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View Full Version : Dropping LRU bar on birdcage question



sj valley dave
05-26-2010, 04:28 PM
We have GRT bearing birdcages with the 3 slots and I'm wondering what the draw back woul be to lower the upper 4 link bar in the bird cage 1/2 down toward the axle. If you lower it the corresponding amount on the frame, keeping the upper bar angle the same, what would be the drawbacks? We were thinking that by doing that you would give yourself more adjustment for upper bar angle on a real slick track...Pros and cons anyone??

JR. MECHANIC
05-26-2010, 05:28 PM
It will produce more roll steer.

sj valley dave
05-26-2010, 06:17 PM
Sorry I wasn't more specific in my question. I realize it will produce more rear steer, but by indexing the bird cage quicker will it give better instant forward bite? If it does, will it go away sooner? Is there a specific upper bar angle that should not be exceeded at ride height due to the chance of the car getting too much of a severe bar angle. We do use a chain to control drop. LR behind axle only. Thanks

grt74
05-26-2010, 06:55 PM
you dont want to get to much bar angle if you drop it on the bird cage make sure you dont over do it you may have to drop it 1 hole on the frame so it doesnt get to much bar angle or shorten your chain limiter but if you do that you will have to make other adjustments make sure to check your bar angle with the lr hanging and the rr jacked up to where it is when your in the corner

WV_Race_Fan
05-26-2010, 07:26 PM
Sorry I wasn't more specific in my question. I realize it will produce more rear steer, but by indexing the bird cage quicker will it give better instant forward bite? If it does, will it go away sooner? Is there a specific upper bar angle that should not be exceeded at ride height due to the chance of the car getting too much of a severe bar angle. We do use a chain to control drop. LR behind axle only. Thanks

If you index the ULB down on the birdcage V.S. raising it on the frame it will give you a more instant and quick response to the throttle. This change works well on that "inbetween" condition where its still a little brown with moisture but the track is blowing dust. You get more instant traction off the corner but it does go away quicker towards the end of the straight, where as doing it on the frame isn't as quick of a response but you keep it longer.

Either change can work and both have their attributes, but the drawback is if the car isn't hooked up to the racetrack, that instant harder response will simply make the tires break loose easier and that makes the drivers job harder at keeping them from spinning.

Also, when the track is very heavy and fast, try indexing the RR upper link down 1/2" on the birdcage. This helps free the car up and lets it turn on the throttle easier..

Later,

WV Race Fan