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240sx suspension swap kit interest?

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i have an 83 with s13 rear suspension and s14 front suspension, all 5 lug 


what i wanna know is if there would be any interest in a swap kit for the front and if there is i might duplicate what i did for the rear as well, the main point of the front kit is to change the tension rod mounts to the s14 ones, i can take pics as well if you guys would like to see

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Adjustable s14 front lower control arms and tension rods (needed trimming to fit the zx crossmember)


S14 front spindles


S13 front coilovers


S13 modified tension rod mounts


Q45 inner tie rods s13 outer


Z32 brakes (almost done just need lines)

Edited by noilan
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I am 75% finished with my s130/s14 suspension project.  Rear is basically complete, but the front is giving me headaches.  I attempted to modify the s14 front crossmember to fit the s130 chassis and the result basicaly works, but was a lot of work and isn't quite complete.  I think Noilan's use of aftermarket LCAs, tie rod ends, radius arms, and coilovers is possibly a much better solution.  I've also been working on a OEM sourced brake upgrade.


Rear s14


Front Brakes (85 Maxima)


Rear Brakes (03 Sentra SE-R)



The whole story so far:


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What are the benefits over a properly sprung s130 suspension?  To me it seems like an awful lot of work to convert to 5 lug/ better brakes.  Especially when you consider that most of the upgraded components (brakes, coil overs, wheels bearings, etc) are easily upgraded to the stock suspension.  And when you upgrade said components you retain the trailing arm rear which from what I've seen is a much better sports car suspension than that of the s13/s14.

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Well, the benefits for me were better design and parts availability.  My stock brakes needed upgrading, my half shafts and LSD were worn out, and even with fairly stiff coil-overs, the car was a handful at the track.  The stock rear just felt sloppy.  Probably some beefy anti-roll bars and wider tires/rims would have gone a long way to keeping the car composed in the corners, but in the end, it just felt like an interesting and original project.  Here are some quick notes on my s14 swap for the curious:



I tried both an s13 and s14 rear sub-frames. The s14 was better suited because it was slightly wider, uses longer shocks that will reach the tops of the 280zx shock towers, and have perfectly angled lower shock mounts. I never tried a z32 subframe.

I extended the front mounts of the s14 subframe to reach the existing 280zx mounts and the rear subframe bushings line up with the existing rear crossmember so all you need is to weld on some beefy mounts there. I did have to 'massage' the chassis below the two tool boxes behind the seats quite a bit to clear the front of the subframe that curves over the nose off the differential, but the tool boxes still seem to fit just fine.

The fuel and brake lines must be redirected to clear the new subframe. The fuel lines are easy, but I re-engineered the passenger side brake line to mirror the driver's side so that identical flexible hoses could be used for both calipers. For the moment, I am using the longer s14 front brake hoses to reach the calipers. I ditched the fuel damper and made a simple bracket to suspend the fuel pump from the subframe right behind the differential, but I plan to have an in-tank fuel pump at some point.

I had some coilover perches and springs from my old suspension that transferred over easily. You may be able to use any aftermarket s14 coilover system, but trying to use the OEM springs would mean precisely located the upper shock mount to adjust ride height. That could mean hacking up the shock tower and a lot more work. The tops of the shocks do not match the angle of original shocks, it's not horribly off, but I may need to cut and weld here to make it right.

You will need a custom drive shaft. I cut a 2+2 drive shaft and welded a z32 rear u-joint/flange to it just so I could move the car around and do some testing, but I doubt it's balanced very well.


I attempted to narrow an s14 crossmember to fit the 280zx frame rails, but it was a lot of work and my first prototype has issues. I mainly went this route to be able to use all s14 parts including the steering rack to keep the suspension geometry from getting wacky. The main issue is that while the s14 subframe engine mounts line up well with the L28 mounts, they are a couple inches shorter so that the oil pan barely clears the steering rack and is not well protected by the crossmember. Also, the s14 steering shaft is a different diameter.

The s13 radius arms are also not compatible with the 280zx tension arm mounts, but I discovered that the z31 tension rods are a perfect combination of 280zx at the front and s14 at the rear. They are even the perfect length.

I had to slot the tops of the strut towers outward as far as I could to keep the camber reasonable, so a nice set of camber plates may be coming at some point.

The s14 anti-roll bar almost fits into place, but the 280zx mounts are too small and the s14 mounts don't line up the same, so I still have to work on that.

I removed the spring perches from the s14 struts just so I could use the coil-overs from my old suspension, but I don't think the OEM s14 springs will fit the 280zx strut towers anyway.

I used s14 brake hoses for the stock s14 calipers, but my maxima rotor/z31 bracket/altima caliper upgrade will have to have altima brake hoses because the banjo ends are clocked differently.

That's it for now. The car runs and drives, but I've still got some work to do.

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Hmm... have any of you who have performed this swap collected any measureable data using the same tire, spring rate, brakes etc. from a before/after swap comparison? Or is the consensus that brand new parts from a new chassis works better than wore out stuff on old tires.  That would be a no brainer.  Not trying to hate on what you guys have done as I understand it is a ton of work.  We are currently in the process of swapping the hubs and bearings (s13), coilovers, and brakes (z32) on my personal s130 and I am looking for appreciable gains.  To say that it is a better design could be considered somewhat of a stretch when you look at actual race cars that use trailing arm suspension.  Rally, road, autox, even drag racing but more specifically anytime you want to put (a lot) of power down on corner exit from what I have seen the semi trailing arm is superior. 

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Was it Colin Chapman who said any suspension can be made to handle well if you keep it from moving too much?  I find this true of the s130's semi-trailing arm suspension.  I personally like the s14s dynamics over the s130.  I've driven both my 280zx and 240sx at the track and I found it much easier to balance the 240 in the turns.  The 280zx's rear is oddly sensitive to throttle.  As roger280zx said, it squats down and puts power down well, and even rotates nicely with a bit more throttle.  Conversely, attempting to correct a little understeer by lifting off the throttle, especially over a rise, can cause all hell to brake loose.  Challenging, yes, interesting, yes, a little frightening, yes, and ultimately controllable, well, yes.


Of course I would love to spend a few track days comparing a stock(ish) 280zx to s14 suspensioned 280zx, but alas, my 280zx has been stuck in project status for several years while I have been wasting my time LeMons racing our 240sx.  Hopefully I will have the Z at the track by next spring, but even though it will be riding on the exact same coil-overs as before, I won't be able to run the same wheels/tires for an accurate before/after comparison.  Also, my track skills have improved a lot over the past few years since I had my z at the track, so in the end, it won't be a fair comparison anyway.


Since starting this project I have learned to appreciate the value of driving skill over equipment, so in the end, I might actually miss the old suspension. But really, this project is more for the fun of working on cars than anything.  

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