cobra marty

It's almost ready to test on a boat. This is a measuring device to measure the crankshaft TQ, rpm. and HP while on the boat while on the fly. It mounts inside a Bravo 1 Stellings extension box. It's output can go to a datalogger, digital display or a guage.

I had Nordskod build me the guages one is for HP and the other is for TQ. The scale is 0-1000 HP or TQ. They are 2 5/8" white on white. Here is a picture of the TQ guage. As soon as the strain guage is mounted/molded/calibrated I hope to install it on a 32' Skater with 575's and XR's and test it out. Can't wait.

cobra marty

Here's the TQ guage. Bear with me on the picture, I'm still learning this camera/computer thing.

tomcat

Way to go Marty! It's not easy bringing something to market. I wish you luck.

Tom

cobra marty

Thanks. The meters also have a push button tattle tale feature so at the end of a run you push a button and the highest reading will show. The resolution is OK with the guage but within 0.1% with a digital voltmeter. I don't know how much interest there will be in it as it has a very limited application and audience, otherwise I have a very expensive toy for myself.

ragtop409

tell us more how dose it work

cobra marty

I can measure TQ going thru any shaft. TQ will cause any shaft to twist slightly and this twist is measurable and proportional to TQ applied. The strain guage is a simple device which attahes to the shaft and will change its resistance when then shaft twists. The hard part is making it work, wireless connection to the shaft, electronics and calibration. This is allready is use on top fuel and funny cars to measure their TQ. These cars/engines run for such a short time-- 5 seconds, and there is no dyno which will hold them. They put out ? between 5,000 and 10,000 ft.lbs. TQ. They won't give up the actual numbers but 5,000 was being pegged and so far 10,000 is holding.

All this came about because I guess I am too cheap to pay to have my motor pulled and dynoed and set up the fuel and spark curves and obtain max HP and TQ every time I change something like cam, manifold, boost. Plus the dyno uses different exhaust, ignition, fuel pumps etc than in the boat. I thought that a dyno on the boat would solve this expense and hassle of pulling the engine etc. The boat and propeller act as a moving waterbrake and so why not measure it and make it a dyno.

I would love to put my device on that 191MPH cat and see what kind of power it puts out.

Hey Tomcat-- how are you doing with your intercooler designs. Check out the articles in the recient Hot Rod and Car Craft mags. SB and BB carb, box, non-intercooled, blowthru, Vortech SC. They also addressed the carb problem and seemed to have it licked.

OkieTunnel

What kind of cost do you think this might be able to get to if it were reasonable produced, like a knock meter or something. Most people don't have them but you can pick up the Livorsi catalog and drop $600 and have one. Do you think under $1000? If so I think every serious big inch blown 100+ offshore boat owner would want one.

Vinny P

Congrats Marty!! That was one hell of an idea you had there. I am glad to see it come together for you. Keep us posted on the progress.

Cord

This is something that's on my x-mas wish list. Right now it's a bit too rich for my blood, but I find the idea very intreging. What happens when the drive comes out of the water? Do you see the numbers fall off only to spike on reentry?

BTW-does nordskog have any of those dual gauges? It would be really neet to have both numbers on one gauge or a digital gauge.

cobra marty

Humm? When the boat comes out of the water? The prop and shaft will be loaded and unloaded and then loaded again. Well I can buffer the signal from 0 to 3-5 seconds. It will take some trial and error to find the best but I think a 1-3 sec. buffer will do.

Realize that the guage is the smallest part of the project. A single dyno session is what? $500. What would unlimited, lifetime, anytime, everytime dyno session be worth? Yea a big buck instrument but I've seen many waste much more on 'Snake oil' and have no idea if they are any better for it. And in a $200,000 Skater, Outerlimits, Formula, Fountain, etc its less than a set of 5 blade props.

Oh look, my motor is off 20HP, I better check those valve springs before I launch the motor and require a major rebuild.
If I turn up the boost 1 pound will I have more power or will the additional heat from the blower offset the additional boost?
Is 36 degrees more powerful than 32 degrees timing?
How much power do I lose/make in 110 degree summer heat?
Did that new exhaust make more power or did I just waste $2500?
The questions are endless.
Those new Kilo records-- how much power do they make. And if I make more can I make a new record.