More 280ZX strut swap questions

[dozenhundred]

I have been collecting parts for a while for a strut swap. I bought struts off a 280ZX a year and half ago in Phoenix before moving to Utah. I bought a coilover kit from ebay. I was going to do ground control since the kits I had seen on ebay would need different springs, making the cost too high. I wound up winning the sleeves and springs for $5.00, but as anyone who has seen these on ebay the springs are WAY stiff. 8" springs with a 450 pound rating. The stock front rate is like 90-110 pounds from what I have seen. I do want stiffer than stock but not much. I'm thinking 125-150 pounds. I can't seem to find any 8" springs with that rate but I have in 10" lentgh. I'm wondering what others have done for spring rate and length. I have the collars ready to fit, I will weld some 2" pipe on the strut tube for the sleeves to sit on. I figure the sleeves would line up with the top of the strut but wonder if the 2" increase in spring length means I need to lower the sleeve that 2" also. I do not plan on dropping the front much if at all.

 

I plan on the MR2 strut inserts in some sort of adjustable variety.

 

I'm also thinking of some wilwood four piston calipers, but don't see much out there on conversions that isn't too expensive. Anyone done something like this. I do have the stock calipers/rotors but figured lighter is better right?

 

I'd love to hear opinions/advice.

 

These will go on my 73 coupe, sorry I don't have pics of the parts right now but could post them if needed.

[VintageRice]

I believe the Mr2 inserts are shorter than stock 280zx are are used if you plan on shortening the strut tubes.

 

If not get the stock 280zx inserts.

[datsunfreak]

I'm also thinking of some wilwood four piston calipers, but don't see much out there on conversions that isn't too expensive. Anyone done something like this.

 

I bought brackets from EDP for $65, new Wilwood Dynalite calipers for $150 each, used stock 11" 300ZX rotors. So if $350+ is not out of your budget, you could do it that way? Going to lightweight Wilwood rotors makes it a lot more expensive. And will probably require at least 15" wheels. The set-up I used allowed some 14" wheel choices. ;)

 

I do have the stock calipers/rotors but figured lighter is better right?

 

It is always better, but not crucial. Is this a street car or race car? Street car, I'd stick with the 280ZX stuff. It's fairly bulletproof, and you won't notice much gain until you get it on a race track anyway. Even then, the 280ZX stuff with quality pads is almost impossible to fade even on a fast track.

 

FYI, most Wilwoods aren't terribly weather resistant either as they are intended for track use, not street use. In a place like Oregon, you might be cleaning and replacing seals on those calipers at least once a year.

[dozenhundred]

Hadn't heard those concerns about the wilwoods. I was only thinking of them since I have two sets of pad for them. I will likely stick with with stock ones. This is a street car, with the intent of converting to electric later (ala white zombie) but I have also thought of adding efi and a 5 speed cause they get such great mileage.

 

Thanks for the comments guys.

 

Still wonder about the springs though. Anyone with some experience with this?

[datzenmike]

Don't weld them get these: Split collars. The 2" ID will support 6,600 lbs.

 

[Skib]

Don't weld them get these: Split collars. The 2" ID will support 6,600 lbs.

 

 

 

thats what I had on my 510

 

i hit some super gnarly pot holes and stuff at speed too and they never once slipped

[datsunfreak]

Still wonder about the springs though. Anyone with some experience with this?

 

From what you describe, I'd bet money that 175 is just about perfect. 1200s that see a lot of track time (and very little street time) run anywhere from 225 to 300, and 150~ is likely gonna be the closest to the stock comfort levels.

[dozenhundred]

Here is what I have: (sorry the pic isn't that good)

 

 

The sleeves, adjusters, top cap and springs I won for $5.00 on fleabay.

 

The little ring is a hunk of 2" pipe.

 

The one kinda assembled is with the sleeves even with the top of the strut tube.

 

I will weld the pipe ring on then the sleeve bears on it. The springs I will buy are 2" taller without the weight of the car on them. So I don't know if I need the pipe ring lower on the housing to deal with the added spring height.

 

I will need to machine something up for the top so it clears the strut isolater at the top.

 

As it sits now I plan on weighing the car at each corner and calculating how far the spring will compress with that weight on the corner. Measure the stock strut length as it sits now and put the sleeve at a level to have the current ride height about mid height on the sleeves so I still can adjust up or down.

 

Hope that is pretty clear. Any comments?

[littlejason]

I figured you'd get this done before me! Whatever... I went with 250# springs. When I tried to bounce the car by hand, I thought "what have I done?" but I love the way it drives! The car doesn't get tossed around by stuff in the road, it feels more in control. It's hard to explain... I don't feel like I need to keep both hands on the steering wheel anymore. And I'll never worry about bottoming out the suspension again. To me, it's not any less comfortable. I thought I'd hold off saying anything until I did an autocross, which I did last Sunday. The pavement was not great, but I have no complaints about the car. I can still control the rear with the gas pedal. I should have done this a long time ago.

[datsunfreak]

I figured you'd get this done before me! Whatever... I went with 250# springs. I'll never worry about bottoming out the suspension again. To me, it's not any less comfortable. I should have done this a long time ago.

 

That's good to hear. I wanted to go 250-275 but was scared. :P

[ggzilla]

Yes, you guys are right on the spring rates.

 

* The dedicated road racers often use 275 pound front springs as they don't go over many potholes or large bumps on the track.

 

* stock front springs are 90 pounds, which is good for handling bumpy roads and is fairly smooth with a good set of struts

 

* if you have the 1200 lowered at all, then 150 pounds will help a bit with preventing bottoming but still feel close to the stock springs