240Z: The ultimate guide to Factory Suspension and options

When it comes to 240Z / Fairlady Z factory Suspension setups it might get a bit confusing. Especially if you don’t own an American Market 240Z. Information is rare and there are too many Options and a lot of missinformation floating around the WWW. I tried my best to put all Information together in this one post. It contains a ton of data which has been sourced from official JDM and USDM Manuals, Parts books, E-Fast, the original Microfiches, Option parts catalogues, official sales brochures and other trustworthy sources.
Picture shows S30 suspension, scan from the Japanese Motorfan Fairlady Z Special book:

As always i spent countless hours on this post and tried my best to get all the data correct. If you find any fault or have additional information, please let me know. And please ask before you copy my hard work!

1. General Information
As you can see from the pictures above (and according to the Service bulletin vol 124 “introduction of the 240Z”), the suspension on all S30-chassis cars had an independant Strut type suspension with a hydraulic cylindrical multi-motion shock absorber and coil springs. Depending on the car version and market there were more or less (or thicker or thinner) additional stabilizer bars installed on the car and the specification of the springs and absorbers where different too.

1.1 Why and what Different Setups?
In accordance to different Road conditions and different Markets requirements as well as different suspension loads depending on the equipment of the dififerent car versions and options, Nissan made a few different Suspension Setups.
Here you can see different Car overall heights in the different JDM-market cars thanks to different loads and Suspension setups:

I checked all the Manuals, all sales brochures and some japanese magazines and found following data for overall height of the car (which depends on the suspension setup, as the body is always the same). Not sure about the data in the norwegian Sales brochure, tho. Maybe a typo? Same for the swedish user manual info. probably they just translated the info without changing the specs to actual specs?

240Z Austria: 1283mm (Austrian sales brochure)
240Z Switzerland: 1283mm (Swiss sales brochure)
240Z UK: 1283mm  (UK sales brochure)
240Z Norway: 1286mm?,  correct is 1283mm (they copied data from US manual)
240Z Sweden: 1285mm? (Swedish 240Z user manual), wrong, correct is 1283mm  (they most probably copied the data from US manual)
240Z Australia: 1286mm (From the Australien Microfiche CD)
240Z USA: 1285mm (Including Canada) (also = FIA Homologation Fiche 3023)
Fairlady 240Z Japan: 1285mm (Including 240Z-L and ZG versions)
Fairlady Z Japan: 1285mm (Including Z-L Version)
Fairlady Z 432 Japan: 1290mm (Including Z432-R version)

I believe the difference between 1285 and 1286mm in some countries which have the same suspension setup is just because of a rounding error in the calculation.

Here’s an interesting Picture from Kats over at ClassicZcars. which is from the High-speed stability countermeasurement test document of the “final Euro” spec cars vs the
Portuguese cars. As you might know the portuguese cars where a bit special compared to the rest of the european market. At least in the beginning of the Z-story.
So the Portugues cars came with a “standard” (refered to the Japanese Z432) 1290 mm height,
while the rest of the european cars came with the 1985 or 1983 spec height, depending on which specs you believe in…

The tests mentioned above  (more on that in a future separate story) resulted in (besides other changes) a different suspension setup for the European market, which is also mentioned in the 1972 Datsun “240Z introduction” Bulletin (See detailed specification changes also further down the story):

To make it a bit more complicated, Nissan offered a variety of Options (which sometimes were the factory Setup in other markets) as well.
Here’s a part of the USDM Sports option catalogue explaining the difference between European and American Springs (See orange box):

Now they didn’t only Change the spring and damper Specifications but they changed the whole Strut housing design. So combining springs, dampers and strut housings from different markets will end up in a strange look, feel and handling of the car! Be Aware!
Nissan sold the Euro-Spec II springs in USA with optional european strut housings only (See later) because of that reason!

1.2 Problem
The main Problem is that today’s aftermarket replacement dampers and Springs are mainly for the USDM Model as it’s the biggest volume market, and in comparison, european and japanese (and other markets) models are relatively rare. So most People will put USDM springs and / or dampers into their non-USDM cars. Most of the guys don’t even know there’s a difference. I asked a lot of People what Setups they use and most People with European cars running USDM gear told me that the car looked strange, felt strange, had a weird ride-height or stance, etc. It can definitly work but it’s not correct! see solutions i found later on in this post 🙂

2. Springs
2.1 Original Manufacturer
The Original Manufacturer of the factory Datsun 240Z / S30 Fairlady Springs was  TORCO Ltd Japan, as seen on the labels originally attached to the Springs:
Update 22.02.2018: It turns out i was wrong and the Manufacturer is  “NISSAN MOTORCO LTD”, if you check the complete Label in the next Picture! (By user NVZEE ). Thanks for the Input!

2.2 RHD / LHD Spring specifications
If you check the Data in the table (2.6) you might note that the front springs have different specs left and right side. Some sources say that the springs have different specifications for Right-hand-Drive (RHD) and Left-hand-drive (LHD) reasons to compensate the Driver position.
That is clearly wrong – if you compare the spec-tables and partnumbers you will see that the same springs are used on the same side in both RHD and LHD cars. So the reason might be other weight distribution compensation like the Motor Position etc, i guess.  Note that some “sports Options” use the same springs left and right in front. The rear springs are always the same for left and right!

2.3 Spring markings
The Factory springs were marked with color stains to identify different specifications.
In this picture (courtesy of Zhome.com) you can clearly see the markings on what appears to be new springs:

For comparison, these are the color stains on my factory springs after 44 years. The markings are nearly invisible on the right spring, but thanks to the small color pigments still visible, i was able to identify my springs as factory EUDM Springs (Also known as optional “Euro Spec II” in the US-Market)

Here’s a part of my JDM Service manual, explaining the different color marks for JDM Springs (See full list of all springs and known color marks in the complete table below):

2.4 Spring version explanation:
Because differently equipped cars mean different suspension loads, Nissan made different spring rates for the different car versions. The standard 240Z S30 had two base sets, which  could vary in the different markets.

– Standard springs for Manual Transmission
– Optional springs for Automatic transmission and A/C equipped cars (front only, rear
were standard)

Later cars (260Z, etc) had different springs again and additional Spring sets for the 2+2.

here you can see the “standard” and “European” Spec rear springs in the original Microfiches. (Couretsy of Heiko from Datsun.ch, thanks for taking the pictures for me!).

And here is the part of my JDM Service Manual explaining the front springs for the different JDM versions of the Fairlady Z (S30, HS30 and PS30).

2.5 Factory Options / Racing suspensions:
European spec springs were sold in the US-Market as “Euro Spec I” and “Euro Spec II” Springs as an “sports option” due to the stronger spring rates, lower ride height and more sporty feel. The spec II Springs were only available with the European strut housing (lower spring seat mounting!). See detailed explanation at chapter 3.1.2

From another USDM Sports option catalogue the “Rally” and “Racing” Suspension kit including the springs and a complete coilover setup, which was also used in some works rallye cars, was offered:

I wasn’t able to find anything about optional springs in Europe or the rest of the world, except Japan. Here’s a Listing of the Optional Springs (later sold as “NISMO”) in the JDM HS30 Sports option catalogue. Note that front springs are the same for Left and Right position!:Depending on the version of the catalogues the partnumbesr and specs vary 🙂

2.6 Complete 240Z Factory springs and options table.
I made a table of all available data i found for factory and optional 240Z / Fairlady Z Coupe springs, with all the specifications i found in official documentation or by trustworthy sources, including spring specs, Colour markings, Partnumbers and which markets they were used in. Enjoy it 🙂

Click here to download the full pdf chart:
240Z S30 factory springs and options by www.JDMjunkies.ch

3. Shock Absorbers / Dampers / Struts
3.1 Strut Housing
As seen in the Picture below (courtesy of Fabian, thanks!), the Strut housings were manufactured by AMPCO japan. The ones in the picture come from an 1972 USDM 240Z and has the nissan part number engraved alongside other numbers and notes:

Note that i wasn’t able to find any marking on both of my car’s (1972 Euro Spec’s), but it may be that it just was invisible since one of them has fresh powdercoated strut-housings and the other one has a lot of rust and a ton of grease on it, so it may be that there was a text in the past.

3.1.1 Euro Strut housings.
Euro strut housings have a distance from the lower mount to the spring mount perch both 24cm’s (or 34,5cm depending on how you measure) front and rear (Pictures by myself, from two swiss-spec cars. Also got confirmation from Andreas Carlsson in sweden that specs are same on swedish factory setup):

3.1.2 North american Strut housings:
USDM (and Canadian) Cars came with a lower upper spring perch mounting position of only 21,5cm (Difference to euro is about 0.7 inch!), While the rear difference was measured by only 0,5cm which may be a measuringe tolerance i guess.
(Left front, right rear)
Partnumbers the same USD und EUDM Rear??

As the European springs would look and feel wrong on an USDM car and vice versa, Nissan USA sold the European spec (“sportier”) Springs as a sports option together with the European spec strut housings. The Sports option catalogue explains what we already figured out above:

Here’s a comparison of the two struts. While the “how to hotrod your datsun” book, from which the picture came from, says that the difference is about two inches,
according to my measurements and the picture above it’s only approximately 0,7 inches. But of course there might be the possibility of additional, even lower competition strut housings which i’m not aware off…

 

3.1.3 Other Market strut housings
Unfortunately i have no spec for the other market cars but if someone has a genuine local market car and want to measure it and take a picture (front and rear) that would be great to complete this documentation! (Specially Australian and JP cars). This can be done while everything is installed on the car 😉

3.2 Original shock Absorber design (Strut inserts)
The original shock Absorber Nissan used to install to the Z was quite different to what you see today: It was an “open” Strut insert damper design wich got installed together with the hydraulic oil directly into the strut housing.
Picture courtesy of Heiko from Datsun.ch again, thanks!:

From what i understoud these could be maintained, other than a “closed” shock cartridge which can not bee serviced. But the service manual clearly tells not to separate the parts and “Handle it as an assembly”:

3.3 Replacement cartridges
Now i guess the handling of above original Design during maintenance / replacement was a bit tricky. So Nissan came up with complete replacement cartridges (like all aftermarket brands did). Honestly, i never saw a car in real life still using the original “open” Shock Absorbers. All of my cars came with OEM or Aftermarket replacement cartridges even with low mileage, so i guess the original design wasn’t that Long-Lasting. If you check the Partnumbers in your parts list, or, as here, in E-FAST, you will see a note “FOR SERVICE”, which means this is a replacement part in case of service:

Update January 2022: The swiss 1979 Datsun mechanic training course documentation shows the details of the cartridge type strut inserts and the diffferences (all parts marked with a box around the text) compared to the original “open” shock absorber design. Note that this might not be an S30 chassic specific picture, but a general purpose Datsun training document:

And how to bleed it, after installation (get the air out of the system):

Here’s a NOS set of Euro spec 260Z (2+2) rear insert replacement cartriges, Part No 56105-N3785

If you look closely, the Nissan Logo, Part Number and Atsugi Brand is stamped into the housing:

Here you can see those struts with the original Installation manual (japanese on one side, english on the other):

And here’s a closer look at the installation manual:

It seems like the original strut manufacturer was AMPCO (Atsugi Motor Parts Corp.) Japan, but it seems like also Tokico made some OEM shock absorbers so there might be different versions, probably also depending on the Market.
I cannot guarantee these were OEM Shocks, but one of my cars came with Tokico front shocks which appear to be (as said, no guarantee) Euro Factory replacement cartridges:

3.4 Different dampers and specs
Aside from the different strut housings (see above), the 1969 to1973 Z’s worldwide appear to only have had two different sets of Suspension dampers. One for the European market (Including UK), and one for the rest of the world (Including USA, Canada, Japan, New Zealand, Australia).
However it gets a bit confusing here. Most part lists worldwide list two types of dampers of which one is an “option”, while the european microfiches list the option als as partnr for the european cars with “hard suspension”.
Stock dampers for Left and right side are always the same.
Also checking the specs worldwide it appears that there are dampers for the european market and dampers for the rest of the world (See expansion / contracting rates):

Rear strut specs:

Front strut specs:

Here are the Japanese ones which seem to be close to the USA ones. the main difference from europe to USA to Japan is the expension / Compression
Data from the JDM Service manual:

3.5 Factory options / Racing suspensions
As seen above with the springs, there were several options available in different markets.
From simple “sporty” struts to complete adjustable coilover systems. everything was available. See 3.6 for full listing of all factory and option struts and inserts.

At one later point, NISMO sold a set of complete strut inserts for the S30Z, as the ones shown in the picture below (From Yahoo auctions)
Front: 56110-RRE72
Rear: 56210-RRE72

3.6 Complete 240Z Factory Struts / Inserts and options table.
I made a table of all available data i found for factory and optional factory 240Z / Fairlady Z Coupe Struts and inserts, with all the specifications i found in official documentation or by trustworthy sources, including strut specs, strut housing specs, Partnumbers and which markets they were used in. Enjoy it 🙂

Click here to download full pdf file:
240Z S30 factory dampers and options by www.JDMjunkies.ch

4. Aftermarket Replacement Options
In Order to find a neat set of fitting Suspension i asked a lot of people and got a variety of answers about who makes springs and dampers for the Z. Therefore i decided to contact all of the known manufacturers myself and ask them what they make. Surprisingly there are not too many out there and most of them are based on the USDM cars. Note that availibilty might be different in different markets, but these were the answers i got by 2016 from the manufcaturers i contacted worldwide:

4.1 Today
4.1.1 Springs:
First the bad news, i contacted all of following manufacturers in 2016 and got a feedback that they DON’t offer springs (either factory spec nor aftermarket lowering sprigns) for the S30 chassis (while some of them can make custom Springs to your needs):
Trust / Greddy, HKS, RS-R, TEIN, Swift / Tohatsu, Tanabe / Sustec, H&R

Swift (Tohatsu), Eibach (350 to 400.- CHF without swiss homologation) and TEIN offered me to make custom springs to my specs, but i guess most others will also do if you ask them gently.

Eibach is also making lowering springs for Z cars, exclusively for MSA. Since it’s an american shop, i’m pretty sure they’re based on the US-spec cars.

Vogtland 35-40mm lowering springs, partnr: 9161031, based on US-spec cars.
Data by Vogtland representative. (Picture from Fabian, Thanks):


Kameari (JP-Spec, most probably for Drag racing, probably rock-hard) springs.
Kameari catalogue:

MJP Eastern Auto (https://www.mjpshop.co.uk/) has a long history with the Z and offers to make custom coil springs. I heard they have the knowledge to build you standard or lowered “Euro spec” 240Z springs if you ask them and they acn basically have them made to your specs. Seems to be closest to the factory springs you can get (without any flashy colours or manufacturers logo, just plain black springs with correct specs):

Others
I also know some Racing shops in switzerland (and most probably many around the world) have some Euro or racing spec springs in small batches in stock or at least the knowledge to get them produced.
I guess a lot of the smaller Japanese restauration / tuning shops offer a range of suspension springs for the S30 chassis, based on the JDM cars specs, but i haven’t checked out them all.

4.1.2 Dampers
While there are many “tuning” options around, i figured out that some japanese manufacturers make OEM replacement dampers again:

Tokico now has these replacement dampers. However the list is a bit confusing since the “OEM part nr” is the complete strut assembly and not just the damper. I guess these are based on the JDM market cars since only sold locally. (Click for lager image)

They also offer their “illumina” and other series for gas filled “performance” shocks.
Update 2018: It appears that Tokico (owned by  Hitachi group) has been sold and the new company is not producing these anymore!

KYB / Kayaba now came up with the “SR-Special” Replica Classic dampers as an OEM Replacement (again i guess based on the JDM Model)

They also offer the “Excel-G” for the US-market cars as a replacement for the worn out factory shocks:

KONI (USA) offers some of their “Classic” line dampers for the 240Z. Partnr 86-1811 & 86-1812. According to a KONI Germany representative, they’re based on the US-model and only officially sold in the US-market.

4.1.3 Coilover Setups
I’m Not a huge fan of those BC Weld-in Coilovers. I know they may work well but i wouldn’t trust myself welding suspension strut housings and it seems like it’s just a “cheap” solution for those who want to “slam” their car without spending a lot of money.
I figured out that there are still “high-end” solutions available, but probably more track-oriented setups with less ground clearance but more performance. Also they will not allow you to weld it yourself, but you have to send the original Strut housings to them and they will modify them to your needs.

KW Suspensions germany offered me to build a set based on the original strut housings to custom Specifications for 3645.- CHF including swiss homologation. They sent me a picture of a set they did in the past. (Picture sent by KW Sales person)

Intrax Racing in Holland offers three different types of Coilover setups with TÜV Certificate. Click  here for details. (Picutre shows Intrax 1k2 system, from Intrax website):

TEIN: Like KW, TEIN Japan has a “specialized” program in which they can build whatever you wish. They already did several S30 Suspension setups if you check their List and all information about the procedure and options here: https://tein.co.jp/e/products/spd.html (Picture from TEIN website):

Protec / Aragosta: Japanese Suspension manufacturer Aragosta builds these for the japanese classic car specialist Protec Japan it appears to be reworked factory strut housings as well..

4.2 Past
Since the Z was a common and “cheap” sports-car in the past, there were a lot of manufacturers offering Suspension replacement parts. Most of these companies still exist but they do not offer parts for the Z anymore

4.2.1 Springs:
Haven’t found a lot of useful stuff here. will update in future
Tokico made HP Performance springs (Partnr 5020-R for rear and 5020-F for front) in the past, but it seems like they’re NLA. If you browse the internet for these partnumber you see that a lot of people had problems with these. Not sure which marked they were based on. most probably Japanese / USA.

Japanese manufacturer Toyoshima also once produced reinforced “racing / Sport” springs under their RSST label (Race and street service Toyoshima). But the RSST sub-brand doesn’t seem to exist anymore. Most probably based on the JDM Model cars.

Also Suspension Techniques (Now ST-suspensions) had some in the past, which are now NLA.
The optional Competition and racing springs were later sold under the NISMO brand, but also NLA now.

4.2.2 Dampers:
Monroe (Belgium?) made a variety of dampers in the past but now don’t supply the 240Z anymore.

Some of these were installed in one of my cars when i bought it as an OEM replacement:

Again there were many other suppliers of aftermarket dampers in the past. now many are obsolete and NLA.

5. Conclusion:
I’d like to repeat once again what i said above manytimes before. Be careful when choosing your setups. I’ve heard about people mix-and-matching various products from various markets now many times and none of them was really happy. The Z was originally known for the superior handling. please don’t destroy it by choosing wrong parts (and spending a lot of money for that too). Myself i haven’t chosen any option yet. still will think about which fits best for me.

6. Links:
Here i put some important links that may be helpful:
– Carl beck’s description on the original BRE Race car suspension setup:
https://zhome.com/BRE/BREFrontSuspension.htm