The 24 Hours of Lemons Forums → Lemons Tech → BALLS!!!
Any objections to stiffening up coil springs with tennis balls? While I could understand an objection based on the possibility of a loose ball bouncing across the track, I think the red-neck engineering aspect is inkeeping with the spirit of the event enough to override posible safety concerns. But, it doesn't matter what I think, what do the Tech Enforcers think?
I'm no engineer but I wonder if a coil spring loaded up with tennis balls and a means to keep them there for a 14 hour endurance race would a. hold up and b. make any noticable difference on the spring rate. Color me curious.
an old rallycross trick is to stick thick pieces of rubber in between a couple coils to increase the spring rates.....I was going to do the same, but I intend to use some steel hose clamps or heavy duty zip ties to hold them in place...
I've seen quite a few drag racers use cheap leather footballs from Wal-Mart...
I'm certain that a saw a photo on Jalopnik from a recent race with tennis balls stuffed in the springs of one of the larger cars... I think it was even a car that finished.
Real, full coil, spring rubbers can be had cheap - like $10.
I'm certain that a saw a photo on Jalopnik from a recent race with tennis balls stuffed in the springs of one of the larger cars... I think it was even a car that finished.
+1 I can't say which race or car, but a Lemons team has done the tennis ball trick already per the Jalopnik photo.
Found it: http://jalopnik.com/5533979/bs-inspecti … gallery/27
I was there. Saw it!
KT
So how much does the spring rate increase per ball???
Hadn't thought about tennis balls. I remember there being a car in the 20XX challenge for GRM using hard rubber held on with zip ties. I didn't realize that you could buy real ones. Tennis balls seems more in the spirit of Lemons.
Real, full coil, spring rubbers
LOL
Adding rubber to the suspension springs?! What if your suspension springs ALREADY ARE rubber? 
Sorta like one great big bump stop.
Gotta love that whopping 2" of suspension travel (on a good day). Our rear ones collapsed so much that they were the primary cause (or perhaps secondary to driver input) for our 3 spins in 2 hours at Thunderhill. No springiness left the rear tires to try to absorb the shock and when they too hit their limit the rear just broke loose. We've got some other well-loved springs (aka "cones") on there now and they did us well for the Sunday session.
Hope they will hold up another race or two. However, for 48-year-old British rubber, they did pretty well.
We ran tennis balls in the rear coils of our e30 at Summit Point to try to cut down on the massive sway that was killing us. It worked a little and none of the balls came loose. The drawback was the jacked up 4x4 like suspension even more.
Loren wrote:I'm certain that a saw a photo on Jalopnik from a recent race with tennis balls stuffed in the springs of one of the larger cars... I think it was even a car that finished.
+1 I can't say which race or car, but a Lemons team has done the tennis ball trick already per the Jalopnik photo.
It was our car. BMW 302i. Once was painted bright green w/ tiger stripes; was matte black last time.
As for whether it works? It does stiffen things up a bit, but does jack it up as well. None of ours have come out in 3 races, though I think they've been replaced at least once.
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