Some stock suspension calculations and measurements

[Snacktime]

I want air ride, truly progressive when you use air bags.

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[Muffin Top]

What’s funny is we’re ditching the dual rate springs to experiment with linear.

The progressive springs I picked out for my jeep TJ deliver massive performance advantages in terms on on-road traction, yet being able to firm up quite a bit, but gently, off the road.


Another advantage of progressive is being able to have more uptravel than downtravel without topping out the shocks.


Having lived with these performance advantages for more than 10 years, I'll favor progressive whenever available, if I don't have to buy a highly priced package including pre-runner shocks I don't need (and don't even have the travel of economical Bilsteins).


Maybe the concept of a package deal with over-priced shocks reflects the lack of aftermarket product offerings? We'll pay $2,000 for hyped shocks because there's not enough competition?

 

[SierraBronco]

The progressive springs I picked out for my jeep TJ deliver massive performance advantages in terms on on-road traction, yet being able to firm up quite a bit, but gently, off the road.


Another advantage of progressive is being able to have more uptravel than downtravel without topping out the shocks.


Having lived with these performance advantages for more than 10 years, I'll favor progressive whenever available, if I don't have to buy a highly priced package including pre-runner shocks I don't need (and don't even have the travel of economical Bilsteins).


Maybe the concept of a package deal with over-priced shocks reflects the lack of aftermarket product offerings? We'll pay $2,000 for hyped shocks because there's not enough competition?

In our case we have a heavy rig. Bigger axles, UHMW armor, winches, tools, etcetera-it starts adding up. 5800 something before portals and fordies. For a rough idea of how our weight affects the dual rate-Our bronco coil (the spring itself) is at 9.5” long while sitting at 1.5” preload. RK bronco is 10.75” with 1.8” preload. With the dual rate starting on the light side, it’s like we blow through all the available 8” of 525 rate so quickly that the 6” of heavy 625 doesn’t help at moderate speeds and we bottom out. Could bump up the preload but don’t want to sit higher, and that will put us into the 625 rate sooner. It will be interesting to see if we can notice the change from 625 to 600 while rock crawling. It’s not a huge rate change but maybe it adds up and we can tuck the wheels more easily than the heavier rate.

And, of course, we don’t actually know how dramatic the change from 525 to 625 is. So it’s all just a big experiment.

 

[RobBob22]

Okay, I have some additional shock length data, and I’m curious if any of you have thoughts could be of help in my decision paralysis here.

I’m eyeballing the Teraflex falcons for the bronco, they come in 2 versions. 1 for broncos with 35s and 1 for broncos with 37s. It’s hard to find people actually running these, everyone’s seems to be getting the 37s version.

I reached out teraflex they gave me dimensions for compressed and extended length for both. The suspension for 35s have some impressive numbers of course I don’t want to compromise. I’d love to get all the travel I can, run the 35” suspension and run a 37” tire.

I’m willing to mod crash bars and trade out flairs, and run a “small” 37 if I can do it, but keep my stock fenders.

Comparing to the icons it seems like I should be fine, I know several people running icons with 37s and no contact. I’m also not desert racing.

The trick is it seems, the teraflex design extends the mount point above the shock towers both front and rear, by my estimate ~0.75in. There is about 0.46in less compression front then the icons, 0.58 more in the rear. I’m not really sure this matters, in my head, if the compression between the maxed out lower and tower is = or less than any of the existing options I’m not sure I’ll see any issues.

So, what are my odds of making fender contact if I ran the max travel setup with 37s, and if I do what can a do about it. Will take any thoughts.

 

[87-Z28]

Okay, I have some additional shock length data, and I’m curious if any of you have thoughts could be of help in my decision paralysis here.

I’m eyeballing the Teraflex falcons for the bronco, they come in 2 versions. 1 for broncos with 35s and 1 for broncos with 37s. It’s hard to find people actually running these, everyone’s seems to be getting the 37s version.

I reached out teraflex they gave me dimensions for compressed and extended length for both. The suspension for 35s have some impressive numbers of course I don’t want to compromise. I’d love to get all the travel I can, run the 35” suspension and run a 37” tire.

I’m willing to mod crash bars and trade out flairs, and run a “small” 37 if I can do it, but keep my stock fenders.

Comparing to the icons it seems like I should be fine, I know several people running icons with 37s and no contact. I’m also not desert racing.

The trick is it seems, the teraflex design extends the mount point above the shock towers both front and rear, by my estimate ~0.75in. There is about 0.46in less compression front then the icons, 0.58 more in the rear. I’m not really sure this matters, in my head, if the compression between the maxed out lower and tower is = or less than any of the existing options I’m not sure I’ll see any issues.

So, what are my odds of making fender contact if I ran the max travel setup with 37s, and if I do what can a do about it. Will take any thoughts.

I think most of the coilovers available are designed with some jounce left on the table, ie, they don’t max out compression. Thus travel is not maximized so that 37s can fit without smashing fenders when getting after it. I would imagine the treaflex are similar.

I would not worry about any analysis numbers under an inch. I doubt any any analysis has that much resolution.

a small body lift (<1”) is always in the arsenal. Helps keep cg down. And allows for less suspensions lift via spring compression. Helps ride height be closer to center of shock travel.

 

[SierraBronco]

I think most of the coilovers available are designed with some jounce left on the table, ie, they don’t max out compression. Thus travel is not maximized so that 37s can fit without smashing fenders when getting after it. I would imagine the treaflex are similar.

I would not worry about any analysis numbers under an inch. I doubt any any analysis has that much resolution.

a small body lift (<1”) is always in the arsenal. Helps keep cg down. And allows for less suspensions lift via spring compression. Helps ride height be closer to center of shock travel.

I think body lifts got a bad rap from people overdoing it and putting their body on stilts. They can be pretty useful.

 

[87-Z28]

@SierraBronco

Yeah I wouldn’t go more than 1 inch. But that can be a big help. A series of compromises if you are truly trying to max out travel and articulation while keeping cg down with bigger tires.

edit. Or just remove the fenders.

 

[SierraBronco]

@SierraBronco

Yeah I wouldn’t go more than 1 inch. But that can be a big help. A series of compromises if you are truly trying to max out travel and articulation while keeping cg down with bigger tires.

edit. Or just remove the fenders.

They are modular for a reason!

 

[mpeugeot]

@SierraBronco

Yeah I wouldn’t go more than 1 inch. But that can be a big help. A series of compromises if you are truly trying to max out travel and articulation while keeping cg down with bigger tires.

edit. Or just remove the fenders.

Maybe I should hold off on the 2" body lift.

I don't want to look like I am on stilts, I just want to make it more of a challenge for my 4'10" girlfriend. LOL

 

[SierraBronco]

Maybe I should hold off on the 2" body lift.

I don't want to look like I am on stilts, I just want to make it more of a challenge for my 4'10" girlfriend. LOL

I did 1.5" and realllllllly hate the gap on the rear bumper. But it made is nice for running winch wiring and reaching the clutch on the rear winch. Wifey can just reach right in there no problem.

 

[RobBob22]

I think most of the coilovers available are designed with some jounce left on the table, ie, they don’t max out compression. Thus travel is not maximized so that 37s can fit without smashing fenders when getting after it. I would imagine the treaflex are similar.

I would not worry about any analysis numbers under an inch. I doubt any any analysis has that much resolution.

a small body lift (<1”) is always in the arsenal. Helps keep cg down. And allows for less suspensions lift via spring compression. Helps ride height be closer to center of shock travel.

So what is the vote here? Run the teraflex 35s with maybe a runs small 37” tire like the BFG to start and hope for success?

Word from the teraflex folks was to expect some rub doing that, but counter point and hear me out, so what, do it for the vine?

 

[nolimits]

Trying to take advantage of some BF deals and would appreciate some honest feedback on this plan:

> Eibach pro stage 2 coil over kit
> Kit is the newer one w/ HD front & rear springs to play nice with bumper & winch
> Icon tubular UCA with delta joint
> Alternative is Zone UCA
> Icon Rebound Pros, 17x8.5 +25
> Flip flopping on 35” and 37”
> Shortages on Cooper STT Pros but they are my first choice; Yoko Geolandar MT G003 are the backup plan

Any benefit to either set of UCA’s if I stay with 35’s? I don’t see going larger than 37’s. Like the +25’s to keep scrub radius to a minimum although I know that means some trimming.

I’m currently stock, 23 Badlands 4 door non-squatch, 2.7 with 4.46’s and hardtop.

End goal would be to increase articulation, get a better ride both on and off the trails and not just completely murder my bank account. Generally speaking I prefer quality over dollars, within reason of course.

If the plan sucks, say so. I am okay with honest feedback.

 

[RobBob22]

Trying to take advantage of some BF deals and would appreciate some honest feedback on this plan:

> Eibach pro stage 2 coil over kit
> Kit is the newer one w/ HD front & rear springs to play nice with bumper & winch
> Icon tubular UCA with delta joint
> Alternative is Zone UCA
> Icon Rebound Pros, 17x8.5 +25
> Flip flopping on 35” and 37”
> Shortages on Cooper STT Pros but they are my first choice; Yoko Geolandar MT G003 are the backup plan

Any benefit to either set of UCA’s if I stay with 35’s? I don’t see going larger than 37’s. Like the +25’s to keep scrub radius to a minimum although I know that means some trimming.

I’m currently stock, 23 Badlands 4 door non-squatch, 2.7 with 4.46’s and hardtop.

End goal would be to increase articulation, get a better ride both on and off the trails and not just completely murder my bank account. Generally speaking I prefer quality over dollars, within reason of course.

If the plan sucks, say so. I am okay with honest feedback.

Eibach appear to be a solid choice, and I do think heavy duty springs are the choice especially if you like to load up stuff. We just swapped a buddy onto the heavier springs in the rear and I knows he’s considering front. We did notice his rear suspension appears to have a leak. He’s been running them about a year. So look into that. I have the Bilstein 6112s currently. You gain ride hight only, they do appear to be good quality. Maybe a bit stiff.

I’m still running stock UCA, tire size shouldn’t matter much. I did an install with the Zone for another bronco, seems good enough quality.

If you think you want 37s just do it, because you’ll just do it later. I don’t think most 37s will cause issues with the eibachs. That said, bigger tires faster wear everywhere. Soo… if you’re not off-roading a bunch, maybe 35s.

Don’t know anything about the coopers, I like the Geolanders, people I’ve seen running those seem to get over everything easier then some. Stick with a D rated tire max, you’ll feel stiff ride if you go higher up to E. This is why some people like the BFGs from the Raptor because they C rated.

 

[87-Z28]

Trying to take advantage of some BF deals and would appreciate some honest feedback on this plan:

> Eibach pro stage 2 coil over kit
> Kit is the newer one w/ HD front & rear springs to play nice with bumper & winch
> Icon tubular UCA with delta joint
> Alternative is Zone UCA
> Icon Rebound Pros, 17x8.5 +25
> Flip flopping on 35” and 37”
> Shortages on Cooper STT Pros but they are my first choice; Yoko Geolandar MT G003 are the backup plan

Any benefit to either set of UCA’s if I stay with 35’s? I don’t see going larger than 37’s. Like the +25’s to keep scrub radius to a minimum although I know that means some trimming.

I’m currently stock, 23 Badlands 4 door non-squatch, 2.7 with 4.46’s and hardtop.

End goal would be to increase articulation, get a better ride both on and off the trails and not just completely murder my bank account. Generally speaking I prefer quality over dollars, within reason of course.

If the plan sucks, say so. I am okay with honest feedback.

Sounds good. I don’t think you will need new UCAs. I would try my best to keep spring preload as low as possible, just enough to fight clearance issues with 37s. That should also keep from needing a new UCA for alignment.

I would also consider a small body lift (<1”) to gain extra clearance if needed and keep cg down. The +25 mm offset wheels will work fine with either 35s or 37s and have a near oem scrub radius. May help some with inner fender clearance also.

it’s good you have the 4.46 gear ratio. Should help some with the 37s if you go that route. I am not going bigger than 35s right now, don’t need them. When I get more time to play I will move up in tire size and change out the gear ratios in the diff.

 

[Fordified1]

Just saw this on a YouTube channel. What has this setup? Ranger Raptor and or Braptor?
Wats link (sp?) and drop out diff? We should all have this on our regular Broncos. (I know not everyone needs it but man that’s a better setup).

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