I'm about to start reworking my rear suspension since I've completed the front. I was gonna use my stock control arms and just put poly bushings in them. However I've run across these on summit UPI-301516-R. What I like is that there greaseable and will be stronger than stock. Would it be worth the money to buy these instead of just replacing bushings. Also how much better would the adjustable ones be.
rear control arms
- Thread starter 1Bad4558
- Start date
- Status
Those arms will bind up and could cause snap oversteer. Poly bushings are just a bad idea for 4 link rear suspensions . The stock arms and rubber bushings are designed to flex and deflect to prevent binding problems. If you need boxed or tubed LCAs you will need ones with some sort of roto joints since the stock rubber bushings act like roto joints as required and expected for normal operation.
The set your thinking about are made by UMI who is one of the supporting vendors here. Contact UMI cause they will help you out
I would like to think that UMI has tested these arms and they aren't going to "bind up and cause snap oversteer".
Shortly after I bought my Monte 14 years ago,I boxed both upper & lower control arms and installed poly bushings.I put this car through some very spirited driving over the years and never once saw any signs of the rear suspension binding or snap oversteer.
Guy
Shortly after I bought my Monte 14 years ago,I boxed both upper & lower control arms and installed poly bushings.I put this car through some very spirited driving over the years and never once saw any signs of the rear suspension binding or snap oversteer.
Guy
No idea what "snap oversteer" is either. I also highly recommend the UMI rear control arms, I have them on my rig. If I remember correctly these arms feature their roto joint bushing instead of a run of the mill poly bushing.
In any case, give the guys at UMI a call and they will take care of you.
In any case, give the guys at UMI a call and they will take care of you.
You might also check out PMT Fabrications. Good pricing. I've got them on my Elky.
http://pmtfabrication.com/product-categ ... onte-carlo
http://pmtfabrication.com/product-categ ... onte-carlo
1Bad4558 said:
it's an incorrect term being used. The top control arms need to twist cause they end up in a bind. With a solid upper they will bind but there is no snap unless something breaks. If something does break you won't need to worry about an oversteer. Mid engine cars were known to have a problem with snap oversteer if you let up on the gas in the corner, the car will turn more sharply without turning the steering wheel
Snap oversteer happens when you're pushing the car to the limit around a turn, the suspension binds (because of the poly) and since it can no longer move, sends the tail end of the car swinging around on you in a "snap".
A converging 4-link rear already has binding built into it, however they rubber bushings help fight this, or at least make it tolerable do to their elasticity. Once you take those out of the system and replace them with something of a much harder durometer, you now have issues.
Now, if you place a greaseable spherical joint on the frame side, then poly bushings on the rear end side have very little affect. They give you the range of motion you need back in the system.
For a drag only, straight line car you can probably get away with all poly but for a street car or anything you want to go around a corner at a reasonable speed, I wouldn't use them.
I had the complete Hotchkis rear suspension setup years and years ago and it was terrible. Two of the things they did wrong on that setup is to install poly bushings everywhere AND completely box the upper rear control arms. There was virtually zero compliance in that rear suspension. It road rough on the street and would snap oversteer at autocross events extremely easily.
A converging 4-link rear already has binding built into it, however they rubber bushings help fight this, or at least make it tolerable do to their elasticity. Once you take those out of the system and replace them with something of a much harder durometer, you now have issues.
Now, if you place a greaseable spherical joint on the frame side, then poly bushings on the rear end side have very little affect. They give you the range of motion you need back in the system.
For a drag only, straight line car you can probably get away with all poly but for a street car or anything you want to go around a corner at a reasonable speed, I wouldn't use them.
I had the complete Hotchkis rear suspension setup years and years ago and it was terrible. Two of the things they did wrong on that setup is to install poly bushings everywhere AND completely box the upper rear control arms. There was virtually zero compliance in that rear suspension. It road rough on the street and would snap oversteer at autocross events extremely easily.
I have this nice used pair of Global West rear lower control arms I need to sell. They have the roto joint one end and are built well. $200 for the pair. Here are some pics
[URL=http://s686.photobucket.com/us...com/albums/vv225/Anubis442/DSC_0295.jpg[/img][/url]
[URL=http://s686.photobucket.com/us...com/albums/vv225/Anubis442/DSC_0295.jpg[/img][/url]
- Status
Similar threads
