Looking for info on old Nissan comp springs

[fixitman]

I have a different problem with European springs. I have an early '74 260Z with Stage 1 European springs, part nos. 54010-N3500 & 55020-N3501, and Bilstein shocks. As you can see in the attached photo, the ride height is rather high. Granted, the bumpers, exhaust, interior and spare tire still need to be installed but the ride height still seems excessive. Will the ride height decrease with more weight and use?

Thanks,

FixItMan

[FilipeA]

Hi

Fixitman, I have the same problem as well !! I have the European springs and Tokico HP struts and the car seems too high before I changed that.

As same as you I need to put the bumpers, the spare tire and the seats, but the ride I think will be like a rock!!! Don`t know what to to do now??

Someone give me a tip, because I would like to keep my springs originals!

Thank You

Filipe Azevedo

[Carl Beck]

Hi Derek:

Most of the Nissan Competition Catalogs that I have, offer a couple options related to springs.

1) you could order the Euro Spec. Stage I or Stage II springs

2) you could order either the Factory Racing Suspension Package, or the Factory Rally Suspension Package.

I do not find "competition springs" offered as stand alone sets - they all seem to come as part of the more inclusive "Suspension Packages".

Note that I said above; "of the catalogs that I have".... there may have been something other offered in some other years catalogs.

It is more likely that you ordered either the Stage I or Stage II Eupro Spec, Springs...

Stage I

Front = 101 lbs/in

Rear = 112 lbs/in

Stage II:

Front = 122 lbs/in

Rear = 140 lbs/in

Spring in the Racing Suspension Package are listed as:

Front = 218 lbs/in

Rear = 271 lbs/in

Springs in the Rally Suspension Package are listed as:

Front = 149 lbs/in

Rear = 174 lbs/in

I agree with some of the earlier comments that it's the combination of Springs and Shocks that effect the ride quality - I'd also add that a new set of tires will usually result in an improve rid quality..

Tire inflation pressures also have an effect on ride quality - there is about 650 lbs being carried at each tire.. and as I recall (without going to look it up) .. the recommended tire pressure on a 240-Z with stock size tires was around 28psi under 100mph. Most people I've talked to routinely carry 32psi in their tires on these cars... the result is a somewhat harsher ride - and the center tread wearing out ahead of the outside treads...

Then too there is the effect of all the suspension bushings...

FWIW,

Carl B.

[Carl Beck]

fixitman/FilipeA

We've had a lot of discussion related to the effects of installing both the Euro Spec. Springs and the newer higher pressure gas shocks available today - on the ride height of the 240Z.

1. The North American Spec. 240-Z's actually had a relatively high rid height to begin with. Measured at the front frame rail - where it meets the fireall... they sat 6.5" off the ground. This puts the center of the headlight 24.5" off the ground.

2. Installing the Euro Spec. Springs - on the North American Spec. Struts - well raise the ride height between .75" and 1.25". If you want the car to set lower, you have to cut about 1 and 1/2 coils off the front - and 2 coils off the rear. (average reported by others over time - but it also depends on what shocks you install with them).

3. Installing most of the modern high pressure gas shocks will raise the ride height of the 240-Z. That is because there is only about 650lbs loaded on each spring to begin with.. A high pressure gas shock off-loading 50 to 100 lbs... will raise the rid height of the car. The stock front springs only compress an inch for each 83lbs of load... likewise the rears are 112 lbs/in...

FWIW,

Carl B.

[Derek]

Hi Derek:

Most of the Nissan Competition Catalogs that I have, offer a couple options related to springs.

1) you could order the Euro Spec. Stage I or Stage II springs

2) you could order either the Factory Racing Suspension Package, or the Factory Rally Suspension Package.

Carl B.

Thanks for the info Carl.

I guess I have either the stage I or Stage II springs. I'm almost positive I have a conventional shock not gas.

It seems to be getting a little better the more I drive it. Probably just me getting used to the ride is all!

I'll probably run it for a month or so and then tear it down and measure the spring rates.

Thanks again

Derek

[fixitman]

fixitman/FilipeA

We've had a lot of discussion related to the effects of installing both the Euro Spec. Springs and the newer higher pressure gas shocks available today - on the ride height of the 240Z.

2. Installing the Euro Spec. Springs - on the North American Spec. Struts - well raise the ride height between .75" and 1.25". If you want the car to set lower, you have to cut about 1 and 1/2 coils off the front - and 2 coils off the rear. (average reported by others over time - but it also depends on what shocks you install with them).

3. Installing most of the modern high pressure gas shocks will raise the ride height of the 240-Z. That is because there is only about 650lbs loaded on each spring to begin with.. A high pressure gas shock off-loading 50 to 100 lbs... will raise the rid height of the car. The stock front springs only compress an inch for each 83lbs of load... likewise the rears are 112 lbs/in...

FWIW,

Carl B.

What are the differences between the US and European suspensions to account for the increase in ride height?

Thanks,

FixItMan

[Arne]

What are the differences between the US and European suspensions to account for the increase in ride height?

Thanks,

FixItMan

Best guess at this point is that the lower spring support was located farther down on the strut tube for the European cars.

I have the Courtesy repro Stage 1 springs on my car. When I had them with non-gas struts (Mulhollands) I had to cut them down by 1.5 coils in front, and 1.25 coils in the rear to get close to stock ride height. Now with KYB GR-2 struts, I have them cut a total of 2 coils in front and 1.75 in back to get back to stock height. The extra 1/2 coil on each end was to compensate for the gas pressure.