Suspension help required. Egads!

[garion]

This thread made me go out and check the clearance i have on my stops...

I have the AR lowering springs, and koni's on 1/2 turn from full soft.. I have about 1 inch clearance to the stops. And my ride is stiff.

I wonder if I cut an inch off, if it would soften it slightly?

[phaetn]

Well, I can't say for sure. If you're touching the bump stops you would go from your dampers working to a very harsh moment as the upper control arms hits the rubber. In old cars like ours they act as crash-barriers to prevent any more upward wheel movement, whereas modern bump stops on performance cars can actually be progressive and work as an integral part of the suspension to absorb load. Once our cars hit the stop the dampers at that point are essentially just along for the rid and aren't doing anything.

Since the damper is no longer doing its job and the control arm movement is effectively fixed, all load is then being transferred through the frame to either the wheel on the other side, or, I imagine, to the opposite rear wheel.

The good news is that this way you get immediate transfer of loads, so it's very responsive and quick (think a go-cart with no suspension), especially if you are on a very smooth surface. The very bad news is that is constantly putting a lot of stress on components that weren't built for it (cross member, frame rails) and if there any undulations in the road or bumps it they can't be absorbed -- it just gets effectively hammered through the car itself and will negatively affect traction.

I had this happen at the very end of last year. Not only was some cracked up pavement that I couldn't avoid incredibly jarring (it dislodged a headlight ring!) but at highway speed I hit a small bump that was perpendicular to the road that was like a frost-heave as it crossed the whole lane. I think the front end of the car jumped laterally about a foot. It definitely hopped. Not good...

If you see a full 1" of clearance now, it's definitely less when your weight is in the car. I'm 170lbs and the car drops 1/2" when I'm in it on A/R springs, but my car may be lower than yours since it's the last of the small bumpers. I chopped about 3/4" off the bump stop. I guess I should have someone put their weight on the front of the car and watch the distance of the tire the wheel well arch and see how much room there is to the bump stop... Maybe I have to take a bit more off...

Maybe someone from A/R can comment on the spring rate and how much they compress...

Cheers,
phaetn

[phaetn]

Reading more into this: The shape of the bump stop allows for it to be somewhat progressive. There is some give to it before it "stiffens". Now that mine is square cut there's much less give and the control arm may slam into it. On the other hand, there's more room for the damper to actuate, unlike before.

I guess it's a trade off. In a perfect world I would have kept the bump stop's original shape and size but changed the mounting location (a lot of work). Next would have been to shave/shape it to be conical again.

Cheers,
phaetn

[spiderdan]

With 4uall's helps this weekend I might just have 4 Koni Yellows all around in time for the alignment re-do.

What day are you going to tackle this?
If it helps, I could drop by with some installation lubricant.
I can also bring my Awe.

[4uall]

[spiderdan]

https://youtu.be/2EaflX0MWRo

[phaetn]

Cool. I bring the shocks you bring the awe.

Plan is for Saturday pm. The front shocks should be pretty easy: just up on ramps, disconnect, swap, reconnect. 4uall- consider using liquid wrench a day before to let things soak.

Replacing my rear shocks will be a bit more tricky as taking off the dampers will drop the axle. So that means lifting the rear, taking off the wheels to get access, support the axle, undo the shocks, gently drop the axle while the rest of the car is still in the air, and the coils should drop, too. While the coils are out and accessible I'll take a hacksaw to the remainder of the u-bolts and dremel them smooth. Then put it all back together.

Do you guys want to work in my garage or should we do this at your house, 4uall? I have space for two cars in my garage. It might be better for me here as this is my wife's rough weekend after chemo. That way I can still be around should the kids need attending to.
I have most tools, but you might need to bring a few of your own, too. I have one low floor jack and an older style one, too. Let me know what you would prefer.

Looking forward to it!!!

Cheers,
phaetn

[124JOE]

just keep an eye on the rear brake line
and all should be well

[phaetn]

Yes, thanks. I was hoping to avoid having to pull the brake lines and then bleed the system. I'll see how much free play there is.

Maybe it's an excuse to get A/R's solo bleeding nipples. That sounds gross, but you know what I mean...

Cheers,
phaetn

[4uall]

[garion]

I install speedbleeders on all the cars I own, that I do brakes on. Just easier that way. They work great.

[rjkoop]

Yes, thanks. I was hoping to avoid having to pull the brake lines and then bleed the system. I'll see how much free play there is.

Maybe it's an excuse to get A/R's solo bleeding nipples. That sounds gross, but you know what I mean...

Cheers,
phaetn

Phaetn,
When I did the rear suspension (included removing the entire rear axle in my case) I clipped the ties that hold the rear brake lines to the rear axle. I also had a bungee cord going over the top of the trunk holding the calipers to get them up out of the way. Worked well and then I just reattached the brake lines back to the rear axle with heavy duty zip ties.

Here's a link to my work if it helps.

http://www.fiatspider.com/f15/viewtopic ... 30&t=32106

Richard

[narfire]

Thanks Jay, now I have to wipe tea off my computer screen.....

[4uall]

[phaetn]

Phaetn,
When I did the rear suspension (included removing the entire rear axle in my case) I clipped the ties that hold the rear brake lines to the rear axle. I also had a bungee cord going over the top of the trunk holding the calipers to get them up out of the way. Worked well and then I just reattached the brake lines back to the rear axle with heavy duty zip ties.

Here's a link to my work if it helps.

http://www.fiatspider.com/f15/viewtopic ... 30&t=32106

Richard

Thanks for the advice, Richard. Will try it this afternoon with 4uall and Spiderdan's help.

I used liquid wrench for all the damper top nuts. Rear ones easily came loose, but the fronts not so much. The passenger side one just twists the rubber mount, and the driver's side one is hard to get at because the master cylinder and hoses for the crank breather and the charcoal filter are in the way. I may have to unplug and then replug some stuff there...

Feel free to come on by if you want. We should be here a big chunk of the afternoon. I'm in New Edinburgh.

Thanks again and cheers,
phaetn