Pictures of some coilover setups.

[G-E]

when you suggest caution when lowering the car onto the wheels and ultra-stiff springs.... makes me think bad things can happen if you use it on bumpy roads

the only solution would be is an adjustable upper perch to bring the spring down matching the height at full droop

[Z Envy]

Lets be honest, the only time your car would ever see the suspension travel needed to un-seat things, your not going to be happy with the other damage it creates. I have driven the car on bumpy roads and the suspension just doesn't move that much under "normal" conditions. If the road is rough enough to reach full suspension travel:

1 - you should be in a 4x4

2 - you will have some bent rims / flat tires

I had lowering springs in the car before and they would become un-seated if you jacked the car up. I never had any issues then and so far I haven't experienced any problems. I wouldn't let that keep you from trying.

Finally............ if you have really bumping roads then you should probably stick to a stock style set-up...... performance suspensions transfer much of the road back ( to your butt and hands ) as you drive. This is not fun on rough roads.

[G-E]

I'm thinking about the unexpected kinds heh

and depending on the racing you do and the track you do it on, you could actually drop the rear fully, there is the off chance the swaybar won't save it if you are really close to the top of the collar

[Z Envy]

I understand........... I haven't had any issues and I also know of several others that have coilovers on other cars. They have the same issues if the car is up on a jack. It is obviously a possibility but a very, very small one. I haven't experienced the rear unloading enough to allow what we are talking about. Springs with enough rate just don't allow enough body roll to completely extended the rear.

I thought about what you wrote with the adjustable top perch and I don't think that would help much.............. If you adjust the top perch down then the car still has to settle onto that perch .......... the lowered stance is primarly due to the shorter springs and lower bottom spring seat. The only resonable alternative is helper springs..... they sit over the main spring and have no real spring value except to keep some tension on the setup in the event the suspension does see full droop. Once the vehicle weight is back on that corner the helper spring compresses flat and the main spring does the real work.

[Jason84NA2T]

The only time I have ever fully unloaded my rear is by entering steep driveways at an angle. I don't see it as being very likely it will ever pose a problem, because the spring just sits on the lower perch and then upper makes a little noise when it hits the seat it rests on. You would need some kind of lateral force to knock the spring off center on the lower perch before you have an issue besides noise (which is the primary reason for using helper springs; quiet operation). I pretty much just stopped entering steep driveways alltogether now anyway as it tends to rip my splash guards off the car.

I really would like to know if the rear tokico illuminas for our car will hold a 450lb/in spring, and if so... on what setting and how long will they last? 400 is as low as I would want to go in the rear, and I may just to be sure the illuminas I already have sitting in the garage can handle it.

Now I just need some money so I can do it!

[G-E]

you going to try one of everything hehehe?

87t getting the budget coilover I take it

[Z Envy]

Ground Control asked me what type of inserts/shocks I'm running. There was no mention of the Tokico's not being able to hold up. I am sure that the life is shortened by the added rate but that is a small part of the performance you get. Good luck with it, when you do it.

Just picked up another project car today. Me and a friend are going to VG30DET a 1977 280Z car as a track car. We now have the chassis, motor, trans......... now all we need is the time and the extra money to get what we don't have.

[Z Envy]

I didn't mention what my spring rates where in this thread....... I did in another one, just forgot....... May help others decide

Front - 600lb/in 7" Long Spring

*Note - I am changing to a 6" spring to gain some needed clearance when my 9" wide track rims are on the car.


Rear - 500lb/in 8" Long Spring

As I have said ........ this is primarly a track set-up, it's pretty harsh on the streets. I think a F-500 / R-400 ratio would be much more resonable for dual purpose (street/track)

[cheezmonta]

http://www.arizonazcar.com/newparts.html
http://www.arizonazcar.com/strassy.html

Buddy of mine showed me this stuff and I thought it looked interesting. Especially since the 240-280Z suspension is so similar!

[Kennedy]

I understand that JIC Magic has done Z31 part in past?

I just check they web site and notice this. http://www.jic-magic.com/ViewProduct1.aspx?ProductID=34.

[attachment=0:4d828]z31_401-2.gif[/attachment:4d828]

Does that FLT-A2 VIP model have that part i have rounded in attachment? (don't know the english word for that strut part)

Maybe they can made directly these with coilover connections - >

[Butter]

1 kg/mm = 55.88 lb/in

My suggested Spring rates:
Stock setup or GC coilovers-350in/lb or 6/6
Any higher, and your aftermarket shocks are going to be overwhelmed unless you have custom-valved.

S-chassis subframe swap-8/6 (daily driver), 11/9 (track car w/full interior)
I use 10/8 with no interior and it is still very comfy.