So I dont know how popular these springs are for the Z but I have always loved the technology in their spring so I purchased a set of Swift Spec R springs for my car.

The Spec R springs are made by swift to be as performance oriented as possible. This means that they are very careful about their drop rates and generally do a lot of research and development before they actually release their product.

I spoke to Leonard at Swift a few times and he told me that if Im looking to slam the car then don't bother going with the Swifts. These springs are the cheaper alternatives to coilovers and are tested on circuits in japan as well as over here before they are even released so they are already a track ready setup.

In my opinion the drop is perfect for me. I wouldnt even say its a mild drop, it's much more aggressive than what I was expecting.

When I first took this car out on the street with these springs, the first thing I noticed was it's silky smooth. It is more comfortable than stock even with the increased rates. Just like all the other reviews for every vehicle out there All I can say is that these springs really live up to there name.
When I corner there is really almost no roll. I am a track fiend so it is only a matter of time before I take this out onto my local track and see how it handles there.

So in my opinion there isnt a flaw in the spring
drop- 8/10 Its a good drop but Im sure people on here want it even more slammed
comfort- 10/10 seeing as though in my opinion they are more comfortable than stock, this was an easy one. Also hasn't bottomed out once yet.
performance- so far 10/10 Absolutely no body roll so far from the small corners I take around my neighborhood. We will see how it does at much higher speeds when I get out there.

My next track event should be this weekend. I will update as I go.

Here are the pictures. Forgot to take befores, I only have after the install. Sorry guys for the major failure on this part of the review.

 

+1, Awesome spring. I had a set and they had a great ride until the stock shocks began to degrade (note my shocks are +100,000 miles). The drop is not really all that conservative but is very effective in relocating the car's CG and keeping roll to nearly non-existant (with stock roll bars). That ride height is actually very well matched to the car. I found that out this weekend when I took a new set of coil-overs out to California Speedway, set about .375-.500 inch higher with springs rates that are substansially higher. To my suprise the roll was noticably greater... but wait that shouldn't be the case. The only answer I have is the Z is really height sensetive (Note: also had a little stickier rubber on the car which would cause that as well). I more than likely will be mimic'ing the ride heights from this setup and fine tuning from there. These springs don't have a pronoucned progressive spring feel but they in fact are. I attribute that to the R&D Swift put into this setup. In short... great set of springs.

 

Thanks for the review! These are the springs I am going to get, eventually, lol. Thanks for the pictures!

 

How much drop and spring rates do they actually advertise?. Quoting them here would be helpful for anyone considering buying based on your review. I know GSedan35 has them posted somewhere

 

So when swift designed these springs they pretty maxed out the stock valving of the shocks. And then figured out the optimum front to rear spring rate bias for the circuit. So they are designed for the Stock shocks, obviously upgraded shocks would be better but these are true performance springs, with probably the stiffest rates on the market.

You would be surprised how comfortable it is though.

 

7.5kg in the front
8.2kg in the rear

1.2inch drop on the front and 1inch drop on the rear.

 

Hey,

those are in stock and we have them on sale if anyone is interested

http://www.kamispeed.com/Swift-Spec-...swf.4n014r.htm

 

Can you compare ther spring rates with stock in terms of percentages to make it easier for those not used to the Kg units?.
1.2 front and 1.0 rear is not bad of a drop. I know most people desire the rear to be lower or same amount for front and rear

 

OK stock Z
F-314lb/in
R-417lbs/in

Swift Spec R
F-420lb/in
R-460lb/in

Kind of shows you the huge increase in rate.

 

haha thanks

 

I like it. It looks good. I've been considering these for a while, thinking the drop might be a bit too much. However, I think you're right; a bit more aggressive than I expected but overall not too bad.

 

Prior to '05 the rear OEM rates were a little closer to 340'ish. Also being the Spec R's are progressive (having more than one rate, to help blend performance with comfort) I believe they start out in the following ranges.

Front
291-420
Rear
280-460

 

they are step linear springs. At static ride height they are 420 and 460.

Those 2 other rates act as a helper spring in the vehicle. So at static height they are fully compressed.

 

I didn't think mine looked quite as aggressive as the OP's... but the drop is (in my mind) as low as most will want to go.

 

Well I believe people are always looking to slam the car. At this height its not bad at all. I do have a habit of going over driveways sideways but when I drive I've hit speed bumps at not so safe speeds (I didnt see the bump) and also drive fairly carelessly at times through railroad tracks and I havent bottomed out at all. BTW I live in LA. so the roads here are pretty tough to deal with at times.

 

From experience I can appreciate what you say (they do not feel progressive when driven hard), but I'm not convinced the static ride height would use up the softer rates to that extent. Who or where did you get the info from? Not to say you are wrong, because I argee the progressive coils have to "get out of the way" pretty quick to give the level of performance they give but I wouldn't think they are fully compressed at static ride height.

 

I contacted Swift and talked to them about it.
They told me that if they were to make a true linear spring then the spring would have to be shorter especially with the increased rate so it does not droop as much as the stock springs. When this happens if you were to pull up onto a sudden incline the spring would fall out of the shock itself. This is why they have to put in dead coils to take up the slack of the shock. This also has to be done with the same gauge of wire being used to make the spring this is why there is a spring rate to them. But they have calculated it out so that at static ride height the springs are linear.

Apparently I asked all the right questions I am spring pro now. LOL.

 

Interesting, I'll take a look at mine later for the length of the progressive coils. It's possible. But for now, enjoy them. They are really well made and perform well on and off the track, at least until the shocks say "no more". Aside from having a lip or a lower front bumper they are pretty streetable. For me with a V2 type bumper, its really tough going anywhere but still with-in the streetable limits. The ride height is just tall enough to fit on most lowered car friendly service racks but not all. Also mine didn't require the toe bolts and the grinding mods to the frame to get back to stock alignment, however I did get the camber arms to be sure the range of adjustment was there (more insurance than need). Note, the front alignment should net around 2 degrees of camber but the tires can take that pretty well. I average about 20,000 on a 300 treadwear tire with a few track days sprinkled in.

 

I totally forgot to say your ride looks insanely clean.
Thanks for stealing the light on the thread where I'm trying to show off MY car.
Anyways NICE CAR!

 

Thanks bro, sorry for the thread jack.