Who makes small engine Dynos?

[alvin l nunley]

My dyno was a Go Power. Supposedly rated at 120 horsepower. They use to make a smaller dyno. Go Power sold out to somebody in the eighties who, I believe, is now in Texas somewhere. There smaller dyno was for use in schools for testing small 4 cycle engines. It was a complete unit. I use to own one. Not much use for a 2 cycle. But it was a nice unit. No software in those days, which you really need. I have an Excel spreadsheet dyno chart. It's free. The important thing when dyno testing is to have correction factors. The correction factors compensate for differences in barometric pressure and temperature. A dyno with no correction factors is useless. My Excel dyno sheet has those things. With a graph. There are 2 pages, one page for a single run, and one page for two runs. Of course you need Excel.

Email: alnunley@austin.rr.com and ask for the 2 run spreadsheet.

 

[jglenn]

here's TDKs site for building an inertia dyno

http://performancetrends.com/tdkmotorsports/shortcut.html


tons of them have been built from these pages. mine included. I use a much cheaper software that has worked very well for me over the years..

http://www.ontrackdigital.com/



I've owned and built quite a few dynos of various types and the inertia is by far the easiest to use and most repeatable for the $$. IMHO hard to fool one

 

[Jamie Webb]

Performance Trends is sending me a quote, but they're not cheap. And I'll tell Ya, they are not used to talking to a dumb Karter like me. I'm sure they're very good, no doubt, but the simple needs of a go kart dyno seem way under anything they offer.

They are very familiar with karting dynos and they have helped a lot of people with their software needs and don't mind doing custom applications also. Talk to Kevin, he has helped me out a lot of times.

 

[unclelou]

I made my own with a disc brake caliper, spindle and bearings from S-10 truck. It is mounted on pillow block bearings that are on same axis as spindle. Brake is applied via master cylinder and acme thread arrangement. There is a lever attached to the spindle that acts on a piston when brake is applied. The cylinder is plumbed to pressure gauge. Once pressure, area of piston, and arm length is known the torque may be calculated. I have a spreadsheet that does that however data must be entered manually. I use a tiny tach to get RPM. RPM and torque are entered into spreadsheet at multiple data points and a graph is constructed. It does work but is hard to control. I can apply a load and run a 7 hp mostly stock predator at max load for several minutes and it will reject the heat necessary to keep disc at under 300 degrees. I have added a large blower since pic was take. Sometimes the lever (moment arm) oscillates at certain RPMs and makes the pressure gauge needle oscillate as well. I am going to drastically increase the mass (MOI) of the arm to stop or slow the oscillation. I can also dampen the gauge by using a smaller id tube to connect it. I don't thing that I will be putting any dyno shops out of business but boy have I had fun building this thing.

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[Don K]

jglenn, We built ours from TDK instructions and used OnTrack software as well. I donated an old Windows 98 PC to run the software and my buddy welded the frame up. We had a total of about $1,000 in it.

We were running Yamaha and Briggs at the time and performance in both classes went straight to the top. Best tool we ever bought or built. Excellent for tuning carbs, clutches and gearing.

DK

 

[MWeisman]

Hi Al,
I tried emailing to request the above spreadsheet but the email bounced, indication was non-existent email address. Would you be willing to send this to me?
You can send it to matt at weismans.org.
Thanks much

 

[JLSRacing]

I have a older Stuska dyno that got from a package of parts. But no data hook up or gauges. $350, + shipping. Can run 2 or 4 cycle on it. But I have not run any motors on it.

 

[HMR]

Look @ Land and Sea , kart specific set ups and super accurate and great repeatability . Not cheap but with the right sensors you will find power quickly . JMO .