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View Full Version : j-bar -vs- straight bar ??????



racinjason29
01-20-2013, 06:50 PM
I have a Rayburn swingarm that currently has a straight bar. What would the straight bar do -vs- what a j-bar would do. Whats the difference in handling, and what are some suggestions? Im new to latemodels so if you need more info on the current setup of the car just ask, thanks in advance!

7uptruckracer
01-21-2013, 11:49 AM
The shorter bar will gain dynamic angle or rake quicker. More and quicker hike or roll over

Matt49
01-21-2013, 12:14 PM
7up is correct assuming we are talking short bar mounted from the left side of the pinion to the left side of the chassis.
This can be a good setup for stop and go race tracks. Car will rotate quickly because of the sudden rear steer and have good LR bite coming off because of the way the bar loads the rear end.

7uptruckracer
01-21-2013, 12:36 PM
You normally have to run less static rake when you set it up because that short bar does gain rake a lot quicker! Good luck!

racinjason29
01-21-2013, 06:58 PM
I run typically on small 1/4 -3/8 tracks. Tight corners, so the straight bar would be a better choice for these tracks? The bar is mounted on the left side of the chassis to the left side of the pinion plate. What happens when I move it up and down on the chassis or pinion plate?

abe_05
01-21-2013, 08:03 PM
If you are running pull bar, you will have to pay close attention to pinion angle and keeping rearend in same spot (left to right). Measure from brake rotor to bolt mount at swing arm on frame. Unless you have the updated new pull bar mount that Rayburn has come out with. If not, I would highly reccomend looking at updating and changing to new pull bar system.

Matt49
01-21-2013, 08:13 PM
I run typically on small 1/4 -3/8 tracks. Tight corners, so the straight bar would be a better choice for these tracks? The bar is mounted on the left side of the chassis to the left side of the pinion plate. What happens when I move it up and down on the chassis or pinion plate?

It could work great but some of this is driving style preference. The short bar is VERY quick to react to lateral weight transfer.
Adjustments follow the same general rules as any lateral locating device that is somewhat controlling rear roll center...to a point...too much angle and you'll have your hands full.

Matt49
01-21-2013, 08:21 PM
Good question from abe on your lift-bar vs. pull bar situation. I assumed lift bar (not sure why since you didn't say in the OP).

After re-reading your OP, I see "new to late models". Unless you have been in a modified previously, I would recommend doing what you can to SLOW down the action of the car until you get used to it. A longer bar (j-bar) would do that for you.

I'm certainly no expert on Rayburns so some other guys on here can help set you straight on setup but IMO a short bar is going to be a bit of a shock if you're new to the seat of a late model.

Get yourself a good baseline from some of these Rayburn guys on your overall setup and go from there but like I said, the short bar is going to be VERY touchy. Good luck!

old17ford
01-21-2013, 09:51 PM
I have a Rayburn swingarm that currently has a straight bar. What would the straight bar do -vs- what a j-bar would do. Whats the difference in handling, and what are some suggestions? Im new to latemodels so if you need more info on the current setup of the car just ask, thanks in advance!

What about a straight bar from right side of pinon to right side of frame ?

twisterf5
01-21-2013, 10:09 PM
What about a straight bar from right side of pinon to right side of frame ?i built a stock clip car and ran one like that behind rear at 10 degrease down at frame worked good until the sorry a tec banned it. the strait bar on left can be very violent when getting into the corner not something you should try at first. stay with the j-bar.

95rayburn
01-21-2013, 10:52 PM
Twisterf5. What do u mean by violent in the corner. Would u use the straight bar on a dry slick track

7uptruckracer
01-22-2013, 08:34 AM
Violent because a short bar makes a tighter arc then a long bar so the car can roll up very very quickly and react very quickly so you can run into the combo of too much static rake combined with how quickly it can gain rake the car can react so quickly that its not beneficial to use and not consistent. Definitely use a suspension limiter.

twisterf5
01-22-2013, 08:50 AM
Violent because a short bar makes a tighter arc then a long bar so the car can roll up very very quickly and react very quickly so you can run into the combo of too much static rake combined with how quickly it can gain rake the car can react so quickly that its not beneficial to use and not consistent. Definitely use a suspension limiter.
yep that be it. broke a j-bar mount on pinion a couple of years ago just before our feature did not have another one so we put the strait bar on at a long 1/2 mile track the first corner was a hand full almost rolled it over. it also changes roll center the bad thing with it is if you hit a hole going in you will regret having it on. i always carry one as a back up it it would be a last resort for me to use one.

ev36rayburn
01-22-2013, 09:31 AM
We ran straight bar on our rayburns for several years before switching chassis brands, but, it worked great and helped our car tremendously. Just keep your angles to a minimum and def use a chain to limit travel etc.

racinjason29
01-22-2013, 06:38 PM
the car currently has a chain on the left rear to limit travel and the bar doesnt have alot of angle, if I switch to j-bar, should I remove the chain? Also I am on the new pull bar set up, my Rayburn has all the 2012 updates

twisterf5
01-22-2013, 06:57 PM
the car currently has a chain on the left rear to limit travel and the bar doesnt have alot of angle, if I switch to j-bar, should I remove the chain? Also I am on the new pull bar set up, my Rayburn has all the 2012 updateskeep the chain keeps the car more consistent.
how long is there new set up. pull bar end to end

abe_05
01-22-2013, 07:04 PM
Keep the chain on, this will keep you pulling shock apart. If you have new pull bar setup, it will have slider bracket will a monoball inside mounted on frame with rod going down to pinion on rearend. This is what you need to be on.

95rayburn
01-22-2013, 07:12 PM
Was wondering if anyone can show me a link or has a picture of rayburn new pull bar setup

ALF401
01-22-2013, 10:03 PM
I would like to see a picture or a link to see the new Rayburn pull bar set up.

abe_05
01-23-2013, 08:52 PM
I don't know if CJ has made changes to pull bar mount in last 6 months but this is how it works: pull bar is mounted to rearend like before on top, the mount on frame is what is so different, it is a tube with a ball and the ball has a shaft that runs thru it, the tube is sloted on both sides so shaft is sticking out both side like a slug mount. One side the pull bar is mounted to and the other side has a rod that goes down and mounts to pinion plate. The idea is keep angle in pull bar. The ball mount just rolls down, it stays constant height over the rearend. I personally had run Rayburn for couple years and I was playing running rear trailing arms down low on both sides, this was picking rear of car up a lot give more rear steer, more bar angle was giving instant tracktion and it was correcting my problem with being so tight in corners, one problem with body coming up so high the pull bar is now strait, it had lost all angle and now forward bite is gone. This was working good for me on really hooked up tracks. Car was driving more like 4-bar car but with this new setup the pull bar stays constant a lot all times. Adjusting pinion angle will be easy, the only problem is last summer CJ working with couple drivers on fine tuning exactly were to mount it, how much angle on pull bar, if you keep a lot of angle in it the pull bar never stops picking up on car so trailing arms and swing arms have to fine tuned as well. I sold my car last year but very interested in how this car is going to work. I think this will be have to fine tuned some what but this is going to be good.

dualdj1
01-24-2013, 09:52 PM
Abe that sounds exactly like the issues we were having in the Rayburns when we left them. Had bars good, short straight bar and traction shock for great hike/transfer, but just couldn't get any foward bite. We actually ran 2 pull bars a couple times and it was better, but not enough. I'm very anxious to see how that works out.


For shot straight bar, it's very usable, especially on rayburn if you want hike. It works great in the tacky, just keep the rake real low. 3-4". However, in the slick, I'd think you'd be better off with the purple bar, and not have it hike up so the pull bar works better.