What's the best setup for a street car?

Tarret bronze/urethane? (Sounds like a good idea, but never heard from anyone running them)

Needle Bearings? ( I worry about rust and maintenance issues)

Stock with 40K on them? (Has a low "trick" factor, but probably works good)

Delrin/urethane (squeeky........don't want them)

Ditto for rear trailing arm bushings????

I think the Elephant poly bronze is a good solution but if your stock bushings only have 40K on them and haven't sagged then I'd just stay with those. There are tons of threads BTW on the 911 bird board about poly bronze bushings.

I think most people with street drivers would love to have A-arms with low mileage, excellent condition stock rubber bushings on them.

I know I would! I'd take those over any of the others you mentioned, hands down, for my street car.

if you have good stock bushings...
then I'd agree.
I had a lowish mile green car for a while with NOT SHOT stock bushings.
that was a sweet ride for the street!
compliant and comfortable.

plus you'll never be able to go back to that!


oh by the way.
the poly aren't so bad if you install and zerk them.
they are certainly cheap.

although I agree that spending the $ for something like mueller bearings or Racer chris bushings are certainly better...

I have a poly car and a mueller bearing car currently.
brant

What's wrong with keeping the stockers? Double check that they aren't sagging by taking a peek at the end of the torsion bar closest to the passenger compartment. If they are sagging, there will be a little groove worn into them just in front of the spline.

I wish I still had my stockers sometimes whenever the squeaks remind me that I put the urethane ones in...

Steve

QUOTE (East coaster @ Mar 19 2006, 10:48 PM)

Delrin/urethane (squeeky........don't want them)

Well made/installed Delrin bushings aren't squeeky.
Weltmeister Poly bushings are. No matter how much time you spend on the installation they won't be quite right.
People with needle bearings swear by them, even for street use.

QUOTE (Racer Chris @ Mar 19 2006, 08:45 PM)

QUOTE (East coaster @ Mar 19 2006, 10:48 PM) Delrin/urethane (squeeky........don't want them) Well made/installed Delrin bushings aren't squeeky. Weltmeister Poly bushings are. No matter how much time you spend on the installation they won't be quite right. People with needle bearings swear by them, even for street use.

Do the needle bearings bottom out after extended use?

Bump.


I meant, do the bearings wear on one side more than the others, since the bearing rarely makes a full turn and so a portion of the bearing is under load ALL the time while other parts or never under load.

QUOTE (alpha434 @ Mar 19 2006, 09:08 PM)

Bump. I meant, do the bearings wear on one side more than the others, since the bearing rarely makes a full turn and so a portion of the bearing is under load ALL the time while other parts or never under load.

The idea behind a bearing is it distributes the load reguardless of position.

QUOTE (alpha434 @ Mar 19 2006, 10:08 PM)

Bump. I meant, do the bearings wear on one side more than the others, since the bearing rarely makes a full turn and so a portion of the bearing is under load ALL the time while other parts or never under load.

I don't have the specs in front of me, but the bearings are rated for something like 15,000 pounds static (way more dynamic)...now times that by 4 and you have plenty of support......we've pulled apart bearing after street and track use after 2 years, no signs of problems or rust.....

I'd opt for the Delrin bushings from Chris Foley and then the Elephant bushings.....I no longer make the needle bearing kits but as far as I know they are availabe from Shine racing....

QUOTE (alpha434 @ Mar 20 2006, 12:08 AM)

I meant, do the bearings wear on one side more than the others, since the bearing rarely makes a full turn and so a portion of the bearing is under load ALL the time while other parts or never under load.

That is one of my concerns regarding needle bearings used as suspension bushings. The needles will always be loaded on the same surface and will eventually become flat spotted.
My other concern is that the factory components the needle bearing outer sleeves press into aren't round, therefore the needle bearings have to be loose or they will bind.

That idea only applies to load during rotation.

When the load on a bearing is pulling it one direction, and the bearing doesn't make a rotation, the load remains on one place until it wears.

With a wheel bearing, the wheel is turning, and no one bearing is exposed to the load for any readily calcuable amount of time.

The bearing at "TDC" is taking no load in the example of the wheel bearing. The bearing at BDC is taking 100% of the load. But the two change positions very quickly to compensate.

Chris, can you give some info on your delrin bushings?

QUOTE (Mueller @ Mar 19 2006, 09:33 PM)

QUOTE (alpha434 @ Mar 19 2006, 10:08 PM) Bump. I meant, do the bearings wear on one side more than the others, since the bearing rarely makes a full turn and so a portion of the bearing is under load ALL the time while other parts or never under load. I don't have the specs in front of me, but the bearings are rated for something like 15,000 pounds static (way more dynamic)...now times that by 4 and you have plenty of support......we've pulled apart bearing after street and track use after 2 years, no signs of problems or rust..... I'd opt for the Delrin bushings from Chris Foley and then the Elephant bushings.....I no longer make the needle bearing kits but as far as I know they are availabe from Shine racing....

A raw strength rating doesn't protect it from abrasive machining. Wear. I never thought that they would bend or break under load. A LOT of the wear variable would depend on the lubrication system. But I suppose that a good a-arm regreasing could be a smart part of regular maintenence. Especially if the performance is better.

QUOTE (914-8 @ Mar 20 2006, 12:38 AM)

Chris, can you give some info on your delrin bushings?

Have a look at my Suspension Webpage first so you can ask me specific questions.

the bearing races are hardened to 60R, "if" and when there is wear, it'll be many, many moons down the road...the bearing itself cost $6 each (4X) so what if you have to replace a few 10 years from now???

none of the rubber bushing replacments are perfect, there will always be some sort of comprimise with each solution

QUOTE (Mueller @ Mar 19 2006, 09:42 PM)

the bearing races are hardened to 60R, "if" and when there is wear, it'll be many, many moons down the road...the bearing itself cost $6 each (4X) so what if you have to replace a few 10 years from now??? none of the rubber bushing replacments are perfect, there will always be some sort of comprimise with each solution

Fair enough, Mueller. I always liked the idea of needle bearings there anyway. I just wanted some input and maybe open discussion on it. Thanks.

QUOTE (Mueller @ Mar 20 2006, 12:42 AM)

none of the rubber bushing replacments are perfect, there will always be some sort of comprimise with each solution

The primary compromise with my bushings is that the tooling required for fitment is too expensive for everyone to purchase their own, so it isn't a DIY same-day method. You have to ship the trailing arms or the front brackets to me for proper installation of the bushings. The big advantage is the ID of the bushings will be sized accurately and will be truly round.

QUOTE (Racer Chris @ Mar 19 2006, 09:42 PM)

QUOTE (914-8 @ Mar 20 2006, 12:38 AM) Chris, can you give some info on your delrin bushings? Have a look at my Suspension Webpage first so you can ask me specific questions.

I've had a lot of porsches over the past 25 years and done a lot of work on them, but replacing the suspension bushings is one of the things I've never done.

So forgive me if the answers to this are obvious or I'm off base.

But your website says"

"Exchange your old carrier brackets for powdercoated ones with Delrin bushings.

The bushings are pressed in, then reamed to a precise tolerance."

Would I have to send the A-arms to you? Because my understanding was that the a-arms themselves are the things that have loose tolerances. So without my actual a-arms, how can you ream the IDs of the bushings to a "precise tolerance?" What tolerance do you ream them to?

QUOTE (914-8 @ Mar 19 2006, 10:02 PM)

QUOTE (Racer Chris @ Mar 19 2006, 09:42 PM) QUOTE (914-8 @ Mar 20 2006, 12:38 AM) Chris, can you give some info on your delrin bushings? Have a look at my Suspension Webpage first so you can ask me specific questions. I've had a lot of porsches over the past 25 years and done a lot of work on them, but replacing the suspension bushings is one of the things I've never done. So forgive me if the answers to this are obvious or I'm off base. But your website says" "Exchange your old carrier brackets for powdercoated ones with Delrin bushings. The bushings are pressed in, then reamed to a precise tolerance." Would I have to send the A-arms to you? Because my understanding was that the a-arms themselves are the things that have loose tolerances. So without my actual a-arms, how can you ream the IDs of the bushings to a "precise tolerance?" What tolerance do you ream them to?

The delrin has to be pressed in first, so that the material won't flex during cutting, then he will measure your a-arms and cut EXACTLY the right size +- .001 or so to the specific A-arm part. THAT is why he has to have your a-arms on hand. They are low tolerance and the bushings won't work properly at that low of a tolerance. He matches the sizes and everything is better.

But I'm a big fan of burnishing the delrin instead of reaming. More expensive tooling initially, but there isn't any raised surface after the reaming, and the finish can come out VERY smoot. Up to a 4 micron finish on mechanical grade delrin.

Good question Alpha,

I wanted to run a set of Mueller bearings, front and rear on my street car that will be occasionaly A/Xd.

So I asked Brad Roberts about the proverbial needle bearings set up about 6 months ago at Bmundays house.

He said the same thing as Mike.

In two years he has not seen any wear or compromise to the needle bearings kit on both street cars and the race cars he has installed them on. That was good news for me.............

The reason i was so interested in them was:

I wanted an almost zero bind suspension that would allow me to have spring rates and shock valving that aren't trying to compensate for a "erraticly" binding rubber bushed suspension.

In essence, I want something closer to Heim Joints with out all the fabrication inolved. (CSOB)

Here is my thinking............

When a suspension binds in an erratic fashion. The pivot points act like nonlinear springs to a degree. The harder the suspension is pushed sideways. Or when hitting a bump... or worse...BOTH...!!!!!
RESULTS: Instabind of unknown rate...

Now add a hot day or a cold day and the durometer of the rubber bushing changes to some degree. (not so for delrin)

The problem is that I can't plot a friction curve for this. Cause it changes erraticly in a way I can't calculate.

So I can't create shock valving curves/rates or spring rates that have any consistency, based on known suspension compliancys.

And it gets dam hard to tune the suspension when there is no consistency to the sticktion of the bearing surfaces.

Thats my thinking anyway.

The tradeoff will be a bit more of a harsh ride as I will lose some bushing compliency. Thats OK.. This car isn't a daily driver...

Then again, There are a many race cars out there with rubber, delrin, poly bronze and other bushing that are VERY competitive without needle bearing suspensions.

I think if I have a low stiction suspension.
I can more than make up for the less compliant ride with appropriately valved shocks.

Yea there are tradeoffs in everything. I think this is a very good tradeoff.

I haven't done this yet. So this is just talk at this point.

This is the plan i am going to do............. As others have done before me.

Mueller bearings are my choice

AND:

ALSO:

PLUS:

The real reason I want them....
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Aaron will feel like a loser because he uses "Slits Bearings" in his car.......

They are loose in turns. But make up for it by looking cracked and old....

Claytonovich

I don't think that the "bound" pivot will act as a spring. I think that it will act as inconsistant damper in both directions instead, slowing the response of the spring. Regardless, you are right. It will make it harder to fine tune your suspension. I want needle bearings for my car, but all the local guys want me to make them delrin assemblies for their cars for the reason I mentioned. I couldn't imagine the load variations to affect such a hefty assembly. But it is good to discuss it. At least in my mind.

HEY. And congrats on thinking things through to the "fine tune" stage in your car. Your logic is correct.

Yep, you said it. Real cars have heim joints and spherical bearings...




I do think on a street driven car , the absorption of stock rubber or poly bronze is better. Theoretically the bearings should rotate over every bump, but in reality, there are 3 axes of rotation to to compensate for (rotation in x-y-z). The bearings do a great job in one direction of rotation, but for the other 2, they dont do much. In fact, you have straight metal on metal contact. Normally with bushings the "give" in the rubber will absorb the bumps in the road so your chassis (and butt) doesnt have to.
Moral of the story: with bearings, all that force from the other 2 axes of rotation are being absorbed by the chassis, which isnt a problem on a track car, but it kills yur butt... especially if you're an old phart like me (3 months and I can legally drink!!!)

With that said, I've never been in a car with mueller's bearings. Only in street 996 gt3s (rubber bushed) and then track 996 gt3s (spherical bearings).

Your 996s have wishbone suspension. And 5 link. We don't have that kind of control over all three axis. All we can do is get two as good as we can.

And the rubber bushing shouldn't be acting as a chassis damper, even if it does. Are you sure that the difference your feeling between Cup cars and stock isn't the huge difference in springrate and shocks. The tighter bushings are more of a "handling" upgrade, since it doesn't "float" around with solid mounting, causing minute changes in toe and camber.


The next generation. Hard at work.

This kinda takes me back to the big bar/soft spring or the small bar stiff spring theorys.

Matt. You guys are right on the wear characteristics of the bearings.

Then again. I probably won't wear out a set of em any quicker than rubber bushings.

I am gunna guess that Mueller bearings will out last Delrin and poly bronze bushings by a factor of 2.

This is based on NO DATA except when I was driving round"D"round cars. We would replace delrin control arm bushings and sway bar bushings every half season or sooner.

They would elipse after a while and have to be changed out.

Me thinks bearings either brake.. or they work..
And they don't go out of round.

If ya haven't been in a car with Mueller bearings that has been setup correctly.

You wouldn't even know they are in the car.............

Cause it's that smooth...................

Clayton


Oh..And your ugly too.... God dam kids...!!!!!!!!!!!!!!!!!!!

Matt.. Aren'y you supposed to be studying?????????????? GDK!!!!!

QUOTE (MattR @ Mar 20 2006, 08:38 AM)

Moral of the story: with bearings, all that force from the other 2 axes of rotation are being absorbed by the chassis, which isnt a problem on a track car, but it kills yur butt... especially if you're an old phart like me (3 months and I can legally drink!!!) With that said, I've never been in a car with mueller's bearings. Only in street 996 gt3s (rubber bushed) and then track 996 gt3s (spherical bearings).

theoretically, you are right, but in the real world it will make very little difference

I had the Elephant poly-bronze bushings on my '87 tail dragger, monoballs in the front top strut mounts and monoballs at the inner rear trailing arm mounts

so the only rubber left in the suspension were in the rear shock mounts and those big round things around the wheels

the car was NOT uncomfortable at all, even with the heavier springs (22/29mm t-bars, 22mm tarett sways front/rear and bilstein sport shocks) and f/g bucket racing seats

the suspension worked much smoother cause the springs/shocks could do their job as they were supposed to

there wasn't any noticable added road noise transmitted through the metal/metal bushings either

QUOTE (914-8 @ Mar 20 2006, 01:02 AM)

Would I have to send the A-arms to you? Because my understanding was that the a-arms themselves are the things that have loose tolerances. So without my actual a-arms, how can you ream the IDs of the bushings to a "precise tolerance?" What tolerance do you ream them to?

I measured many a-arms and found that the bearing surface diameters are very consistent. The carrier brackets, on the other hand, are fabricated and welded which makes for significant variability. I ream the bushings after installation in the carrier brackets, always to the same dimension, and I don't think I need the a-arms for verification. I suppose I could be wrong about this - only time will tell.
The trailing arms are a different story. I ream the trailing arms to a precise diameter and concentricity so the delrin bushings always fit the same and I install reground pivot shafts that fit precisely. My data indicates that the pivot shafts are often not truly straight and the two bushing bores in the trailing arms aren't concentric. These factors will contribute to binding unless they are addressed in addition to the precise ID tolerance of the bushings.

Not one single person has complained about a rough ride with the needle bearings.....in fact it's been the complete opposite...Hank Watts (yes, THE Hank Watts, author of Secrets of Solo Racing, auto-x and track guru)...instructed Britain at Laguna in a street/track 3.0 /6...upon coming back to the pitts, Hank jumps out of the car and immediately lays on the ground to inspect the suspension...he totally thought it had a full on tricked out hiem-joint suspension due to the car just "floating" over the course...you hit a berm, the suspension moves up, not the car.....

Installed correctly, the plastic bushings do work, I've used them in the past..the key is installed correctly.....

what many people do not realize is that the plastic bushings, the bronze bushing and the needle bearings change the original design of the suspension, with the rubber bushings, the rubber not only isolates the car from the road, but they also act as a torsion spring (gives resistance to the a-arm going up and going down)

as for any of the replacement bushing, I think the ride can be just as good, but I do believe noise will be increased, however with the 914 being as loud as it is (same for many 911's), I don't think many people will notice the differance....

my car will be a good test bed for people to see how bumpy or noisy or not, the suspension can be.....needle bearing on all 4 corners and running 205/40/17's stretched out on 7" rims....the tires alone ought to make for one rough ride

QUOTE (Mueller @ Mar 19 2006, 10:42 PM)

the bearing races are hardened to 60R, "if" and when there is wear, it'll be many, many moons down the road...the bearing itself cost $6 each (4X) so what if you have to replace a few 10 years from now??? none of the rubber bushing replacments are perfect, there will always be some sort of comprimise with each solution

Mike, I'm going to PM you about spare parts...

I have something to add to this thread.
I (2 weeks ago) disassembled my mueller front bearings for inspection and grease re-packing.

This was after 1 season of use and that included I think 17 track days.

We had used white grease to pack them, and RTV to seal the ends like a dust cap.

So after disassembly, washing and visual inspection I'm happy to say there is NO VISIBLE wear. They were still clean and looking good.

I expect that annual re-packing will be good preventative maintence. Plus during reassembly they are randomly put back into a different position and load surface, the annual inspection should reduce wear also.

only 1 year instead of 2, but I'm happy to report positive results!

brant

QUOTE (alpha434 @ Mar 19 2006, 11:58 PM)

Your 996s have wishbone suspension. And 5 link. We don't have that kind of control over all three axis. All we can do is get two as good as we can.

Every component in the physical world is subject to the same 6 forces - translation in x, y, and z, and rotation in x, y, z. 996s use spherical bearings that allow for free rotation in x, y, and z. What I'm feeling when we hit a bump is the solid connection between translation in x, y, and z (which is lessened because its free to rotate). The 914 still rotates in x, but we feel the rotation in y and z and translation in x, y, and z. We have much more force being absorbed by the chassis if its a solid mount... which doesnt feel good. Theoretically we need a really stiff chassis that lets the suspension do the work, but we all know that aint true in a typical 914. So either we stiffen the car considerably, replace the joints with spherical bearings, and install high quality dampers OR we enjoy what we have and drive the piss out of it and try not to fine tune the "suspension."

QUOTE

And the rubber bushing shouldn't be acting as a chassis damper, even if it does. Are you sure that the difference your feeling between Cup cars and stock isn't the huge difference in springrate and shocks. The tighter bushings are more of a "handling" upgrade, since it doesn't "float" around with solid mounting, causing minute changes in toe and camber.

I dont know who told you rubber bushings shouldnt be acting as a chassis damper on a street car, and PLEASE dont say Al... I'm pretty tired of you being his puppet...

And yes, I know what overdamped and oversprung cars feel like.

QUOTE

The next generation. Hard at work.

Nah, I just wing it...

QUOTE (Jeroen @ Mar 20 2006, 04:45 AM)

QUOTE (MattR @ Mar 20 2006, 08:38 AM) Moral of the story: with bearings, all that force from the other 2 axes of rotation are being absorbed by the chassis, which isnt a problem on a track car, but it kills yur butt... especially if you're an old phart like me (3 months and I can legally drink!!!) With that said, I've never been in a car with mueller's bearings.  Only in street 996 gt3s (rubber bushed) and then track 996 gt3s (spherical bearings). theoretically, you are right, but in the real world it will make very little difference I had the Elephant poly-bronze bushings on my '87 tail dragger, monoballs in the front top strut mounts and monoballs at the inner rear trailing arm mounts so the only rubber left in the suspension were in the rear shock mounts and those big round things around the wheels the car was NOT uncomfortable at all, even with the heavier springs (22/29mm t-bars, 22mm tarett sways front/rear and bilstein sport shocks) and f/g bucket racing seats the suspension worked much smoother cause the springs/shocks could do their job as they were supposed to there wasn't any noticable added road noise transmitted through the metal/metal bushings either

So, either we believe the theory (spoken by a KID), or we believe a "my friend has a 911" story. I hate to be a dick about this, but nobody gives engineers any credit now days.

QUOTE (Mueller @ Mar 20 2006, 07:30 AM)

..instructed Britain at Laguna in a street/track 3.0 /6...

yeah, but did he go over the bumpy section of ... laguna seca?

the plot thickens.... and then congeals.....

QUOTE (Aaron Cox @ Mar 20 2006, 11:10 AM)

the plot thickens.... and then congeals.....

..... then dries.... and becomes a stain on your favorite stuffed animal

Actually, I thought rubber was only used for suspension mounts since it was cheap and readily available at the time. I never asked Al.

And even though we experience forces in all 6 of the axis, our suspension is only ment to move in a few of them. That was my point. With full 5 point, you can control most of those axis and how your car reacts under those forces. With our cars, we can only tune a few and try to eliminate the rest from being variables.

Engineers suck to deal with. They overthink things that aren't problems and underthink things that are. I used to work with kids from Co School of Mines. They all whined and bitched when I did math in my head. They used to say "all that engineering we do and then he plugs numbers."

(I'm going to Mines NEXT year!)

QUOTE (MattR @ Mar 20 2006, 11:55 AM)

QUOTE (Mueller @ Mar 20 2006, 07:30 AM) ..instructed Britain at Laguna in a street/track 3.0 /6... yeah, but did he go over the bumpy section of ... laguna seca?

no, I'm pretty sure he only drove on the smoothest-mirror- polished-freshly-paved and graded surface

QUOTE (Mueller @ Mar 20 2006, 12:25 PM)

QUOTE (MattR @ Mar 20 2006, 11:55 AM) QUOTE (Mueller @ Mar 20 2006, 07:30 AM) ..instructed Britain at Laguna in a street/track 3.0 /6... yeah, but did he go over the bumpy section of ... laguna seca? no, I'm pretty sure he only drove on the smoothest-mirror- polished-freshly-paved and graded surface

id like a sarcasm sandwich plz

QUOTE (alpha434 @ Mar 20 2006, 11:21 AM)

And even though we experience forces in all 6 of the axis, our suspension is only ment to move in a few of them. That was my point. With full 5 point, you can control most of those axis and how your car reacts under those forces. With our cars, we can only tune a few and try to eliminate the rest from being variables.

We're talking about different things. The real world only has 3 axes (x, y, z). Translation is a force. Rotation is a moment (force about an axis). An SLA suspension can control the upright/wheel, but I'm not talking about that. I'm talking about number of Newtons going into the wheel through the road and how thats absorbed through the spring/damper and the mounts. Simple force balance equation. Its not easy, but simple.



Most engineers are dicks. Especially young ones with good jobs... big brains, bigger egos

QUOTE (Aaron Cox @ Mar 20 2006, 12:27 PM)

QUOTE (Mueller @ Mar 20 2006, 12:25 PM) QUOTE (MattR @ Mar 20 2006, 11:55 AM) QUOTE (Mueller @ Mar 20 2006, 07:30 AM) ..instructed Britain at Laguna in a street/track 3.0 /6... yeah, but did he go over the bumpy section of ... laguna seca? no, I'm pretty sure he only drove on the smoothest-mirror- polished-freshly-paved and graded surface id like a sarcasm sandwich plz

funny thing is that I don't even make or sell the darn things anymore and here I am "defending" them \

all that really matters is that I got 'em and like 'em and so do others that have them

QUOTE (alpha434 @ Mar 20 2006, 11:21 AM)

Engineers suck to deal with. They overthink things that aren't problems and underthink things that are.

There's always at least 1 machinist in any shop I've worked with or at who has the "engineers don't know shit" chip on the shoulder. Alpha, I've heard your argument countless times..even years BEFORE I was an engineer. It's got nothing to do with that engineer "having a degree"... it's that two guys together that both want praise and go out of their way to find flaws in the other guys arguements... pretty well DOESN'T matter what the topic is....


My advantage was growing up working IN a machine shop, and having a machinist as a father. I respect the trade, and show respect to the machinists (especially the crotchity old German ones...) You sow a few seeds of respect... and soon you have these guys doing first class "G-Jobs" FOR you.. including making 914 parts!!!

I pride myself in "knowing shit" ( at least SOME of it which I can remember, but I do confess to suffering often from CRS (Can't Remember Shit...)) but I'm certainly NOT a shit specialist...I leave that to strange Japanese pron.....

You definitely are an intelligent guy and I'm sure you will be successful in most anything you try, but NOT if assume every engineer is an ahole...


Back to the BUSHING Issue:

Herb Adams published a great book called "Chassis Engineering". It makes the science of suspension approachable in that he explains everything in layman's terms. All the basics on how to set up a car are covered really well. He has a whole section discussing bushings, delrin, poly, needle, and stock rubber. (He favors STOCK rubber and makes and exellent arguement why....)

QUOTE (MattR @ Mar 20 2006, 07:54 PM)

So, either we believe the theory (spoken by a KID), or we believe a "my friend has a 911" story.  I hate to be a dick about this, but nobody gives engineers any credit now days.

I wasn't talking about "a friends 911", I was talking about MY car, which I drove on a daily basis

How many cars with these kinds of bushings/bearings installed did YOU drive on the street/track for a longer period of time?

There's lots of things that can/will make your car uncomfortable (or hurt your butt as you put it), but these metal-to-metal bushings/bearings ain't one of em...

call me weird, but I'll take real world BTDT advise over theoretical-engineers-poop-talk any day

Should you ever take out your T-bars, look for radial scratches/gouges on them. This means either your rubber bushings have given up or (as in my case) you're overloading them.....smashing them down to next to nothing in thickness.
Mine had mild scratching near the rear mounting point, but none at the front (pitch in Z or yaw in Y if anyone has been reading).

If that is the case, it's time for new bushings.....even if the rubber is good. I've been using Meuller's bushings for 2 seasons and an very happy with them. The first year, mine was still a street car and any harshness they added was not an issue. The compliance they added was a positive.....tho revalved shocks may have some effect on this.

QUOTE (Brian Mifsud @ Mar 20 2006, 11:55 AM)

Herb Adams published a great book called "Chassis Engineering". It makes the science of suspension approachable in that he explains everything in layman's terms. All the basics on how to set up a car are covered really well. He has a whole section discussing bushings, delrin, poly, needle, and stock rubber. (He favors STOCK rubber and makes and exellent arguement why....)

And if that's not available, what's his second choice, and why?

Although (as usual) I don't have anything to add to this debate/discussion, I do find it to be the most informative in regards to the "what's better" question. It actually goes beyond the "this/that sucks" and gives real world BTDT advise and theoretical engineers poop talk. So I request his thread be added to the classics section.

Wow........Lots of good info!

I'm thinking if I can preserve my stockers I will (for now). My next question is, since I already disassembled my front end (including removing the stock rubber bushings) have I sealed their fate? In other words is it posible to re-use/re-install the stock rubber?

Here's my actual scenario just for reference. I have a '85 Carrera front end and the stock 914 front end. The stock 914 front end is the 40K original mile portion. Can I take the A-arms from the 911 front end and use the stock bushings from the 914 front end??

QUOTE (East coaster @ Mar 20 2006, 08:12 PM)

In other words is it posible to re-use/re-install the stock rubber?

Once you pull them apart they're done. That is unless you can come up with a way to compress the rubber enough to put them back in between the metal parts.

Thanks Chris, I was afraid of that !!

Needle bearings or bronze bushings here I come !!

QUOTE (Brian Mifsud @ Mar 20 2006, 11:55 AM)

Back to the BUSHING Issue: Herb Adams published a great book called "Chassis Engineering". It makes the science of suspension approachable in that he explains everything in layman's terms. All the basics on how to set up a car are covered really well. He has a whole section discussing bushings, delrin, poly, needle, and stock rubber. (He favors STOCK rubber and makes and exellent arguement why....)

I have that book along with a dozen others within arms reach for these types of internet battles. They're really good reference and do a pretty good job of explaining the theory rather then going through proofs, which is nice for a quick reference. Its the cliffs notes of engineering.

I'm no engineer, just a student with a hair up his ass.

QUOTE (Jeroen @ Mar 20 2006, 03:53 PM)

call me weird, but I'll take real world BTDT advise over theoretical-engineers-poop-talk any day

Thank you for making my point. I couldnt agree more with Brian Mifsud. Being able to design stuff that works is more of a male rite of passage then trade. Thats why so many people dont like engineers, who design stuff by trade. Many guys think they've seen enough to know what works, and anyone younger then them hasnt seen as much as they have.

I go through the same thing every day. I have way more hands on experience then other engineering students at UCI who havent opened the hood of their car except to install an AEM hot air intake. When they say something I dont agree with (even when its right), I jump on them and tell them exactly how wrong they are in the "real world." Yeah, I'm wrong 99% of the time, but I never let them know. Its a guy thing and I love it.

QUOTE (MattR @ Mar 20 2006, 07:25 PM)

Its a guy thing and I love it.

I withdraw my vote for classic status