Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.
Interesting idea, seems like overkill. Why complicate such a simple part? They would have to be pretty damn nice bearings to survive, hard to keep crap from getting in there given the environment they'd be in.
Are similar style bushings used in any production/race vehicles?
Xanth wrote:Interesting idea, seems like overkill. Why complicate such a simple part?
Exactly. Complete waste of money IMO.
And they never require maintenance during their entire lifetime? How long is their lifetime? The wheel bearings on my nitro RC car are of the same type, just in a smaller scale, and those only last 1 season, if that.
Im sure he's tested these for a couple years though :bs:
Shoulda and Coulda are two totally different words. A buddy of mine is making all his bushings out of titanium... because he can. $145 is a buttload. Poly works just as well.
Well, I think they're a great idea, just poorly executed (bearing choice). Sure, there are other areas that would see better improvements/$, but the concept of eliminating play makes sense to me. Like going from poly to aluminum cradle bushings... :la:
I don't think I would've used such a small bearing. When cornering at 1g, those things are going to be loaded pretty close to the static load rating, and the big issue is that those bushings can get hammered pretty hard if you hit a bump on a corner. Ball bearings don't work as well when the race has a bunch of dings in it.
yes, roller/needle bearings would have been a better approach - but - again - if you are squeezing out every last dime of handling - would you not go with a '88 cradle.....
Pyrthian wrote:yes, roller/needle bearings would have been a better approach - but - again - if you are squeezing out every last dime of handling - would you not go with a '88 cradle.....
This part doesn't seem to be for true-performance though. Its more of a symbolic gesture. Also much cheaper than getting an 88 cradle.
In this app, these bearings do NOT take the static weight of the car and jounce/rebound loads. To a first order estimate, they only take cornering loads.
I've seen '88 rear cradles as low as $300...
The S1 through S3 Jaguar XJ-6's use both needles and tapered rollers in their rear suspension. It's an arrangement somewhat similar to Corvette rear suspension. They have a suspension cage which is rubber mounted to the chassis. The diff (Salisbury) is hard mounted to the cage. The axles use a pair of universal joints and have static length. The LCA is an H-arm pivoted at the cage with needle rollers. These bearings last forever. The H-arm has dual coil over shocks mounted to it and is pivoted at the hub carrier with tapered rollers. These bearings need to be replaced about every 30-40K miles. The cars weigh ~4,000# and handle very nicely.
So in the Jaguar, the bearings DO take static vehicle weight, jounce/rebound loads AND cornering loads. They also have very limited servo type motion. The needle do just fine and the tapered rollers suck. My dad recently re-engineered the outer joint to take rollers, so we'll see how that works out eventually.
The Jaguars also have inboard mounted brakes, so the brakes end up being SPRUNG weight. They ride extremly well.
for such short motions and high loads i wouldn't put anything but needle bearings in there. balls have higher point loads and in such short motion as our suspensions have most of the time they would develope flat spots on the balls or pits in the races quickly. needles would be fine because they have such a smal diameter they are able to fully roll around.
a lot of work and expense for something that doesn't work any better in the fiero than lubricated poly. (its really easy to add a grease fitting to the swing arms for poly bushings.)