Swift PERFORMANCE Springs....for NC!

[Brian]

Okay, latest project! We are working with Swift Springs on some serious performance springs for the NC. If you don't know Swift Springs, read around a bit, they are TOP quality ultra high performance springs, lighter yet more consistent in rate than competitors. We typically use their metric coilover springs in our race cars as upgraded springs in our Ohlins Racing coilovers....but they also can make standard lowering springs and we are working with them on an NC set of springs that will be quite a bit higher rate than our Progress/Eibach/Racing Beat springs yet less than what we typically use in coilovers.

I currently need a set of PRHT NC1 springs (2006-2008). Does anybody have some they can donate to the cause? I already have our stock NC1 softtop springs and our stock 2012 PRHT springs in the project. Thanks in advance.

[JamesK383]

Maybe we could negotiate a swap?

Unfortunately, I am kinda attached to mine at the moment.

[matthew-m]

I have an un-used set from my 2007 PRHT. I will get them back eventually, correct? Send me an email at mmetoyer at gmail.com with your UPS shipping account and I can box them up and ship them from central California.

[Chuck H]

Not sure if you also need NC2 soft top springs to compare all the variations, but I have a set from my 2012 Touring soft top (with suspension package, if that matters) if you want to compare those as well. They're all-but-new with about 6 months and 4000 miles on them.

Good to hear that there will be another fairly high rate option other than the FM springs.

If you haven't already decided on spring rates, 300F/250R might be a reasonable starting point. It's in the same ballpark as FM springs, but has a better F/R bounce frequency ratio, according to FCM's on-line suspension calculator. And it works well with your popular swaybar options. It would be too stiff for OEM shocks, but Konis should be able to handle those rates with no problems.

[njaremka]

looking forward to seeing the outcome with these

[Brian]

The Spring rates question is a great question. I have been thinking everything from about 200 front for more mass appeal to something like that 300/250 you mention above. Any other thoughts on the rates?

[Chuck H]

I posted over on miata.net and it seems to be generating a bit of buzz.

http://forum.miata.net/vb/showthread.php?t=492353

I thought this was some good input:

This is really good news for those who don't want to fit coilovers due to cost. Swift springs are definitely well regarded.

IMO, rates should target FM rates (my preferred non-coilover spring rate) but go one better by designing for a drop to 13", which is a ride height that works well real world (sufficient ground clearance for most any paved situation) and actually gives nice even wheel well gap around the tire as well.

The only tricky part about the ride height is whether you're targeting 13" on Konis or on Tokico HTS or Bilstein Sport.

I don't think 300/250 is too much spring, assuming that you've got the right shocks. It's softer than the 390/280 Ohlins setup that's always praised as riding better than stock. And it's about on par with the FM springs, which I've never seen a review that said that the springs were too stiff.

Not sure that something like 200/170 is stiff enough. I suspect that the OEM and Mazdaspeed/Eibach springs end up getting almost that stiff by the time you compress them down to normal ride height. It would give people a nice range of options if these Swift springs with Konis end up being about halfway between a Progress/Koni setup and a Tein Flex setup.

[Brian]

I have an un-used set from my 2007 PRHT. I will get them back eventually, correct? Send me an email at mmetoyer at gmail.com with your UPS shipping account and I can box them up and ship them from central California.

Hi Matt

Yes, we will get them back to you. Only need one front and one rear to measure them up. Will send you an email and thanks for your help!

[matthew-m]

I posted over on miata.net and it seems to be generating a bit of buzz.

http://forum.miata.net/vb/showthread.php?t=492353

I thought this was some good input:

This is really good news for those who don't want to fit coilovers due to cost. Swift springs are definitely well regarded.

IMO, rates should target FM rates (my preferred non-coilover spring rate) but go one better by designing for a drop to 13", which is a ride height that works well real world (sufficient ground clearance for most any paved situation) and actually gives nice even wheel well gap around the tire as well.

The only tricky part about the ride height is whether you're targeting 13" on Konis or on Tokico HTS or Bilstein Sport.

I don't think 300/250 is too much spring, assuming that you've got the right shocks. It's softer than the 390/280 Ohlins setup that's always praised as riding better than stock. And it's about on par with the FM springs, which I've never seen a review that said that the springs were too stiff.

Not sure that something like 200/170 is stiff enough. I suspect that the OEM and Mazdaspeed/Eibach springs end up getting almost that stiff by the time you compress them down to normal ride height. It would give people a nice range of options if these Swift springs with Konis end up being about halfway between a Progress/Koni setup and a Tein Flex setup.

For comparison, my FCM coil-overs are currently at 300/224, and I have the car height at roughly 13.5" after corner balancing. The car is my daily driver, so I wasn't willing to go with higher spring rates. I love the way it corners - much easier to rotate with the throttle, and very neutral front to rear. I do have issues with over steer on slick pavement, and there is a tendency to oscillate front to rear on the freeway over the expansion joints. One of these days I will get around to trying 250 or 280 pound rear springs to adjust the oscillation, as discussed with FCM.

[fprintf]

And this is why I haven't pulled the trigger on Progress springs just yet! I really like the idea of PRHT springs with a stiffer rate matched with Koni shocks, standing about 13" ride height for a combined price under $1,000. The next best thing are some of the bargain coilovers @ $1,400, which really only offer height adjustability for corner weighting (mostly unnecessary in a street car).

[Cookie Monster]

I would be very interested in these springs if they are as stiff or stiffer than the FM springs while providing a 13" ride height. I like the stiffness of the springs I have but I would like the ride height to go down by an inch or so.

[Chuck H]

For comparison, my FCM coil-overs are currently at 300/224, and I have the car height at roughly 13.5" after corner balancing. The car is my daily driver, so I wasn't willing to go with higher spring rates. I love the way it corners - much easier to rotate with the throttle, and very neutral front to rear. I do have issues with over steer on slick pavement, and there is a tendency to oscillate front to rear on the freeway over the expansion joints. One of these days I will get around to trying 250 or 280 pound rear springs to adjust the oscillation, as discussed with FCM.

I've spent hours throwing different spring rate combos at FCM's suspension setup spreadsheet, and that's where I came up with the 300/250 numbers. It balances the natural frequency almost perfectly front to rear, and the front roll couple works out well with most of the popular front sway bar options paired with the factory rear bar.

If Swift only does metric spring rates, then the next best option that I came up with was 6k/5k, or 336/280. That's starting to get pretty stiff, though, and starting to compete with coilovers. The only thing you wouldn't have with those springs and Konis would be height adjustment. But if they gave you a nice even 13" all around, who needs it?

[Spungus X]

I would like to see a spring rate matched to the Bilstein HD/SP shocks. I'm guessing 250 / 170 - front / rear should work. This would make an awesome low cost suspension option.

[Spungus X]

I would like the height to be approx. 13.5".

Red color would also be nice.

[Spungus X]

I'm itching for a Bilstein shock friendly spring rate for a number of reasons.

1- I think, when not overworked, it is the best mass market shock available.
2- It would be nice to have a third proven spring / shock combo for those of us who cannot afford coilovers. "MSR" - Koni / Progress, FM stage 1 - Tokico HTS / FM springs, and Bilstein / Swift.
3- It would be the cheapest entry to a matched spring / shock combo.

I'm keeping my fingers crossed....