With all the work involved in removing the suspension to pull out the springs, I would replace them with new lowering springs. Brand-your choice. Your car will handle better. If you have the money, replace the shocks while the suspension is out of the car.

 

I asked the same question about 2 years ago and got many varied answers. A few peaple whos opinions I respect said go for it. There is alot of people who from the grapevine have heard that this is such a horrible thing.

Well I have cut my springs enough to lower my car 2.5" and put on tokico adjustables, and let me tell you. This car handles awesome. When you cut the springs, you raise the spring rate, so yes it will change the rebound. If you just want to lower it an inch then you can also just buy lowering springs. But i wanted lower, and could not find any springs offered for the 240 that would lower it more than an inch or so. So I cut them.
Theres alot of myths out there that people without personal experiences like to pass around. Like you dont put nitrouz on a turbo car. If I listened to everyone that turned my ideas down, my car would be a fraction of where it has come to date. Besides if your gonna get rid of the springs, go ahead and cut them first. what have you got to lose? NB

 

I like your attitude, Nitrouz!!!...and from what I have read from the pros NOS works great with a turbo...and the only bad things I know (from experience) about cutting springs is that torching them can do weird things to the temper...springs then sag,
change rebound rates, etc...not too good if you get 4 different springs as a result...
use a cutoff saw (hacksaw if you have the time...snicker) or cool the cut to prevent overheating the spring...I dropped my 280 with Suspension Techniques springs...
but that's another story...long & boring... )

 

I like your attitude, Nitrouz!!!...and from what I have read from the pros NOS works great with a turbo...and the only bad things I know (from experience) about cutting springs is that torching them can do weird things to the temper...springs then sag,
change rebound rates, etc...not too good if you get 4 different springs as a result...
use a cutoff saw (hacksaw if you have the time...snicker) or cool the cut to prevent overheating the spring...I dropped my 280 with Suspension Techniques springs...
but that's another story...long & boring... )

 

When you lower a car, the chamber will also change. The tops of the tires will tuck under the fenders. This chamber change will wear the tires on the inside and reduce tire footprint. Therefore, you may also want to get a chamber adjustment kit.

Another thing you can do is re-locate the spring perches in the rear. I followed the JTR V8 conversion manual and moved my spring perches up 2.5 inches and cut down my springs with a cut off wheel. This will allow you to stick a 245-60-15 tire under the stock fender if you use a 15X8 wheel with a 5.5 inch offset. However, it takes a few times to get the ride height just right. JTR recommends moving the spring perches up 2.5 inches and using 280zx 2+2 rear springs with 3.25 coils cutout to maintain stock height. So if you want to go lower than stock then you would need to cut move than 3.25 coils out. For the front, JTR recommends using a smaller diameter spring with a threaded spring perch to adjust ride height. I may be easier just to buy new springs that will lower the car one inch.
Good Luck.

 

Cutting the spring will increase the spring rate, since it is a wound up torsion bar.

 

Yes, when you lower the car your camber will imrpove, your toe will need to be adjusted, and your caster will change as well. So basically after you lower the car you should go get an alignment.

On a stock spring I would NEVER cut 2.5" off of it, while the rate will increase, unless your car happens to be a 4x4 truck it will NOT increase the spring rate enough to avoid slamming the ground under duress. Technically speaking with increased spring rates you should also get increased shock absorbtion, and if you shorten the travel by lowering the car you force the shock to work harder as well, and will possibly bottom out the shock rod as well, which is not good. This is why for really lowered cars you will want to shorten the rod on the strut/shock.

1" cut should be no problem though, just dont use a torch =)

 

Funny that an old Porsche guy would have something to cut coil springs. Porsche has always used torsion bars. What folks have posted above is correct. You will increase the spring rate by removing a coil or two and you should replace your shocks at the same time. Stock shocks are designed for a spring rate around 100 lb. in. Anything over about 125 lb. in. and the shocks have difficulty controlling spring rebound. Liekwise, Tokico non-adjustables are limited to about 200 lb.in., Tokico Illkuminas to about 300 lb.in.

- John

 

Heh heh heh...

"Drop the spline count outboard, and reindex inboard for partial inch movements" the mantra of the VW/Porsche Torsion Tube Trot...

 

Cute them if you want lower then a 1.5" drop. You will not find lowering springs that will give you more then that. If you go lower then 2" you should consider sectioning the strut case so you won't bottom out every bump. Also invest in some bump steers to realign you geometry, otherwise, you may experience some uncontrolled movements while driving a straight line.
Good Luck,

 

I personally like to be able to go over speed bumps. mine makes enough noise when I do it with good stock springs, I would hate to use stiffer lowered ones.

 

Bah! Four Coils was O.K.

Not much suspension travel, but with Tokikos on "5" and four full coils cut, I was not adverse to the ride on an early 240Z.....
Then again, many consider me diseased.