What springs to run on Gen 1 with Gen 2 shock and bucket conversion?

[FishFreak]

i think you need to stick with the Gen 1 spring unless the gen 2 top hat is compatible with the new coil buckets. you may want to look at re-valving the shocks too as they are probably a bit soft for the gen 1 (heavier) truck especially with the stiffer gen 1 spring.

I talked to a shock tech at Rock & Road Performance Suspension about revalving for the stiffer gen 1 spring and he said it's not necessary, because the spring stiffness is offset by the heavier V8 engine, so the valving difference is moot. It's a balancing act.

 

[Gumby]

I talked to a shock tech at Rock & Road Performance Suspension about revalving for the stiffer gen 1 spring and he said it's not necessary, because the spring stiffness is offset by the heavier V8 engine, so the valving difference is moot. It's a balancing act.

Not sure I agree with this ^^^^ but I guess it is plausible.

 

[FishFreak]

Not sure I agree with this ^^^^ but I guess it is plausible.

I didn't agree with it either at the time, but hung up the phone and said, "Damn! He's right!" Made total sense. The spring rate increase is offset exactly by the weight increase, thereby negating the notion you need more rebound damping cuz the spring is stiffer and pushing back harder.

 

[FishFreak]

My next biggest question is if you do the bucket swap and use a Gen 1 spring. What is the best route for ride height?

Because the Gen 1 spring is shorter I'm pretty sure this would lower the front of the truck with the bucket swap.

To gain ride height you would have to use either:

- Aftermarket Gen 1 springs like Geisers or Eibach's
- Use the Gen 2 perch collars
- Or a RPG / SDI top hat with lift built-in

You definitely want to use a Gen 1 spring for the diameter, higher rate(then gen 2) and length. Use the gen 1 top hat assembly to match. You don't need to use Geiser or Eibach springs, the rate of the oem Gen 1 spring is fine. You may want new ones if yours are sacked out or badly rusted. The Eibach are actually 'lifting springs' and you don't need that. The gen 2 fox shock is longer, so your truck will sit about 1 1/4 inch higher. The gen 2 shock does not have any perch collars like the gen 1, so run it as-is, and never ever, ever run any kinda top hat spacers or lift kits, they'll cause all sorts of geometry problems and axle cv joint bind. I really do think we all should run the weld-in Evil Offroad front limiting strap kit, on any gen 1, because we're topping out on our shocks, some the springs hit the UCA, and/or cv bind. Unfortunately, they're out of business right? Kicking myself for not ordering that kit when I wanted it 2 years ago...

 

[blueherron96]

I dropped my FRS shocks off yesterday to be gone through and revalved and had an interesting conversation with the shock guy. The FRS shocks come from Fox with a 550lb spring that is designed to work with the gen 2. I was thinking of stepping up to a 600lb spring because all the aftermarket gen 1 shocks come with a 600-650lb spring and I believe that the factory gen 1 spring is less than 600lbs. I was concerned that if I ran the lighter spring I would have the same issues that the factory gen 1 spring has with the gen 1 shocks (nose dive under braking, hard bottom out in g-outs, etc). But because the gen 2 FRS shocks are wildly different than any gen 1 offerings, you can do more with the shock to help control all that because there are more IBP zones. Although he did say up here in the dunes alot of people are having to run heavier springs to deal with the big g-outs. Also when you really think about it, yeah overall the gen 2 is lighter but the nose weight isn't all that different with 2 turbos and all the additional piping, IC, etc. Would be really interesting to scale out both and compare the nose weight. For now I will be running the 550 spring and see how that does.

 

[SilverGen1]

You definitely want to use a Gen 1 spring for the diameter, higher rate(then gen 2) and length. Use the gen 1 top hat assembly to match. You don't need to use Geiser or Eibach springs, the rate of the oem Gen 1 spring is fine. You may want new ones if yours are sacked out or badly rusted. The Eibach are actually 'lifting springs' and you don't need that. The gen 2 fox shock is longer, so your truck will sit about 1 1/4 inch higher. The gen 2 shock does not have any perch collars like the gen 1, so run it as-is, and never ever, ever run any kinda top hat spacers or lift kits, they'll cause all sorts of geometry problems and axle cv joint bind. I really do think we all should run the weld-in Evil Offroad front limiting strap kit, on any gen 1, because we're topping out on our shocks, some the springs hit the UCA, and/or cv bind. Unfortunately, they're out of business right? Kicking myself for not ordering that kit when I wanted it 2 years ago...

I have made my own front limit kit that is almost exactly what the evil kit was, and was wondering if trying to sell them would be worth it.

 

[FishFreak]

I have made my own front limit kit that is almost exactly what the evil kit was, and was wondering if trying to sell them would be worth it.

Well you could put me on your list if your limit strap kit is working correctly? Did you use a 13" strap and weld on a bracket on top, and use a bolt-on mount on the lca like Evil did? Does anyone else already retail a kit for our truck?

Would it be worth it? It'd be fun for a minute, but unless you're already in the truck parts mfg business, chances are you'd be doing it out of the goodness of your heart. I hope you could make a $100 profit a kit?

 

[FishFreak]

My next biggest question is if you do the bucket swap and use a Gen 1 spring. What is the best route for ride height?

Because the Gen 1 spring is shorter I'm pretty sure this would lower the front of the truck with the bucket swap.

To gain ride height you would have to use either:

- Aftermarket Gen 1 springs like Geisers or Eibach's
- Use the Gen 2 perch collars
- Or a RPG / SDI top hat with lift built-in

You may be right, Gen 2 adjustable perch collars may help set your gen 1 springs at the right height.

Check with @pat247 ? I believe he did his with no adjustable collars, no KHC buckets, and oem gen 1 springs and wedges. Pat?

These sure looks like the best gen 2 adjustable collars though:

 

[SilverGen1]

Well you could put me on your list if your limit strap kit is working correctly? Did you use a 13" strap and weld on a bracket on top, and use a bolt-on mount on the lca like Evil did? Does anyone else already retail a kit for our truck?

Would it be worth it? It'd be fun for a minute, but unless you're already in the truck parts mfg business, chances are you'd be doing it out of the goodness of your heart. I hope you could make a $100 profit a kit?

Unfortunately I am not, lol, but it would be something that would be interesting to do. I ended up going with the PRP 12" strap (Evil's Gen 1 kit was a 13", and the Gen 2 kit was a 14") I had all three sizes, but felt that the 12" was the best. I've put about 400 miles on them already, and they seem to be holding up very well. I just don't understand necessarily how the straps are supposed to hold up with the tie rod so close at all times. I get that the limit strap isn't taught unless your front end is off the ground, or close to, but I am seeing some strap wear. I am curious as to how the Evil Kits are holding up




The picture below is with the 13" strap, and I didn't think this was enough, so the pictures above are with the 12" strap

 

[pat247]

The key element in any modification to the Raptor suspention system is: can it be aligned back to factory specs?

I put Gieser springs on Gen 1 shocks and then the Gen 2 shocks using Gen 1 spring, spring hat and angle wedges and both times was able to get it aligned to factory spec afterwards. Neither of these mods caused a single issue with the driveability or cause parts to fail.

The bucket mod and limit strap look cool but at the end of the day is it really the right way to do the Gen 2 shock mod if it can't be aligned and needs more and more modifications to keep from breaking stuff. Just my 2 cents on this subject.