my speedo dont work, and i am trying to figure out how fast i am going. with the stock setup i have in my sig.

at 2500 i think i am doing about 60-63
what am i doing at 3500 ?
anybody have a formula foir this ?

 

need tire size.

 

let's see if I can remember some basic physics/math


speed= (RPM/ratio)*(tire diameter inches)*Pi* (1mile/5280 ft)* (1ft/12inch)*(60 minutes/hour)

that should all cancel out and lleave miles/hour


you can get your tire diameter at www.4lo.com

 

Yep, need tire size. If you want to know for sure real time, use a GPS unit. Most can spit out MPH. Just keep a real steady speed while it gets a fix. You can also use the stopwatch/mile marker scheme. MK

 

stock 16 in

 

LMAO!!! Ya buy and old-school truck because, like me, you like to be able to identify everything under the hood. Then you get a GPS unit so you know how fast you are going. To Funny! Thanks guys I needed a giggle today.

 

Lots of calculators on the web, here's Woody's:

http://www.woodyg.com/fairlane/finfo/mph.html

 

hmm, I know that when I'm turning 3000 rpm I'm going approx. 62 mph. I thought that I had 4.11 gears and I know I have 31x10.50 tires. When I punch in that info it says I would be going 67 mph and if I had 4.57 gears I would be going 61 mph. Could my truck really have 4.57 gears? I tempted to jack her up and see.

 

Then you get a GPS unit so you know how fast you are going. To Funny! ......

That ain't nothing....You should see my radio gear. My modern radios clash with the ancient looking truck interior. I usually use an icom IC-706mk2g which has a remote faceplate. Actually, myself, I drive an old truck because they cost me less money than a new one. I can work on a new one just fine, but I can't afford the dang things. It's like flushing cash down the toilet the way they depreciate. If anything, my 68 is worth more every year. Better investment of money the way I see it. It's like my brother and his 50k corvette convertable. To me, it's a money pit that is worth less every year. Drastically less in the first year or two.
I'd rather spend that 50k on a vintage corvette, and watch it grow. Before too long I expect to get a laptop just for mobile use. The GPS and the radios will all tied into the laptop which will be set up about like what you see in a police car.
With GPS, I'll be able to watch a moving map, with constant MPH readings, or I can flip a switch and go to the radio. I'll be able to copy wx sat images, slow scan TV, digi modes like PSK31, etc while driving down the interstate. Add wireless internet, and I'll be able to check onto this site while on the interstate. MK

 

I have a buddy that does train spotting. To me this is a lot like disco, I just don't get it, but he likes it so what the hey. He has his laptop wired to his GPS unit and he can track trains. He does this so he can be at the train crossing to take pictures of the engine as it goes wizzing by. Don't ask me why I just don't know.

Amen to the vintage corvette. I would take a 58 or a 63 split window over a new one anyday.

 

Way above my intellect. Got a laptop, but I ain't sure about all that stuff. Sounds cool though. You're right about the new truck versus old truck. I have a 2002 XXXXX and it is already a loss as far as money goes. Nice truck, runs great, all that good stuff, but the money I paid for that thing, my 69 F100 could be completely rebuilt from the ground up.... oh well. We live and learn. I reckon the idea is to learn from the mistakes, just some are more painful than others.

 

NM5K, I hope you're keeping an eye on the road while you're doing all that stuff Then NM5K must be your callsign.

The GPS device would cost more than I paid for the truck.(got it free) Wouldn't mind having one, though. they're pretty cool.

 

Oh yea, Usually I'm just talking. I actually prefer to do the other stuff once I stop somewhere. Good for camping, etc. No matter where I am in the world, I can get in touch with someone on some band. If I get bit by a deadly rattlesnake out in the AZ desert, I'll at least be able to die live on the air, if they don't get to me in time...
My usual driving antenna covers 80-6 meters, "all HF bands, except 160m", and I have 2 meters and 70 cm antenna on the cab roof. I can rig it up for 160m, and also longer mast/higher performance on the other bands when parked. The radio is pretty much general coverage 30 hz up to 470 mhz, except for a gap from 200-400 mhz. So I can receive police, aircraft, AM/FM/TV broadcast, etc, etc also. And it's legal for me to have, being I'm a ham. "Local" scanner ordinances have no jurisdiction over me. I'm licensed by the feds. I do keep my radio "factory locked" though so they can never accuse me of trying to talk on one of those bands. If I tried to key on say the local police freq, even with the proper PL tone, it just errors out, and doesn't even try to transmit.
The 706mk2g is a cool radio. I've had quite a few over the years, and that single radio is way more versatile than any other I've had. And it's very small. About the size of an average 70s-80s mobile CB. It runs all modes on all bands, and does the normal 100 watts out on HF. Has menus with all kinds of features including DSP, mini band scopes, etc.. The faceplate can detach from the radio and be mounted up on the dash, or anywhere you want, while the main unit can be stashed away somewhere. BTW, once I get a laptop in there, it will be my music machine also. Tape decks, CD's, etc, no need... MK

 

lol, hope that doesn't happen, atleast not on air I've been a ham for 12 years now, my callsign is N7TTI. If you look on the bumper of my truck you'll see a screw-type hf antenna. My dad ran a hf radio in for years(he took the radio out unfortunately). Now I have a yaesu 2m radio in it. Good for around town.

That's a pretty nice radio. Lot's of bells and whistles. Laptop for a music radio,ehh? are you gonna run your truck's speakers thru it?

 

to get back to the topic i started
235/85 r 16
these are the tires on the truck
how fast am i going at 3500 rpms
my speedo is broke
so i dont have a clue to my speed
and can someone tell me a easy way to
figure this out