Pfadt poly bushing review...
02-20-2012, 06:19 PM
#1
Pro
Thread Starter
Pfadt poly bushing review...
First background info....
I have had my 2000 frc for about 28 months. I have c6z06 shocks, c6 z-51 sways/poly bushings, and corbeau trs seats. I log 10k street miles per year and I have 4 hpde weekends at RRR in the car along with 3 open track days at TGPR. I am in the "blue" group in hpde. I have been told by every instructor I could be more agressive, lol.. ok so that's out there....
Install...
I would say the install was easy.. Following instructions here and tips from the forum I used a BS vise from northern tool and sockets for the fronts. The rears were more difficult, however, a co-worker suggested using a threaded rod and that worked great (I made a thread on that). The "difficult" portion was in the front upper conotrol arms. I did not know that the retaining clips should NOT have to be forced on with a vise or large c-clamp. so I had to redo those. I had to press them out and sand the ends down and sand around the outer diameter of the 2 halfs. This was very time consuming to ensure I did not remove too much bushing material. Pfadt has made install instructions to make this MUCH clearer and easier to understand. So good on them! I also added zerk fittings just to make servicing the bushings easier.
Initial impressions..
NVH is WAY up. And everything on the road can be felt, and I feel much of the road surface in the steering wheel now. The whole car tightened up. Less body roll, quicker responses to inputs, and more neutral sides when forced(closed parking lot)
But, it felt "wrong" cause it was so tight. I was so concerned that I messed up the install, I drove out to drivnhard's and had him drive it to make sure nothing was binding (THANKS AGAIN MARK!!!!), and nothing was binding. It was just a very dramatic change.
600 mile road trip review....
Went from Marietta GA to Savannah GA and back. If you have ever used I-16, you know it is not the nicest road out there. However, the ride was not bad. It was not jarring, but more "stiff" and loud. But, you felt when the road was uneven or when you changed lanes. The "crown" of the road could be felt. The right hand lane is worse than the left lane, but the right lane was not horrible. My mom or GF would have not been happy. I however, had no real issues. And on the noise, I had plenty of volume on the stereo to hear nothing else. Even after a 1 day hpde and little sleep, the ride was not bad. I was not sore/stiff/unhappy when I got home sunday.
2 day @ RRR hpde review...
I had not been at RRR since Apr. 2011. So I was rusty and again, I am overly cautious sometimes. It was suppose to rain so I took my street tires and street brake pads.
Saturday No rain. I got 3 sessions saturday. Session 1&2 was me sucking and knocking rust off. 3rd session was good for me. I was able to get some speed and hit the line for a few laps. Car felt VERY good. I was gaining confidence in the suspension quickly. I kept wanting to go faster. I was mentally pulling myself back remembering I was on bfg kdw's and pfc Z rated pads. But, I felt more connected to the car than I ever had. The steering felt less numb, the rear felt more planted than ever. Every lap I gained more trust and confidence.
Sunday, rain. So I did 1 session and drove like a little old lady. So I will say it was a 1 day hpde.
All in all, I am very happy I did the upgrade. However, I would think this is not for everyone who wants a "street" car. I don't DD my vette, but I drive it lots of places. And sometimes in downtown atlanta I am having to drive it like I am in a mine field. But, even with that, I am happy I upgraded.
I have had my 2000 frc for about 28 months. I have c6z06 shocks, c6 z-51 sways/poly bushings, and corbeau trs seats. I log 10k street miles per year and I have 4 hpde weekends at RRR in the car along with 3 open track days at TGPR. I am in the "blue" group in hpde. I have been told by every instructor I could be more agressive, lol.. ok so that's out there....
Install...
I would say the install was easy.. Following instructions here and tips from the forum I used a BS vise from northern tool and sockets for the fronts. The rears were more difficult, however, a co-worker suggested using a threaded rod and that worked great (I made a thread on that). The "difficult" portion was in the front upper conotrol arms. I did not know that the retaining clips should NOT have to be forced on with a vise or large c-clamp. so I had to redo those. I had to press them out and sand the ends down and sand around the outer diameter of the 2 halfs. This was very time consuming to ensure I did not remove too much bushing material. Pfadt has made install instructions to make this MUCH clearer and easier to understand. So good on them! I also added zerk fittings just to make servicing the bushings easier.
Initial impressions..
NVH is WAY up. And everything on the road can be felt, and I feel much of the road surface in the steering wheel now. The whole car tightened up. Less body roll, quicker responses to inputs, and more neutral sides when forced(closed parking lot)
But, it felt "wrong" cause it was so tight. I was so concerned that I messed up the install, I drove out to drivnhard's and had him drive it to make sure nothing was binding (THANKS AGAIN MARK!!!!), and nothing was binding. It was just a very dramatic change.
600 mile road trip review....
Went from Marietta GA to Savannah GA and back. If you have ever used I-16, you know it is not the nicest road out there. However, the ride was not bad. It was not jarring, but more "stiff" and loud. But, you felt when the road was uneven or when you changed lanes. The "crown" of the road could be felt. The right hand lane is worse than the left lane, but the right lane was not horrible. My mom or GF would have not been happy. I however, had no real issues. And on the noise, I had plenty of volume on the stereo to hear nothing else. Even after a 1 day hpde and little sleep, the ride was not bad. I was not sore/stiff/unhappy when I got home sunday.
2 day @ RRR hpde review...
I had not been at RRR since Apr. 2011. So I was rusty and again, I am overly cautious sometimes. It was suppose to rain so I took my street tires and street brake pads.
Saturday No rain. I got 3 sessions saturday. Session 1&2 was me sucking and knocking rust off. 3rd session was good for me. I was able to get some speed and hit the line for a few laps. Car felt VERY good. I was gaining confidence in the suspension quickly. I kept wanting to go faster. I was mentally pulling myself back remembering I was on bfg kdw's and pfc Z rated pads. But, I felt more connected to the car than I ever had. The steering felt less numb, the rear felt more planted than ever. Every lap I gained more trust and confidence.
Sunday, rain. So I did 1 session and drove like a little old lady. So I will say it was a 1 day hpde.
All in all, I am very happy I did the upgrade. However, I would think this is not for everyone who wants a "street" car. I don't DD my vette, but I drive it lots of places. And sometimes in downtown atlanta I am having to drive it like I am in a mine field. But, even with that, I am happy I upgraded.
Last edited by bags142; 02-20-2012 at 06:23 PM.
02-20-2012, 11:24 PM
#4
Pro
Thread Starter
I have the driving skill of a teenage girl texting, driving, and complaining about her parents at the same time.. so it will be awhile before I even think of TTA..lmao..
But, I will be coming to hangout at more NASA events
Yall just want more fresh meat to shred!!!!!!!
But, I will be coming to hangout at more NASA events
Yall just want more fresh meat to shred!!!!!!!
02-21-2012, 07:10 AM
#7
Burning Brakes
Just wanted to come in here and thank you for your review and provide some of my own insight. Over the winter holidays I installed the PFADT poly bushings and Featherlight coilovers. Because these were installed at the same time I am not in a position to say what effect was caused by the bushings vs the coilovers, but I will say that I did not notice a big increase in NVH.
It is my opinion that this may be due to the fact that I used marine grease instead of the extremely sticky grease included with the bushings. I was advised to do this by a forum member(RaamAudio) who wrote me the following in a PM:
I already knew I wanted to install Zerks but wasn't fully convinced on the marine grease. Since I bought my bushings used and pressed into a set of control arms, I was able to observe how smoothly the pins rotated in the bushings with the original "sticky" grease. It wasn't easy to rotate the pins at all.
Since I was going to be taking everything apart so that I could install zerks, I choose to clean everything and switch to marine grease. The difference in smoothness of operation was huge. It is my opinion that the marine grease would not be appropriate without Zerk fittings as the lubrication frequency would be too high for something that requires so much work. However with the Zerks, the work is minimal so grease life isn't as big of a concern.
I would describe my suspension as stiff but smooth. It definitely does not feel any less streetable and I could not be more satisfied.
It is my opinion that this may be due to the fact that I used marine grease instead of the extremely sticky grease included with the bushings. I was advised to do this by a forum member(RaamAudio) who wrote me the following in a PM:
Originally Posted by RAAMaudio
This is a pretty big job, even if using their new version I would take a serious look at putting in zerts, I have 22 in my car, 10 hours of hard work but now I can lube it in 10 minutes when on my lift.
I called and asked and was advised I did not need zerts, old style bushings, less than 1k miles I could barely stand to drive the car. 10 hours of hard work is a huge loss of my time as I am a very busy business man and have had many injuries so it was painful as well.
My car rides and handles far better with marine grade grease in the bushings that it did the first day with the sticky goo they shipped with them.
Even if the new style works for quite some time it is still going to be a huge job to relube them eventually, not for me now though
I know the Pfadt guys, and Robin, been there many times, run many of their parts, great people and parts but nobody is perfect, certainly not me, I just want my car to be easy to maintain, quiet over bumps and not binding which it was a great deal.
Sincerely
Rick
I called and asked and was advised I did not need zerts, old style bushings, less than 1k miles I could barely stand to drive the car. 10 hours of hard work is a huge loss of my time as I am a very busy business man and have had many injuries so it was painful as well.
My car rides and handles far better with marine grade grease in the bushings that it did the first day with the sticky goo they shipped with them.
Even if the new style works for quite some time it is still going to be a huge job to relube them eventually, not for me now though
I know the Pfadt guys, and Robin, been there many times, run many of their parts, great people and parts but nobody is perfect, certainly not me, I just want my car to be easy to maintain, quiet over bumps and not binding which it was a great deal.
Sincerely
Rick
Since I was going to be taking everything apart so that I could install zerks, I choose to clean everything and switch to marine grease. The difference in smoothness of operation was huge. It is my opinion that the marine grease would not be appropriate without Zerk fittings as the lubrication frequency would be too high for something that requires so much work. However with the Zerks, the work is minimal so grease life isn't as big of a concern.
I would describe my suspension as stiff but smooth. It definitely does not feel any less streetable and I could not be more satisfied.
02-21-2012, 11:56 AM
#8
Track Junky
Just wanted to come in here and thank you for your review and provide some of my own insight. Over the winter holidays I installed the PFADT poly bushings and Featherlight coilovers. Because these were installed at the same time I am not in a position to say what effect was caused by the bushings vs the coilovers, but I will say that I did not notice a big increase in NVH.
It is my opinion that this may be due to the fact that I used marine grease instead of the extremely sticky grease included with the bushings. I was advised to do this by a forum member(RaamAudio) who wrote me the following in a PM:
I already knew I wanted to install Zerks but wasn't fully convinced on the marine grease. Since I bought my bushings used and pressed into a set of control arms, I was able to observe how smoothly the pins rotated in the bushings with the original "sticky" grease. It wasn't easy to rotate the pins at all.
Since I was going to be taking everything apart so that I could install zerks, I choose to clean everything and switch to marine grease. The difference in smoothness of operation was huge. It is my opinion that the marine grease would not be appropriate without Zerk fittings as the lubrication frequency would be too high for something that requires so much work. However with the Zerks, the work is minimal so grease life isn't as big of a concern.
I would describe my suspension as stiff but smooth. It definitely does not feel any less streetable and I could not be more satisfied.
It is my opinion that this may be due to the fact that I used marine grease instead of the extremely sticky grease included with the bushings. I was advised to do this by a forum member(RaamAudio) who wrote me the following in a PM:
I already knew I wanted to install Zerks but wasn't fully convinced on the marine grease. Since I bought my bushings used and pressed into a set of control arms, I was able to observe how smoothly the pins rotated in the bushings with the original "sticky" grease. It wasn't easy to rotate the pins at all.
Since I was going to be taking everything apart so that I could install zerks, I choose to clean everything and switch to marine grease. The difference in smoothness of operation was huge. It is my opinion that the marine grease would not be appropriate without Zerk fittings as the lubrication frequency would be too high for something that requires so much work. However with the Zerks, the work is minimal so grease life isn't as big of a concern.
I would describe my suspension as stiff but smooth. It definitely does not feel any less streetable and I could not be more satisfied.
Do you have any info on the zerk fittings (part numbers)? I assume that you had to drill through one wall of the poly bushing to allow the grease to reach the center pin. Any other mod to the bushing? What if the bushing rotates slightly and the holes do not line up anymore?
I guess if the zerk has enough threads it could lock the bushing in place...
Please provide more detail if you can. Pics could help as well.
Thanks.
02-21-2012, 01:00 PM
#9
Le Mans Master
I've not put poly bushings in my C5, but have for my LS1 Miata and my old '94 Z-28.
Most of the poly bushings assemble split, and as long as the zerk is centered up on the bushing sleeve the grease will migrate through that seam easily.
For the single piece bushings I just make sure I use a zerk that's long er than the thickness of the bushing sleeve. Since you have to drill the bushing through anyway to get grease to the center the zerk then anchors that bushing in place.
Zerk part numbers? Just go to your local Fastenal store and get a bag of them. Size/thread pitch isn't that important.
HTH, and have a good one,
Mike
Most of the poly bushings assemble split, and as long as the zerk is centered up on the bushing sleeve the grease will migrate through that seam easily.
For the single piece bushings I just make sure I use a zerk that's long er than the thickness of the bushing sleeve. Since you have to drill the bushing through anyway to get grease to the center the zerk then anchors that bushing in place.
Zerk part numbers? Just go to your local Fastenal store and get a bag of them. Size/thread pitch isn't that important.
HTH, and have a good one,
Mike
02-21-2012, 02:26 PM
#10
Thanks for the real world install thoughts bags142! We're really glad to hear you're very happy with the new setup.
A word of caution on zerks, our bushings are not cast with a pattern that promotes grease movement from outside to the inside diameter that rides on the pin or bolt, the pattern also does not have provisions for pushing old grease out when pumping in new grease. We've had folks who are really happy with their Zerk installs, but keep in mind that you are adding a stress riser in the control arm with the hole you drill for the zerk it's self. While it's still not likely they will crack, it's also not extremely likely that the grease being pumped in is going to where it needs to be either. The best way to periodically service these poly bushings is to disassemble and regrease with the provided extremely sticky grease.
A word of caution on zerks, our bushings are not cast with a pattern that promotes grease movement from outside to the inside diameter that rides on the pin or bolt, the pattern also does not have provisions for pushing old grease out when pumping in new grease. We've had folks who are really happy with their Zerk installs, but keep in mind that you are adding a stress riser in the control arm with the hole you drill for the zerk it's self. While it's still not likely they will crack, it's also not extremely likely that the grease being pumped in is going to where it needs to be either. The best way to periodically service these poly bushings is to disassemble and regrease with the provided extremely sticky grease.
02-21-2012, 03:07 PM
#11
Burning Brakes
Do you have any info on the zerk fittings (part numbers)? I assume that you had to drill through one wall of the poly bushing to allow the grease to reach the center pin. Any other mod to the bushing? What if the bushing rotates slightly and the holes do not line up anymore?
I guess if the zerk has enough threads it could lock the bushing in place...
Please provide more detail if you can. Pics could help as well.
Thanks.
I guess if the zerk has enough threads it could lock the bushing in place...
Please provide more detail if you can. Pics could help as well.
Thanks.
One thing I should mention is that when it comes time to grease them via the Zerks, I will still have to remove some washers/bolts to allow grease to pass through.
02-21-2012, 03:26 PM
#12
Melting Slicks
Member Since: Jan 2009
Location: Easley/Anderson South Carolina
Posts: 2,127
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24 Posts
FINALLY!! A picture of some of the zirt fittings placement!
I will be installing the bushings within the month, been sitting on them for about 2-3 months.
I will be installing the bushings within the month, been sitting on them for about 2-3 months.
02-21-2012, 07:25 PM
#15
Pro
Thread Starter
Well if they give tires for last place I am in! lol
Welcome. I know there are other folks who posted reviews, but I wanted to add to the list. Never hurts to get the most info possible 
If you have any questions just ask me. I will do my best to help
Hmm that is interesting. I noticed it as soon as I got going 10mph in my subdivision for the test ride. My GF noticed it as well.
I will NOT be taking them apart anytime soon.. between life and work it took me 3 weeks to get the whole job done.
Well the 2 peice one for the front you could sand the center down slightly to create a void. ( Pfadt recommends this if they are not flush anyway)
I will post a PN later for mine.. but take your control arm with you and the bushing to the local fastenal place.
Mike nailed it
Very happy thank you! And very happy about the customer service as well. Thanks for following up with the phone call after the install and letting me know the directions were modified 
And on the zerks, I will NOT hold anyone accountable for them other than myself. I have read your stance on them and understand it 100%. I am lazy and was trying to take the easy way out while still trying to keep the bushings lubed and working/quiet.
If you need pics, I can post/email them. Just find a place they can mount as to not contact anything fully compressed or fully unloaded
If you have any questions just ask me. I will do my best to help
Just wanted to come in here and thank you for your review and provide some of my own insight. Over the winter holidays I installed the PFADT poly bushings and Featherlight coilovers. Because these were installed at the same time I am not in a position to say what effect was caused by the bushings vs the coilovers, but I will say that I did not notice a big increase in NVH.
It is my opinion that this may be due to the fact that I used marine grease instead of the extremely sticky grease included with the bushings. I was advised to do this by a forum member(RaamAudio) who wrote me the following in a PM:
I already knew I wanted to install Zerks but wasn't fully convinced on the marine grease. Since I bought my bushings used and pressed into a set of control arms, I was able to observe how smoothly the pins rotated in the bushings with the original "sticky" grease. It wasn't easy to rotate the pins at all.
Since I was going to be taking everything apart so that I could install zerks, I choose to clean everything and switch to marine grease. The difference in smoothness of operation was huge. It is my opinion that the marine grease would not be appropriate without Zerk fittings as the lubrication frequency would be too high for something that requires so much work. However with the Zerks, the work is minimal so grease life isn't as big of a concern.
I would describe my suspension as stiff but smooth. It definitely does not feel any less streetable and I could not be more satisfied.
It is my opinion that this may be due to the fact that I used marine grease instead of the extremely sticky grease included with the bushings. I was advised to do this by a forum member(RaamAudio) who wrote me the following in a PM:
I already knew I wanted to install Zerks but wasn't fully convinced on the marine grease. Since I bought my bushings used and pressed into a set of control arms, I was able to observe how smoothly the pins rotated in the bushings with the original "sticky" grease. It wasn't easy to rotate the pins at all.
Since I was going to be taking everything apart so that I could install zerks, I choose to clean everything and switch to marine grease. The difference in smoothness of operation was huge. It is my opinion that the marine grease would not be appropriate without Zerk fittings as the lubrication frequency would be too high for something that requires so much work. However with the Zerks, the work is minimal so grease life isn't as big of a concern.
I would describe my suspension as stiff but smooth. It definitely does not feel any less streetable and I could not be more satisfied.
Hmm that is interesting. I noticed it as soon as I got going 10mph in my subdivision for the test ride. My GF noticed it as well.
I will NOT be taking them apart anytime soon.. between life and work it took me 3 weeks to get the whole job done.
Do you have any info on the zerk fittings (part numbers)? I assume that you had to drill through one wall of the poly bushing to allow the grease to reach the center pin. Any other mod to the bushing? What if the bushing rotates slightly and the holes do not line up anymore?
I guess if the zerk has enough threads it could lock the bushing in place...
Please provide more detail if you can. Pics could help as well.
Thanks.
I guess if the zerk has enough threads it could lock the bushing in place...
Please provide more detail if you can. Pics could help as well.
Thanks.
I will post a PN later for mine.. but take your control arm with you and the bushing to the local fastenal place.
I've not put poly bushings in my C5, but have for my LS1 Miata and my old '94 Z-28.
Most of the poly bushings assemble split, and as long as the zerk is centered up on the bushing sleeve the grease will migrate through that seam easily.
For the single piece bushings I just make sure I use a zerk that's long er than the thickness of the bushing sleeve. Since you have to drill the bushing through anyway to get grease to the center the zerk then anchors that bushing in place.
Zerk part numbers? Just go to your local Fastenal store and get a bag of them. Size/thread pitch isn't that important.
HTH, and have a good one,
Mike
Most of the poly bushings assemble split, and as long as the zerk is centered up on the bushing sleeve the grease will migrate through that seam easily.
For the single piece bushings I just make sure I use a zerk that's long er than the thickness of the bushing sleeve. Since you have to drill the bushing through anyway to get grease to the center the zerk then anchors that bushing in place.
Zerk part numbers? Just go to your local Fastenal store and get a bag of them. Size/thread pitch isn't that important.
HTH, and have a good one,
Mike
Thanks for the real world install thoughts bags142! We're really glad to hear you're very happy with the new setup.
A word of caution on zerks, our bushings are not cast with a pattern that promotes grease movement from outside to the inside diameter that rides on the pin or bolt, the pattern also does not have provisions for pushing old grease out when pumping in new grease. We've had folks who are really happy with their Zerk installs, but keep in mind that you are adding a stress riser in the control arm with the hole you drill for the zerk it's self. While it's still not likely they will crack, it's also not extremely likely that the grease being pumped in is going to where it needs to be either. The best way to periodically service these poly bushings is to disassemble and regrease with the provided extremely sticky grease.
A word of caution on zerks, our bushings are not cast with a pattern that promotes grease movement from outside to the inside diameter that rides on the pin or bolt, the pattern also does not have provisions for pushing old grease out when pumping in new grease. We've had folks who are really happy with their Zerk installs, but keep in mind that you are adding a stress riser in the control arm with the hole you drill for the zerk it's self. While it's still not likely they will crack, it's also not extremely likely that the grease being pumped in is going to where it needs to be either. The best way to periodically service these poly bushings is to disassemble and regrease with the provided extremely sticky grease.
And on the zerks, I will NOT hold anyone accountable for them other than myself. I have read your stance on them and understand it 100%. I am lazy and was trying to take the easy way out while still trying to keep the bushings lubed and working/quiet.
02-21-2012, 11:18 PM
#16
Safety Car
I've had mine in for over a year of racing and TT use and haven't needed to touch them. I think the idea of "stiction" is way overblown when you have 3100lbs of person/car on them going 150 mph and pulling almost 2 gs.
I had my front suspension apart installing SKF hubs a few weeks ago and the UCA and LCA still moved around fine. The LCA is heavy enough that it will fall down on its own, but the UCA will stay where you put it. In the rear I had to wedge the LCA in place with a pry bar and smack it with a mallet so I don't think a little "stiction" is going to do much when the bushing is wedged into the rear cradle.
Just my $0.02. If they ever get to creaking and affecting my lap times or the feel of the car I'll worry about them.
Oh... and having to take the suspension 1/2 apart to give the grease somewhere to go sort of defeats the purpose doesn't it?
I had my front suspension apart installing SKF hubs a few weeks ago and the UCA and LCA still moved around fine. The LCA is heavy enough that it will fall down on its own, but the UCA will stay where you put it. In the rear I had to wedge the LCA in place with a pry bar and smack it with a mallet so I don't think a little "stiction" is going to do much when the bushing is wedged into the rear cradle.
Just my $0.02. If they ever get to creaking and affecting my lap times or the feel of the car I'll worry about them.
Oh... and having to take the suspension 1/2 apart to give the grease somewhere to go sort of defeats the purpose doesn't it?
02-22-2012, 02:38 AM
#17
Burning Brakes
I've had mine in for over a year of racing and TT use and haven't needed to touch them. I think the idea of "stiction" is way overblown when you have 3100lbs of person/car on them going 150 mph and pulling almost 2 gs.
I had my front suspension apart installing SKF hubs a few weeks ago and the UCA and LCA still moved around fine. The LCA is heavy enough that it will fall down on its own, but the UCA will stay where you put it. In the rear I had to wedge the LCA in place with a pry bar and smack it with a mallet so I don't think a little "stiction" is going to do much when the bushing is wedged into the rear cradle.
Just my $0.02. If they ever get to creaking and affecting my lap times or the feel of the car I'll worry about them.
Oh... and having to take the suspension 1/2 apart to give the grease somewhere to go sort of defeats the purpose doesn't it?
I had my front suspension apart installing SKF hubs a few weeks ago and the UCA and LCA still moved around fine. The LCA is heavy enough that it will fall down on its own, but the UCA will stay where you put it. In the rear I had to wedge the LCA in place with a pry bar and smack it with a mallet so I don't think a little "stiction" is going to do much when the bushing is wedged into the rear cradle.
Just my $0.02. If they ever get to creaking and affecting my lap times or the feel of the car I'll worry about them.
Oh... and having to take the suspension 1/2 apart to give the grease somewhere to go sort of defeats the purpose doesn't it?
Here is what is wrong with what you posted(partially quoted from wiky):
Static friction is friction between two or more solid objects that are not moving relative to each other. The coefficient of static friction, typically denoted as μs, is usually higher than the coefficient of kinetic friction.
The static friction force must be overcome by an applied force before an object can move. The maximum possible friction force between two surfaces before sliding begins is the product of the coefficient of static friction and the normal force: Fnormal. When there is no sliding occurring, the friction force can have any value from zero up to Fmax. Any force smaller than Fmax attempting to slide one surface over the other is opposed by a frictional force of equal magnitude and opposite direction. Any force larger than Fmax overcomes the force of static friction and causes sliding to occur. The instant sliding occurs, static friction is no longer applicable—the friction between the two surfaces is then called kinetic friction.
Your argument that stiction is overblown because the weight of the car will overcome the friction forces is contrary to the laws of physics and to the definition of friction quoted above. As the definition explained, the force required to overcome the friction force is linearly proportional to the normal force(in this case the weight of the car). So if you are seeing 800lbs at each wheel and you have a coefficient of friction of .2 then you will need a 160 lbs of force before the friction is overcome.
That 160lbs of force may not sound like much, but because the spring rate of suspension at the point is practically infinite, it results in an extremely harsh ride(imagine having the coil springs in a coilover replaced with a solid steel cylinder).
Your 2nd point about the Zerk fittings being pointless is also baseless. To properly regrease a set of poly bushings without Zerks requires the pins to be pressed out of the upper control arms and the inner sleeves to be pressed out of the lower control arms. When I bought my bushings used, they came pressed into a set of control arms. The previous owner used the sticky grease. I was forced to use a C clamp with a large combination of wheel bearing fittings until I finally got the pins to come out. For the front arms this took approximately 5 hours.
When it comes time for me to regrease the upper control arm I simply remove the C clip and pull back the washer a little bit. I don't even need to remove the bolt that goes through the upper pin.
For the lower control arm I simply loosen the lower bolt and pivot the arm a little bit. The extra work required is about 5-10min per arm.
02-22-2012, 02:45 AM
#18
Burning Brakes
Since you never came in to backup your point I will provide what I have based decision to run marine grease on.
The main reason for switching to marine grease is due to the apparent lack of lubrication the Energy Suspension Formula 5 grease provides(this is what PFADT uses).
The common argument is to not use a petroleum based grease(marine grease) as it will eat away the polyurethane. What's interesting about this is that almost all modern poly is resistant to petroleum.
Additionally, VB&P recommends that its C4 Poly bushings be lubricated with... marine grease.
http://www.vbandp.com/Download-docum...-Bushings.html
The main reason for switching to marine grease is due to the apparent lack of lubrication the Energy Suspension Formula 5 grease provides(this is what PFADT uses).
The common argument is to not use a petroleum based grease(marine grease) as it will eat away the polyurethane. What's interesting about this is that almost all modern poly is resistant to petroleum.
Additionally, VB&P recommends that its C4 Poly bushings be lubricated with... marine grease.
http://www.vbandp.com/Download-docum...-Bushings.html
02-22-2012, 09:22 AM
#19
Safety Car
My point is that after a year of racing/TT use mine are no different than when they were when first installed, brand new, with fresh grease. The A-arms don't freely move like they do with sphericals; especially if you use the Gorilla Jiz lube stuff that sticks to everything. That said, they work on track as intended.
02-22-2012, 09:22 AM
#20
Drifting
Love the discussion on this, I have my arms sitting on the floor with the bushings installed and will be putting them in shortly. I'm sitting on the fence on whether to install zerks or not.......
On one hand you have the designer and manufacturer saying they weren't designed with that in mind, but on the other hand you have a bunch of real world experience saying that it works well.........
