Maybe you'll just get a laugh out of this, but one day I heard a Nascar announcer talking about the pit crew "puttin' in a spring rubber" cause its pushin'.

From another site:
"What a spring rubber actually does is connect the coils to coils in the springs, which drives the spring rate up and makes it stiffer. Spring rubbers come in 2 1/4” to the larger 5” version. They also come in full, half and quarter pieces for very specific adjustments."

I saw something like this at an auto parts place... its a chunk of rubber with grooves in it that twist, so you can put it into the coils of a spring.

Anyone ever experiment with one of these for RR or AX?

 

i assume this is essentially like changing out the bumpstops for softer or harder units.

no, i have not tried it.

 

Never tried it, but the thought has crossed my mind before.

 

i assume you got that quote from this site...
http://www.circletrack.com/techarticles/39758/

 

havent tried it either, but i've seen them and it looks interesting...

on a sorta related note, i also hear that the new mini's dont use springs on their shocks, but rubber donuts instead which act sorta like springs but save a lot of space in an already cramped car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tnord &raquo;</TD></TR><TR><TD CLASS="quote">i assume this is essentially like changing out the bumpstops for softer or harder units.</TD></TR></TABLE>

No, it isn't like a bump stop since it acts throughout suspension motion, not just at full bump. Spring rubbers are supposed to increase the rate of the spring by effectively shortening the spring. For example, it might turn a 500# spring into a 520# spring (numbers are just examples, I have no idea how big the actual effect is).

A lot of people like to scoff whenever this topic comes up, but there shouldn't be anything wrong with it as long as you don't shorten the spring so much that you have problems with coil bind.

And no, I don't have any direct experience with it, either, just an engineer's understanding of how it's supposed to work.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">i assume you got that quote from this site...
http://www.circletrack.com/techarticles/39758/</TD></TR></TABLE>

Yep. It would be cool to see what 700# feels like without the commitment.

 

A coil spring is actually a torsion bar - that resists force in twisting motion - wrapped into a helical form.

The rate of a coil is dependent on the diameter of the wire, the number of coils and the diameter. The last to factors are really just a proxy for "length" since, the longer a torsion bar is, the "softer" it is.

A spring rubber prevents one coil of the spring - or a length equivalent to one circumference of the helix - from twisting, taking it out of the equation and as has been suggested, essentially shortening the coil. This works the same as cutting out a coil, but in a reversible way.

It's a band-aid but is not completely loony. It does take an amount of vertical travel out of the spring, equivalent to the space between two coils.

K

 

actually, the rubber property of the spring rubber makes the spring overall progressive, instead of just dropping a coil as your explanation suggests. but i know you knew that.

firmly binding the coils would do as you suggest.

 

So in theory, one could take these in and out of his daily driver on weekends...but the shocks would need to be adjustable. This could be useful for a weekend warrior car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Maengelito &raquo;</TD></TR><TR><TD CLASS="quote">on a sorta related note, i also hear that the new mini's dont use springs on their shocks, but rubber donuts instead which act sorta like springs but save a lot of space in an already cramped car.</TD></TR></TABLE>

Nope. The new Minis have normal coil springs at each corner (McPherson strut front, multi-link rear). You're thinking of the ORIGINAL Mini, which did have rubber cones instead of springs. They used the cones because they wanted to get away with having very short suspension travel at the same time as high load capacity (four people plus luggage can almost double the car's curb weight).

 

Back in high school, one of my buddies used these 'rubbers' on his car. I never could remember what they were called. IIRC he bought them from the shop that sold him his suspension.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">firmly binding the coils</TD></TR></TABLE>

You could use this to firmly bind coils...
http://www.jcwhitney.com/autop...10101

 

A spring rubber comes in different stiffeness 5 lbs 15lbs 20 lbs etc.... It comes as a dounut and you can cut it with a knife. Throw it in your spring to increase the spring rate. If is good if you need to bump a spring rate due to track conditions or if your thinking you will need to lower a spring rate through the weekend, put a spring in the car with a rubber... pull the spring and instally you have a lower spring rate. As for long term adjustment go buy a new spring with the rate your looking for. You have to remeber that NASCAR teams are always adjusting on the cars to stay with track conditions through out a 500 lap race. Sometimes thier races start in the afternoon and end at night... during with the track temp can drop drastically. That is why they need that quick adjustment in the car.

 

Also a lot of Saturday night Circle track racers also use rubbers during qualifing since it is about 2:00 in the afternoon and they race at 8:00 big differnce in track temp.... As far as using it on a daily driver during track days You are only going to be able to increase your spring rate by 30 lbs... Is that the difference your looking for? Will you be able to stiffen your stock chassis enough to make a diiference if you can only increase spring rate by 30 lbs?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by oxstarsstripesxo &raquo;</TD></TR><TR><TD CLASS="quote">You are only going to be able to increase your spring rate by 30 lbs... Is that the difference your looking for? </TD></TR></TABLE>

Well, I guess that's why everybody isnt doing this already.

 

It's just another adjustment that can be made to car that is fast. Not meant to be permanent solution or an alternative to selecting proper spring rates.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AKADriver &raquo;</TD></TR><TR><TD CLASS="quote">Nope. The new Minis have normal coil springs at each corner (McPherson strut front, multi-link rear). You're thinking of the ORIGINAL Mini, which did have rubber cones instead of springs. They used the cones because they wanted to get away with having very short suspension travel at the same time as high load capacity (four people plus luggage can almost double the car's curb weight).</TD></TR></TABLE>
Yep. The original Mini had some weird suspensions. The other option was a hydraulic suspension on the Cooper S.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AKADriver &raquo;</TD></TR><TR><TD CLASS="quote">

Nope. The new Minis have normal coil springs at each corner (McPherson strut front, multi-link rear). You're thinking of the ORIGINAL Mini, which did have rubber cones instead of springs. They used the cones because they wanted to get away with having very short suspension travel at the same time as high load capacity (four people plus luggage can almost double the car's curb weight).</TD></TR></TABLE>

bah, i kenw it was one of the minis... interesting concept

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Maengelito &raquo;</TD></TR><TR><TD CLASS="quote">bah, i kenw it was one of the minis... interesting concept</TD></TR></TABLE>
They're very progressive, MUCH more so than any progressive springs I've seen.

 

Well what they do with suspension on oval track cars are at times diametrically opposed to "common wisdom" in road racing. One of my oval track buddies who runs what Late model modified or something like that was talking about spring rates and shock dampening. They have their spring rates down in the 200 lb.range and have shock settings that are "unusual" too. The SCCA F500 formula cars use "rubber bumper" technology for springs.
Barry H.

 

The rear springs on the late model stock car that I work on are between 150 and 250 lbs/in

the fronts are between 700 and 1000 lbs/in

There are some major differences though:
we only turn left
Solid Rear axle with a spool (no differential)


each corner of the car has a different spring rate, tire size, tire pressure and ride height.
There are certain targets that we try to hit, such as cross weight (which effects how loose or tight), stagger (which also effects how loose it is), left to right weight% (which is limited in the rules).
But depending on the weather, track conditions all this changes.

One day we had the car "dialed-in" we were running the fastest we ever had run.
But for race day the next day, we had to use a new set of tires (which were impounded until raceday).
We set up the tires to be the closest they were for practice, and changed nothing else (except the weather which was about the same) and we were way off the mark. The car was VERY loose.

 

For the most part I think most people would agree,
that in stock car racing
the right front spring is probably the stiffest,
but for this one car I worked on,
it was '72 nova, the RF spring was lighter than the LF spring!
I never asked why... but we won the championship that year

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crazydave &raquo;</TD></TR><TR><TD CLASS="quote">For the most part I think most people would agree,
that in stock car racing
the right front spring is probably the stiffest,
but for this one car I worked on,
it was '72 nova, the RF spring was lighter than the LF spring!
I never asked why... but we won the championship that year</TD></TR></TABLE>

Might have been a street stock or hobby stock class car where the rules prohibit a LSD or locked rear end. An open diff requires a pretty strange chassis setup to try and keep the inside rear tire planted to the ground in the turns. Just a guess...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">

Might have been a street stock or hobby stock class car where the rules prohibit a LSD or locked rear end. An open diff requires a pretty strange chassis setup to try and keep the inside rear tire planted to the ground in the turns. Just a guess...</TD></TR></TABLE>

You're right the rules do prohibit a locked rear end..
but our's was a pretty tight rear end

whats also funny is that we never changed the front left tire the entire season, the only time it was on the ground was in the straights

 

i can see this as something a drag racer might want to try at the track.