slaponte

iTrader: (2)

Trying to make some suspension decisions, but not the biggest expert in the area. Please explain if you can for me.

If I understand correctly, the 350Z came originally with a set of springs and struts, front and back. I have been considering changing the springs, but the Eibachs have a drop and I don't want to drop the car.

So coilovers : these coilover kits I see for the Z, do they replace the springs and struts? Or do you just replace the struts and leave the OEM springs?

Sorry for the dumb question...

2k3silver350z

coils are full replacements for both the spring and shock. you can set the drop to whatever you want.

there are no dumb questions, only dumb people

Jspec350z

iTrader: (3)

1st off no question is dumb!! Our car has struts on it not shocks. The difference being that a shock has a separate spring and a strut incorporates the spring and strut into 1 assembly. Coilovers are a good alternative to this setup. A coilover is an adjustable spring/strut assembly. Typically you can adjust ride height 0-4 in and on some sets you can adjust shock dampening. I have not looked into any struts released for the 350 yet, but from the sound of your application you will not be tracking your car. I would say get some adjustable struts. They made a huge difference on my eclipse with my stock springs. I ended up putting coilovers on the eclipse. The fake kind that cost like $400. I have not seen any of those out for the 350 yet but they will come. I suggest against these as they are kind of a half assed way of doing a coilover. I hope this helps. I am no expert I am just sharing what I have learned from past experience. Good luck and keep us updated.

Brad4rdHay

Im posative that the rear suspension has the spring and shock separated, and the front has the spring coiled around the shock.

Jspec350z

iTrader: (3)

I believe you are correct we do have seperate shocks and springs in the rear. I stand corrected!

Chebosto

iTrader: (43)

there are two types of 'coilovers'

there is 1 type which is just a spring and an adjustable perch, which you slide over your exsisting shock or strut mount and you adjust the heigh according to your tastes. these sleeves (common companies such as ground control or skunkworks2) often are not well matched to the stock shocks and some bouncing might occur if slammed too low when there is not adequate dampening for the slowered stance. since its just a sleeve, they are fairly inexpensive if paired up with an aftermarket shock. normally bought for looks mainly for the drop it can give the car. again, i might stress that ride quality might suffer some..

the 2nd type of coilovers are an 'all-in-one' piece. this includes the entire shock body with an integrated perch for the spring. often companies such as TEIN, HKS, CUSCO, and JIC, will match the dampening/rebound of the shock with the spring rates that come with the kit. Normally, these kits will also allow you to move the strut body it self, so as not to limit the piston travel. i.e. so you dont hit the bump stops every time you go over a bump hard.
these kits, although sometimes three to four times more expensive than the simple sleeve coilovers, offer tremendous advantages being the correct spring rating and matched dampening. .. often these coilovers are ideal for racing application but also good for street.

if you dont plan on racing the car *too much* or dont plan on showing the car, a simple spring replacement, such as Eibach or when the h&rs come out, will provide plenty good handling and a lowered stance...


hope that helps?

--Cheston

slaponte

iTrader: (2)

I had seen of pictures in the back from people who have installed exhaust or brakes, and I could see those springs sitting way in there beyond the wheelwell. So I was wondering, if you get a set of "coilovers", do you take out those inside springs in the back?

I imagine the front piece is the typical "strut" running up the center of the spring, which is what a coilover looks like. So I didn't have any problem visualizing the front. It was the back that had me lost there.

So, the Eibach set (for example) has the front springs for the struts (remove from car, compress, remove spring, place new spring, decompress, back tot he car) while it would have stand alone springs for the back.

It all makes more sense once you see the picture. Thanks.

krinkov

Now I gotta come along and be an *** and tell you that your all wrong

heh, well not really but! The actual term "coil over" was originaly used to describe a suspension system where the spring mounted over the shock body and had nothing to do with adjustability. Back in the days of leaf spring suspensions, the shocks and springs were mounted seprate from each other. They didnt start mounting springs over the shock body to save space until smaller cars and macpherson struts came around in the 70s and called this set up "coil-over-shock" suspension. So tecnicaly the stock Z(in the front), and just about 99% of all cars being sold today use a coil over suspension and it has nothing to do with adjustability. Now heres the weird part...

What you guys here are used to calling "coil overs" should really be called "threaded body struts"(when incorporated on a strut like on the fronts of the 350Z tein kit) or "adjustable perches"(as in the rear of the 350Z tein kit) how the threaded body strut and adjustable perches became refered to genericaly as "coil overs" will probably never be known, but this is what they really are and when you call them coil overs around guys like the ones at my old garage they will all point and laugh at you hehe, I know this probably just confuses things more, but Im on a crusade for proper automotive grammer

Jspec350z

iTrader: (3)

Well that being said!! I hope you feel good proving everyone in the sport compact world wrong Whatever you want to call them they are expensive as hell for the Z. I would love some eibach with less of a drop or some adjustable struts. Oh well I can wait until they come out.

slaponte

iTrader: (2)

Maybe that is the whole reason behind all this. I am an older guy so I came from :

- leaf springs, regular springs and shocks everywhere... to

- Struts (McPearson style), which I have never seen used in the back, only front... to

- Coilovers (SHOCK through the spring/coil to save space)... to

- Adjustable "coilovers" which could resemble adjustable struts....

etc, etc... Like I said, I wouldn't understand how you go from spring/shocks to "coilovers" in the rear.

So, and forget how many mistakes I just made above, what DO we have on the 350Z?

- Front look like McPearson (sp?) struts to me.
- Rear is a spring/shock combo.

Correct?

ZISBAK

I was wondering? If you lowered the car with Eibach, Can the toe be adjusted by alignment or it will need to have the camber kit install? because I've been getting different answer from Eibach and tech..... etc. One would said alignment will cure, and another one say will need camber. I just don't want to have to get new tires due to uneven wear!

krinkov

toe and camber are seperate alignment angles. lowering the car will not affect your ability to adjust toe. Camber on the other hand will be affected by lowering the car, there is no factory adjustment for camber so a camber kit will be required. I would like to find out just how much camber is affected by the eibachs .8" it might not be too bad and the added negative camber it creates actually aids in handling.

jackwhale

Hi Krinkov
There was an article by an engineer, Dave Coleman in Sport Compact Car about a year ago. He had a pre-production car for a week and had custom shops make and install upgrades to the brakes, suspension, and exhaust. The car ended up being at least 1-2" lower than stock. It looked great but even with bigger brakes the car stopped in a greater distance than stock. He ended up attributing this to the change in camber--which in turn decreased the size of the contact patch of the tires--less rubber on the road longer stopping distances

I couldn't find the back issue but maybe it will turn up. It was an interesting article. Their first attempts to improve the exhaust lost hp.

Stone Z

And I'm on a crusade for proper forum spelling

krinkov

This is true, for drag racing you want camber as close to zero as possible. The benifit of negative camber is when you are cornering and the car leans on its outside tires contact the negative camber flattens out and you keep a wider contact patch on the ground. This is also the benifit of unequal legnth control arm suspension(multi link/dual wishbone) over machperson suspension. Macpherson is fixed, so wherever the camber is set it will remain there at all levels of compression, whereas the unequal legnth usues shorter upper arms and longer lower arms, so as the suspension compresses the upper arms swing in a shorter axis than the lower arms thereby pulling the top of the wheel toward the car creating more negative camber the harder you corner.
I think that car in the test did better in the slalom than stock though

krinkov

Ha! Busted! mispelled grammar, ohhh the irony!