This is not really a track question, but I figure the track people are very familiar with the suspension on the S and how to tune it.

I have a 2003 and on twisty backroads the car feels planted and corners as i think it should. On the highway however, at speeds above 65-70 mph the car feels knife edge. By that I mean it feels like the back end is right on the edge and is going to come around. It is not confidence inspiring. This "feeling" is most noticable on long downhill sweepers. Uphill or on flat ground the car feels good.

The car curently has Goodyear F1 GS-D3 tires in the OE sizes on it. I know these tires are about an inch narrower than S02s so I have less than OE contact patch and stagger

My quetion is what is the fix?

UK alignment? AP2 rear sway bar? Are my rear tires really too narrow?

All thoughts and suggestions will be appreciated

Thanks!

 

Before the really knowledgeable guys chime in, I wanted to ask if you really feel there's a handling problem, or if it is just a confidence problem? Are you lifting on that downhill sweeper or are you keeping the rear planted with a touch of throttle?

That said, you may want to look at some different tires the next go around.

 

get a rear wing

 

^^ he should know!

 

Not the answer. Many folks have run their cars successfully without a wing. The NASA National TTC winner was an S2000 owner... without a wing.


Stock suspension? Lowered? Alignment? Tire pressures? My guess is rear toe is not "in" enough.

 

I have a stock suspension. The car has not been aligned since I have owned it. Tire pressures are 34 psi front, 32 psi rear cold, checked before every use.

e3opian, I understand what you are saying about confidence. But I do not think this car should feel so edgy. I feel I should be able to run a downhill sweeper on the highway and have a car in front of me force a lane change in the middle of it without my car feeling like it wants to swap ends.

 

Never felt that way at speed in mine, granted mine is a 2005...and it's lowered and different tires with a different amount of stagger.

 

Run a little bit of toe in on the rear tires.

 

Topping the car out on the highway ftl. LOL Rashad you crack me up.

 

Good input from everyone so far. Just would like to add something else that I have learned from autocrossing my 350Z with adjustable swaybars.

When I had the car dialed in to perfect neutrality on the autocross circuit, the rear end felt loose at speed (3rd gear + corners).

When I had the car set up for the street (less stiff in the rear, more stiff in the front), the rear was glued and the car was overall neutral at speed, but would push understeer in the tight stuff.

I realized I had two options:

1 - set the car for autocross and slow it down on the highspeed stuff

2 - set the car for the highspeed stuff, and kill cones during the autocross sessions.


I chose option 3 - buy a "previously loved" S2000 for the lowspeed stuff, and set the Z for the highspeed where the extra 400 lbs won't be noticed as much.

The moral of the story: A car that handles well in the slow will not always handle well in the fast. A balance between the two is probably your best bet, short of buying another car.

I'd advise a set of adjustable sways (if they make them for this car, I'm a noob.. sorry) and use those to dial in what you need. Hope this helps.