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Duff 4-Link Street Version

rguest3

Contributor
Bronco Guru
Joined
Dec 13, 2012
Messages
3,778
Jason - Thanks for the info and the additional pictures.

Do you have 2 1/2" or 3 1/2" Springs up front?
 

ZOSO

Full Member
Joined
Jan 25, 2003
Messages
345
Looks good. I still want to see flex pics. Im wanting to upgrade to a 4 link and this is my option. I use my bronco offroad and do not want a 2" body lift. That's the only reason I haven't gone with their OG 4link.
 

Madgyver

Bronco Madman
Joined
Jul 30, 2001
Messages
14,678
jason, how did you know what height to set your upper coil mount on the rear?
what size coils are those?
 

bigmuddy

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Dec 28, 2004
Messages
7,001
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Marthasville Missouri
Yeller, this is the type of vehicle I have experience with.
https://images.app.goo.gl/t4U929raoPFhJmno7
Obviously they are in a perfect world where they can do whatever they want and put the output shaft wherever they want. But I know in these applications, the geometry let's the pinion angle radius match the drive shaft and the plunge is usually less than 1in over 36in wheel travel. They also have perfect antisquat and all that, to where having over a 1000 foot pounds of torque down the driveshaft has no affect or input on the suspension raising or squaring. Drive shaft angle is also almost the same as the lower links. Everything about the duff kit seems abnormal. I'd like to see it performs in a high horsepower application under acceleration and cornering under power

I was at one of the local shops that had installed one of the Duff kits on a 250K bronco build. Bronco had a high end coyote motor (lots of HP)

Speaking with the builder, he said it drove poorly cornered like hell. You could see when he powered up the bronco and put it in gear it squatted tremendously. When he parked the bronco look to unload the suspension and the bronco lifted what appeared to be six inches. Not saying this is good or bad, just observations and conversation from the builder.

After seeing it for myself I would have to question spending the money on the kit for my uses.
 

rguest3

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BigMuddy - Were there Sway Bars included in that build?
 
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jasonmcc

jasonmcc

Sr. Member
Joined
Dec 1, 2018
Messages
395
Loc.
Nola -> Utah
I was at one of the local shops that had installed one of the Duff kits on a 250K bronco build. Bronco had a high end coyote motor (lots of HP)



Speaking with the builder, he said it drove poorly cornered like hell. You could see when he powered up the bronco and put it in gear it squatted tremendously. When he parked the bronco look to unload the suspension and the bronco lifted what appeared to be six inches. Not saying this is good or bad, just observations and conversation from the builder.



After seeing it for myself I would have to question spending the money on the kit for my uses.



Seems from what I’ve heard and seen is that installation and sway bars make a huge difference in outcomes. I spoke to several people and did research prior to purchasing. Shocking as it may be some of these big builders do shoddy work. I’ve read here and seen in pics some examples of this (Gateway/Velocity). Obviously you can’t take a N of one and apply it to the whole. I’ll of course share my experience once I’m done whether it’s good or bad.


Sent from my iPhone using Tapatalk
 
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jasonmcc

jasonmcc

Sr. Member
Joined
Dec 1, 2018
Messages
395
Loc.
Nola -> Utah
jason, how did you know what height to set your upper coil mount on the rear?
what size coils are those?



Instructions said to line bottom of upper bucket with bottom of frame. We had it a little lower but once we added weight we raised it to get it at about 1/2-1” rake from rear to front knowing it would settle about a 1/2” and ultimately at normal driving weight giving me a roughly level vehicle. Coils are 2.5”


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bigmuddy

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Dec 28, 2004
Messages
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Marthasville Missouri
BigMuddy - Were there Sway Bars included in that build?

I can't say for sure, but based on the comments about the way it drove I would be surprised if they were installed, and yet would be surprised that they weren't.

I can't imagine spending that kind of money and driving like crap...
 

bigmuddy

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Dec 28, 2004
Messages
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Marthasville Missouri
Seems from what I’ve heard and seen is that installation and sway bars make a huge difference in outcomes. I spoke to several people and did research prior to purchasing. Shocking as it may be some of these big builders do shoddy work. I’ve read here and seen in pics some examples of this (Gateway/Velocity). Obviously you can’t take a N of one and apply it to the whole. I’ll of course share my experience once I’m done whether it’s good or bad.


Sent from my iPhone using Tapatalk

I can see the sway bars making a huge difference. This was Gateway bronco build but man it looked like no expense was spared to me..
 

Yeller

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Mar 27, 2012
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Rogers County Oklahoma
I’m familiar with that build, lots of things going on aggravating those issues. Let’s just say 92” WB, high profile vehicle, supercharged crazy hp and not following all of the instructions and recommendations doesn’t work out the best.

And everyone is shocked when they do 5x normal horse power than what everything was designed around that it doesn’t magically handle like a Ferrari %)
 
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jasonmcc

jasonmcc

Sr. Member
Joined
Dec 1, 2018
Messages
395
Loc.
Nola -> Utah
I can see the sway bars making a huge difference. This was Gateway bronco build but man it looked like no expense was spared to me...

Let me start off first by saying I've never seen any Gateway broncos in person. I have however heard from people whose opinion I trust say that they thought they had sloppy work and it looked "half a$$ed". I remember someone here saw their work at Barret Jackson and posted some pics....looks pretty bad. https://classicbroncos.com/forums/showthread.php?t=283360&page=2 starts at post #24

Hopefully, mine turns out nice as its the only "street version" I've found online except for rguest3 and his rig. This means I kind of had to take a gamble on this purchase. I have however had good and not so good things to say about James Duff products so I can guarantee you an honest review from me once I get back on the road.
 

rguest3

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Dec 13, 2012
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My Street 4-Link has not been completed yet. However, with Most projects it's the quality of the install that makes the big difference. It's not just the welds but how it's set-up as well. Mine will be mocked-up, brackets welded, dis-assembled, sand blasted, powder coated and then re-assembled the final time. Gonna be awhile.

I have had Great Luck with all of Duffs parts and they have done their homework on the engineering of this kit. They have been selling their Off Road Version for many years now with great results.

I will also post my results once installed.
 
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Madgyver

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Joined
Jul 30, 2001
Messages
14,678
I’m familiar with that build, lots of things going on aggravating those issues. Let’s just say 92” WB, high profile vehicle, supercharged crazy hp and not following all of the instructions and recommendations doesn’t work out the best.

And everyone is shocked when they do 5x normal horse power than what everything was designed around that it doesn’t magically handle like a Ferrari %)

what's up dude? nice to see you here... i still want your Broncno
 

Madgyver

Bronco Madman
Joined
Jul 30, 2001
Messages
14,678
I am anxious to hear what Madgyver has to say about his kit when it finished.
We are working on it with a mock-up frame to see what needs to cut and fab up. a swaybar will be used.
my arm is still healing so i can't do much fabbing for now. messing with a one piece power window set up at the moment.
 

Monster Mike

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Dec 29, 2010
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I was at one of the local shops that had installed one of the Duff kits on a 250K bronco build. Bronco had a high end coyote motor (lots of HP)

Speaking with the builder, he said it drove poorly cornered like hell. You could see when he powered up the bronco and put it in gear it squatted tremendously. When he parked the bronco look to unload the suspension and the bronco lifted what appeared to be six inches. Not saying this is good or bad, just observations and conversation from the builder.

After seeing it for myself I would have to question spending the money on the kit for my uses.

Everything you are saying did happen immediately after they installed it and test drove it. I work very closely with Gateway's shop foreman and we have a great working relationship. Sure, the owner was very concerned at first but they slammed that suspension together due to very tight deadlines and when they got it back to the shop they went back through their checklist and found a handful of issues they were able to correct. Corrections to the install not to the system we sold them. They also had more challenges to face than normal due to how much low end torque that super charger makes. Everything on that Bronco needed to be dialed in to handle that power with a 92" wheelbase and 5.5" of total lift on 35" tires

Fast forward two weeks before Barrett Jackson 1-18-2020 and the final piece of the puzzle they needed was shocks. They tried the off the shelf offerings from Fox and Bilstein and just weren't happy. I told them for that 750hp build they really should consider custom valved shocks. They decided to try our new MS2020 shocks first and they were thrilled with how they work and sent it to get auctioned off.

How do we know they are happy with our Monster street 4 link? They just had 2 more of those exact same setups ship out today.

MM
 

bigmuddy

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Bronco Guru
Joined
Dec 28, 2004
Messages
7,001
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Marthasville Missouri
Everything you are saying did happen immediately after they installed it and test drove it. I work very closely with Gateway's shop foreman and we have a great working relationship. Sure, the owner was very concerned at first but they slammed that suspension together due to very tight deadlines and when they got it back to the shop they went back through their checklist and found a handful of issues they were able to correct. Corrections to the install not to the system we sold them. They also had more challenges to face than normal due to how much low end torque that super charger makes. Everything on that Bronco needed to be dialed in to handle that power with a 92" wheelbase and 5.5" of total lift on 35" tires

Fast forward two weeks before Barrett Jackson 1-18-2020 and the final piece of the puzzle they needed was shocks. They tried the off the shelf offerings from Fox and Bilstein and just weren't happy. I told them for that 750hp build they really should consider custom valved shocks. They decided to try our new MS2020 shocks first and they were thrilled with how they work and sent it to get auctioned off.

How do we know they are happy with our Monster street 4 link? They just had 2 more of those exact same setups ship out today.

MM



Mike, I don’t mean to start a tit for tat argument. But that bronco had already left the building when I was there but I am glad they fixed the issues before it went to auction. The truck that was said to have drive ability issues was being loaded up for delivery.

Because a builder is buying more of the kits doesn’t necessarily mean they are happy with the kit but might mean it’s convenient.

I am not trying to dig the kit at all. And
If I needed a 4link kit I would look at buying the duff kit out of a bolt on convenience type thing as opposed to buying my own parts and starting from scratch.







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