Start Your Go-Fast Build-Rear Suspension

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Hauls Assington
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Re: Start Your Go-Fast Build-Rear Suspension

Post by Hauls Assington »

yikes wrote:
Hauls Assington wrote:I have deaver j-40's in the back with threat shackles, and 2.5x12" king rezis with threat under bed shock mount. I have a race stack in the shocks.

I am having what seems to be a situation where after hitting a bump, the rear end wants to rebound more than I would like, I have 150 psi in the shocks, would more pressure help or hurt?
Increase your shock pressure to 200 minimum. I've been told it takes 250 to prevent cavitation when running the stiff valving required with the Broncos' falling rate geometry. That's what I run. Focus on your compression valving first. Is there enough control on compression, or does it feel soft and blow through the travel quickly through mild bumps? Rebound should exhibit just enough control to prevent pushing the suspension, but return quick enough to keep the wheels on the ground. Too much rebound results in a harsh ride and poor control on washboards and other high frequency bumps.
I don't really know if they are mild, bumps, more like pretty serious. but, I think the compression is too soft too. Would you go to 250psi? I told them to put stiff valving, they did a .12 .20 flutter stack.
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PaulW
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Re: Start Your Go-Fast Build-Rear Suspension

Post by PaulW »

250 is correct. Then if you do not like the result change the valving. Back in the day King would look at a video of your rig going thru the whoops and washboard and change the valving to fix what they did not like. I wonder it they will still do that?

The 250 number came from the tech guys at both Fox and King. Maybe it could be a little lower? Like my Fox's on the EB we use 150, but it is a trail rig and not a go fast on the washboards or whoops. No cavitation would be expected on a go slow rig.

So if the shock guy knew what the shocks were going to be installed on then the valving should be close at 250. The shock guys are smart and they do a lot of shocks. It would be rare that they would get it wrong - Ha. That would be the case if you bought shocks from the shock company and not a vendor or from an unknown use. Having said all that I bought Bilstien 5100s on the web for the Jeep at the lowest price I could find and they work fine.
And my Kings on the front of the desert Bronco came directly from King and the valving was incorrect and the shocks were not the same.
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yikes
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Re: Start Your Go-Fast Build-Rear Suspension

Post by yikes »

Hauls Assington wrote:I don't really know if they are mild, bumps, more like pretty serious. but, I think the compression is too soft too. Would you go to 250psi? I told them to put stiff valving, they did a .12 .20 flutter stack.
Just because this always drives me crazy....the valving shim thickness numbers would be represented as .012 and .020. Twenties on compression? That sounds a bit stiff. How many bleed screws are out of the pistons? The combination of free bleed and low pressure is likely the problem. Put all of the bleed screws in and increase pressure to 250, then give it another go.
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Hauls Assington
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Re: Start Your Go-Fast Build-Rear Suspension

Post by Hauls Assington »

Excellent, I will give that a shot!
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BDKW1
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Re: Start Your Go-Fast Build-Rear Suspension

Post by BDKW1 »

Putting all the bleed screws in will make it really harsh in the little stuff. I have never run all bleeds in on a leaf sprung truck. Usually it's all out. You need to know exactly what your stacks are. If it's a flutter, you need to now the thickness and diameter of the spacer shim. Moving that shim in the pack can have some significant effects.
300
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Re: Start Your Go-Fast Build-Rear Suspension

Post by 300 »

PaulW wrote: Back in the day King would look at a video of your rig going thru the whoops and washboard and change the valving to fix what they did not like. I wonder it they will still do that?
Yes King will still do that with a video. It is still far better to meet them in Barstow when they are doing a shock tuning session. You have to call and find out when that is. Not reasonable if you are on the other side of the country but definitely worth it if you can pull it off. They have all the parts, tools, nitrogen and technicians there to do the work. Doesn't matter if you are a racer or not, they will tune their stuff.
Chris18
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Re: Start Your Go-Fast Build-Rear Suspension

Post by Chris18 »

Maybe a dumb question, but would a f31 deaver work on my big bronco? Only asking cause I found a smokin deal on a set! ????????
dtbback
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Re: Start Your Go-Fast Build-Rear Suspension

Post by dtbback »

Chris18 wrote:Maybe a dumb question, but would a f31 deaver work on my big bronco? Only asking cause I found a smokin deal on a set! ????????
Those springs are meant for rangers. Too light for a bronco.
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ChaseTruck754
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Re: Start Your Go-Fast Build-Rear Suspension

Post by ChaseTruck754 »

Agreed - way too light. If the deal is that smoking then buy them, re-sell them higher & use your profit towards the correct springs.
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Re: Start Your Go-Fast Build-Rear Suspension

Post by dtbback »

What size bolts are used with a bolt on under the bed shock tower? I am installing a Rancho lift for Stage 1, which means I will be drilling out a lot of rivets. I figured I might as well drill out the factory rear shock rivets and replace them with bolts while I am at it.
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birdco85
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Start Your Go-Fast Build-Rear Suspension

Post by birdco85 »

1/2"
dtbback
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Re: Start Your Go-Fast Build-Rear Suspension

Post by dtbback »

Thanks Darren!
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Re: Start Your Go-Fast Build-Rear Suspension

Post by dtbback »

What length?
-JD5353-
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Re: Start Your Go-Fast Build-Rear Suspension

Post by -JD5353- »

My whole truck is 1.5" long fine thread with nylocks and washers, so that will work for you. you could try 1 1/4" too but no reason.
dtbback
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Re: Start Your Go-Fast Build-Rear Suspension

Post by dtbback »

-JD5353- wrote:My whole truck is 1.5" long fine thread with nylocks and washers, so that will work for you. you could try 1 1/4" too but no reason.
Thanks!
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Wrightracing.net
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Post by Wrightracing.net »

I have a question for the guys that are running a linked rear end on their Bronco. How long are your lower links you are running?

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VintageIronFab
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

David I'm guessing you got the Ruff Stuff email with their new links??
http://www.vintageironfabworks.com

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baja-chris
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Re: Start Your Go-Fast Build-Rear Suspension

Post by baja-chris »

I don't know how long they are but if you draw an imaginary line through the front of the lower link pivots (side to side), then the u-joint on the back of the transfer case is exactly on that line. we had to angle the drivetrain down to get there. the the front of the upper links are 5" up and 5" back from there. the rear end has the lower links clocked up so they are partially rolled forward/up instead of fully under the housing. did this to reduce roll steer but it does place more strain on the upper links so those mounts have to be stout.
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Wrightracing.net
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Re: Start Your Go-Fast Build-Rear Suspension

Post by Wrightracing.net »

VintageIronFab wrote:David I'm guessing you got the Ruff Stuff email with their new links??
No, I have not seen it.


Thanks Chris.
Ya, I knew that it would be along the same as the drive line, I was not sure if it was common to run them much longer. Thanks for the info.

I am not sure if I will link mine, but when I break the leafs, it maybe time.

David...
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Re: Start Your Go-Fast Build-Rear Suspension

Post by VintageIronFab »

DW - take a look at them pretty nice pieces for the money those links are
http://www.vintageironfabworks.com

77- "Victoria"
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