Jump to content




Photo

Can a dyno find the good motors?


  • Please log in to reply
112 replies to this topic

#101 NJ Racer

NJ Racer

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,759 posts
  • Joined: 08-March 06
  • Gender:Male
  • Location:Delran, NJ

Posted 10 March 2016 - 08:23 PM

Another  issue is when A Mainer guys go up there with five cars. Practice and checking cars is out the door for a lot of us... Just saying...

 

Mike M. at Tom Thumb has timed practice per lane with rotation. Works great and is fair.


  • Samiam likes this
"Ya gotta be in it to win it"

Ray Carlisi




#102 Noose

Noose

    Grand Champion Poster

  • Advertiser
  • PipPipPipPipPipPipPipPip
  • 20,845 posts
  • Joined: 08-November 06
  • Gender:Male
  • Location:Denville, NJ

Posted 10 March 2016 - 09:51 PM

We do it at the Fall Brawl, too.

Joe "Noose" Neumeister
Sometimes known as a serial despoiler of the clear purity of virgin Lexan bodies. Lexan is my canvas!
Noose Custom Painting - Since 1967
Chairman - IRRA® Body Committee - Roving IRRA® Tech Dude - "EVIL BUCKS Painter"

"Team Evil Bucks" Racer - 2016 Caribbean Retro Overall Champion
The only thing bad about Retro is admitting that you remember doing it originally.


#103 Marty N

Marty N

    Race Leader

  • Banned
  • PipPipPipPipPip
  • 544 posts
  • Joined: 23-February 11
  • Gender:Male
  • Location:Kingston, IL

Posted 11 March 2016 - 10:33 AM

The truth is about half way between Sheldon Cooper and Fred Flintstone. ​Good thread.


  • Cheater likes this
Martin Nissen
 
So hard a judge they hope never to meet as themselves.

#104 smokie

smokie

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 466 posts
  • Joined: 13-November 06
  • Gender:Male
  • Location:Crashville, Tennisippi

Posted 15 March 2016 - 08:12 PM

My vote is for Howard Walowitz... he's an engineer, and his "wife" is pretty hot, too.


  • Tater likes this
Jeff Bigelow
"It's not about winning or losing the race,
it's about how good you look for the concours judge"

#105 Booger

Booger

    Backmarker

  • Subscriber
  • PipPip
  • 96 posts
  • Joined: 15-June 15
  • Gender:Male
  • Location:SoCal

Posted 25 March 2016 - 02:10 PM

If the object is to get faster,I think you would be better off with the dyno attached to the driver....... :D


Gary "Booger" Baker

#106 John Luongo

John Luongo

    Rookie Keyboard Racer

  • Full Member
  • Pip
  • 19 posts
  • Joined: 01-August 16
  • Gender:Male
  • Location:Haverhill, MA

Posted 02 August 2016 - 06:30 AM

a "dyno" or other measuring device can be useful in gauging the effectiveness of either motor rebuilds/improvements or to cherry pick motors that seem to perform better. years ago when racing in a class which limited motor mods, I made up a motor tester (not exactly a dyno where you adjust the motor load). simple 16D or super 16D motor as the mule with a flex coupling attached to the test motor. volt meter attached to mule which would measure output as the mule was spun up by the test motor. added an ammeter to test motor also. this set up allowed me to measure and document readings related to motor component changes, both good and bad. keeping careful notes would show a trend if the "improvements" were useful. in all cases, this motor performance data was directly applicable to on-track performance. depending on the track configuration and class, mid-range power/torque improvements were harder to identify without adding a variable load feature. sealed motor/spec class racing allows us to spend more time on the chassis set up and driving, not a bad thing. but, finding that one motor in 10 that has the potential to pull a couple of tenths/lap from the field is nice to know. best, john


  • Samiam likes this

#107 Brian Cochrane

Brian Cochrane

    Brian Xpro Retro East Member

  • Full Member
  • PipPipPip
  • 133 posts
  • Joined: 05-June 14
  • Gender:Male
  • Location:Long Island, NY

Posted 13 September 2016 - 10:19 AM

When it comes to doing dyno testing and amp draw and ect to see which motor could be that rocket, that's all fine and good to do if you are really into learning about motors .But like most people are saying,testing them in the car tells all. A motor that draws more amps than others might do so because of friction due to misaligned bushings which will increase drag. When you work on a motor at the bench, many times you are hurting that motor in the process and by the time you get it in the car it has already been ruined. Overheating the brush springs or arms is a non repairable damage. Arcing of the brushes is a nonrepairable damage. When you free rev these motors ,the windings expand out which causes damage. The fast guys have cars that handle and keep momentum all around the track.Their cars roll smoothly and their tires {front and rear} are the correct hardness needed for the optimum results.Their cars don't bind up in the corners and their driving style is to go into a corner as deep as you can and power up out of a corner as soon as possible. A fast car doesn't just go down the main straightaway fast,but is fast on the back end of the track and in  the  donut. The hawk motors have had good batches and not so good batches. I have also noticed that some of them have darker windings than others. If you want to purchase 2 motors at a time or 20 at a time that's up to you. Racing has been like this forever,even  in classes that you build the motors.


  • Half Fast, JerseyJohn and Samiam like this

#108 NSwanberg

NSwanberg

    Race Leader

  • Full Member
  • PipPipPipPipPip
  • 968 posts
  • Joined: 01-April 09
  • Gender:Male
  • Location:Canton, MI

Posted 14 September 2016 - 01:15 AM

What I have learned, from the chassis dyno engineered and built for me by AJ Hoyt, is that the motor/car combination that performs best on the dyno may not perform well on the Downriver grandstand track.

 

At my testing parameters, that being a constant 7 volts of supplied power to the car on a rolling dyno, a Proslot FK setup that outputs around 3 volts quite often runs better laps than a setup that outputs 3.5 volts. You can see it in the performance of the car. It may not be the fastest on the straightaway and through the bank but it goes deeper and breaks better in the dead man's, It is faster on the back half and just chews the donut up.

 

The lesson I have learned is to not look for the best numbers but to build for the numbers that are best on our track. To me it means gearing that car for for the best performance not the highest numbers on the dyno. In the end you still have to prove it out on the track.

 

I don't pay much attention to amp draw other than making sure they are reasonably within average and not pulling a lot of amps when I break in a motor.


Remember the Steube bar!
SUPPORT YOUR LOCAL RACEWAY!!
"The denial of denial is the first sign of denial." Hank, from Corner Gas
Nelson Swanberg

Peace be with all of us and good racing for the rest of us.
Have controller. Will travel. Slot Car Heaven

#109 LindsayB

LindsayB

    On The Lead Lap

  • Full Member
  • PipPipPipPip
  • 241 posts
  • Joined: 11-August 08
  • Gender:Male
  • Location:Sydney, Australia

Posted 14 September 2016 - 02:33 AM

Built and tested 6 motors recently for a race (Grp 27 US nats). Ran on power supply all seemed consistent, had one that seemed like a dog, ran hot felt rough - pulled much higher amps. Was so bad that I was going to pull down and start over as there must be something wrong.

 

Anyway before I did anything -tested on the track - interesting 5 motors were with .001 of each other. The dog - the fastest and the smoothest.


  • Tim Neja likes this
Lindsay Byron

#110 MarkH

MarkH

    On The Lead Lap

  • Subscriber
  • PipPipPipPip
  • 375 posts
  • Joined: 26-November 12
  • Gender:Male
  • Location:St. Louis

Posted 15 September 2016 - 04:54 PM

Nelson, I don't understand why you would be testing at 7volts.

My experience is with engine dynos and we always test at full throttle unless there is a partial throttle response problem.

It seems to me your results may have been different if your were testing at or closer to the full voltage the track is supplying. The tool you have might be able to net your some predictive numbers if the voltage was matched to the track. I would try running those again and see if there is a difference now that you know which ones were faster. Just thinking out loud.


Mark Horne

SERG - www.slotcarenduro.club
"Racing is life... everything else is just waiting." Steve McQueen - LeMans
There are only two things in life that make me feel alive. Racing is one of them.


#111 NSwanberg

NSwanberg

    Race Leader

  • Full Member
  • PipPipPipPipPip
  • 968 posts
  • Joined: 01-April 09
  • Gender:Male
  • Location:Canton, MI

Posted 16 September 2016 - 02:02 AM

I don't like running the motors with so little load at track voltage. I find a constant supply, adjusted during the evaluation to 7 volts, to account for the voltage drop of the current source, seems to provide reasonable indication of on track performance. The drum in this dyno is basically free wheeling and turns motors used as generators to measure their voltage output. I think that as long as I am consistent with the bench test I can get a feel for how the setup should be expected to perform.

 

Sometimes I use the the current measuring capabilities of the VOM to measure the amperage the motor in the dyno produces. This may be a better real world indicator of the setup's performance. When the dyno is allowed to produce current you can hear the the setup rpms drop and the voltage of the power source drops do to increased load and the resultant increased current draw.The primary concern is just to help ensure there is nothing seriously wrong with the setup. If  the numbers are suspect it is back to the bench.


Remember the Steube bar!
SUPPORT YOUR LOCAL RACEWAY!!
"The denial of denial is the first sign of denial." Hank, from Corner Gas
Nelson Swanberg

Peace be with all of us and good racing for the rest of us.
Have controller. Will travel. Slot Car Heaven

#112 Tim Neja

Tim Neja

    Grand Champion Poster

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 5,423 posts
  • Joined: 11-June 07
  • Gender:Male
  • Location:Orange County

Posted 16 September 2016 - 10:34 PM

Bottom line is like Lindsay B found-- ya don't learn anything worthwhile till ya BOLT IT IN THE CAR!!! :)


  • MSwiss and Tom Eatherly like this
She's real fine, my 409!!!

#113 crazyphysicsteacher

crazyphysicsteacher

    Mid-Pack Racer

  • Full Member
  • PipPipPip
  • 143 posts
  • Joined: 04-March 12
  • Gender:Male
  • Location:NJ

Posted 18 September 2016 - 06:00 PM

Bottom line on all of these is this. A retro hawk is good if at 3-4V on the power supply it should pull .35-.45 amps. If you rev it higher then be ready to throw a wind. Second, it should be fairly smooth and a dunk in the water tank helps some motors out. However, oil the bushings and run it for 5 minute intervals on the power supply, letting it cool between runs. Do this 2-3 times to heat cycle the motor. I do this for all my motors. My 16D' run one tooth smaller on the pinion than the rest of the field. My can am did the same at Fasttrackshobbies in august and only my finger slowed me in the donut. If you have ever heard a good box stock, the retro should have a high pitch tone, not a low rumble. It will be fairly good and not a mess.
Chris Wendel
Silver Side Down Racing
 
"Failure teaches way more than success. It shows what does not work and what to never do again, again..." 🙊🙈🙉  





Electric Dreams Online Shop