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Author Topic:   Can't Get Four Bar To Roll
Matt418
Dirt Roller

Total posts: 20
posted July 10, 2002 03:10 PM
We recently converted one of our 3-Link cars to a 4-Bar and cannot get it to roll over onto the right rear. We have tried various combinations of angles on the bars on both sides, stiffer LR springs, softer RR springs,
and have tried locating the right-rear birdcage at different distances from the tire. Please help! We are about ready to trash the car and go back to our 3-Link.

alkyholic
Dirt Roller

Total posts: 19
posted July 10, 2002 05:24 PM
that would be your best bet, go back to the good ole 3 link. alot of local drivers are going from there z-links and 4 bars back the 3 links cause of easiness to adjust and there less sensitive to track conditions.

28
Dirt Full Roller

Total posts: 36
posted July 10, 2002 07:58 PM
I agree with ALKY, but to help, where is your j-bar or panard bar? Lower that thing and hold on. I run my on the bottom hole and pretty flat and I feel like she's tippin over in every turn. This is very unlikely but you might have your lower links too steep and the car can get stood up and really stiff. Another unlikely could be that your upper Right bar is too steep. This would make sense only if you are on the gas through the whole turn. Once you got off the gas, it should let that bar down and the car roll. My bet is that you need to lower your entire panard/j-bar to lower your roll center. How about the fuel cell? Is it mounted too low?

Matt418
Dirt Roller

Total posts: 20
posted July 11, 2002 12:46 PM
We generally race at three different tracks in our area, two of which are always dry-slick. We have always run in the top three or so unless we have a problem and have won quite a few features with our 3-link. However, it seem this year we have been finishing 2nd to 5th and it is always the guys running the 4-bars that are kicking our a$$ - and by a big margin. We finally decided "if you can't beat 'em, join 'em."

The first night with the 4-bar we ran a long panhard bar behind rear-end and had no bite -
side or forward. The next race we switched to the short bar mounted to pinion and have run this way for about five races. We have tons of forward bite but still no side bite, the car won't get on the right rear at all.

Last week we ran with the upper links one hole from the top on both sides and the bottom links level. Short bar was in second hole from bottom on pinion at about 30 degrees angle. 250 lb spring on LR and 200 lb on RR. This was the best the car has been and we managed a second place, but the car is still not rolling. Do we have too much angle in our short bar? The least amount we have tried was about 22 degrees.

marty
Dirt Forum Racer

Total posts: 96
posted July 11, 2002 12:57 PM
You could try checking the back suspension for binding. Just disconnect the shocks/spings, jack up the back of the car & try lifting each end of the axle (so that one side is in full bump & the other full drop). If the opposite side tries to lift up with it you have a bind up.
Probably teaching you to suck eggs but its easy to overlook.
marty.

28
Dirt Full Roller

Total posts: 36
posted July 11, 2002 02:56 PM
I tried the short panard and didn't like it. I felt like it would jack up the car too much and make it eratic. I run a J-bar and it seems to be a happy medium. That seems like a lot of angle to me in your panard. When it is that steep and pushing on the drivers side of the housing, it is loading the LR in the turns. Of course your side bit is RR so you need to get more weight there. I know a DW-8 4 bar car in CA that is running about 60 LBS of RR bite. He has steep angles, short bars and it works great. I suggest lowering to the bottom hole on the pinion and keeping the same angle with the short bar. If it feels better, keep droping the chassis side until it is where you like it. With your top links so steep, you have to something drastic to get the body roll.

Matt418
Dirt Roller

Total posts: 20
posted July 11, 2002 03:23 PM
Thanks for the input. Those Dirt Works cars are the ones that seem to kicking our butts!

We may try the J-Bar this weekend. That's about the only thing we have not tried. We tried the short bar in the bottom hole for one race but maybe we had too much angle in it. Maybe we will try that with less angle.

Thanks for the suggestion Marty. We have tried jacking our car up and moving things around and found a few problems the first week but cannot find any binds in suspension now.

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