lost Spark) you not only remove a coil, points, & condenser, but you increase ignition timing accuracy because the cam chain is no longer involved in the timing process.

The only downside? You have to accept the wasted spark, and points adjustment becomes twice as critical. Electronic ignition solved that part by eliminating all those points and condensers (well, except for CDI bikes) and it brought other improvements as well, all of which increased performance and reduced emissions.

BTW, I think I figured out that the Nomad uses Wasted Spark because the ignition is crank triggered, and so naturally endows that capability. Accepting it as such reduces the complexity of the computer program that runs the ignition. Now it seems to me that it would only reduce the complexity slightly, but I could be wrong, or it could be that the programmers were (as in the days of DOS) fighting for every extra available bit and byte because what they had to work with was very restricted in terms of memory and processing speed.

[moenko]

Wow, you got my head spinning now, Cadd, and all I wanted to do is add a tach to the handlebar http://s2.images.proboards.com/grin.gif

[Top Cat]

I have a 2007 , 1600 and i put a tach on it. When I first installed it I was told I needed to use an adapter. i bought one for $20 and installed my new tach. It didn't read properly. Then i was told I didn't need an adapter so I took it off and the tach mow works fine.
Soooooooooo........I am fairly certain you DO NOT need an adapter.

[moenko]

Looks that way, TC! Not that it's a big deal to make one yourself, two diodes and two resistors and you're in business, pennies to make one yourself if you know how LOL. I will probably look at a Cobra when the checking account has recovered from today's withdrawal for the purchase of the 'puppy' - will have her home tomorrow - YEAH!!!!!

Ooooh!

Guess who's not getting any sleep tonight?

http://s2.images.proboards.com/cheesy.gif

[Top Cat]

Looks that way, TC! Not that it's a big deal to make one yourself, two diodes and two resistors and you're in business, pennies to make one yourself if you know how LOL. I will probably look at a Cobra when the checking account has recovered from today's withdrawal for the purchase of the 'puppy' - will have her home tomorrow - YEAH!!!!!
Yeah, I took mine apart to see what I wasted my $20 on http://s2.images.proboards.com/angry.gif:(" title=">:(" border="0"/>

[moenko]

LOL, Caddy, actually I'm exhausted from excitement, I think I'll have a good beer and retire soon ;)

TC - if you knew what I have invested in the C50 and what I am letting it go for, you would dfinitely agree that I'm the king of waste http://s2.images.proboards.com/grin.gif

[csguru]

Not sure if it applies or is even in the same ball park but the HD folks say that the Harley's have the dual spark system to create the Harley sound.

http://www.harley-links.com/?p=7

It goes on to say that HD even tried to trademark the sound/design but withdrew after 6 unsuccessful years.

So maybe Mawkaw was going for the "sound"...

/shrug

[redeye]

(That was back in the day when adding machines, calculators, and cash registers all had a physical crank you had to work. ;) )

HOW OLD ARE YOU??

(That was back in the day when adding machines, calculators, and cash registers all had a physical crank you had to work. ;) )

HOW OLD ARE YOU??

Not as old as the mathematician that coined the phrase "turn the crank". http://s2.images.proboards.com/grin.gif

Not sure if it applies or is even in the same ball park but the HD folks say that the Harley's have the dual spark system to create the Harley sound.

http://www.harley-links.com/?p=7

It goes on to say that HD even tried to trademark the sound/design but withdrew after 6 unsuccessful years.

So maybe Mawkaw was going for the "sound"...

/shrug

"Wasted Spark" ignition actually has nothing to do with how a Harley sounds.

It's strictly based on the 45^o angle between cylinders, the fact that it's a 4-stroke engine, the bore is slightly smaller than the stroke, plus the two-valve heads with large valves.

The firing sequence discussed in the article would be identical for the 45^o engine regardless of which ignition type they used. 45-315-405.

The Nomad sounds a little different because its firing sequence is 50-310-410 because it's a 50^o engine, plus the bore is slightly larger than the stroke, and it has 4 smaller valves per cylinder.