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Author Topic:   4/2 ?
Todd83C
Dirt Forum Racer

Total posts: 76
posted December 11, 2005 05:38 AM  
I was wondering what is better on the left rear bottom bar short or long? Right now it is 20 3/8 center to center and 16 3/4 on the top bar spring in front not on floater. The left is 20 3/8 with spring on top of housing. What are the pros and cons of running a long or short bar on the left on this setup? Thanks

ENFORCER
Dirt Newbie

Total posts: 1
posted December 11, 2005 01:53 PM  
quote:
Originally posted by Todd83C:
I was wondering what is better on the left rear bottom bar short or long? Right now it is 20 3/8 center to center and 16 3/4 on the top bar spring in front not on floater. The left is 20 3/8 with spring on top of housing. What are the pros and cons of running a long or short bar on the left on this setup? Thanks

typically your left side lower bar should be about 2" shorter than the top bar, maybe you could re-explain what your r.side set up is and your l.side.

Todd83C
Dirt Forum Racer

Total posts: 76
posted December 12, 2005 04:20 PM  
Didnt think it would confuse anyone but. It is a 4/2 set up left side 4 bar lenghts are top bar 16 3/4 lower bar 20 3/8 spring is on slider in front of axle and is clamp to rear end. Right side is 2 link bar lenght is 20 3/8 spring is on top of rear end. Would i be better off to put a plug in the left lower to shorten that bar? What would this help over the long bar? anyone?

[This message has been edited by Todd83C (edited December 12, 2005).]

washeduptoo
Dirt Maniac

Total posts: 171
posted December 12, 2005 04:31 PM  
Go to the green Menu box on the top left of screen, click on it,click on tool box,scan down screen to designing and tuning 4-link,click on it, it explains very well what you are asking about shorting bottom bar way lot better than I can. Hope this helps you. If you need help with the 2-link, I might can help you as we have run the 4-2 with the spring on top and behind.

Kromulous
Dirt Forum Champ
Total posts: 842
posted December 13, 2005 05:50 AM  
The long lower bar 4-Link is good, but i've never run it with it clamped in front.

The two main reasons to run it are, less rear steer, and indexing of the birdcage. The birdcage indexes alot more, into the spring on a LR behind. SO alot of guys that run the long LR lower run spring behind, with it clamped up front, you wouldnt get that benifit.

Only thing you would be gaining is less rear steer. You will probaly find that the car is often serously tight on a decent track, but good on dry slick. The long lower on the LR is generally a dry slick deal.

We have been running it, and like it. I just run alot of rear stagger to get it to turn off, and LR bite to turn in when the track is ripe.

Alot of LR bar angle in the lower will help as well, my base on a small 1/4 mile is 11* up on the lower. Less (about 5* up) on a couple bigger tracks.

Krom.

[This message has been edited by Kromulous (edited December 13, 2005).]

WPP
Dirt Freak

Total posts: 464
posted December 13, 2005 08:38 AM  
I have also a ran the long lower bar with the 4-bar clamped on a 2003 dw the lower bar was 20 3/4 with the upper 14.5 on the dw .I wish i would have tried the spring behind with it . I did have a lot of bite.The car was very hard to turn. But my tuneing was not the best at that time. I had way too much angle in the short upper bar the lower long bar was level and i can look back on that set-up i should have addes angle to the lower bar took angle out of the top bar .At this time i was running a 175 lr it should been around 200 or 225 with a 175 on top of rear with z-link and i had 50pds rr bite .Still packed the wheel down the shoot. I think this can be made to work. I just sold the car and bought a pierce.

dirtbuster
Dirt Forum Champ
Total posts: 2030
posted December 13, 2005 11:15 AM  
We ran a long lower on our DW. Just took the plug out and ran a regular 2 link bar there about 21" long with a 17" upper. They are right its hard to get it to turn sometimes but it will keep rear steer out. We had about 10-12 degrees in the lower vs. 5 with a shorter bar.

oldfordmod
Dirt Full Roller

Total posts: 54
posted December 15, 2005 05:55 PM  
You guys are confusing me, I thought you wanted rear stear. Whats the idea behind reducing it.?

Todd83C
Dirt Forum Racer

Total posts: 76
posted December 15, 2005 06:29 PM  
I also dont unstand that. The more rear steer should work good on a dry slick bucause it keeps from breaking the grip as much, to were less swhould be best on a tacky track or do i have this backwards?

zeroracing
Dirt Forum Champ
Total posts: 1928
posted December 15, 2005 08:31 PM  
I run the long bar ALOT, sometimes run a short one. The longer bar on the bottom allows the car to do a few things at once.
1) Most important-Indexing, the longer left rear lower bar will cause the bottom of the cage to be held further back, while the top is stil being pulled forward. The increase indexing will allow the car to keep the LR behind spring loaded for a longer amount of time, and to a larger amount, whereas the shorter lower will pull the bottom forward also which can cause the spring to become completly unloaded, we have all seen the car jacked up or hiked up and the spring just dangling. When your car is like this your not using the spring as much, your just going off the solid links, as if your spring rate is approaching infinity.
2) Decrease of rear steer, It lower the rear steer of the car somewhat. Everybody says you want the rear steer. Well on some tracks larger, or some others you dont want the large rear steer. Alot of 4 bar cars will get hiked up, and have a TON of rear steer to them. They will then have the rear wheels pointed to the wall, so the car will feel as if it is starting to pivot around the center and spin itself out. So the driver automatically will do what comes natural and turn the front wheels slightly to the right to compensate for the car feeling loose. Now you have all 4 wheels pointed to the wall. Where is the car going to go??? Now sometimes on a short tightcorner track the rearsteer maybe needed to keep the car loose in the center of the corner and hope you have room to throttle all the way out and down the straight.
3) help to lesson the violent reactions of the car with the track surface, short bars can hit ruts and knock themselves down, but the longer bars take more to upset them.

In the end, I feel thru testing that long lower bars, and short lower bars all have a place. Knowing where to use them is the key.
If the track is rough, tacky all the time, longer track stuff like that, lots of traffic maybe. Any of thoes the long lower can work well to give you a drivable and consistant car, Also sits on the track smooth when letting out of throttle.
Short lowers on places where a ton of rearsteer is needed. Or you want the look of the pogo stick. Or its super smooth and you want an infinate lr spring.

I have been running the long left rear lower and working with it for over 2 full season, before there was much talk about it. I got alot of funny looks at the track, but sitting and thinking it out this is how i wanted my car.

Notes to keep in mind though. 1. Make sure you will not be going overcenter on your birdcage, that will keep you hiked up all the time. You dont have to have monster amounts of bar anlge,I run my lower level most the time and upper like 15 deg.

Final note to think about people out there,this goes with another post on the forum. The days of pogostick racing was short lived and this is the days of balanced cars both forward bite/drivablity.
goodluck
jason

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