Home Forums Tech Talk dyno testing

This topic contains 9 replies, has 6 voices, and was last updated by  Rick Brown 3 years, 10 months ago.

  • Author
    Posts
  • #37318

    Anymore know any good karting company or engine builders that do dyno tuning, ? Looking for good work at a price, can’t afford to pay reine at swedetech or Darcy at DDR $1,000,000 a pull Lol please help me!!!

  • #37407

    Walt Gifford
    Participant

    Best dyno is use your DA at the track.

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #39296

    Jerry Revely
    Participant

    While track testing is better than nothing, some parameters can’t be held constant. Keep that in mind when you evaluate the track testing data.

  • #39363

    Walt Gifford
    Participant

    Like what?

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #39377

    Jerry Revely
    Participant

    Climatic conditions, driving conditions (perfectly matched corner entry, lines, and exit), tire conditions, to name a few.

    I did say it was better than nothing at all. However you need to be careful when looking at the data.

  • #39395

    Walt Gifford
    Participant

    You’re just looking at clutch stall to top end on the longest straight.

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #39488

    Jerry Revely
    Participant

    I will assume that you are not coming to a stand still on track for your longest straight run. With that said for discussion sake, any deviation in the corner leading up to this straight can effect your results at the end of the straight.

    Any trajectory deviation in the corner, any throttle deviation, any brake deviation, etc. will make comparing results interesting. How do you know if the set up change made the difference or maybe the deviation of the driving line was the real difference?

    Add in barometer changes, wind changes, cloudy or sunny changes, temperature swings, and tire grip level changes, it adds more complexity to evaluating results.

    With a dyno, you have less variables to worry about.

    Neither method is without potential error. IMHO the dyno has the better repeatability.

    As always, the stopwatch is the final word. Run whatever yields the quickest lap.

  • #45257

    Mark Horne
    Participant

    Raymundo, Data you will only find testing on a Dyno:

    1) Finding your best carb. Best to start with a few because some are just better than others or require different jetting to provide max power output. Some carbs are junk(depending on make).

    2) 2-Cycle: Best Header, Flex Length and Pipe combination. With the power curve detailed at SAE corrected numbers you kind find the max a setup will provide and evaluate it to another. Perhaps one for short tracks and one for long. Then use the DA to help find fastest setup on track. You can adjust if the AD changes.

    3) Peak Torque. Every one needs to know this. If you racing single speed you will use it for clutch hook up. If you are shifting you will want to bang into the next gear where the most acceleration will happen.

    4) Torque at MAX revs. With the DA you can tune the final drive for top end speed. This is really a fine tune thing. If you think you need more torque to the road and want to add a tooth or two just do a quick calculation to find out where you will loose the top speed. If it takes 8lb/ft of torque to push your ride at top speed you can multiply that by your final drive. Then if you add teeth (you should know how much RPM gain per tooth and find the torque number there) you refer to power data to see if 3 teeth is too many to push your ride again to the same MPH.

    5) EGT vs HP/Torque. Peak for each are at different values. While we know cooler for better torque and hotter for better top end performance, the latter can be the sucker punch. Over a full race if you constantly are at the top end of EGT the engine could, most likely will, drop off in power output. This can be seen on the DA when at the track if you isolate the data for a longer straight with equal entry speeds, Distance / Time.

    6) Your best Engine package. Most have more than one more and with manufacturing tolerances one most likely will perform better than the other. Perhaps one will be better on the top end.

    ————

    These are just a few of the key points. For those who say a Dyno Tuned motor won the race is only telling part of the story. They had to set the ride up correctly and drive consistent laps. While some will also argue track testing is the only way, I agree only in part. The track run is the application of the best available package. For the experienced, hard learned lessons tell them which way to alter a setup. This requires extensive note taking and great feed back from the driver. Over time this works but it has its elevated cost most ignore.

    If the program followed will find the key data listed above you will know exactly what you are showing up with and be more apt to use the DA more to your advantage in shorter period of time. While the cost may seem high at first to Dyno test, how much does it cost to travel, buy tires, race fuel and entry/practice fees for each time out to the track? Will the data collected be as accurate and can you use the data at different tracks?

    Lastly, if Dyno testing was not an essential tool to reach the top step, the professionals in motorsport would not bother. Some will also argue that they have never been beat by a Dyno. While that is 100% accurate, what they were beat by was a better package, Car/Driver, that out performed them.

    Just my 2-cents

    • #45315

      john Dillon
      Participant

      Mark, very well put. I invested in a Dyno jet chassis dyno about 4 years ago. Ive raced and built shifters for 18 years. My clients and myself won many times without the use of a dyno.

      With that said, I purchased the dyno when I jumped into a 250 superkart. With those karts you cant just go to the local track for testing. The dyno became an invaluable tool for me. I built a mule chassis so I could dyno the engines I built for customers. When I handed them a fresh engine with a dyno sheet, it increasded the confidence of both myself and them. So when they got to the track, if the kart would not fall out of a tree, they knew to change there set up and or their driving. That eneded the your engine doesnt make any power problem.

      Another customer I convinced that the dyno was worth it is a gentlemen that races several LO206 class karts. This is a sealed engine. But we found 1 hp and solved his problem of the kart laying down at te end of a long straight.

      Is a dyno completely necessary, no, but it can provide a lot of info on what works and what doesnt. All the engines and karts that leave my shop have been dynoed.

  • #45320

    Rick Brown
    Participant

    Hey John care to elaborate on that 1hp on the LO 206?

You must be logged in to reply to this topic.