Lowering the 240z

Zed2k

Zed2k

Well-Known Forum User
I am thinking of lowering my 240 I was wondering which is the best way to lower the car and by what amount, is it better to modify the struts so they are adjustable up and down or just to fit lowered springs which are uprated. And to go with these what type of shocks do people recommend as a uprated shocker from the standard. what do you all think thanks
 
1) Lowering springs has to be the economic way to go. Springs can be made for you to do a specific job - my advice would be to err on the moderate side. Disadvantages: upsets steering geometry if taken too far, reduces travel on the damper rod, springs may lose contact with the pans on full extension.

2) Be careful which dampers you choose to go with lowered springs - not all will be happy to live pushed further into the bottom end of their travel. Tokico HP state that they are OK for use on cars lowered by up tp 1.5".

3) The expensive way to go is to cut down the struts and weld on the adjuster thread so that you can use smaller diameter springs and wind the lower seat up and down to trim the car. Various damper options are available, eg. Leda do their own inserts, Tokico provide an adjustable (for rate) Illumina in a shortened version for 240Z struts. Advantages: perfect trim and damper rod travel not compromised.More inboard tyre clearance for those huge wheels you want to fit! Disadvantages: deciding on spring rates for road vs. track use, some loss of comfort factor. Do you want a race car on the road? Then why not couple this with adjustable camber / caster plates and go the whole hog? Just be sure that you have access to a good set-up system.

4) Significant steering and suspension improvements can be made by using urethane bushes throughout and fitting uprated front and rear anti-roll (anti-sway) bars - often neglected as a suspension tuning aid and give improved roll stiffness without reducing comfort.
 
I just went for shortened springs with a 15% uprate. I didn't see the point of adjustable ride height, not for a road car. I use Tokico non-adjustable dampers and they work fine together. Adjustable dampers would have been nice, but well out of my budget. I also have a full complement of urethane bushes, uprated anti-roll bars and strut braces front and rear.
I get zero body roll, and with the spring damper combo, the ride quality doesn't suffer too much.
The car handles like a dream, but does understeer on very tight second gear turns (usually roundabouts). Some negative camber on the front should rectify this. I am yet to push the back end wide, but we'll see what happens once my horsepower rises this summer.
 
Now you should have an idea of what I meant by "zero body roll". My fancy new avatar shows my car during hard cornering. Picture courtesy of Classics Magazine.
 
I'm about to have -2" springs put onto my 260 2str and I expect that I'll need the bumpsteer spacers too. I know that -1.5 is usually the max, so I'm pushing my luck a little bit - I'll let you all know whether she survives it!

And whether my spine does too for that matter... :)
 
Hi Tony,
Thought I'd better let you know I have just taken the bump steer spacers off of my car. My car is not quite a 2" drop on the front, but it certainly exceeds 1.5". I took them off because of the positive camber it put on the front suspension. The consequence of this was very bad understeer, in the wet it was dangerous and I had one or two very hairy moments. The car also felt like it was on it's tip toes at the front and felt unstable at speed.
After removing them, the car had much more front end bite due to the restored camber. It felt much much better.
My advice would be to measure the slope on the steering after you've lowered the car, just to be sure that they are necessary. The spacers aren't that cheap as they have to be shipped from the States.
And "no", you can't buy mine. I intend to keep them for now because the car needs dropping a little more. I may need them again, but I will be sure to get it measured first. They are made of aluminium, so I guess they could be trimmed down to suit my requiements. We'll see what happens, but for now I'll trade a bit of bump steer for a car that feels safe.
 
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