Should I cut my Eibachs?

[acador]

Last year I installed Eibach springs and Tokico Illumina struts on my 240z. The ride hieght looks nice and it rides and handles great springs on the street. I finally got my car road and track worthy this year so I've started doing autox events. Now that I have learned to navigate the cones more aggressively, I think the spring rate is too soft for my taste. I would also like to lower it another 1/2" or so to get more camber out of the front end. Is there a linear coil higher rate spring available for a stock strut assembly (non-coil over)? If I cut the progressive section of the Eibach spring to lower the car a bit more, would that have any effect on the spring rate? I was thinking about cutting 1/2 coil off to see what happens.

[240ZGL]

You might run out of strut travel, I know my Koni/Koni combo is giving me about 2" of travel. It's not that smooth on the street.

[Oiluj]

I had to remove 1 coil from my front Eibach springs to get the car to sit flat. I took the coils from the top. Since it only lowered the front about 3/8", I noticed no significant difference in suspension travel. However, with so little change, it also did not seem any significant effect on camber either.

[LeonV]

You're not going to get much negative camber in the front of a Z by just lowering it, other measures are required. My 260Z is lowered about 2" in front and I have -0.5deg of camber.

If you plan to do a lot of autoX and track work, I would highly recommend switching to adjustable coilovers. Instead of spending valuable time trying to make a setup with very limited adjustability work right, just spend the time and money now on the coilovers if you're truly serious about this. Otherwise, minimal changes in the current setup will yield small (if any) gains.

[acador]

Thanks for the input guys. I hadn't taken the spring travel into consideration. I'm a little nervous about cutting up strut housing to change to coil-overs but i'll just have to get over that and do it right. I plan on switching to larger wheels and tires in the near future. Will the tire diameter need to be factored into the spring selection or cut point of a coil-over install? I'm trying to figure out if I need to wait on the coil-over conversion until I know the final tire size. I'm leaning towards going from a 205/60/14 to a 225/50/16 which I believe is about 1" larger diameter.

[LeonV]

That tire size (225/50-16) typically works even without coilovers, but of course depends on wheel offset. Coilovers will give you more room for increased wheel backspacing.

[motorman7]

I had to remove 1 coil from my front Eibach springs to get the car to sit flat. I took the coils from the top. Since it only lowered the front about 3/8", I noticed no significant difference in suspension travel.

Installed the Eibach springs on my Yellow Z last weekend. I had been running the stock springs with the Tokico 5 way adjustables. The stock 40 year old springs were getting pretty weak and the rear was sagging more and more. Guess that happens with age  . I even went so far as to cut 1.5 coils off the front stock springs just to get the car level.

Anyway, I am very happy with the Eibach springs. I did cut off one coil on the front Eibach springs to get the car level. I can slide my hand in between the top of the tire and the fender well. Both front and rear have the same amount of clearance. I will post pictures once I get a chance to take a decent photo. I am running 16 X 7 Offset Panasports and 205/60/16 Yokohama 520’s.

The best part of the springs is that my steering wheel shimmy is gone when driving at freeway speeds. My steering wheel used to oscillate back and forth about .5 inches between 50 and 70 MPH. I thought it was wheel bearings or alignment. Had the car aligned and no difference. Now with the Eibachs, the steering wheel shimmy is gone. A very pleasant surprise.

Now I need to see if the rear end vibration at 100 MPH is gone. Haven’t had a chance to take the car to that speed yet, but I am hoping the springs were the problem. Will post again here once I get pics and 100MPH data.

Rich

[John Coffey]

Buy or download the rule book for the club you plan to autocross with. Read it carefully before making any modifications to your Z. If you're just starting out, as you mention, do NOT spend any moeny or your car making it faster. Spend ALL your money on making the car safe and reliable and then spend the rest on seat time.

Wait at least a year after you start autocrossing before making any performance changes to the car. This is the best advice I can give and I make my living building and modifying race cars.

[motorman7]

Here are the pics of the ride height on my Yellow Z with the Tokico 5 way's and the Eibach springs. I cut one lower coil on each of the front springs. This is exactly what I was looking for in ride height. I can slide my hand between the top of the tire and the fender well on both front and back. The wheels are 16X7 Panasports with 205/60/16 Yokohamas. The car handles great...I love it.

[boro92]

My Z used to ride on cut lowering springs (not me, but previous owner). The increased drop on stock strut housings really limited front end travel to something like 1 inch if not less. I could tell when I went over speed bumps and it hits the bumpstop!

Anyhow, like you, I switched to the Tokico Illuminas, and I'm running the Tokico springs which lower similar to the Eibachs. Travel is significantly better and handling actually is improved (old shocks were kyb with cut msa springs). You've probably already tried this, but for those who have not tried: tire pressure does a lot! Play with the pressure--drop the front a couple pounds and try again.

Does your Z have a rear antisway bar? you can add one in to get the rear to rotate better.

Since you run the Tokicos, run softer settings up front and harder out back if you havent already tried.

Lastly, if camber is absolutely needed, then try those eliptical control arm bushings. I read they get you an additional -1.5 degrees.

I too track my car, and am finding understeering tendancies -- esp once my tires heat up. It get's worse with a passenger in the car!

Seems like out of the box, these cars will tend to push. At the moment, I have front and rear anti sways, and run softest in the front, and #3 out back on the tokicos & 0 degrees front toe. These settings helped somewhat with the push (ps my tire pressure for track was 28f, 29r cold). I may try some toe out in the front and go with the camber bushings...

If you want a cheap way to gain steering, you could of course also disconnect that front bar!

Edited August 31, 2011 by boro92

[cozye]

I'm curious as to why the lowering springs for the 240 won't sit the car level? The eibach springs for the 280 are perfect right out of the box? Are they selling the 280 springs as 240 springs or something? I'm assuming you guys are putting the shorter springs in front, right?

[boro92]

FWIW I run springs made specific to the 240 and my car sits level (tokico advanced susp kit).