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Author Topic:   Adding swingarm
Desert Mod
Dirt Full Roller

Total posts: 60
posted February 05, 2005 07:53 PM  
What advantage is there to running a LR swingarm on a three link and a regular trailing arm on the RR? Will that work with the long panard bar behind the rear end or would I need to switch to a J bar?

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 07, 2005 07:48 AM  
No one has any thoughts on this?

Chad
Dirt Freak

Total posts: 269
posted February 07, 2005 11:32 AM  
What are you trying to accomplish???

I know everyone's quick response is "more forward bite", but are you also trying to make the car work better on rough track, smooth slick track, or what???

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 07, 2005 12:41 PM  
This is the setup I'm going to start the year off with. From what I have been told, and seen, the car goes better on rough tracks, and also on the slick has more foreward bite. My suggestion would be to run either a J bar or a Shorty bar. With the spring on the arm remember you'll need a little stiffer spring. I'm starting with a 225 on the arm and then a 200 on the right rear on top of the housing.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 07, 2005 01:34 PM  
Extreme,

That's what I'm after. Have you heard of this being tried with the long panard bar? I'd have to put in a new frame mount for a left-side (or right-side for that matter) mounted J bar. And how much stiffer on the springs? I'm currently running a 150# RR and 175# LF as I recall. Are you increasing both rates or just the left?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 07, 2005 01:46 PM  
The short bar or J bar would be better. Fabbing up your mount shouldn't take much work. Use a 2x2 square tube for the mount. The only way you'll get a real good bite from your long bar is a TON of angle in it.
I'd increase both sides. 175/150 seems very soft. The softer the track the softer the spring, the harder the track the harder the spring. Same goes with shocks.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 07, 2005 01:53 PM  
Thanks, Extreme. I'm new to the J bar. Do the angles work the same with that as with the long bar? Also, is a solid J bar better than one with a snubber on it?

Also, thanks Chad for your response, as well.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 07, 2005 03:36 PM  
Desert Mod

The J bar will work just like your Long bar. For increased side bite, add more angle on the frame side, less vice versa. We have always ran the solid J-Bar. No reason to have your rearend shifting when you are in the corner more then the bar allows. Some guys have snapped the ends off of them but I have never seen it.
You'll want to start with the bar basically level, but your mounting points will be different. As a rule of thumb at ride height, take and get yourself right on the ground and look over the top of the axle tube. From there estimate about 1 inch up off of that and clamp your clamp on bracket right there on the chassis. That should put the J-bar on the pinion about even or one hole below the pinion. You can always play around with the bar as in how high you mount it at the same angle, how low you mount it with the same angle. I do prefer the Short bar with less angle, but the J bar does the trick on a lot of tracks. Don't be afraid to play around with it, just keep it at a reasonable angle.

What kind of chassis is this going on?

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 07, 2005 03:56 PM  
Extreme,

2000-1 Shaw. What is a good thickness for the 2 x 2 square tubing? .095, .120?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 07, 2005 04:53 PM  
I'd go with the thicker stuff. Lay a real good thick bead down. You'll like the J-Bar. Most guys are getting away from the Long panhard these days. I remember an article that the jet was quoted in saying "i'll never run, or build a car with short links it just isn't the way to go" and now thats all he runs is short links and short panhards. Tune it to your liking and go win some races!

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 07, 2005 09:14 PM  
Thanks, Xtreme. Very good info. I'm not sure if I have the time to convert it before the next race but I think I'll be doing it soon.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 07, 2005 09:21 PM  
Take some pictures of the left rear with the tire off and shoot them to me. I'll see if I can help you out. Should be able to do a good job in a matter of an hour or so. One thing you'll want to do is go ahead and hook up your j bar, and then hold it where the 2x2 tube will be, and make sure you get the 2x2 in there ahead of where your going to mount it, that way when the rearend crawls foreward you have good clearance.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 07, 2005 10:07 PM  
I appreciate the offer but I think I can figure that part out. It's just that lately I'm pretty much a one-man show, although my one occational helper/engine builder did show up on Saturday for a few hours to get the new block ready to assemble. :-0 I've still got a bunch of frame patching to do on the front end, plus the reassembly and set up once the new engine is finished, assuming he shows up again to work on it. If I can get everything else done, I may try to get it done next week.

Are you running a coil over kit on your swingarm and, if so, which one?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 07, 2005 10:15 PM  
I had thought about it, but really all the coil over's do is make it take twice as long to change a shock. I just run a good quality coil over elimnator, or I'd even run it off a jack bolt. If you don't plan on changing shocks much, then run a coil over. I also just run cheap Pro WB shocks, they work just as good no matter what anyone says, and when I break one it doesn't cost me an arm and a leg to fix or replace.

Another thing you might fabricate is a mount for the top moutning point of your COE or Coil Over. Weld on a Jack bolt where the mount would be, and then on the bottom of a Jack Bolt weld a shock mount on, so that you can adjust your ride height when you change swingarm angles. That is the only downside to the swing arm is that it is a son of a beach to change your angle. How much angle are you currently running??

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 08, 2005 08:40 AM  
That's a good idea on the new jack bolt if I go that route. I was thinking of a coil-over so I could just use the existing shock mount. The existing spring mount is over the rear end so I wouldn't be able to use it with the swing arm.

I don't curently run a lot of panard bar angle; maybe 1" - 2" depending. I haven't regularly raced for a while and this year the local place is openning back up so it's sort of like starting over on setups.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 08, 2005 11:22 AM  
With your J bar, set it like I stated, with the rearend at ride height. If you are still lacking side bite you can always slide that bar up and get more angle. How far down off the bottom of the axle does your trailing arm mount?

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 09, 2005 08:30 AM  
The current straight trailing arms mount 3 3/4" below the axle housing, as per mfg. specs. There is another hole about a inch up. The bars on both sides are mounted in the upper hole of a two hole mount.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 09, 2005 09:31 AM  
A suggestion, go to a local s**** yard and pick up some 1/2 inch thick steel, and cut yourself 2 new mounts for the rearend. Make them 8 inches from the bottom of the rearend. What you'll do is cut yourself like a 9 inch peice and then take something that is a 3" OD pipe and trace it on the top of this piece you just cut. Then cut out the part you marked. This will give a flush fit on the rearend. Then from there take and measure 7 inches down and drill a hole for the trailing arm to mount. If you are running 3/4 trailing arms drill and tap for that arm, and same for a 5/8 tube. Then what you'll want to do is drill another one about 2 inches up from that.

On the chassis, order 2 5 hole brackets from places like A&A Manufacturing and cut off the existing mounts and weld these on. You can never have too much adjustment on a 2 link. Some nights we see about 35 degree's uphill angle in our left rear bar. I can draw out a plan for the rearend brackets if you'd like.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 09, 2005 09:40 AM  
What are you doing with the RR trailing arm? Leaving it as it is?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 09, 2005 11:35 AM  
Your going to want to do the same thing on the right side also, but not as much angle. Say 10 degree's to 15 uphill to start, if it is tight move it up a hole, if it is loose move it down a hole or two

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 09, 2005 12:39 PM  
Are you changing the length of the bar each time you move it in order to maintain rear axle location or is the point to put in and take out lead in the RR?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 09, 2005 01:24 PM  
Normally when you adjust your angle the bar length doesn't change. You can always lengthen them out but really the left side should stay one hole from the top and that way you can put it on kill mode (top hole) when it goes dry

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 09, 2005 01:28 PM  
So I guess now I'm confused about whether you are talking about the RR or the LR. Could you clarify. I really appreciate the input, Xtreme12x.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 09, 2005 04:32 PM  
I'm talking about the left side in the previous post, but you'll want to give the RR a lot of angle too with new mounts. Do the same you do on the left side to the right but don't start with as much angle. You will want to be ready for a little three wheel action but if you tune it right you'll get the left front to stick down good. Keep on top of all of your heims and bolts to make sure there good and tight.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 10, 2005 07:30 PM  
Thanks, Xtreme. I may look at converting in a few weeks. As it is now, my help bailed on me again so I'll be lucky to make the next show in a week with the old engine and the car back in in its original setup. I may give you a shout when I get ready to make the change. BTW, this has been a great discussion. Thanks again.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 11, 2005 02:33 AM  
Whenever you get stuck or have questions you can always e-mail me xtreme12x@mchsi.com or post on here and there are quite a few of us that are real knowledgeable in this department. When you get it done check all your angles and shoot us some pics.

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