|
|
Topic: Sprint car torsion bars?
|
Email this topic to a friend |
Subscribe to this Topic
| Report this Topic to Moderator
|
Page 1 of 1 of 17 replies
|
|
|
November 17, 2008 at
12:46:02 PM
|
|
Joined:
|
02/25/2008
|
Posts:
|
116
|
|
|
hey guys,
I'm new to the sprint car scene. Can anyone explain to me how sprint car torsion bars work? Please keep in mind im a newbie so details are always welcome.
Thanks guys
|
|
|
November 17, 2008 at
01:06:52 PM
|
|
Joined:
|
10/21/2005
|
Posts:
|
526
|
|
|
Every material on earth has certain properties that give it a torsional rigidity, which is basically the material's resistance to being twisted. This resistance can be used as a spring, which is what a torsion bar really is. Nowadays sprint car torsion bars are all made of tubular steel, so the material properties are very similar from bar to bar. What makes one bar a stiffer spring than another is the thickness of the tubing wall. The spring is actuated using the torsion arms and torsion stops. The torsion stops hold one end of the torsion bar fixed in place, while the torsion arms follow the motion of the axle to twist the other end of the torsion bar.
Signature here.
|
|
|
November 17, 2008 at
01:25:30 PM
|
|
Joined:
|
11/26/2004
|
Posts:
|
3334
|
|
|
Reply to:
Posted By: Jake B. on November 17 2008 at 01:06:52 PM
Every material on earth has certain properties that give it a torsional rigidity, which is basically the material's resistance to being twisted. This resistance can be used as a spring, which is what a torsion bar really is. Nowadays sprint car torsion bars are all made of tubular steel, so the material properties are very similar from bar to bar. What makes one bar a stiffer spring than another is the thickness of the tubing wall. The spring is actuated using the torsion arms and torsion stops. The torsion stops hold one end of the torsion bar fixed in place, while the torsion arms follow the motion of the axle to twist the other end of the torsion bar.
|
Torsion bars have been used on older Chrysler products and some Jap pick ups for years, they seem to be far superior to coil springs as far as performance goes, but in the case of cars, the ride was usually more harsh.
Save your butt, get a colon screening TODAY
For complete line of Sponsor Awards check out
MarshallTownLaser.com
Duane Davis
Laser Engraving
641-751-7777
101 N Center
Marshalltown, Iowa
|
|
|
|
November 17, 2008 at
02:25:14 PM
|
|
Joined:
|
11/30/2004
|
Posts:
|
720
|
|
|
Took me forever to realize that a piece of metal that thick could actually twist while suspending a load and then return to its original shape. Our good friend Mr. Wiki can give us a hand with this one....
http://en.wikipedia.org/wiki/Torsion_bar
|
|
|
November 17, 2008 at
04:47:22 PM
|
|
Joined:
|
08/08/2006
|
Posts:
|
319
|
|
|
You can also think of a torsion bar as just an uncoiled spring. I am guessing that the reason they are so popular is sprint car racing is their compact size, weight, and the traditional approach that sprint car racing takes i.e. no starters, international truck axle front suspension design, etc...
They are also used in the front of MANY 4wd. Chevy pickups.
|
|
|
November 17, 2008 at
05:19:43 PM
|
|
Joined:
|
09/30/2005
|
Posts:
|
1387
|
|
|
upon shopping for bars, the measurement made is at the center of (say, a common 30" bar) in Inches dia , after handeling a few ,you will notice the outer diameter will be larger or smaller, thus a softer or stiffer bar, remember to observe the middle, center ,approx 15" from one end of the bar , keep the corrilation or direction of twist (rotation) the same ALL of the bars life, a LR can go to the RF or the RR can go to the LF keep #s on stop side, or Arm side, or faceing inside of chassis, or facing outside of the chassis, everybody has a preferance , whichever the case keep your bars runing in routine on your car ,some of the new bars are not identified on the ends anymore, keep a close eye on bars acting goofy or giving up (going soft) replace them as you can afford, some guys ditch them quite frequently(proubly not a bad idea) if you can afford it , then again, keep in mind, It could cost you, if not replaced .
|
|
|
|
November 17, 2008 at
06:07:02 PM
|
|
Joined:
|
10/31/2007
|
Posts:
|
374
|
|
|
This message was edited on
November 17, 2008 at
06:07:36 PM by talk2drivers.com
I can concur my 65 Plymouth Valiant Signet soft top has torsion bars in it. I can also say the ride is not that bad it corners quite well!!!!
Hi im Kyle Hendershot
check out my website talk2drivers.com
|
|
|
November 18, 2008 at
04:29:09 PM
|
|
Joined:
|
12/05/2004
|
Posts:
|
305
|
|
|
Also a common tool to the modern day racer is a Torsion bar tester/dyno.
When the bar is twisted and will not return to with 10% of it original spec it will be thrown away.
Larry "O"
|
|
|
November 20, 2008 at
08:28:03 PM
|
|
Joined:
|
02/25/2008
|
Posts:
|
116
|
|
|
Thnaks guys for all the help its really appreciated!!
So what is the sold(non adjustable) end of the torsion bar connected to?
What do the different torsion bars do to the chassis that make them more favorable to different track conditions?
Thanks!
|
|
|
|
November 20, 2008 at
08:50:04 PM
|
|
Joined:
|
11/30/2004
|
Posts:
|
1973
|
|
|
Dry, slick track = softer bars to allow the car to hook up to the track
Heavy, tacky track = heavier bars to all the cars suspension to "drive" through the holes or bumps on a tacky track.
One end of the torsion bar is attached to a "stop", a locking device that allows the crew to adjust the spring rate of the bar; the other end is attached to a lever, or arm, that presses down on the axle in the front; the torsion bar is connected to the rear of the car through arms to the rear bidcages.
You need to pick up a copy of Sprint Car ChassisTechnology from Steve Smith Autosports; there are pictures and explanations of the basics of sprint cars and their set-up..
http://www.ssapubl.com/productList.aspx?track=DirtTrack&car=Sprint.
It's a good way to start to learn about sprint cars....
Chuck.....
|
|
|
November 20, 2008 at
09:40:29 PM
|
|
Joined:
|
12/05/2004
|
Posts:
|
305
|
|
|
"Bird Cages" are 'bearing' carriers that slide over the ends of the rear axel. They allow the torsion bar
arms (rear) to attach to it and also allow a radius rod to attach to it also, keeping the rear axel square
to the motor plate. Since the bird cages is slid over the rear axel , as the axel moves up and down
the torsion bar arm twists the torsion bar or untwists it and hence that is your "spring" action. Much like a coil spring in a conventional car. It serves the same purpose. Torsion bars seem to deliver the spring action at a slower rate than a coil spring. Hence a torsion bar car is less "reacting" than a coil spring car.
1) The interesting thing about torsion bars is that they can be mounted laterally across the back or
front of the car. They can be mounted 'longitudinally along the length of the car or even at a angle,
with one end of the bar inboard of the frame and the other outside the frame.
2) If you ask anybody about torsion bars, I bet one of the key points in mounting them, is the Height of the bars above the ground. It seems there is a relationship for height of the rear torsion bars as complared to the height of the front torsion bars.
3) Another interesting thing is you can mount them with one rear bar in front of the other or
visa versa called a "flop tube". I'm sure all rear torsion bars are mounted with a 'slight' angle in them.
They are not exactly parrallel with the ground.
4) Over the year bars have changed in length and of compostition. Some are hollow/'gun drilled'
and some are solid. I think the hollow ones are stiffer and the solid ones are softer.
5) I think one of the common tricks used today is what we call "reverse" split. This is where
the RR torsion bar is smaller in diameter than the LR. By having a softer bar in the RR it allows
the car to roll over in the turns. Just like a skier who buckels in the middle and leans outside the
turn. As the car leans over in the corner is allows the sprint car to turn sharper.
Well I think I said enough....LOL!
Sincerely,
Larry "O" and it' been fun!
|
|
|
November 20, 2008 at
10:32:00 PM
|
|
Joined:
|
09/27/2005
|
Posts:
|
50
|
|
|
The torsion bar is connected to an "arm" and a "stop" on each end. The torsion arm connects to the axle. This is the suspension of the car using the twisting of the bar as a spring. The stop prevents the bar from perpetually spinning. The stop prevents the bar from working out of its housing. The stop also allows for raising and lowering the entire car with a screw adjustment. The size of the bar determines the distance that it will travel. The shocks determine the speed that the distance is covered. I hope you continue to pursue your interest in sprint cars. Remember everyone started out knowing, nothing including Karl Kinser. The only way to learn is to ask and experiment.
|
|
|
|
November 20, 2008 at
11:56:09 PM
|
|
Joined:
|
09/30/2005
|
Posts:
|
1387
|
|
|
with the name of Karl being mentioned I think Karl summed it up with the best piece of observation of ,why he preferred sprint car racing ? it was something to effect of "so much equipment is just hanging together by just one bolt" truly the reason why allot of us follow the sport and a large desire in what makes them work specifically , Steve Smiths book will be good to get a start, read it again and again, follow up questions with a Knowledgeable (but approachable) driver or crew that will let you get your fingers dirty , start busting tires,etc (grunt work, but nessessary), keep in the path (safe distance ) of weekly routine, try to understand changes made to track conditions and why? ( remember drivers are different, and preferr different changes), soon you'll be looking at the latest and greatest innovations in the market, you'll know all about the past, and what is betterand why,Sprint cars are the most interesting cars to learn about ,as a outsider or casual fan, they look pretty complex, reality is, their pretty simple, 90% of the time, the setup to the car will make or break your night . you'll be amazed what you learn , I'm sure your full of questions, I was ! and Im still learning ! , good-luck
|
|
|
November 21, 2008 at
07:54:38 AM
|
|
Joined:
|
07/10/2007
|
Posts:
|
947
|
|
|
Personally, i have never read any of the steve smith tech books but i will say this. I'm sure to someone that doesn't have a basic understanding of how a sprint car works, these books will have a great start point for someone. The only bad thing i can tell you (and i speak from experience) is don't do everything by the book.
*I was asked to help a friend of mine who was starting out with his young son racing and the first night at the track after hot laps (in which the kid looked damn impressive to me for the first time) I asked how much fuel we had for the heat race? He answered, I filled it all the way up cuz i bought a book and thats what it said to do...lol. Thats why i say the book isn't always correct. Nobody needs 28 gallons of methanol for a 3 lap hot lap session lol.
do it in the dirt
|
|
|
November 21, 2008 at
12:28:32 PM
|
|
Joined:
|
09/30/2005
|
Posts:
|
1387
|
|
|
Ya, some of the information in Smiths book is pretty goofey,(mine is the older version) but, the basic knowledge will be introduced and new questions will arise from the reading, its a just a good start ,at a relatively low cost . weed through the personal ideas , and like I said, follow up with someone you can trust that doesnt leed you a stray, maybe hand them the book and they (tutor) can rip out the pages that dont help! LOL
|
|
|
|
November 21, 2008 at
12:37:18 PM
|
|
Joined:
|
11/26/2004
|
Posts:
|
3334
|
|
|
Reply to:
Posted By: meatbag on November 21 2008 at 07:54:38 AM
Personally, i have never read any of the steve smith tech books but i will say this. I'm sure to someone that doesn't have a basic understanding of how a sprint car works, these books will have a great start point for someone. The only bad thing i can tell you (and i speak from experience) is don't do everything by the book.
*I was asked to help a friend of mine who was starting out with his young son racing and the first night at the track after hot laps (in which the kid looked damn impressive to me for the first time) I asked how much fuel we had for the heat race? He answered, I filled it all the way up cuz i bought a book and thats what it said to do...lol. Thats why i say the book isn't always correct. Nobody needs 28 gallons of methanol for a 3 lap hot lap session lol.
|
filling up a fuel tank makes sense to me, now if we could get all racers to do it, maybe we wouldn't have fuel stops in a 12 mile race lol lol lol.
Save your butt, get a colon screening TODAY
For complete line of Sponsor Awards check out
MarshallTownLaser.com
Duane Davis
Laser Engraving
641-751-7777
101 N Center
Marshalltown, Iowa
|
|
|
April 11, 2009 at
09:46:45 PM
|
|
Joined:
|
10/20/2008
|
Posts:
|
33
|
|
|
Reply to:
Posted By: larryoracing on November 18 2008 at 04:29:09 PM
Also a common tool to the modern day racer is a Torsion bar tester/dyno.
When the bar is twisted and will not return to with 10% of it original spec it will be thrown away.
Larry "O"
|
do you know of any good low cost or home made torsion bar testers?
|
|
|
September 13, 2011 at
04:20:35 PM
|
|
Joined:
|
09/13/2011
|
Posts:
|
1
|
|
|
Im alittle late but check out OC Shocks Torsion Bar Dyno.
www.ocshocks.com
|
|