15 replies to this topic

[Madlock]

I have the option to try a couple of different uprated LCAs.  Both are tubular, so I'm anticipating similar amounts of deflection mitigation but one set has spherical ends while the other has urethane bushings.

How much, if any, additional NVH should I expect from the spherical ends and do they offer enough additional improvement to offset the NVH tradeoff?

Thanks!

[svt13]

Well spherical is metal on metal. So how much noise do you think it will cause when 2 pieces of metal rub up against each other? lol. Plus they will obviously give some benefit but its not say the difference between going stock to aftermarket. It's kind of like running and health. If you run a lot, your cardiovascular health will be much better obviously. But if you run EVEN MORE the increase this time will be a little bit better. You get diminishing returns.

I would only get a spherical bearing if my car was a track driver and that is it. Stick with utherane. Though for LCA I would go poly. Me personally I'm getting the roush LCAs which are rubber but still better than stock. I don't trust aftermarket bushings. Heard of too many issues. Plus after a couple years you have to replace them. Yes lots of people run poly bushings with no NVH increase but all it takes is for something in your car to be off a little bit when installed at the factory for you to hear lots of noise. Someone gave me a very good explanation as that is why some people experience more NVH than others. It depends essentially how perfect our cars were built in the first place.

[Afdharley]

I went with the Steeda poly on chassis mount and spherical at the axle mount. Reason I was directed in that route is that the poly bushings on the axle end can get in a bind and break the LCA. The spherical will not bind. Yes, it did add a little notice at low speeds over bumps but its not unbearable and let's me know that they are moving and not binding. I would not get spherical at both ends, that would be too much added noise.

Try out both if you can and let us know what you think.

[2010KonaBlueGT]

Madlock, on 23 September 2012 - 06:39 PM, said:

I have the option to try a couple of different uprated LCAs.  Both are tubular, so I'm anticipating similar amounts of deflection mitigation but one set has spherical ends while the other has urethane bushings.
How much, if any, additional NVH should I expect from the spherical ends and do they offer enough additional improvement to offset the NVH tradeoff?
Thanks!

I went with the Roush spherical end trailing arms (and 3rd link) and they ARE noisy. I hear every bump and road seam as a clunk. I can reduce the noise stubstantially by lowering the rear tire pressure to 20psi but that's just a band-aid. With the side effect of a HUGE increase in traction (KR winged boot F-1's).

If my car wasn't so much of a 'toy' as a daily driver, I'd switch them out for poly or urethane units in a heartbeat.


Phill

[svt13]

Afdharley, on 24 September 2012 - 06:42 AM, said:

I went with the Steeda poly on chassis mount and spherical at the axle mount. Reason I was directed in that route is that the poly bushings on the axle end can get in a bind and break the LCA. The spherical will not bind. Yes, it did add a little notice at low speeds over bumps but its not unbearable and let's me know that they are moving and not binding. I would not get spherical at both ends, that would be too much added noise.

Try out both if you can and let us know what you think.

I bet it was Alex who told you that about the bind and break in the LCA

[Tob]

Madlock, on 23 September 2012 - 06:39 PM, said:

I have the option to try a couple of different uprated LCAs.  Both are tubular, so I'm anticipating similar amounts of deflection mitigation but one set has spherical ends while the other has urethane bushings.

How much, if any, additional NVH should I expect from the spherical ends and do they offer enough additional improvement to offset the NVH tradeoff?

Thanks!

If I were behind the counter and you asked me that I'd reply by asking how you plan on using your vehicle, who will be doing the service/inspections, and finally, how would you quantify improvement and how much NVH is acceptable to you?

svt13, on 23 September 2012 - 07:04 PM, said:

Well spherical is metal on metal. So how much noise do you think it will cause when 2 pieces of metal rub up against each other? lol. Plus they will obviously give some benefit but its not say the difference between going stock to aftermarket. It's kind of like running and health. If you run a lot, your cardiovascular health will be much better obviously. But if you run EVEN MORE the increase this time will be a little bit better. You get diminishing returns.

I would only get a spherical bearing if my car was a track driver and that is it. Stick with utherane. Though for LCA I would go poly. Me personally I'm getting the roush LCAs which are rubber but still better than stock. I don't trust aftermarket bushings. Heard of too many issues. Plus after a couple years you have to replace them. Yes lots of people run poly bushings with no NVH increase but all it takes is for something in your car to be off a little bit when installed at the factory for you to hear lots of noise. Someone gave me a very good explanation as that is why some people experience more NVH than others. It depends essentially how perfect our cars were built in the first place.

If you are using a 'metal on metal' spherical bearing the only thing you are helping is the Chinese economy. If you are serious about total performance - maximum articulation, strength/durability, zero deflection, then there really is no other choice. A properly designed and manufactured Teflon lined, three piece, rod end. Teflon liners are constructed utilizing a Teflon component and a carrier component. The Teflon liner and bearing race are bonded together, as such, the inner 'ball' rides on the liner. A top notch, high end, composite Teflon liner will have a compressive strength on the order of 50,000 to 60,000 psi. This allows an extremely 'tight' fit with regard to tolerances. Garbage rod ends may still claim to utilize a Teflon liner but will have a compressive strength of less than 15,000 psi. Either way, a polyurethane bushed control arm can't begin to approach the precision or durability of a quality rod end. Diminishing returns? I'd argue that a polyurethane bushing defeats much of the purpose in swapping arms in the first place.

Polyurethane cold flows, squeaks and tears. The inherent deflection in a poly bushed control arm makes consistency a larger variable than it should be. They require the use of a friction reducing grease that attracts contamination as well. In addition, they remain a bind component and can constrict freedom of movement within a given plane. They are everything you don't want in a bushing. Their saving grace is that they have the potential to deflect and as such 'absorb' component noise transmission that would otherwise be directed elsewhere. A compromise, if you will, that has neither the absorption qualities of an OEM rubber joint nor the bind free, deflection elimination qualities of a rod end.

2010KonaBlueGT, on 24 September 2012 - 09:19 AM, said:

I went with the Roush spherical end trailing arms (and 3rd link) and they ARE noisy. I hear every bump and road seam as a clunk. I can reduce the noise stubstantially by lowering the rear tire pressure to 20psi but that's just a band-aid. With the side effect of a HUGE increase in traction (KR winged boot F-1's).

If my car wasn't so much of a 'toy' as a daily driver, I'd switch them out for poly or urethane units in a heartbeat.

Phill

The S197 chassis is a rather fickle one when conventional suspension enhancing wisdom is imparted upon the rear suspension links. I'd argue that the most critical change with respect to NVH on these cars is a change to a solid (steel) joint at the UCA juncture. Its short length (in comparison the LCA's) and close proximity to the gear housing all but ensures that frequency specific resonances will amplify the meshing order of the axle gears as well as transmit road surface irregularities normally absorbed by the vehicles stock suspension and bushings. In other words, the UCA is a critical path for noise that is transferred and amplified within the cabin. I prefer an OE style high durometer rubber bushed arm (such as the Roush wheel hop reduction arm) here for most anything except an all-out drag or road racing effort. In those cases, where NVH transference isn't an issue, a (quality) steel joint will outperform poly or rubber joints.

[svt13]

Tob, on 24 September 2012 - 05:13 PM, said:

If I were behind the counter and you asked me that I'd reply by asking how you plan on using your vehicle, who will be doing the service/inspections, and finally, how would you quantify improvement and how much NVH is acceptable to you?



If you are using a 'metal on metal' spherical bearing the only thing you are helping is the Chinese economy. If you are serious about total performance - maximum articulation, strength/durability, zero deflection, then there really is no other choice. A properly designed and manufactured Teflon lined, three piece, rod end. Teflon liners are constructed utilizing a Teflon component and a carrier component. The Teflon liner and bearing race are bonded together, as such, the inner 'ball' rides on the liner. A top notch, high end, composite Teflon liner will have a compressive strength on the order of 50,000 to 60,000 psi. This allows an extremely 'tight' fit with regard to tolerances. Garbage rod ends may still claim to utilize a Teflon liner but will have a compressive strength of less than 15,000 psi. Either way, a polyurethane bushed control arm can't begin to approach the precision or durability of a quality rod end. Diminishing returns? I'd argue that a polyurethane bushing defeats much of the purpose in swapping arms in the first place.

Polyurethane cold flows, squeaks and tears. The inherent deflection in a poly bushed control arm makes consistency a larger variable than it should be. They require the use of a friction reducing grease that attracts contamination as well. In addition, they remain a bind component and can constrict freedom of movement within a given plane. They are everything you don't want in a bushing. Their saving grace is that they have the potential to deflect and as such 'absorb' component noise transmission that would otherwise be directed elsewhere. A compromise, if you will, that has neither the absorption qualities of an OEM rubber joint nor the bind free, deflection elimination qualities of a rod end.




The S197 chassis is a rather fickle one when conventional suspension enhancing wisdom is imparted upon the rear suspension links. I'd argue that the most critical change with respect to NVH on these cars is a change to a solid (steel) joint at the UCA juncture. Its short length (in comparison the LCA's) and close proximity to the gear housing all but ensures that frequency specific resonances will amplify the meshing order of the axle gears as well as transmit road surface irregularities normally absorbed by the vehicles stock suspension and bushings. In other words, the UCA is a critical path for noise that is transferred and amplified within the cabin. I prefer an OE style high durometer rubber bushed arm (such as the Roush wheel hop reduction arm) here for most anything except an all-out drag or road racing effort. In those cases, where NVH transference isn't an issue, a (quality) steel joint will outperform poly or rubber joints.

This is why I am getting the roush billet control arms and wheel hop reduction arm.

And buying a shelby in general helps the chinese economy half the crap in this car came from China

[Madlock]

svt13, on 24 September 2012 - 05:25 PM, said:

And buying a shelby in general helps the chinese economy half the crap in this car came from China

Correctness or not be damned, what possible basis do you have for making such a statement?

[svt13]

If you take off a lot of your parts u will see made in china stamped all over them

[Madlock]

svt13, on 24 September 2012 - 06:50 PM, said:

If you take off a lot of your parts u will see made in china stamped all over them

With the exception of certain wheel styles, the vast majority of non-U.S. component content I've seen is sourced from Canada.

[svt13]

Madlock, on 24 September 2012 - 07:13 PM, said:

With the exception of certain wheel styles, the vast majority of non-U.S. component content I've seen is sourced from Canada.

So then we are helping the Canadian economy?

[glroy]

svt13, on 24 September 2012 - 07:16 PM, said:

So then we are helping the Canadian economy?

For sure as you can see by the chart there has been steady growth in the Canadian economy since the relaease of the GT500. A little blip when they released the ugly but 2010 LOL.

[svt13]

glroy, on 25 September 2012 - 11:48 AM, said:

For sure as you can see by the chart there has been steady growth in the Canadian economy since the relaease of the GT500. A little blip when they released the ugly but 2010 LOL.

lol

[Madlock]

svt13, on 24 September 2012 - 07:16 PM, said:

So then we are helping the Canadian economy?

Try a semester of even undergrad economics.  There is no such thing as just the "Canadian" economy - especially when they're paying through the nose for GT500's from the U.S..

[svt13]

Madlock, on 25 September 2012 - 12:25 PM, said:

Try a semester of even undergrad economics.  There is no such thing as just the "Canadian" economy - especially when they're paying through the nose for GT500's from the U.S..

I have a masters in economics. But I was just messing around with my comments. I fully understand the concept of a global economy

[Tob]

Madlock, on 25 September 2012 - 12:25 PM, said:

Try a semester of even undergrad economics.

svt13, on 25 September 2012 - 12:42 PM, said:

I have a masters in economics.

That got a good chuckle on my end. MS in Counseling and I just love the twists and turns that certain threads take.