To Spinalguy.
They have 3" and 4.5" lift coils.
Same $ for either set.
$478.50 for the front and rear,You can also buy them seperately,fronts or rear only.
They recently designed the 4.5" lift.
Here's an old copy&paste from the head chief on one of the Jeep forums.
Here is a post that Jim Frens (owner of Nth) posted on 1 of the forums.Just so you know,before Jim started Nth he was a Chrysler tech and actually worked on the development and design of the TJ.
To anyone interested in this topic. These are direct quotes
"Several Posters – regarding spring spacers vs. tall springs. If you consult SAE (that’s Society of Automotive Engineers in case some don’t know), there are many design standards published as technical papers that essentially are the ‘gospel’ of spring design used at the OEM’s (as we of course did at Jeep). One of the most important relevant issues here is what’s called the ‘slenderness ratio’ – that is the practical limit of how tall a loaded spring can be relative to it’s functional diameter (taken at center of the wire’s thickness)…any TJ front ‘lift spring’ that is over about +4” or so violates this ratio. What does it matter? It matters because it means that you encounter a limit on how soft you can make the spring before all it will want to do is buckle out to the side. Consequently, when we tested a bunch of competitor’s springs, we found that every front spring was too stiff for proper frequency tuning – all presumably because of this issue. Nth springs are designed based on frequency for best combination of ride and handling, and so we couldn’t accept this limitation…we get around it by using a shorter spring plus a spacer up front, but there’s much more to it than this…a shorter front spring is also part of the way to avoid any annoying ‘twangs’ from the front springs contacting the stock front bumpstop cups – the springs not only don’t want to buckle, they also don’t have 5 or six coil winds above the cup lip that have to pass it during droop travel. On our SA kits with the GyroJoints and the subframes they mount into, the rest of that solution comes from the flatter arm geometry that happens since the GJ is lower than the stock LCA bolt by 1.75” (but the bracket is only 1.0” lower than the stock bracket) – and this flatter front SLCA geometry along with the GJ is why our SA kits ride better than even a typical LA kit.
For those still reading at this point: We also use a shorter rear spring for coincidental reasons because it allowed us to design the rear spring relocation bracket (which is not an angle-cut spacer as someone speculated!). Here too, but opposite the front issues, all existing rear lift springs we tested were way way too soft versus what’s needed for proper ride and handling…the resulting frequency split between front and rear on several lift kits were absolutely comical…some where even NEGATIVE (rear frequency lower than front)…which explained why they floundered so badly in fast whoop-de-doos (frame-bending out-of-sync slams after only two or so whoops). The frequency split on our springs is actually nearly what Chrysler/Jeep wanted to get the stock vehicle to when doing the original TJ (I didn’t do the base TJ, but years later I did a 1-ton TJ for the Egyptian military and learned all about TJ springs and tuning them…see Nov ’02 Off-Road about page 4 if I remember right…there’s a picture of me driving TJL prototype #2 here in Nevada). The production TJs’ springs were changed to increase the frequency split for ’98, but have never reached the ideal target…but we’ve come as close as I felt I dared without making a ‘slot car’ out of a +6” lifted TJ (which just invites people to drive too fast and crash them!)….driving our springs both on-road and off will reveal a drastic difference from what everyone’s been used to
Topic: Nth Degree Mobility TJ Susp. and specialty parts. (Read 5031 times)