A-arm bushings, Pros - cons?? Options

[Jeroen]

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.

(IMG:http://www.914world.com/bbs2/html/emoticons/WTF.gif)

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

[J P Stein]

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.

[914-8]

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?

[lagunero]

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.

[East coaster]

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??

[ChrisFoley]

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.

[East coaster]

Thanks Chris, I was afraid of that !!

Needle bearings or bronze bushings here I come !!

[MattR]

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....)

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif)

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.

[MattR]

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.

[lagunero]

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

Its a guy thing and I love it.

(IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

I withdraw my vote for classic status

[Twystd1]

Albert,

You just MattRd yourself......

Twystd1

[Jeroen]

QUOTE (MattR @ Mar 21 2006, 04:25 AM)

Thank you for making my point

I guess I missed your point then, but thanks for clarifing (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
Well... sort of

Personally, I don't have issues with engineers
You can read a thousand books on suspension set ups and still be lost
Or you can ask a question here and get some good answers on what really does work in our cars

That's why I love this place. You get real info here (pretty much most of the time) and very little "internet myths"

And to get back to the bushings topic, that exactly what I think is the problem here. Metal-to-metal bushings being harsh/uncomfy is just another one of those "internet myths"

[Mueller]

for those that 'diss the notion of needle bearings being used for applications "not" involving 360° motion:

this is from Pegasus Autoracing I would tend to think, they know what they are talking about (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

QUOTE

Part No.: 3080-Size Nadella Combined Needle Bearing Nadella bearings are used in many racecar applications because of their small size, low weight and high load capacity. A common use is in rocker pivots on cars with inboard suspension. In order to achieve rated capacity and life, the mating surfaces should have a smooth, hard finish. A Rockwell hardness of C58 will ensure full rated capacity. Using a matching Thin Nadella Thrust Washer or a Thick Nadella Thrust Washer will provide the proper hardness and finish in the axial direction.