GoFastBroncos.com

I am building up a '93 bronco I recently purchased and I ordered Threat's 4.5" over c&t beams and am planning on running 14" Kings. I just dont know what spring rates I should use so I figured I'd ask on here. What are you guys are running, how do you like the ride, and what do you recommend? Thank you.

On my stock width I ran 16" 500 lb lowers and 10" 400 lb uppers on 14" swayaways. Ran bitchen on street n dirt.

I run 350/450 both 14" works great!

Thanks for the responses. Dave at threat suggested I run 400 over 450. Seeing if anyone has run that and how they like it.

So I went to King yesterday and was talking to Bret, he told me i should do 350 over 500. So thats what I'm going with. I'll let you guys know how I like it.

Running 500 over 500 on race bronco, coilover on front of radius arm, bypass in front of beam.
Have spring lengths and divider set so it sits on the soft (250) rate and for a couple inches of uptravel before it transitions to the single (500) rate.
I might try a 700 under the 500 so soft rate is 292 then transitioning to 500 but would have to special order the coil.
I know most think that is stupid but until they show me a bronco that works better than ours I'll keep doing it my way.

keenanduran1 wrote:So I went to King yesterday and was talking to Bret, he told me i should do 350 over 500. So thats what I'm going with. I'll let you guys know how I like it.

What lengths did he suggest. I just bought a pair of Kings for the front of my bronco and was told they were 450/500 and when they arrived, they were 250/300. I was going to do a 16" 500 and a 14" 400. Maybe 350 now that I am seeing this and two of my friends here in MI are running the 350/500 on F150's.

Cool thing is I spoke to King about the C/O mess up and they told me as long as the springs were new and I would pay shipping, they were happy to swap out with whatever rate I wanted free of charge. Thats some pretty awesome customer service considering I am the second owner, granted; the C/O's are still in the bag and the reservoirs still have the sticky packing foam on them.

I've heard that 16" is "overkill" I went with the 14" 2.5 once they are in I'll let you know how it rides

Really depends on where the shock is mounted. I'm happy with 400/450 with my shock on top of the beam at right about where the radius arm ties in (Threat Beams/radius arms)

I have a couple set's for mine when I get them on. I have 16"×2.5 and have 16" springs. I have a set of 400lbs springs and like Chris, I have two sets of 500 lbs springs. I have rode in a Bronco with 500 over 500 and liked the ride.

The 14" fit better if you still are running the heater core and vacuum assist Brakes but I am running a hydro boost brakes and a Vintage Air , AC/heater in cab so my Firewall area is open for the 16" shocks to kick back. I am running a coilover and a bypass at each corner.

My reason for the 16's is 2 new fox 2.5 shocks where won at a BITD raffle years ago and the other two were hand me downs that a friend is adding bypass tubes for me. I have been blessed with some great friends.

I've been told by a shock guy never to have more than 100lbs spread between primary and secondary spring because valving becomes a pain. The summary is if the stiffness jump is too large your using the springs to provide dampening rates instead of valving choices. From what the shock guy was telling me the compression for instance would be full open then half closed upon secondary spring engagement and vise versa on rebound fast then slow so tuning becomes difficult. Just passing it along if it helps .

I'm not a shock guy but figured the info should be at least asked about before you decide to return whatever you currently have .

I've got a 450 over 500. Not sure how she rides yet. But my friends f150 with almost the same set up rides pretty nice.

Rmc wrote:I've been told by a shock guy never to have more than 100lbs spread between primary and secondary spring because valving becomes a pain. The summary is if the stiffness jump is too large your using the springs to provide dampening rates instead of valving choices. From what the shock guy was telling me the compression for instance would be full open then half closed upon secondary spring engagement and vise versa on rebound fast then slow so tuning becomes difficult. Just passing it along if it helps .

If you put a 400 under a 400 then what you get is a 200 rate transitioning to a 400 rate.

If you put a 1000 under a 400 then what you get is a 285 rate transitioning to a 400 rate.

So which is the bigger stiffness jump and therefore harder to tune? Answer is the one King and everyone else suggests.
Reason? They don't stock the springs needed to do the 1000 under the 400.

baja-chris wrote:

Rmc wrote:I've been told by a shock guy never to have more than 100lbs spread between primary and secondary spring because valving becomes a pain. The summary is if the stiffness jump is too large your using the springs to provide dampening rates instead of valving choices. From what the shock guy was telling me the compression for instance would be full open then half closed upon secondary spring engagement and vise versa on rebound fast then slow so tuning becomes difficult. Just passing it along if it helps .

If you put a 400 under a 400 then what you get is a 200 rate transitioning to a 400 rate.

If you put a 1000 under a 400 then what you get is a 285 rate transitioning to a 400 rate.

So which is the bigger stiffness jump and therefore harder to tune? Answer is the one King and everyone else suggests.
Reason? They don't stock the springs needed to do the 1000 under the 400.

Wouldn't the 1000 under a 400 be a transition from 285 to 1000? When the spring divider hits the stop, it stops the travel of the top spring and only relies on the lower, I think.

baja-chris wrote:

Rmc wrote:I've been told by a shock guy never to have more than 100lbs spread between primary and secondary spring because valving becomes a pain. The summary is if the stiffness jump is too large your using the springs to provide dampening rates instead of valving choices. From what the shock guy was telling me the compression for instance would be full open then half closed upon secondary spring engagement and vise versa on rebound fast then slow so tuning becomes difficult. Just passing it along if it helps .

If you put a 400 under a 400 then what you get is a 200 rate transitioning to a 400 rate.

If you put a 1000 under a 400 then what you get is a 285 rate transitioning to a 400 rate.

So which is the bigger stiffness jump and therefore harder to tune? Answer is the one King and everyone else suggests.
Reason? They don't stock the springs needed to do the 1000 under the 400.

Not sure if your reply was intended to confuse but right on man! You've proven the point of asking the experts to figure out what you need vs what your friends are running. That was my point.

Yes I said it backwards. Clear as mud, eh? The top spring is the one that "disappears" once you hit the stop collar. So a 1000 over a 400 results in 285 to 400 which is a smoother, easier to valve for transition than a 400 over a 400 which results in a 200 to 400 transition. Problem is, it's a special order coil.

Ah gotcha. I follow now. Like I said I'm no shock expert by any means .