Sphericals or Urethane.... that is the question..

[Steve1968LS2]

Can't seem to decided..

It's between this: (I just need the fronts)
http://www.pfadtracing.com/catalog/product_info.php/cPath/23_29/products_id/104

And this:
http://www.pfadtracing.com/catalog/product_info.php/cPath/23_29/products_id/43


Price isn't the issue.. I worry about going too "race car" but in the effort to squeeze out the most performance it's so tempting to go that extra step.

I know the spericals are technically better and offer zero deflection, but I worry about how much harshness and noise they will add. The urathane are pretty good as well and since they offer alum sleeves they don't have the same "issues" as regular urathane units. And they offer less harshness and noise.

According to Pfadt they remove 90% of the deflection.. So, the big question what is that extra 10% worth?

The big benefit of the spericals is that I can run less neg camber..

Thoughts?

Oh, here's an interesting video showing stock bushing deflection:
http://www.youtube.com/watch?v=nkrH4l_zt2Y&feature=channel_page

[Steve1968LS2]

I will also be running these:

http://www.pfadtracing.com/catalog/product_info.php/cPath/23_47/products_id/123

And these:
http://www.pfadtracing.com/catalog/product_info.php/cPath/23_47/products_id/129


Just seem like good mates to the new billet uprights...

[CarlC]

.....must use spellcheck for thread title.....

Sphericals.

[MuscleRodz]

How much do you actually drive Penny on the street? You are taking the rest of the car the last 10%, why stop here?

[JDP Jordan]

I forgot to mention this earlier, I was just excited talking cars with you!

Here are the biggest differences:

The spherical bearings offer zero deflection and they also allow the suspension to articulate better. For example, before we installed them in our C5 you could stand on the splitter and it wouldn't move with the poly. We installed the spherical bearings without changing spring (650 lbs) and the front end moved up and down freely. It does however increase NHV, nothing crazy as some people can handle it and some can't.

https://static1.pt-content.com/images/pt/2009/02/pfadtracingsaltflats200806-1.jpg
For Sale 888.972.2464

The poly produces more friction then the bearings, however it is much better than bonded rubber.
The polyurethane is a huge improvement over the rubber however. The rubber bushings are bonded into the control arm causing an elastic effect, not to mention major deflection which will effect your camber under load. The poly removes most of this deflection but it doesn't increase the NHV nearly as much.

Both products will allow you to run less negative camber as you won't have as much deflection, in your case it is a toss up! If it were me I'd probably go with the spherical bearings, they are a great product. Talk to you soon!

Jordan
Pfadt Race Engineering

[zbugger]

You've run the Delrin stuff before, right? It should be too much different from that. At least not much more harsh. Could very well be smoother as well. Now, I'm not trying to talk you into the sphericals, although I'm not trying NOT to either. But if you really want the car to go all out, I say do it. But you also should see what Dave and Mary say. I think they'd say to do it the spherical way.

[JDP Jordan]

How much do you actually drive Penny on the street? You are taking the rest of the car the last 10%, why stop here?

:enguard: :idea:

[Steve1968LS2]

.....must use spellcheck for thread title.....

Sphericals.

Be my copy editor???

[Steve1968LS2]

How much do you actually drive Penny on the street? You are taking the rest of the car the last 10%, why stop here?

Well.. I've driven 3,000 miles on the street and maybe a 70 miles of that was on some sort of track. :shrug:

I just don't want to get so carried away with performance that I kill what the car was always meant to be.. a streetcar that can go to the track..

Thanks for the input.. either will be a vast improvement..

[Damn True]

https://static1.pt-content.com/images/pt/2009/02/pfadtracingsaltflats200806-1.jpg
For Sale 888.972.2464



Jordan
Pfadt Race Engineering

Is that the car you guys had at the 25hrs of Thunderhill?

Great looking machine. A shame it just wouldn't hold together. What kept breaking?

[MuscleRodz]

Well then start with the urethane, and if they don't do the trick, then go full monte on it. That way you dont have to wonder if the urethane would have benn "good enough"

[silver69camaro]

I agree, urethane first. You have to burn out the old bushings for either one, so I'd start small. I'd approach this like choosing a camshaft, start on the small side first.

Remember, if you go to far into "race car" territory, the car is no longer fun to drive on the street...which is apparently where you drive 97.7% of your miles.

[JDP Jordan]

Is that the car you guys had at the 25hrs of Thunderhill?

Great looking machine. A shame it just wouldn't hold together. What kept breaking?

Thanks! It is pretty crazy! :cool:

The issues were small but big enough to hold us back. We ran the 3rd fast time overall behind to DP cars. We had a contaminate in the fuel system and once we got it completely flushed the clutch started slipping. Nothing major and it was a learning experience. The car is crazy fast!

This car also won the NASA ST1 National Championship, that was an exciting race! :seizure:

[JDP Jordan]

I agree, urethane first. You have to burn out the old bushings for either one, so I'd start small. I'd approach this like choosing a camshaft, start on the small side first.

Remember, if you go to far into "race car" territory, the car is no longer fun to drive on the street...which is apparently where you drive 97.7% of your miles.

The bushings actually press out of the C5 control arms. It's much cleaner and easier! I hated burning bushings out. I think this is a good suggestion though. :idea:

[Norm Peterson]

The urathane are pretty good as well and since they offer alum sleeves they don't have the same "issues" as regular urathane units. And they offer less harshness and noise.

According to Pfadt they remove 90% of the deflection.. So, the big question what is that extra 10% worth?

The big benefit of the spericals is that I can run less neg camber..

Thoughts?
Take the "90%" at face value and put a few more numbers on it. I think I saw "over 0.25°" mentioned in one of those links, so let's estimate 0.5°. Cutting that down by 90% would leave 0.05° as the remaining compliance camber effect. Downstream compliance effects on toe should be similarly less as well. Your call as to eliminating the last 10%.

Polyurethane's "stiction" effects can be mitigated, but I doubt that the sleeves being aluminum has much to do with that unless they were chosen considering long-term use and the possible development of corrosion on the outer surfaces of the sleeves.


Norm

[Steve1968LS2]

Take the "90%" at face value and putting a few more numbers on it. I think I saw "over 0.25°" mentioned in one of those links, so let's estimate 0.5°. Cutting that down by 90% would leave 0.05° as the remaining compliance camber effect. Downstream compliance effects on toe should be similarly less as well. Your call.

Polyurethane's "stiction" effects can be mitigated, but I doubt that the sleeves being aluminum has much to do with that unless they were chosen considering long-term use and the possible development of corrosion on the outer surfaces of the sleeves.


Norm

You're always like talking to my doctor.. lol. It takes a couple of tries before I figure out what exactly you're really saying.

[CarlC]

Be my copy editor???

I do that for customer technical reports for five guys at work. What's one more? :look:

I get to be gutterball here.

You still missed the spellcheck button. Urethane. Plus, I meant sphericals as the choice. I'm not at all sorry for going that way on the leaf springs.

I have a $1 on what David says.....

[Steve1968LS2]

I do that for customer technical reports for five guys at work. What's one more? :look:

I get to be gutterball here.

You still missed the spellcheck button. Urethane. Plus, I meant sphericals as the choice. I'm not at all sorry for going that way on the leaf springs.

I have a $1 on what David says.....

For some reason spell check has never worked here for me. Actually it does if I use Firefox instead of IE.

Man, you guys are expensive to get advice from.. lol

[jaybee]

"The poly produces more friction then the bearings, however it is much better than bonded rubber." Interesting statement and one that I've wondered about for some time. Many on this board prefer DelAlum and I presume this is because of their devotion to wringing the last ounce of potential out of their car in track day and autocross. That's certainly admirable but sometimes the goal of a car that's significantly better than stock crashes headlong into budgetary reality.

[David Pozzi]

I think it's a toss up too! The Herb Adams Camaro I drove back in 1984 had spherical bearings in the lower A arms and was just fine to drive. We switched it to poly bushings to make it legal for the SCCA national autocross event, and I couldn't tell the difference driving it on the street. Not really any difference on the autocross course either, but in theory the poly will always add some extra friction. We ran stock spring rates, so maybe the extra friction didn't hurt anyway.

I like the spherical bearings, (but I'm not writing the checks) you can always pull them out and sell them if you don't like them. They will feel slightly more harsh on a sharp bump, like when you hit tar strips on the freeway. The Poly is a very close second choice in my book, and a good compromise between race and street. We have Delrin on Mary's 73 Camaro and they are a great way to go. If the choice were between spherical bearings, poly bushings, and Del-A-Lum/Delrin, I"d pick Delrin.
David

[jknight16]

Doesn't sound to me like there's a $1500+ difference then...to dumb ol' me that seems like crazy money for bushings.

Edit: But...If price realllly isn't an issue, then it's a no brainer. Sphericals it is.

[Skip Fix]

I've got sphericals going in my drag Camaro lower A arms so I'll let you know. FWIW my TA has alot of street and track miles on it with sold steel Afco lower A arm bushings and Herb Adams uppers. It still rode softer than my old full sized Bronco!

From what I hear from the street rod guys though is sphericals wear out on the street faster.

I personally hate urethane and they always seem to bind/squeak no matter what lube you use.

[Norm Peterson]

I personally hate urethane and they always seem to bind/squeak no matter what lube you use.
That's because lubing the faces of the poly is only a temporary band-aid. The solution is to avoid compressing the poly when you torque the bolts and lube the outsides of the inner sleeves. Get out your belt sander/disc sander/bench grinder and make the poly a tiny bit shorter than the sleeves. 1/32" shorter is more than enough.


Norm

[JDP Jordan]

That's because lubing the faces of the poly is only a temporary band-aid. The solution is to avoid compressing the poly when you torque the bolts and lube the outsides of the inner sleeves. Get out your belt sander/disc sander/bench grinder and make the poly a tiny bit shorter than the sleeves. 1/32" shorter is more than enough.


Norm

The Pfadt bushing were engineered correctly, no need to trim them. It is important not to over tighten however as you said but with the correct sleeve/poly length in a well designed system it is not touching the bushing but instead it is tightening to the sleeve. :cheers:

[chicane67]

Spherical or Urethane.... that is the question..

Is this really a question ??

Albeit my opinion seems to always lean toward the obvious... I think that the benefits greatly outweigh the possible con's in this case. Your spring/valving combination are soft enough to DD this suspension without a second thought. The Pfadt bushings actually soften up the peak impacts by allowing the suspension to move without restriction. When you add compliance... you add mechanical grip without increasing tactile vibration.

[Steve1968LS2]

I like the spherical bearings, (but I'm not writing the checks) you can always pull them out and sell them if you don't like them. They will feel slightly more harsh on a sharp bump, like when you hit tar strips on the freeway. The Poly is a very close second choice in my book, and a good compromise between race and street. We have Delrin on Mary's 73 Camaro and they are a great way to go. If the choice were between spherical bearings, poly bushings, and Del-A-Lum/Delrin, I"d pick Delrin.
David

Delrin isn't a choice.. unless you know a way to shove one in a C5 control arm.. lol

So, between the two choices what say you?

[Damn True]

Delrin isn't a choice.. unless you know a way to shove one in a C5 control arm.. lol

So, between the two choices what say you?

Oh c'mon Dave's gotta have one of these layin around:

https://static1.pt-content.com/images/pt/2009/02/LATHE11JPG-1.jpg

[JRouche]

Oh c'mon Dave's gotta have one of these layin around:

https://static1.pt-content.com/images/pt/2009/02/LATHE11JPG-1.jpg

Thats nice for making pens LOL Just kidding..

This one works also :) Monarch 10EE, pretty nice to work with. JR

https://static1.pt-content.com/images/pt/2009/02/10EE-1.jpg


But this one is my mule, its a joy to work with..
https://static1.pt-content.com/images/pt/2009/02/SB-1.jpg

Then if I wanna make a bunch of bushings this lil gem is nice...
https://static1.pt-content.com/images/pt/2009/02/emco120-1.jpg

And when all else fails, and they just dont fit, a lil sqeeze of 50 tons MAKES them fit :) J/K, I dont force things unless I have to ...
https://static1.pt-content.com/images/pt/2009/02/IMG_0124-1.jpg

[BRIAN]

Not to get off topic but would using one of the anti friction coatings that a lot of the coating mfg's offer for engine internals help in reducing the friction associated with using say poly bushings. I understand that most of the problem on the cheaper bushings is the length of the inner sleeve but that wouldnt be the case here.

I would think $1500 could make a lot of delrin inserts? It isn't a complex piece?

[Derek69SS]

I don't see any reason to run spherical bearings to be honest... these are for typical A-arm bushings that rotate along one axis, correct? All you need is a low-friction, bushing with minimal deflection. I'm not a fan of poly, since they squeak, and have some "stiction".

I'd make some delrins before I'd spend $1800 for a spherical bearing where spherical articulation isn't needed.

[79T/Aman]

the bushings may be on the same axis but A-arms that have separate mounting points will deflect due to chassis flex under load this is where sphericals have less bind.

[E.rodz]

i have had a set of sepherical rod ends in the rear 4 link in my pick up for 11'000 miles on the streets in minesota and they were great. i was at the same cross road. i wanted more articulation with the 4 link this definitly helped and the rattles were minimun. i agree with the statment obout it changing your spring rates. just somthing you will have to play around with. i love your articals and your car . keep up the good work.

[CapSS92]

I'd lean toward the sphericals. I found my suspension to be smoother with them also.

[Steve1968LS2]

I don't see any reason to run spherical bearings to be honest... these are for typical A-arm bushings that rotate along one axis, correct? All you need is a low-friction, bushing with minimal deflection. I'm not a fan of poly, since they squeak, and have some "stiction".

I'd make some delrins before I'd spend $1800 for a spherical bearing where spherical articulation isn't needed.

I think the control arms move around more than you think and in more directions. Check out the video I posted.

I think their poly is the best option for going poly.. also, I just need the fronts so the cost is quite a bit less than the site price for a whole C5 vette.

[Payton King]

the UCA because they move in the same plane. On the LCA there are 2 eccentrics that are moved independently of each other in setting camber and caster. A derlin bushing will not work here because the plane is different and it would bind.

So it is pretty much factory rubber, urethane or sphericals.

The price you see for the set does front and back on a corvette. Steve would only need the set for the front.

My vote is for the sphericals.

[Steve1968LS2]

Decisions... decisions.. decisions...

[OHCbird]

Seeing as you have the ability to change & tune the suspension settings, I'd go sphericals. Think of it this way- maybe by eliminating the last bits of the suspension you can't tune (unpredictable deflection for one)- you'll be able to tweak the last bits out of your spring rates & shock settings.

I say this based on my impression that you want to extract everything you can from the car, and still have some degree of streetability. When you boil it all down, how much of a compromise is it? A slightly larger 'thud' when you go down the 405? That's an easy fix- get thicker seat padding for the trip to the track!

[LateNight72]

Decisions... decisions.. decisions...
Quit bull****ting us and just get the sphericals.. You know you want to. :moon::rotfl:

[CarlC]

Man up!!

[Steve1968LS2]

Man up!!


Quit bull****ting us and just get the sphericals.. You know you want to. :moon::rotfl:




My vote is for the sphericals.


Fine, I will get the damn sphericals tomorrow.. I'll be eating Top Ramen for a month but my control arms won't deflect!

[slowcamaro]

That a boy. Go big or go home. Besides you have got to fight off them lagunas now you're a defending champ, no?

[zbugger]

That a boy. Go big or go home. Besides you have got to fight off them lagunas now you're a defending champ, no?
lol..... I don't care who you are, that's funny right there!!!:rotfl:

[CarlC]

Come on Steve, live a little. The frozen burritos at the grocery store are about 35 cents each! The spicy beef and bean is quite tasty with a helping of hot sauce.

[Steve1968LS2]

Come on Steve, live a little. The frozen burritos at the grocery store are about 35 cents each! The spicy beef and bean is quite tasty with a helping of hot sauce.

:yum:

[LateNight72]

Fine, I will get the damn sphericals tomorrow.. I'll be eating Top Ramen for a month but my control arms won't deflect!
Top Ramen... Ah college is great. :1st:

[Derek69SS]

the UCA because they move in the same plane. On the LCA there are 2 eccentrics that are moved independently of each other in setting camber and caster. A derlin bushing will not work here because the plane is different and it would bind.I'm not real familiar with 'vette stuff, but that makes sense if the lower mounts do not share a common axis. I wasn't really buying the chassis flex causing misalignment... at least not enough in relation to each other to cause any significant misalignment.

[79T/Aman]

I'm not real familiar with 'vette stuff, but that makes sense if the lower mounts do not share a common axis. I wasn't really buying the chassis flex causing misalignment... at least not enough in relation to each other to cause any significant misalignment.

unfortunatly chassis flex happens and with zero clearance in the poly bushings it only take a couple thousands of inches, magnified by distance to cause bushing bind

[JDP Jordan]

Fine, I will get the damn sphericals tomorrow.. I'll be eating Top Ramen for a month but my control arms won't deflect!

You're going to be happy! We'll worth the cost and a few weeks of Ramen and frozen Burritos isn't so bad! :rotfl:

The spacers shipped today and we'll get everything else out tomorrow! Talk to you soon!

[Steve1968LS2]

You're going to be happy! We'll worth the cost and a few weeks of Ramen and frozen Burritos isn't so bad! :rotfl:

The spacers shipped today and we'll get everything else out tomorrow! Talk to you soon!

Yea, my wallet is cowering in the corner crying.. lol

Oh well, gotta keep pushing forward.. These cars arn't any fun when they're done.

Should make a good combination with the new uprights and I will report on how the car rides/feels with them.

They won't be in by the Costa Mesa Goodguys but they should be in by Del Mar.

Sure are pretty:
https://static1.pt-content.com/images/noimg.gif

[LateNight72]

That orange is going to go well with Penny's paint color.

[Steve1968LS2]

That orange is going to go well with Penny's paint color.

Mearly a side benefit.. although if they were green I might have gone the other way. lol

After all, how many people haven't bought ZEX stuff due to the purple hue?

[LateNight72]

Mearly a side benefit.. although if they were green I might have gone the other way. lol

After all, how many people haven't bought ZEX stuff due to the purple hue?
Hey, I'm just trying to make you feel better. :)

Plus, the Devil is in the Details...

[Steve1968LS2]

Can't wait to get this stuff on the car.. thanks for talking me into the better stuff. I'm broke but happy. lol

ZR1 type wheel bearings, better lower HOWE ball joints, Pfadt bushings, and Raceseng Design drop uprights.
https://static1.pt-content.com/images/pt/2009/03/258uyq8-1.jpg

[JRouche]

Can't wait to get this stuff on the car.. thanks for talking me into the better stuff. I'm broke but happy. lol

ZR1 type wheel bearings, better lower HOWE ball joints, Pfadt bushings, and Raceseng Design drop uprights.

WOW!! Is all I can say. Very nice looking parts. Very nice. Cant wait for the as installed pics. JR

[DarkoNova]

I guess I'm late to the party, but what front clip are you running?

Matt