Should I upgrade the sway bar end links and bushings?

I have a 96 Miata with about 40K miles. I'm planning to replace my
front sway bar with a FM front sway bar to help with understeer and
hopefully better handling.

While I was at the Flying Miata site, I saw some sway bar end
links($120 for front or read) and polyurethane bushings($39). Are
either of these useful replacements or just a waste of money? I'm not
sure how my original brushing are holding up, except that visually,
they seem OK without taking the sway bar off. I'm leaning toward
replacing the bushings just so I don't have to worry about them
wearing out for a few more years. I'm far less incline to upgrade the
end links.

Also, my suspension upgrade goal is to get the FM Stage 2.5, but
piecewise as my budget allows. Is this a good setup or should I look
at something else for a similar price?
http://www.flyinmiata.com/tech/suspension_packages.asp

In article .com>,
"G. Mack" > wrote:

> I'm planning to replace my
> front sway bar with a FM front sway bar to help with understeer...

You don't have enough? Upgrading just the front bar will give you more
understeer. I recommend replacing both bars as a matched set, and
getting a good performance alignment. The FM bars are a good choice.

> While I was at the Flying Miata site, I saw some sway bar end
> links($120 for front or read) and polyurethane bushings($39). Are
> either of these useful replacements or just a waste of money?

They are worthwhile to eliminate swaybar preload, but unless you're an
accomplished autocrosser you'll probably never notice. My OEM swaybar
endlinks and bushings are still OK after 142k miles and 13 years.

I don't know if the OP has an NA or an NB but on the NB I'd have to disagree
with you Lanny on the front bar upgrade (going heftier) causing understeer.
The bigger front bar changes the car much more toward oversteer (in my
experience and others I've talked to). I did the matched set from JR (this
is a poorly designed front bar, look elsewhere. fitment issues) and the car
went from mild understeer to strong oversteer. I've had to use shocks and
tire pressures to 'dial it back' so-to-speak. Recently was recommended (by a
very fast NB auto-x'r) to go back to the stock rear bar to get rid of some
of the oversteer tendencies. We'll see what happens. Of course, YMMV as they
say.

Chris
99BBB

In article >,
"Chris D'Agnolo" > wrote:

> The bigger front bar changes the car much more toward oversteer (in my
> experience and others I've talked to). I did the matched set from JR (this
> is a poorly designed front bar, look elsewhere. fitment issues) and the car
> went from mild understeer to strong oversteer. I've had to use shocks and
> tire pressures to 'dial it back' so-to-speak. Recently was recommended (by a
> very fast NB auto-x'r) to go back to the stock rear bar to get rid of some
> of the oversteer tendencies.

Think about what you experienced, Chris. You got oversteer because the
REAR bar was too large--i.e., the set was poorly matched. Not because
the front bar was too large. JR has a reputation for that on the NB.

IIRC, the OP has a '96. The standard FM set for a 1.8 NA is 1" front,
5/8" rear. The result will probably be mild understeer, depending on the
alignment. My older FM bars are 7/8" front, 5/8" rear, and with a
0.5-degree rear camber bias it was neutral, on the edge of being loose.
I increased the camber bias to 0.55 degree to make the car a bit less
fussy to drive. Perfect (for me).

On Jul 9, 5:42 pm, Lanny Chambers > wrote:
> In article .com>,
> "G. Mack" > wrote:
>
> > I'm planning to replace my
> > front sway bar with a FM front sway bar to help with understeer...
>
> You don't have enough? Upgrading just the front bar will give you more
> understeer. I recommend replacing both bars as a matched set, and
> getting a good performance alignment. The FM bars are a good choice.

Since the FM bars are adjustable, I was hoping that I can soften the
front up a bit. Both setting are probably stiffer than stock, so I'm
barking up the wrong tree. I didn't plan to get a rear bar cause that
puts me into a higher class in autocross. I can probably live with
that if the car is more fun to drive. I'm getting killed in the stock
class anyways since they allow R compounds which I don't have.

> > While I was at the Flying Miata site, I saw some sway bar end
> > links($120 for front or read) and polyurethane bushings($39). Are
> > either of these useful replacements or just a waste of money?
>
> They are worthwhile to eliminate swaybar preload, but unless you're an
> accomplished autocrosser you'll probably never notice. My OEM swaybar
> endlinks and bushings are still OK after 142k miles and 13 years.

Sounds like I'm better off spending the $160 on a rear bar or some
track time.

> IIRC, the OP has a '96. The standard FM set for a 1.8 NA is 1" front,
> 5/8" rear. The result will probably be mild understeer, depending on the
> alignment. My older FM bars are 7/8" front, 5/8" rear, and with a
> 0.5-degree rear camber bias it was neutral, on the edge of being loose.
> I increased the camber bias to 0.55 degree to make the car a bit less
> fussy to drive. Perfect (for me).

My front camber is -.9 and my rear is -1.5. I guess this could
explain why I'm getting understeer, the rear tracks better in turns.
The tech who did the alignment and other autoXers suggested -2 camber
on both front and rear, but my NA can't do that on stock suspension
and wheels. I think I had to lower the car for the front get be able
to get -2. My autoX time has gotten a bit more competitive with this
setting despite the slight understeer. I'm told that the tires will
wear pretty evenly as long as I don't add any toe.

"Chris D'Agnolo" > wrote:

>
>I don't know if the OP has an NA or an NB but on the NB I'd have to disagree
>with you Lanny on the front bar upgrade (going heftier) causing understeer.
>The bigger front bar changes the car much more toward oversteer (in my
>experience and others I've talked to).

I do not understand that. Theory says stiffening up the front should
produce understeer. Hard to see how it would not. Are you running a
weird tire pressure? You had this theory here earlier to go below
Mazda specs on tire pressure to increase traction. (It might well
be true after you have managed to get the car to corner steadily
in a circle at a constant speed, I guess.)

> I did the matched set from JR (this
>is a poorly designed front bar, look elsewhere. fitment issues) and the car
>went from mild understeer to strong oversteer.

If you did a matched set, you have no basis to make a judgment about what
the front bar does.

Like Lanny says, the issue is likely that the rear bar is too stiff. It is
well known that this sort of sets tend to have overly thick rear bars to
produce a "sporty" feel on the street, and a tricky car. See Randy Stoker's
page somewhere on miata.net about this and what are well matched sets.

I had Brainstorm's set on Bozo which was a sporty set like that. To get
it back to a non tricky behavior, I had to thicken the front bar further
to 1 inch equivalent (I put in the Racing Beat hollow front bar.) That
most definitely reduced the oversteer again to manageable levels.

Leon

> I've had to use shocks and
>tire pressures to 'dial it back' so-to-speak. Recently was recommended (by a
>very fast NB auto-x'r) to go back to the stock rear bar to get rid of some
>of the oversteer tendencies. We'll see what happens. Of course, YMMV as they
>say.
>
>Chris
>99BBB
>
--
Leon van Dommelen Bess, the Miata Bozo, the Miata
http://www.dommelen.net/miata
The only thing better than a white Miata is two white Miatas

In article .com>,
"G. Mack" > wrote:

> Since the FM bars are adjustable, I was hoping that I can soften the
> front up a bit. Both setting are probably stiffer than stock, so I'm
> barking up the wrong tree.

Correct. AFAIK, no aftermarket bar is softer than stock. All are much
stiffer--remember, stiffness of a torsion bar increases as the fourth
power of diameter.

> I didn't plan to get a rear bar cause that
> puts me into a higher class in autocross. I can probably live with
> that if the car is more fun to drive. I'm getting killed in the stock
> class anyways since they allow R compounds which I don't have.

A competitive autocross Miata will not be fun (or perhaps even safe) to
drive on the street. The handling balance will be all wrong, because the
vehicle dynamics are so different. Unless you plan on making the car a
dedicated autocrosser, you're probably better off to use the sport to
improve your control of the familiar Miata you drive every day. Leave
the top places to the guys with trailers and deep pockets.

Just a follow up. My FM bars came in yesterday and I installed them
this morning with the FM suggested configuration. I took it out for a
test drive and it felt really solid. Much less roll in the slalom and
when the rear broke, it was much easier to recovery. The car
responded much quicker to steering inputs. I took a friend along and
he thought the car rolled much less than the last time he rode with me
at an autocross event.

My next autocross is Sunday morning, so I'll really be able to test
these bars out. Hopefully, I'll gain a little ground on the top Miata
drivers, though we won't be in the same class anymore now that I
upgraded the rear roll bars.