Which LCA to get for my 2007 GT
08-31-2010, 09:17 AM
#1
Which LCA to get for my 2007 GT
I need to replace my rear LCA's on my 2007 GT. I've been looking at the billet LCA's from Steeda but I wanted to double check with people here to make sure those are recommended pieces or if there is something else that would suite my needs better.
Basically, now that I have the chance to upgrade I want something better than the stock pieces. I may decide to lower my car in the future, but if I do it would be a conservative drop of maybe and 1-1.5 inches. I'm not sure if a set of adjustable LCA's would be better or not.
Let me know...
Basically, now that I have the chance to upgrade I want something better than the stock pieces. I may decide to lower my car in the future, but if I do it would be a conservative drop of maybe and 1-1.5 inches. I'm not sure if a set of adjustable LCA's would be better or not.
Let me know...
08-31-2010, 10:27 AM
#3
The bushings on mine now have started to deteriorate and are making a lot of noise. Plus, I was hoping that better aftermarket units would eliminate some wheelhop. I don't take my car to the strip, but I do enjoy the occasional light to light race.
08-31-2010, 10:35 AM
#4
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Join Date: Sep 2007
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You don't need adjustables because you are lowering the car (or planning on it). Those are for fixing thrust angle in the axle (the axle being cockeyed in vs. the body when viewed from above).
As for which LCA's there are a number of good ones. The Steeda Billets are gorgeous and light---though if you went that way I'd recommend the set with the spherical bearings in the rear position vs. the all poly. UMI also makes a lot of very nice control arms as well. There I'd recommend one of types that are what we call "poly/roto-joint" combinations. UMI stuff is tubular steel, vs. billet aluminum.... of course they cost less for that reason but the quality is very, very good.
As for which LCA's there are a number of good ones. The Steeda Billets are gorgeous and light---though if you went that way I'd recommend the set with the spherical bearings in the rear position vs. the all poly. UMI also makes a lot of very nice control arms as well. There I'd recommend one of types that are what we call "poly/roto-joint" combinations. UMI stuff is tubular steel, vs. billet aluminum.... of course they cost less for that reason but the quality is very, very good.
08-31-2010, 10:58 AM
#7
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Join Date: Sep 2007
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You don't want the axle moving fore and aft freely, but you want it to rotate freely so when you hit bumps or dips with one wheel that impact is not transmitted to the body fo the car. Think of a rock crawler and the articulation needed....
A more solid arm doesn't want to flex like stock. And the poly bushings don't want to flex either. You are basically making the rear suspension more rigid, the ride quality suffers as does the grip in the back of the car on imperfect surfaces.
Poly/poly works great for drag racing, and curing wheel hop--but there are better solutions (and not always more costly depending on the brand and product) for the other aspects of how you drive your car.
A more solid arm doesn't want to flex like stock. And the poly bushings don't want to flex either. You are basically making the rear suspension more rigid, the ride quality suffers as does the grip in the back of the car on imperfect surfaces.
Poly/poly works great for drag racing, and curing wheel hop--but there are better solutions (and not always more costly depending on the brand and product) for the other aspects of how you drive your car.
08-31-2010, 10:59 AM
#8
3rd Gear Member
Join Date: Apr 2008
Location: Texas
Posts: 671
acascianelli, the reason to use a LCA with a spherical bearing is that it allows the axle to properly articulate, reducing bind and the unwanted handling characteristics associated with it. With poly bushings at the axle, when one side is forced up (or down) relative to the chassis, a torsional force is applied through the LCA pivot, which the bushing tries to resist due to its stiffness. This can cause an effective and sudden increase in spring rate, which can upset the chassis. With a Spherical joint the axle is free to continue its travel without that added resistance, allowing for smoother articulation.
08-31-2010, 11:19 AM
#9
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
Easiest way to visualize this is to picture yourself following the car as it rolls in a hard corner or when one rear wheel rolls over a bump.
In both cases, an angle is developed between the body and the axle - either the body rolling or one end of the axle moving up before the body "catches up" - which the end connections of the LCAs have to allow, otherwise the LCAs themselves have to twist. Any spherical joint/rod end/roto-joint/Johnny joint allows this angle to happen without the LCA itself being twisted in torsion. This also applies to the UCA.
Ride quality is better in most respects - your head doesn't get tossed from side to side nearly as much if the LCAs are freely permitting this rotation - and the amount of "lost" roll stiffness is not worth thinking about.
Norm
In both cases, an angle is developed between the body and the axle - either the body rolling or one end of the axle moving up before the body "catches up" - which the end connections of the LCAs have to allow, otherwise the LCAs themselves have to twist. Any spherical joint/rod end/roto-joint/Johnny joint allows this angle to happen without the LCA itself being twisted in torsion. This also applies to the UCA.
Ride quality is better in most respects - your head doesn't get tossed from side to side nearly as much if the LCAs are freely permitting this rotation - and the amount of "lost" roll stiffness is not worth thinking about.
Norm
Last edited by Norm Peterson; 08-31-2010 at 11:23 AM.
08-31-2010, 02:26 PM
#10
3rd Gear Member
Join Date: Sep 2009
Location: Cali
Posts: 702
And despite what people say i really didnt notice much if ane NVH when i installed my poly/rod end LCA's. If you have music on or the windows down or hell even a loud enough exaust you wont notice any noise.