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What is the purpose of a sfd


JackFletcher
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Basically it's the only way to lift over ~2.5".  The CV's in the front end only have so much angle they can handle, so to lift higher you need to lower the diff.  On other 4x4's with full frames diff drops are common (for example, look at a 6" or 8" lift kit for a fullsize IFS truck).  With the R50 platform you can't simply drop just the diff, so the entire front subframe gets spaced down to give lift.  This actually works really well because in addition to moving the diff, it moves the steering and control arms down as well do maintain all of the stock suspension geometry.  Hopefully that description is helpful and not confusing!

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2 minutes ago, mjotrainbrain said:

Basically it's the only way to lift over ~2.5".  The CV's in the front end only have so much angle they can handle, so to lift higher you need to lower the diff.  On other 4x4's with full frames diff drops are common (for example, look at a 6" or 8" lift kit for a fullsize IFS truck).  With the R50 platform you can't simply drop just the diff, so the entire front subframe gets spaced down to give lift.  This actually works really well because in addition to moving the diff, it moves the steering and control arms down as well do maintain all of the stock suspension geometry.  Hopefully that description is helpful and not confusing!

Perfect explanation. Thanks for your help! 

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To elaborate on what mjotrainbrain  said...

 

to lift with springs changes all of the suspension geometry angles which affects all of the suspension attributes (bump steer and alignment for instance).  And the limitation with this vehicle is the CV joint angles, which limit you to about 2.5" maximum.  This also results in a suspension that has more compression than extension which causes another set of problems.

 

When lifting by SFD, none of that is affected and the suspension can retain all of the stock characteristics while getting a lift.  It's great.  The only thing it doesn't improve is the ground clearance at the differentials, but that's the nature of the thing....

All in all, it's the better way to lift IMO.

 

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To elaborate on what mjotrainbrain  said...
 
to lift with springs changes all of the suspension geometry angles which affects all of the suspension attributes (bump steer and alignment for instance).  And the limitation with this vehicle is the CV joint angles, which limit you to about 2.5" maximum.  This also results in a suspension that has more compression than extension which causes another set of problems.
 
When lifting by SFD, none of that is affected and the suspension can retain all of the stock characteristics while getting a lift.  It's great.  The only thing it doesn't improve is the ground clearance at the differentials, but that's the nature of the thing....
All in all, it's the better way to lift IMO.
 

Very interesting. I have been in the process of deciding which form of lift I am gonna do and I haven’t considered this one until now. Due to the fact that I am only interested in a 2-3 in lift would you still recommend the sfd?


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19 hours ago, JackFletcher said:

Very interesting. I have been in the process of deciding which form of lift I am gonna do and I haven’t considered this one until now. Due to the fact that I am only interested in a 2-3 in lift would you still recommend the sfd?

 

Well...there's one caveat: no one's making SFDs.  But, perhaps that'll change soon...

 

The problem is that 2"-3" is no-man's land.  You can do 3" of lift without an SFD, but shouldn't.  The issue is that after around the 2.5" mark, your suspension articulation can cause the CVs to bind due to higher angles, which will eventually lead to breakage.  You could buy lifetime-replacement CVs if you enjoy the work, but the purpose of the SFD is to restore those CVs angles to acceptable specs.  Same is true for the steering/alignment and suspension.

Edited by hawairish
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Well...there's one caveat: no one's making SFDs.  But, perhaps that'll change soon...
 
The problem is that 2"-3" is that no-man's land.  You can do 3" of lift without an SFD, but shouldn't.  The issue is that after around the 2.5" mark, your suspension articulation can cause the CVs to bind due to higher angles, which will eventually lead to breakage.  You could buy lifetime-replacement CVs if you enjoy the work, but the purpose of the SFD is to restore those CVs angles to acceptable specs.  Same is true for the steering/alignment and suspension.


So I’m a bit overwhelmed here. I see all of these options like spacers, lift springs, struts and the sfd. What would you guys do if you were in my position? I’m looking to fit 32s or 33s. Thank you.


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The vast majority of people are running 2” suspension lift. 31” Tires no problem. 32” if you use spacers or a 3.75” backspace wheel. This can be done relatively inexpensively & on your own.

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1 hour ago, JackFletcher said:

So I’m a bit overwhelmed here. I see all of these options like spacers, lift springs, struts and the sfd. What would you guys do if you were in my position? I’m looking to fit 32s or 33s. Thank you.

 

 

Think of the SFD as a means to correct lift amounts beyond 2”, and for the front of the truck only. It’s literally to “drop” the suspension, driveline, and suspension to correct the effects of too much lift. You can do any amount of lift (by means of strut spacers or coils; struts by themselves don’t provide any lift) you’d like, but you just need an SFD to correct everything. 

 

That said, you’re looking at needing at least 4” of lift to reasonably clear 32” tires. To get 4” you can do stock springs on a 4” strut spacer, or 2” lift springs and 2” spacers. You’d then want a 4” SFD to “correct” the OE geometries.  You can put 6” of lift on a 4” SFD...the truck will then have the geometries of a 2” lift, which is acceptable. 

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Think of the SFD as a means to correct lift amounts beyond 2”, and for the front of the truck only. It’s literally to “drop” the suspension, driveline, and suspension to correct the effects of too much lift. You can do any amount of lift (by means of strut spacers or coils; struts by themselves don’t provide any lift) you’d like, but you just need an SFD to correct everything. 
 
That said, you’re looking at needing at least 4” of lift to reasonably clear 32” tires. To get 4” you can do stock springs on a 4” strut spacer, or 2” lift springs and 2” spacers. You’d then want a 4” SFD to “correct” the OE geometries.  You can put 6” of lift on a 4” SFD...the truck will then have the geometries of a 2” lift, which is acceptable. 

Ok thanks to all for the explanation. I have got some time to decide still waiting on the money to pay for this lol. I will let you know what I go with!


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BTW, you have an awesome name! Kind of sounds like Jack Reacher.
 
And just to be clear-@hawairish advice totally trumps mine. He has an incredible amount of hands on experience.
 
 
Lol. Thanks to all for the help.


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Why do people keep saying sfd lift, a sfd doesnt lift your truck at all! It drops the front subframe so that you maintain factory specs when you use spacers or springs to lift. There once was a kit that came with a 4" strut spacer but they don't make them anymore, guessing safety/legal issues. And someone does still make a sfd but he will not make the 4" strut spacers because again, probably legal issues. I have 2" sfcreation spacers upfront and thats max I would go. I have new halfshaft up front and for some reason on every r50 the passenger side halfshaft will bind if you turn to sharp which is what I am currently dealing with and it's annoying. Probably shouldn't lift more then an inch if you want to avoid this. Johann said he would make me a 2"sfd kit but im not sure if I would have to custom fab steering linkage then. I wanted to avoid going to a full 4" lift because the means alot more parts and shocks but dammit I want my half shafts not to bind! If your gonna go over a 2" sfcreation spacer just get 2" spacers and 2" lift spring and get a 4" sfd kit to go with it.

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2 minutes ago, bertrenolds said:

Why do people keep saying sfd lift, a sfd doesnt lift your truck at all! It drops the front subframe so that you maintain factory specs when you use spacers or springs to lift. There once was a kit that came with a 4" strut spacer but they don't make them anymore, guessing safety/legal issues. And someone does still make a sfd but he will not make the 4" strut spacers because again, probably legal issues. I have 2" sfcreation spacers upfront and thats max I would go. I have new halfshaft up front and for some reason on every r50 the passenger side halfshaft will bind if you turn to sharp which is what I am currently dealing with and it's annoying. Probably shouldn't lift more then an inch if you want to avoid this. Johann said he would make me a 2"sfd kit but im not sure if I would have to custom fab steering linkage then. I wanted to avoid going to a full 4" lift because the means alot more parts and shocks but dammit I want my half shafts not to bind! If your gonna go over a 2" sfcreation spacer just get 2" spacers and 2" lift spring and get a 4" sfd kit to go with it.

 

You've answered your own question: they call it a lift because it was once sold as a lift kit; which provided 4" of lift.  I agree that the "SFD" part is worth distinguishing as "not a lift".

 

You've got a lot of other thoughts in your comments, perhaps enough to start your own thread if you're having issues.  As stated above, 2" of lift is in that no-man's land, and it's hit or miss in regards to CV binding.  There no reason one side would be more faulty than another; same exact CVs on a mirrored suspension.  Others have reported differences in CV manufacturers, however.  A 2" SFD would require a modified or replacement steering link.  A 2" SFD is also not as practical as taller sizes, noting that I've fitted 1", 2.5", and 3" SFDs on my own truck, because of tight hardware spaces in the motor mount spacers, and the costs of the steering link (though the joints can be re-used with a longer shaft if you eventually were to jump to taller SFD).

 

Any amount of lift requires additional or replacement parts.  I'm not understanding your complaint there.

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10 minutes ago, hawairish said:

 

You've answered your own question: they call it a lift because it was once sold as a lift kit; which provided 4" of lift.  I agree that the "SFD" part is worth distinguishing as "not a lift".

 

You've got a lot of other thoughts in your comments, perhaps enough to start your own thread if you're having issues.  As stated above, 2" of lift is in that no-man's land, and it's hit or miss in regards to CV binding.  There no reason one side would be more faulty than another; same exact CVs on a mirrored suspension.  Others have reported differences in CV manufacturers, however.  A 2" SFD would require a modified or replacement steering link.  A 2" SFD is also not as practical as taller sizes, noting that I've fitted 1", 2.5", and 3" SFDs on my own truck, because of tight hardware spaces in the motor mount spacers, and the costs of the steering link (though the joints can be re-used with a longer shaft if you eventually were to jump to taller SFD).

 

Any amount of lift requires additional or replacement parts.  I'm not understanding your complaint there.

Yea, just talked to johann and he also said you would still need a modified steering linkage making the 4" lift with a sfd the most practical because of existing info. I have all the specs and cad files but don't know anyone who can make it, maybe but haven't pushed it because I'm not sure I wanna put even more $ into it. Might just deal with a binding drivers side half shaft that has a lifetime warranty and not turn sharp. I wish Krypton or what ever the name was still made a kit dammit. Wanna make me spacers?  I know you can do 2" spacers and 2" springs but you still need the aftermarket steering linkage, longer rear shocks and landrover springs, brake lines, and all the sfd spacers. 

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17 minutes ago, bertrenolds said:

Yea, just talked to johann and he also said you would still need a modified steering linkage making the 4" lift with a sfd the most practical because of existing info. I have all the specs and cad files but don't know anyone who can make it, maybe but haven't pushed it because I'm not sure I wanna put even more $ into it. Might just deal with a binding drivers side half shaft that has a lifetime warranty and not turn sharp. I wish Krypton or what ever the name was still made a kit dammit. Wanna make me spacers?  I know you can do 2" spacers and 2" springs but you still need the aftermarket steering linkage, longer rear shocks and landrover springs, brake lines, and all the sfd spacers. 

 

I'll reply to your other thread (thanks for creating a separate one).

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On 11/8/2018 at 8:47 AM, JackFletcher said:

 

I saw a bunch of people doing these on the forum. I couldn’t find a reason why people do it on here or on the google.

 

While the primary reason may be to correct suspension geometry I'd argue that another massive benefit of the SFD is access to the 3.5 VQ and its accessories. I dropped my transmission and in the process had to work all around the motor, including removing the starter. I have no idea how somone would achieve simple repair work, like replacing the starter, without tearing apart the whole subframe or removing the front differential. With my 4" SFD the starter was a fairly straight forward job with just a hair of extra of room to wiggle around in

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For anyone interested in a 4" sfd and lift. Right now in the facebook r50 lift group a guy is trying to get a group purchase together for 4" lift strut spacers. He found someone to make all the parts and all you would need to do is get the welded. I also talked to johann in this group and he is making me 4" sfd spacers. Now is your opportunity to get in on this. Here is the strut spacer link on the npora fb group.  https://m.facebook.com/groups/2250790128?view=permalink&id=10156357726865129

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