Ok everyone, I just installed my Spohn front A arms(the tubular ones with spring boxes) as well as my Koni red struts and Eibach Pro Kit springs. I was looking to upgrade my front and rear bumpstops to polyurethane but came across an issue....The Spohn a arms only have a provision for the sway bar end link and not a bump stop. What is the deal with that?????? I thought all A arms had some type of bump stop to keep the suspension from bottoming out. Now, I'm not mad or anything, I just want to make sure that everything that needs to be there IS there and working correctly. So I guess it breaks down into 2 things.......

1. What kind of bumpstops do I need to get(remember I want poly) for the front A arms, and what do I have to fabricate/modify to make them work? And who sells them???

2. Where would I get the rear bumpstops that bolt up in the factory location in the rear?

PIctures and part numbers would be a great help as well. Thanks to all who can provide some 'enlightenment' on this subject. Thanks again!!!

 

Looking for help/info on this issue as well as I'm interested in his tubulars. I noticed from the pics on Sphon's site that the arm didn't have provision for the bump stop.

JamesC

 

I'd be mad if I were you, nothing like metal on metal crunching to ruin your day. I would say he designed the arms to work with a coil over conversion which would have the bump stop on the shock shaft, then later added the spring box provision to work with a conventional setup....... only to forget about the bump stop.

You need bump stops, I don't necesarily think poly would be the way to go. Believe it or not it will really effect how the car reacts when you hit a bump mid turn. A softer bump stop will tend to keep the tires from snapping loose, while a stiff bushing or metal on metal contact would cause the offending end of the vehicle to instantly break loose. Circle track guys some times use bump stops to tune their cars. Caroll Smith has a nice section in his book (Tune to Win) on how to tune with bump stops.

A lot of the g-body guys have had good luck with newer blazer bump stops trimmed up to fit. (stock they're almost 4" thick) They're made of some kind of air filled poly and seem to be very progressive with a very soft "engagement". Most guys report a much better ride and smoother breakaway characteristics when the car is pushed hard.

 

Well, I might have another idea about this. I kinda have to agree with you on your previous post BMmonteSS about staying away from the poly bumpstops. After some careful consideration, I figured that a stiffer bumpstop would make the suspension travel stop quite abruptly, which could be very bad or cause damage. Interestingly enough, I was replacing a strut at work tonight(I work at a Lexus dealership) and noticed that they put the bump stop on the actual strut rod itself. Why didn't I think of that before??? It makes perfect sense. That way, it is hidden and out of the way, and the only major load point would be on the strut if it were to bottom out. So now all I need to do is find out where I can get a set of bump stops that will mount on a Koni red front strut and I'll be set.

 

You might look into a circle track supplier that carries coil over stuff, they should have a wide range of bump stops that should work.

For a bucks down approach go to a subaru dealership and order a set of front bump stops for a 98' subaru legacy GT. They are tapered and should give you a nice progressive bump stop. The only reason I know this is that I own said legacy and on a whim I tried slipping the bump stop onto a f-body shock while I had the subaru apart. They are also easily trimable with a razor blade with the stops on the car, that way they'll be no yanking everying apart to shorten them if they are too long.