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Okay, here’s the story. I have a ’72 240 that I’ve owned since 1974. When I had the car in Japan (courtesy USAF) the rear end was sagging so I got the rear springs from a 260 2+2 and put them in, figuring the 260’s heavier rear end would have corresponding heavier springs. Turned out to be a little too much of a good thing. Fast forward to today. While restoring the car, installed new KYB struts. Naturally, with no engine, the front is sitting high. But the rear end is fully reassembled and even with 100 lbs in the tail to simulate a full tank of gas, it is sitting at the top of the struts and takes considerable additional weight to drop the rear end at all. I understand the KYBs give some lift of their own, and I’ve been trying to decide whether to go back with lowering springs, stock springs, or whatever will work. Keep in mind this car will not be driven real aggressively, and at this stage of life, I’d prefer a tolerable ride over razor sharp handling. I’d appreciate any advice on where to go from here.
 

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Okay, here’s the story. I have a ’72 240 that I’ve owned since 1974. When I had the car in Japan (courtesy USAF) the rear end was sagging so I got the rear springs from a 260 2+2 and put them in, figuring the 260’s heavier rear end would have corresponding heavier springs. Turned out to be a little too much of a good thing. Fast forward to today. While restoring the car, installed new KYB struts. Naturally, with no engine, the front is sitting high. But the rear end is fully reassembled and even with 100 lbs in the tail to simulate a full tank of gas, it is sitting at the top of the struts and takes considerable additional weight to drop the rear end at all. I understand the KYBs give some lift of their own, and I’ve been trying to decide whether to go back with lowering springs, stock springs, or whatever will work. Keep in mind this car will not be driven real aggressively, and at this stage of life, I’d prefer a tolerable ride over razor sharp handling. I’d appreciate any advice on where to go from here.
if you want the car not looking like its on stilts, and not feeling every road bump, go get stock 240 suspension stuff
 

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i would just keep the KYB's on there and get some Eibach springs, if available.
I have Eibach lowering springs on my Z31 with KYB struts and they seem to work fine. Doesn't sit high up and the ride is nice. i know its a different car, but its the same principal. if you're just driving daily, then no need to go crazy on fancy suspension. better to spend on a bushing kit and replace all those old worn out bushings.

cheers,

Bon
 

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spring fix

I have a '72 that I bought new in '72. When the first baby came in '75 I rigged a car seat for him behind the drivers seat on the rear deck. The subsequent load (me, wife, baby, plus baby stuff) was too much for the rear springs. I got a new set of 2+2 springs and cut the coil so that the car sat very slightly above level at the rear while unloaded. When loaded with just the driver or the full load it sat level or close to it. The added bonus was that the increased stiffness added to the handling and eliminated the need for a rear anti-roll bar. I still have the car. It is disassembled and in the process of being restored. If you want I can count the number of rear coils and let you know.
 

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One thing you should understand is that 260 springs are now going to be some 40 years old.

You should be able to get some performance springs from some place that actually knows your car.

Sadly, some Z companies are gone, but the performance springs should be a known thing and someone should be able to find what works well for that setup.
 

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a little discussed fact is all modern shocks (to my knowledge) are gas loaded, and they give more than a little lift when used with stock springs, especially old ones. the original shocks were assembled right in the tube that we now use to hold the shock cartridge- they had no gas loading and gave zero lift. thats why you see so many jacked up looking Z's around. The only way to get a stock ride height with modern shocks is to use stiffer after-market springs to counter the lift. I put a set of Tokico Blues and springs on my 240, and man was it a stiff ride, bone jarring really, but it looked and handled great. I'm guessing there is a compromise solution out there.Hold onto that Z and good luck!

Eric
 

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a little discussed fact is all modern shocks (to my knowledge) are gas loaded, and they give more than a little lift when used with stock springs, especially old ones. the original shocks were assembled right in the tube that we now use to hold the shock cartridge- they had no gas loading and gave zero lift. thats why you see so many jacked up looking Z's around. The only way to get a stock ride height with modern shocks is to use stiffer after-market springs to counter the lift. I put a set of Tokico Blues and springs on my 240, and man was it a stiff ride, bone jarring really, but it looked and handled great. I'm guessing there is a compromise solution out there.Hold onto that Z and good luck!

Eric
I've been looking for the same solution for my '72. Eibach lowering springs is the way I want to go, but finding struts is a challenge:
AFAIK:
KYB - doesn't work with lowering springs - only stock
Tokico - NLA
Koni - $400+ each (!)
Coilovers - $$$$ and too stiff for me

I want a stock-like ride, not a racing setup. Suggestions for us?


Rob
 

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I've been looking for the same solution for my '72. Eibach lowering springs is the way I want to go, but finding struts is a challenge:

KYB - doesn't work with lowering springs - only stock


I want a stock-like ride, not a racing setup. Suggestions for us?


Rob
i was concerned about this very thing for my Z31. i did some reading on here and on Z31performance.com and i found several sources that indicated KYB's work just fine with lowering springs, even though KYB says they are not to be used with lowering springs.

My car already had KYBs in the rear, the stock Nissan Mcphersons up front and some real shady cut and welded crap springs all around. the lowering was awful. i couldn't clear hardly anything on the road.

so in order to correct this, I put KYB's up front, replaced the junk lowering springs with Eibach pro springs, replaced the bushings, bumper-stops and dust boots... pretty much everything that was either missing or worn on the suspension. so far, everything seems to be fine.

the ride is not so low now. it is more comfortable and doesn't bottom out anymore. the KYBs don't seem to have a problem running with lowering springs (at least not with Eibachs) and this concurs with what some other folks have stated on the forums. if you're looking for a comfortable daily driver, i don't think you'll have any problems with a setup like this. but in the end, its what you want to do with your car that really matters.

cheers,

Bon

 

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i was concerned about this very thing for my Z31. i did some reading on here and on Z31performance.com and i found several sources that indicated KYB's work just fine with lowering springs, even though KYB says they are not to be used with lowering springs.

My car already had KYBs in the rear, the stock Nissan Mcphersons up front and some real shady cut and welded crap springs all around. the lowering was awful. i couldn't clear hardly anything on the road.

so in order to correct this, I put KYB's up front, replaced the junk lowering springs with Eibach pro springs, replaced the bushings, bumper-stops and dust boots... pretty much everything that was either missing or worn on the suspension. so far, everything seems to be fine.

the ride is not so low now. it is more comfortable and doesn't bottom out anymore. the KYBs don't seem to have a problem running with lowering springs (at least not with Eibachs) and this concurs with what some other folks have stated on the forums. if you're looking for a comfortable daily driver, i don't think you'll have any problems with a setup like this. but in the end, its what you want to do with your car that really matters.

cheers,

Bon

Sounds promising if it will work in an S30. I'm hardly an expert, but isn't the suspension geometry and configuration quite a bit different between 1972 and 1984?

MSA specifically says KYB will not work with a performance lowering spring. Tokico Blue's used to be their recommended strut but are NLA. MSA is working with another manufacturer to bring in a new product that will work...hopefully at a reasonable price.

Rob
 

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Sounds promising if it will work in an S30. I'm hardly an expert, but isn't the suspension geometry and configuration quite a bit different between 1972 and 1984?

MSA specifically says KYB will not work with a performance lowering spring. Tokico Blue's used to be their recommended strut but are NLA. MSA is working with another manufacturer to bring in a new product that will work...hopefully at a reasonable price.

Rob
they should be able to work I would think. i beleive there is a suspension difference between the the 240 and the 300. 300's have the rear shock strut separate from the rear springs, while the fronts are all in one assembly (shock housing, strut tube, spring). and i beleive this was a change that came in 84. could be wrong though... have you looked up any suspension diagrams for the 240?

yes, MSA does specifically say KYB will not work with lowered springs. i bought the exact same set that MSA sells, but from a private seller at a cheaper price. they don't have issues with the Eibach pros, however they may have problems with other types of performance lowering springs such as Moog, that may be stiffer or drop the car lower than the eibachs do. my 300 sits at almost stock height with the eibach lowering springs (they are roughly the same as the 88 Shiro 300zx springs from factory) yet they are considered "lowering springs"

i don't think you can go wrong if you stick with Eibachs and KYBs, but I wouldn't get springs that go any lower than eibach pros if you plan to use with KYB.

you could try gabriel or monroe struts. they might be decent.

Bon
 

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Based on personal experience, I would note the following:

- The fact that one can compress a KBY by hand from full extension, would seem to debunk theories about shocks increasing, in any way, ride height.

- I have cut the stock springs by one coil decades ago, and everything has worked fine with the KYBs installed at the same time. The only real issue with shorter springs is that the shocks could conceivably bottom out. The cut length provided the change in stance I was looking for.

- The color of applicable KYBs may have changed, but the part no. have not, based on the new set I recently installed during a suspension refresh (the old ones had been in for some 150K mi., tho they still worked well).
 

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Strut Mount Upper insulator.

One thing to keep in mind is that the Strut Mount Insulator on 240's and probably early 260s is different from those on 280's and likely the late 260. The early insulator is lets call it 2 inches thick. The later insulator is maybe 3 inches or more thick. It WILL make a difference. You may want to see what size you have on your car, and if it is the later (thicker) model then you can put an earlier (thinner) rubber mount in there. We did this on our 78 280 autocross car in conjunction with Motor Sport Auto's lowering street springs. Later I put the adjustable rubber/poly strut mounts on the front for camber adjustment.
I say this because I noticed an email from Z Car Depot advertising those insulators (early thin) I believe. At least you might want to call and see if they are the thinner variety.
 

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Strut/Spring Issue

Okay, here’s the story. I have a ’72 240 that I’ve owned since 1974. When I had the car in Japan (courtesy USAF) the rear end was sagging so I got the rear springs from a 260 2+2 and put them in, figuring the 260’s heavier rear end would have corresponding heavier springs. Turned out to be a little too much of a good thing. Fast forward to today. While restoring the car, installed new KYB struts. Naturally, with no engine, the front is sitting high. But the rear end is fully reassembled and even with 100 lbs in the tail to simulate a full tank of gas, it is sitting at the top of the struts and takes considerable additional weight to drop the rear end at all. I understand the KYBs give some lift of their own, and I’ve been trying to decide whether to go back with lowering springs, stock springs, or whatever will work. Keep in mind this car will not be driven real aggressively, and at this stage of life, I’d prefer a tolerable ride over razor sharp handling. I’d appreciate any advice on where to go from here.
First of all KYB shocks will DEFINITELY work with lowering springs. I sell both Eibach (progressive rate) and Vogtland (linear rate) springs for the first gen cars and have been using KYB shocks with either one with ZERO problems. Been using the KYB's since 1989 with 100% success. The only other shocks to use would be the Tokico Illumina shocks, not the regular Tokico's. Always be sure to use urethane bump stops too. Some places will tell you that you can't use coupe lowering springs on the 2+2's and you can't use KYB shocks on lowered cars and I'm here to tell you that is bad info. The only time I've ever seen problems with KYB's on z's is when they slammed the car and the shocks bottom out, especially when they don't use bump stops.
Once you jack a z up in the air and then put it back on the ground, the suspension is going to stay in an extended position until you roll the car 5 or 10 feet to settle it back down. If you don't have an engine in it then the front never will settle down all the way without engine weight.
For your application use either a stock spring or the Eibach springs. The Eibachs will give you a little stiffer than stock ride for regular driving. When you push the car harder in the corners then the springs stiffen up gradually according to how hard you're pushing it. Keep in mind that when you lower these cars with either type of lowering springs, then in the rear you must install adjustable camber bushings or adjustable strut tops. In the front you must install ball joint spacers. Other than that either style of spring works excellent. If you want to buy any of those parts from me be sure to let me know you use this forum for a discount. Z man of Washington
 

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Always be sure to use urethane bump stops too.



Keep in mind that when you lower these cars with either type of lowering springs, then in the rear you must install adjustable camber bushings or adjustable strut tops. In the front you must install ball joint spacers.
i tried to get some of these but was unable to find any, so I got the normal ones for the KYBs. do you know whereabout I can find them?


i didn't install the camber kit on my Z31 after the crap lowering springs were removed and the eibachs installed. should I have? previoulsy the camber was way out of whack and my rears were balder on the inside than bald should be. cost me a new set of tires. post eibach install, rear camber was readjusted and is now at -1. is it still really necessary to get the adjustable camber bushings or strut tops and joint spacers? the car rides much better now and sits alittle higher. just curious.

thanks,

Bon
 

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i tried to get some of these but was unable to find any, so I got the normal ones for the KYBs. do you know whereabout I can find them?


i didn't install the camber kit on my Z31 after the crap lowering springs were removed and the eibachs installed. should I have? previoulsy the camber was way out of whack and my rears were balder on the inside than bald should be. cost me a new set of tires. post eibach install, rear camber was readjusted and is now at -1. is it still really necessary to get the adjustable camber bushings or strut tops and joint spacers? the car rides much better now and sits alittle higher. just curious.

thanks,

Bon

Bon, I'm not aware of any camber kits for a Z31. The first and second gen cars didn't come with any kind of adjustment for camber or caster so aftermarket items have been developed. The adj camber bushings, adj strut tops, and ball joint spacers are strictly for the first gen cars. The original post for this thread was for a 240. As far as ball joint spacers go, their purpose is to set a proper attitude for the lower control arm in the front. The LCA should always go downhill as it goes towards the wheel on any vehicle or it causes adverse handling called bump steer. If it doesn't go downhill then it needs a spacer kit to drop the LCA.
Negative one degree on your rear camber adjustment is close enough that it shouldn't be any problem now. Your tires should last you considerably longer of course. Your first question I assume was pertaining to bump stops but I couldn't be sure. I sell KYB bump stops with boots and I also sell Energy Suspension bump stops. ZMOW
 

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Bon, I'm not aware of any camber kits for a Z31. The first and second gen cars didn't come with any kind of adjustment for camber or caster so aftermarket items have been developed. The adj camber bushings, adj strut tops, and ball joint spacers are strictly for the first gen cars. The original post for this thread was for a 240. As far as ball joint spacers go, their purpose is to set a proper attitude for the lower control arm in the front. The LCA should always go downhill as it goes towards the wheel on any vehicle or it causes adverse handling called bump steer. If it doesn't go downhill then it needs a spacer kit to drop the LCA.
Negative one degree on your rear camber adjustment is close enough that it shouldn't be any problem now. Your tires should last you considerably longer of course. Your first question I assume was pertaining to bump stops but I couldn't be sure. I sell KYB bump stops with boots and I also sell Energy Suspension bump stops. ZMOW
Zman,
i didn't realize those parts were specific to the S30, but that actually works out for me because I have a 76 Z as well, so its good to know i can get these parts for it. good information too, btw. the Z31 adjustment kit that I mentioned was offered from the Z store. i just didn't get it since my mechs were able to readjust the rear camber.
i will check out your website for those bump stops. the KYB stock ones I have seem to be working good, but will probably come apart over time. i am considerably happier now with how my car runs suspension-wise. with the camber issues corrected and the missing suspension components having been replaced. feels solid on the road as it should.

Thanks,

Bon
 
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