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.

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 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.. :)

Originally Posted by moenko

...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.