I got my new Poly Performance
springs the other day and have been itching to try them out but work just kept getting in the way. So today about 5pm I finally made some time. So I opened up my boxes from Poly Performance
and dug out a few tools and my 48" hi lift jack and proceeded to swap out my springs. I'm still waiting on my shocks from Poly Performance
but I had to confirm a suspicion I had about the springs that came with my Nth prototype lift and how Jim had underestimated the weight of my reinforced JK.
First some notable difference in the springs. Poly Performance
assured me that they made the calculations in their spring designs to accommodate all the extra steel I have on my JK. It will handle my monster winch all without making the ride like that of a really poor buck board going down the road. The way they accomplished this is by first correct load calculation plus by having progressive rate springs over linear rate springs. Now progressive rate springs are more expensive the design and fabricate so they cost more than the alternative. The benefit of course is you get a nice ride at all your work loads plus as you compress your springs they "stiffen" to reduce the compression. This gives you a good ride throughout your travel.
I was really looking forward to these springs as my Nth springs were linear rate and designed for a load about 1000 pounds less than my JK weighs in at.
So here is some driveway shots of the springs side by side for a comparison.
The springs arrived in excellent condition due to a nice packing job. Made me not wanting to get them dirty by putting them on my JK.
Here you can see the unloaded length differences. Despite the Poly Performance
springs being longer than those I originally had from Nth, this only raised my back end up about an inch to make it a true 4.5" lift over stock.
Here you can see the extent of my tools I used to install the new springs. Well that and the wheel chocks, my 48" Hi-Lift and a little bottle jack.
The front springs.
The front Poly Performance
springs were not a lot longer in comparison to the the Nth springs I had but I gained almost 2" of lift up front as the Nth springs really compressed under the load of the winch and winch bumper.