Let's start with stock D1 spring specs (driver side):
Front: 133lb/in rate at 420mm length
Rear: 208lb/in rate at 390mm length
Now let's look at TF Light/OME Med:
Front: 200lb/in at 400mm
Rear: 220lb/in at 425mm
That's a 50% stiffness increase in the front and 5.7% in the rear. What??? These are specified for up to 44lb additional weight with no mention of ride stiffness changes. Even if all that weight went in the front that's only a 2.5% increase in front axle weight, not 50%! Now I understand the rate is also responsible for the 40mm lift these springs are supposed to provide, but a 50% rate increase seems like the wrong tool for the job. It greatly increases the stiffness and harshness of the ride to get there.
Lets say you wanted the same 40mm lift with 44lb extra weight on the front axle with the same ride quality as stock. You'd be looking at a 138lb/in at 445mm front spring.
Now let's say you wanted an extra 5% stiffness to counteract body roll from the 40mm lift.
You'd be looking at a 143lb/in at 440mm front spring.
Now let's say you wanted another 5% extra stiffness to counteract body roll from sway removal.
You'd be looking at a 152lb/in at 430mm front spring.
We're still nowhere near a 200lb/in spring. You'd have to add nearly 500lbs to the front axle to get stock ride quality, but then of course you'd have zero lift.
Let's say I'm way off on the 5% rate increases for body roll from lift and sway removal and a 200lb/in spring really is required, why only counteract body roll in the front and not the rear (only 5.7% rate increase)?
Maybe someone else understands their logic, but I'm not surprised people complain about harsh ride of aftermarket springs, and we're only talking TF Light/OME Med so far. Next episode: The horrors of TF HD.
Front: 133lb/in rate at 420mm length
Rear: 208lb/in rate at 390mm length
Now let's look at TF Light/OME Med:
Front: 200lb/in at 400mm
Rear: 220lb/in at 425mm
That's a 50% stiffness increase in the front and 5.7% in the rear. What??? These are specified for up to 44lb additional weight with no mention of ride stiffness changes. Even if all that weight went in the front that's only a 2.5% increase in front axle weight, not 50%! Now I understand the rate is also responsible for the 40mm lift these springs are supposed to provide, but a 50% rate increase seems like the wrong tool for the job. It greatly increases the stiffness and harshness of the ride to get there.
Lets say you wanted the same 40mm lift with 44lb extra weight on the front axle with the same ride quality as stock. You'd be looking at a 138lb/in at 445mm front spring.
Now let's say you wanted an extra 5% stiffness to counteract body roll from the 40mm lift.
You'd be looking at a 143lb/in at 440mm front spring.
Now let's say you wanted another 5% extra stiffness to counteract body roll from sway removal.
You'd be looking at a 152lb/in at 430mm front spring.
We're still nowhere near a 200lb/in spring. You'd have to add nearly 500lbs to the front axle to get stock ride quality, but then of course you'd have zero lift.
Let's say I'm way off on the 5% rate increases for body roll from lift and sway removal and a 200lb/in spring really is required, why only counteract body roll in the front and not the rear (only 5.7% rate increase)?
Maybe someone else understands their logic, but I'm not surprised people complain about harsh ride of aftermarket springs, and we're only talking TF Light/OME Med so far. Next episode: The horrors of TF HD.
