Jimmy325

I joined this forum maybe 3 years ago... madly in love with the S2K.
Ended up with an '03 E46 M3 Coupe.

Now, I'm looking at getting an S2K for weekend fun and for DE's up
to perhaps 6 times per year.

I know, and have heard and read, that the rear end of the S2K tends
to be a little bit twitchy, and can snap oversteer without warning if you
are not careful. ('00 to '03. I heard '04 and on the rear suspension
has been modified.)

Questions:

Is there a suspension mod, be it coilovers, control arms, that can make
the rear end more stable or predictable? How about increase the negative
camber on the rear? Has anyone discovered a cure so to speak?

As an example, it is well known that the stock suspension on the M Roadster
and M Coupe suck! I know an instructor in the local area who modded his
M Coupe with Ground Control coilovers, and I rode in his car during hot laps
at the track and it was very stable, very solid, and very predictable. I conclude
that he has found a solution. I was wondering if anything similar to this has
happened to the S2K ('00 to '03) in the past few years from many owners
tweaking around with the car?

Any inputs or comments from you folks would be great. Thanks!

Jimmy

krazik

http://www.gofastlab.com/s2ki/customer/pro...223&cat=0&page=

glagola1

A stiffer front sway bar goes all the way to making the car predictable and even mellow. I would suggest a comptech adj front sway because it works great, is highly adjustable, and uses the stock endlinks so there is no rattle that's associated with after market endlinks.

Jimmy325

Krazik,

Is this kid akin to the update Honda did to the '04 and new S2000s?

Also, when entering a corner hard, does this kit decrease the dendency
to counter steer in order to catch the rear?

You have this kit on your car?

Thanks!
Jimmy

Jimmy325

Glagola,

How does stiffening up the front change the suspension geometry (and toe
changes under load changes) of the rear end?

Thanks!
Jimmy

Nobody

Every suspension and tire change I've made to my car over the past couple years made it more predictable. I was expecting to have to play around with parts and settings to get it right, but to my suprise everything I did made the car handle better, stick better and recover from slides better. I am one of the few who absolutely did not like S02 tires. I found them to have incredible grip for their size, but once things got sideways it was a bitch to get things straight. That, combined with the low spring rates on the stock shocks made the car twitchy at the limit.

Here's what I did in order:
KG/MM Race springs
225/255 Kumho MX tires on 17x8 and 17x9 rims
Tein RA coilovers
Saner front sway bar
235/275 RA-1s on CE28s

I've also played around with several different alignment settings and have found that the following works best for my setup:

FR: Camber -2.3; Caster 5.7; Toe .01
RR: Camber -2.1; Toe .13

My order (just shipped) for the Go Fast Lab's Rear Anti-Bumpsteer kit will solve the only problem I have left (twitchy rear end under braking).

And yes, these bumpsteer kits are similar to the '04 suspension changes, but the kit is actually allows for less toe changes under braking than the '04.

glagola1

Do you understand how sway bars work? If not forgive me but what happens is that the end of the car that has the stiffest roll resitance will be the first end of the car to slide. When the car goes around the corner the weight tranfers to the outside wheel. If the sway bar is stiff more weight goes to the outside wheel and the load is less shared by both tires. More load on less surface area (one tire as opposed to both tires) equals slip. As it is, the S2000 seems to have a tendancey towards oversteer from the factory. If you increase the roll resitance of the front end it does two things. The first is it makes the front end break away sooner and easier. The second is that it allows the rear end to stay more planted. It's really not about rear suspension geometry so much. It's more about the stiffest end of the car.

Forget about spending tons of cash on tires and wheels and springs... just get a front sway bar and an alignment and you'll be good to go. Trust me.

Do a search on here for good alignment specs and get them done too.

Jimmy325

Nobody,

Thanks for the reply.

What wheels allowed you to run such wide tires? Do you get any fender rubbing
with the tirewall?

I've been thinking maybe the Spoon black wheels SW388, but those don't seem
to be quite WIDE enough to accomodate such wide tires as you have listed.

Also, what were some of the main differences in feel and handling that you noticed
when you went from just springs to the Tien coilover suspension?

Thanks!
Jimmy

Jimmy325

Glagola,

Thanks. So, I'm thinking here, sounds like your approach lessens the overall
grip of the vehicle. Wouldn't that be a compromise for the worse? So instead
of increasing rear grip to balance it out, you decrease the front.

Thanks,
Jimmy

RandyP

Decreasing front grip means that the car will scrub off speed when you screw up rather than allowing the driver to overcorrect and spin the car. You could always add race tires to the rear and leave the street tires on the front. This will also cure the twitchyness.