240Z Street Suspension Setups

richiep

Club Member
There’s a few other options missing from this discussion. I know you were trying to trim things down Woody to a shortlist but for completeness, it’s worth mentioning.

Techno Toy Tuning - their units are complete, ie no welding etc. They also now offer an evolved front kit that is entirely new, I.e. doesn’t use Nissan strut cores. If you want a testimony on their quality, ask Skiddell and pmac- Steve’s car is running on them in the Time Attack series, and they are very happy with them. Not out of the question cost-wise either given those insanely priced Intrax ones are being discussed. T3 can be run with a weld-in camber plate, a bolt-on one, or a solid top that can be turned to allow 1.5 deg camber adjustment in each direction without having to cut the strut tower tops.

CX Racing do a version of the BC ones - I’m guessing same factory, different colour coding! Could be had for less than the BC ones if you have someone in the US to take delivery and work a way around USPS’s terrible shipping rates.

Megan Racing - it’s been an option for a while in the US to use the S14 Megan coilovers modded to work on Zs. However, Megan now make a Z-specific kit. It’s similar style to the BC one, but has a weld-in camber plate at the strut top.
 

Albrecht

Well-Known Forum User
...I agree BC definitely fall into the camp where there isn't enough information provided with regard to the suitable damping range given the adjustment available. I suppose the lack of info is associated with the more entry level price point its aimed at. One to add to the cons list!

In case I'm not getting my point across well enough; my suspicion with the BC 'kits' supplied for the S30-series Z is that they are actually adapting (or indeed adopting) an off-the-shelf damper unit which was originally devised for a much later model with a completely different suspension system. The implications are that they are an adaptation of something originally supplied for S13/S14/S15 Silvias, which have semi-trailing arm rear suspension and therefore vastly different pickup points and motion ratios than the S30's 'Chapman strut'/McPherson rear suspension. They certainly have hugely different spring rates, so how can they have the same damping ranges?

If manufacturer/suppliers do a lot of research and testing and want to keep their intellectual property their own then that's probably their right, but I have a feeling the people selling-on the BC kits simply don't know...
 

Albrecht

Well-Known Forum User
Not out of the question cost-wise either given those insanely priced Intrax ones are being discussed.

I don't agree that the Intrax prices are "insane". They may well be a significant jump up from the average via-USA setups (many of which use generic damper units manufactured in China) but they are a European mainland-based company with a good reputation in motorsport who have worked with marque specialists to properly R&D their products. All things considered, their prices are probably quite realistic.

Not much point in going into it here, but some of the Japanese aftermarket specialists can supply ready-made bolt-on suspension kits for the S30 which could make your eyes water. Aragosta in particular have 'reassuringly expensive' price tags that would cost a packet to buy and ship, and then you have the doubtful pleasure of being hit with taxes and import duties on top. And they want you to supply cores too!
 
I think the new ttt ‘evolved’ setups cost more than an intrax rsa once shipped etc. The most important part, the dampers are still off the shelf units. It’s about £2500 for an rsa setup, that’s massive upside down dampers, spring rates designed to suit, supplied welded, with lots of dedicated road,race and track development behind them.

I popped to exe-tc who possibly make some of the best dampers going, they wanted £6k for the same thing, they said go for the intrax as they’re good quality and they’d happily service them(if pushing in and out of my garage causes a leak :)

Also they’re not bright red/gold etc.
 

Albrecht

Well-Known Forum User
Possibly worth adding here:

The classic BILSTEIN inverted monoshock design can be adapted to the S30's suspension legs by utilising Bilstein's weld-on tubes. The historic rally world has been using these for decades and parts are in ready supply. You could put a 'kit' together for yourself.

Here's a setup I've used on a couple of my cars, and is currently sitting in a quiet corner of the loft waiting for another job (I'm working on it...):






Note the insert, readily available from Bilstein, which comes in a few different lengths and can be ordered with your own choice of valving if required:



*Bump/rebound non-adjustable!
 

johnymd

Club Member
I think in the majority of cases (not all and certainly not track) people mainly want to be able set the ride height and having a car that handles a lot better is not of primary importance. This is why I think low end kits like BC's, which can be bought for under £800 including vat and delivery, suit a lot of people (but not all).
 

Albrecht

Well-Known Forum User
I think in the majority of cases (not all and certainly not track) people mainly want to be able set the ride height and having a car that handles a lot better is not of primary importance. This is why I think low end kits like BC's, which can be bought for under £800 including vat and delivery, suit a lot of people (but not all).

In which case it's probably worth mentioning some of the simplest options, which are inserts and springs. Kameari Engine Works in Japan for example offer two options for the S30-series Z range (catering for early and late cars, as well as 2/2, 2+2 models) called 'GS Hard' and 'Street'. I believe the damper units are built to Kameari's specs by KYB?

http://kameariengineworks.co.jp/Catalogue-v3/catalogue-078-2016-05.pdf

http://kameariengineworks.co.jp/Catalogue-v3/catalogue-077.pdf
 
I think in the majority of cases (not all and certainly not track) people mainly want to be able set the ride height and having a car that handles a lot better is not of primary importance. This is why I think low end kits like BC's, which can be bought for under £800 including vat and delivery, suit a lot of people (but not all).

Thats the paradox though isn't it. Its harder to have a setup that works well for road and spirited road driving than it is to have a dedicated track setup. You need a much wider operating window.
 

johnymd

Club Member
When I say set the ride height I should of said "set the ride height to exactly where you prefer it". So adjustable platforms are the easiest way of achieving this. This will then create a problem as if you lower the car more than say 2" you will ideally need to shorten the strut and damper. You then start to get near the cost of a set of cheap BC's.
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
Possibly worth adding here:

The classic BILSTEIN inverted monoshock design can be adapted to the S30's suspension legs by utilising Bilstein's weld-on tubes. The historic rally world has been using these for decades and parts are in ready supply. You could put a 'kit' together for yourself.

Here's a setup I've used on a couple of my cars, and is currently sitting in a quiet corner of the loft waiting for another job (I'm working on it...):

Note the insert, readily available from Bilstein, which comes in a few different lengths and can be ordered with your own choice of valving if required...

Alan is there a load bearing at the top of the front struts for the spring to swivel during steering or is that just the spherical bearing?
 

Albrecht

Well-Known Forum User
Alan is there a load bearing at the top of the front struts for the spring to swivel during steering or is that just the spherical bearing?

There's a spherical bearing inside the top mount which takes the place of the OEM bearing on the front ones, and the required 'swivel' on both ends (if that makes sense).

It's a Tim Riley-engineered setup, so well thought through.
 

Woody928

Events Officer
Staff member
Club Member
There’s a few other options missing from this discussion. I know you were trying to trim things down Woody to a shortlist but for completeness, it’s worth mentioning.

Techno Toy Tuning - their units are complete, ie no welding etc. They also now offer an evolved front kit that is entirely new, I.e. doesn’t use Nissan strut cores. If you want a testimony on their quality, ask Skiddell and pmac- Steve’s car is running on them in the Time Attack series, and they are very happy with them. Not out of the question cost-wise either given those insanely priced Intrax ones are being discussed. T3 can be run with a weld-in camber plate, a bolt-on one, or a solid top that can be turned to allow 1.5 deg camber adjustment in each direction without having to cut the strut tower tops.

CX Racing do a version of the BC ones - I’m guessing same factory, different colour coding! Could be had for less than the BC ones if you have someone in the US to take delivery and work a way around USPS’s terrible shipping rates.

Megan Racing - it’s been an option for a while in the US to use the S14 Megan coilovers modded to work on Zs. However, Megan now make a Z-specific kit. It’s similar style to the BC one, but has a weld-in camber plate at the strut top.

It was more that I was trying to keep my searches to the more local area knowing the cost of shipping as customs from the US. That said really good info, thanks for sharing! :thumbs: A lot of the info on here would make a great sticky thread.

In case I'm not getting my point across well enough; my suspicion with the BC 'kits' supplied for the S30-series Z is that they are actually adapting (or indeed adopting) an off-the-shelf damper unit which was originally devised for a much later model with a completely different suspension system. The implications are that they are an adaptation of something originally supplied for S13/S14/S15 Silvias, which have semi-trailing arm rear suspension and therefore vastly different pickup points and motion ratios than the S30's 'Chapman strut'/McPherson rear suspension. They certainly have hugely different spring rates, so how can they have the same damping ranges?

If manufacturer/suppliers do a lot of research and testing and want to keep their intellectual property their own then that's probably their right, but I have a feeling the people selling-on the BC kits simply don't know...

Quite possibly, as you say though with BC's apparent communication we will never know. Given the entry level cost it would seem highly likely that they have adapted rather than gone for a ground up design specifically for the Z. I'll bow to your knowledge as this is where it starts going over my head in terms of my knowledge.

As long as the end result is what I'm hoping for then I'm happy. Thanks for the info on Bilstein as well, sounds another interesting option. Are you able to advise what sort of price point that comes in at for comparison?
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
There's a spherical bearing inside the top mount which takes the place of the OEM bearing on the front ones, and the required 'swivel' on both ends (if that makes sense).

It's a Tim Riley-engineered setup, so well thought through.

Ok, I understand but I don't think spherical bearings are meant to take the load/weight.
 

Jan - the Dane

Active Forum User
Hi guys,

read through all the posts on this subject and again, great to see the expertise, ideas and comments....

But my suspension needs are a little more simple and I hope to have some input from you all on this. I simply want to drop her a bit for aesthetic reasons...yes, I am that shallow!! Nothing stupid just 20-25mm while still having a decent ride.

Got a fresh set of KYB shocks, running 8x15 with 195/55. I was thinking of going EIBACH progressive as I do not really see the need for a simple drop(yes, I am also cheap!).

Clearance should not be a problem(i think) but I am concerned about ride quality and if I will scrape the floor off on UK roads.

Anyone with a similar set-up or experience?

Much appreciated!
Cheers
Jan
 

Paul_S

Club Member
Yep. Very useful :)

Question - is there any easy way to find out what spring rates have been fitted to a car?

I've got Arizona coilovers on mine but don't know the spec. I have sent an email to Arizona (as I also need the tool to adjust them) but haven't heard back yet.
Well, I haven't heard back from them (I forgot I asked) so I will send another email.

I needed an adjuster tool and got a generic one off eBay:

gallery_245_510_69515.jpg


If fits nicely, and I put some handlebar tape on the handle as the edges are a little sharp:

gallery_245_510_231867.jpg
 

PBJ

New Forum User
Thanks for the feedback John, interesting to hear how it’s all settled down with a few alterations. It sounds like it’s been nailed now for a road car and let’s be honest ultimate grip isn’t as fun in a road car. It’ll be interesting to see what I think with the softer rear end having gone 4/4kg. Given my original aims I think it should hopefully balance nicely as a fast road/GT orientated car. I think when a budget comes into it then this could be the best way forward, I’ll reserve judgement till it’s all done though.

Hi Woody928,

Thanks for this write up! Any update on how your BC Racing setup with 4k front and rear is working out? I'm thinking about purchasing a set soon but I'm stuck on which spring rates to choose.
 

Woody928

Events Officer
Staff member
Club Member
Hi Woody928,

Thanks for this write up! Any update on how your BC Racing setup with 4k front and rear is working out? I'm thinking about purchasing a set soon but I'm stuck on which spring rates to choose.

No worries dude. Personally I’m very happy with them, I’ve now done hundreds of miles with them fitted and they’ve adapted well to everything that’s been thrown at them. The car gets cruised, it gets used as a fast road car and my local area resembles no man’s land with the number of potholes and crap road surfaces around. I’ve been able to dial the ride height in just as I want it so that the car sits nicely but still glides over speed bumps etc with no issues. When pressing on the dampers really seem to absorb the undulations of the road surface and never lose composure.

I’ve got mine set extremely low on the damping settings at about 5 clicks (out of the 30 odd) and haven’t played with it as I haven’t felt the need. I will say that the ride is sporty now, however it’s still very comfortable in my opinion and my dad agrees (which says something). I’m as happy driving long distances in it as I would be throwing it around. With regards to spring rates I think you may be hard pressed to note the differences between 1KG changes, John Palmer has the recommended 4/5KG setup and is very happy with them. I went 4/4KG as I didn’t want to over spring the car for the road, 225 lbs all round seemed like a good point to stop at for a light road car such as the S30 in my opinion. It will obviously depend on the damping as well however I cannot see why anyone would want to be using 300+ lbs springs on road cars, lots of people in the US with very high spring rates which I cannot imagine will be pleasant. Mine’s dialled up enough from the factory rates to give a significant and very noticeable difference before going anywhere silly and just being crashy and unpleasant on the road. With all of my changes to my car the handling is now fantastic and I’ve not looked back.

All of the above is just my opinion though, I’m no expert in the subject short of what I’ve experienced. I believe Nissan used mismatched spring rates front and rear from factory and they must have done it for a reason (I think with a slight bias to the front) however I’d have to check that with Albrecht. I hope that is of some help…
 
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