Angled lower arms on a 4-link?

90pickup · 12-04-2006, 01:10 PM

Do I really need angled lower arms on a 4-link, because of rearsteer? And if yes how much? The upper arms got a (2x20`) 40 degree angle.Thanks

bigblackblur · 12-04-2006, 01:14 PM

Quote:

Originally Posted by 90pickup

Do I really need angled lower arms on a 4-link, because of rearsteer? And if yes how much? The upper arms got a (2x20`) 40 degree angle.Thanks

Your uppers are only 20" long? Pics.

HOT_DAMN · 12-04-2006, 01:22 PM

i think that is supose to be degrees.

90pickup · 12-04-2006, 02:17 PM

Yes, that`s degrees....

bigblackblur · 12-04-2006, 02:26 PM

well the more triangulated they are then the less chance they will interfere with your rear steer. I don't have rear steer but I have about 22 degrees of triangulation on my lowers, and 35 degrees on the uppers. I think that 40 degrees on the uppers allows you to pretty much do whatever you want on the lowers, even put them straight if you wanted.

currupt4130 · 12-04-2006, 03:01 PM

Quote:

Originally Posted by bigblackblur

well the more triangulated they are then the less chance they will interfere with your rear steer. I don't have rear steer but I have about 22 degrees of triangulation on my lowers, and 35 degrees on the uppers. I think that 40 degrees on the uppers allows you to pretty much do whatever you want on the lowers, even put them straight if you wanted.

I think he's referring to rear steer as what happens when the axle shifts position causing the tires to change slight direction under articulation

Quick & Dirty · 12-04-2006, 03:07 PM

If the lowers are not triangulated they have to be nearly parallel to the ground to avoid flex steer. That probably means low hanging frame mounts, or high axle mounts.

To get technical, you want the intersection point of the lower links to be near the same height as the intersection of the upper links. If the lowers are not triangulated the intersection is at infinity, so your roll axis is parallel to the lower links. The farther the lowers are from horizontal, the more roll steer the suspension has.

Triangulating the lowers allows them to be at an angle from horizontal while keeping minimum roll steer.

90pickup · 12-05-2006, 12:55 PM

Thanks for all the replys...I think it saves my some trouble if I put the lower arms angled as well.

12-04-2006, 01:10 PM	#1
90pickup Registered User Join Date: Nov 2006 Member # 82410 Posts: 21	Angled lower arms on a 4-link? Do I really need angled lower arms on a 4-link, because of rearsteer? And if yes how much? The upper arms got a (2x20`) 40 degree angle.Thanks

12-04-2006, 01:22 PM	#3
HOT_DAMN Registered User Join Date: Feb 2006 Member # 66873 Location: Keller, TX Posts: 262	i think that is supose to be degrees. __________________ I wanted it, I built it, Home use or not, I don't care, it's bad ass. 92 Chevy, tubed front and rear, boat sides, sitting on rockwells. Link to my build http://www.pirate4x4.com/forum/showthread.php?t=568414

12-04-2006, 03:07 PM	#7
Quick & Dirty Registered User Join Date: Nov 2004 Member # 38200 Location: Wisconsin Posts: 205	If the lowers are not triangulated they have to be nearly parallel to the ground to avoid flex steer. That probably means low hanging frame mounts, or high axle mounts. To get technical, you want the intersection point of the lower links to be near the same height as the intersection of the upper links. If the lowers are not triangulated the intersection is at infinity, so your roll axis is parallel to the lower links. The farther the lowers are from horizontal, the more roll steer the suspension has. Triangulating the lowers allows them to be at an angle from horizontal while keeping minimum roll steer. Last edited by Quick & Dirty; 12-04-2006 at 03:21 PM.

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12-04-2006, 02:17 PM	#4
90pickup Registered User Join Date: Nov 2006 Member # 82410 Posts: 21	Yes, that`s degrees....

12-04-2006, 02:26 PM	#5
bigblackblur Registered User Join Date: Mar 2005 Member # 44321 Location: Denver Posts: 942	well the more triangulated they are then the less chance they will interfere with your rear steer. I don't have rear steer but I have about 22 degrees of triangulation on my lowers, and 35 degrees on the uppers. I think that 40 degrees on the uppers allows you to pretty much do whatever you want on the lowers, even put them straight if you wanted.

12-05-2006, 12:55 PM	#8
90pickup Registered User Join Date: Nov 2006 Member # 82410 Posts: 21	Thanks for all the replys...I think it saves my some trouble if I put the lower arms angled as well.