Are solid thrust bushings worth it?

I'm going to be installing new lower control arms so this would be a good time to replace the rubber bushings.

Tarret

They will increase NVH.

I like the adjustable ones on the front end because I can precisely dial-in the caster.

Tarret ones are a pain to adjust. I personally use non adjustable ones and get adjustable trailing arms instead like the SPC ones with sealed ball joints.

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Interesting. That's what you would think but some say they have very little increase in NVH. Have you used them?

Its a part u dont need unless u r tracking your car regularly. If u look at a parts diagram u will see its in the middle of several other rubber bushings. If u dont replace all of them with solid heims the ride will be the same and your wallet will be lighter

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I used Elephant Racing LCAs with solid bushings and spherical bearings. Wasn't tracking enough to put up with the NVH and went back to stock (Rennline) GT3 LCAs with rubber bushings and mounts. They were *definitely* sharper with handling, but not really well suited to the roads around where I am.

A clip from an old auto mag on max g force of oem sports cars Car Type of G-force & Peak G-force 2.004 g Dodge Challenger Demon 170 Acceleration g KoenigseggOne:1 Cornering g 1.6 g Porsche 911 Carrera 4S Cornering g 1.39 g Jeep TrackHawk Acceleration g 1.3 g 2020 Chevrolet Corvette Stingray Cornering g 1.3 g Same results more or less in the slalom. The 911 handles with the best of them consistently. Seems the 911 is in good company at 2nd on the cornering pulling g's list, only beat by the hyper exotic cars costing tons more ca$h. So, my question to all those looking to put race car suspension components on their street car or occasional track car, and not in a competitive race series. What is the goal here..? If its to add noise, harshness, vibration & quickly worn out tires, then I understand. Does handling of the oem car really need an improvement/compromise beyond what a total refreshed oem suspension set at somewhat stock alignment specs can achieve with sticky tires..? I say no, unless one is looking for 'show'.... jmho

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How have the Rennline GT3 LCAs been holding up? Are they forged or cast?

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Pretty good so far. yes, I believe they are forged 6082 aluminum.

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Can you run the litronic thingies with them?

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Yep, they have mounting points.

Solid aluminium (Solid rubber ones to a lesser extent) will take away the 'give' that the original rubber bushing, with its voids provide in longitudinal direction. This helps to smoothen driving over repair patches, expansion joints etc. and takes away the sensation of crashing over them without the suspension absorbing anything. At the same time the stock bushings are solid in lateral direction, so any cornering force build-up by the tyres is transferred to the chassis/car with minimum delay. Only if the stiffness of rubber solid bushes in lateral direction is higher than stock, you would feel a quicker response to a steering input. New stock bushes would already be an improvement over old ones in that respect. HTH

That got me thinking about the thrust bushings. Yes as you point out it now seems clear the diagonal provides fore and aft stability for the lower control arm. And the bushing dampens fore/aft forces. I presume these are less significant than up and down forces that the suspension absorbs. I'm going to install these as they are and run them for a while to see how they go. As @De Jeeper noted, there's rubber at both ends of the coffin arms so there will be only partial constraint of the LCA with a solid thrust bushing. Vendors claim there is negligible increased NVH, likely for the same reasons, and therefore recommend them for Street as well as track applications.

How elasto-kinematic toe change works in Porsche suspensions | Tech Tactics tl;dr: the rubber bits in Porsche suspension arms are designed to sharpen cornering (in addition to the NVH and other stuff). You Tube

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Thanks @wdb . Good video. I missed that one when it first came out.

That's interesting. He's saying that rubber bushings are not a compromise, they are a benefit at speed and claiming that they improve geometry/handling. How does that explain using spherical joints and eliminating rubber connections? That aside, I'm still going to install my coffin arms and keep the stock rubber thrust bushings until otherwise.

Haven't watched the video (yet) but elasto-kinematics are designed such, that lift-off oversteer is reduced by reducing the corner outside front wheel's steering (more precisely put: tyre slip) angle. For that you need an elastic joint.That elasticity dulls the response to driver inputs (as well as the vehicle's reaction to any disturbances). A solid spherical joint doesn't allow for elasto-kinematics and the driver himself has to reduce front axle side force by reducing the steering wheel angle in case of lift-off oversteer. Reason to install solid bushes, spherical joints and the like, is the improved/shorter response time to driver inputs. A (very) good driver can drive a course with direction changes in short succession quicker with solid bushes and spherical joints than with rubber bushes. His effort to keep the car under control will rise as a direct consequence of the improved response time, however.

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Solid bushings/sphericals/etc are for survival as much as they are for making the car respond faster to driver inputs. The guy's right, the correct design of rubber bushings is often the secret sauce to making a factory car handle way better than its spec suggests. The problem is that if you want to go "sports driving" and push limits, you're using stickier tires than the factory intended, so 1) the tires are now faster than the chassis, and 2) the factory bushings will literally tear and/or collapse under a few hours of >1G loads. Some of the cars I've raced on rubber bushings would enter the track with 0 toe and come off with 1/2" of toe in. Fresh rubber to bushing failure in 20min.