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Re: Start Your Go-Fast Build-Rear Suspension
Posted: Fri Jan 31, 2014 7:21 am
by tcm glx
baja-chris wrote:long time ago on my Ranger but I took it off and tossed it.
have seen them professionally done on broncos by top shops that did not cycle correct if you took the leaf pack down to a single leaf (and put a spacer in to maintain location) so you could cycle it, and the link itself caused bad motions as the rear cycled, the rear does not cycle in a pure arc with leafs because the length from the eye to the rear end changes as the spring arch reduces and yet the link wants to cycle in a pure arc, it does not grow to match what the leaf is trying to make the rear end do. the path along the leaf spring from the pivot eye to the rear end is not a straight line, it has arch to it and that arch changes as the spring cycles so the distance changes. not much and probably taken up by all the slop of stock rubber or poly bushings but when that slop is removed, there is nothing to take up this mismatch so it forces the spring to unnatural shape. if i wanted to run links, then i'd go back to rubber bushings and i'd rubber mount the links too so it would all be so sloppy that it would work (and might need links because of this). just my opinion, i'm sure there are guys with links who disagree so keep that in mind.
Right on, appreciate the extra insight.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Fri Jan 31, 2014 1:57 pm
by BDKW1
Having set-up a couple of trucks with links and leafs, I do believe in them. It does take some cycling to get the correct mounting points. Yes, the points move around a little and are not 100% perfect all the way through the travel. but the amount they are off distorts the springs much less than stomping on the go pedal. Pick your poison.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Fri Jan 31, 2014 2:01 pm
by BDKW1
philofab wrote:Spring under:
3. Different geometry due to front pivot being higher. (changes anti squat & affecting roll understeer/oversteer) (usually worse)
Also has less DS plunge and a better path through the travel.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Fri Jan 31, 2014 6:58 pm
by SteveG
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Fri Jan 09, 2015 8:09 pm
by dtbback
For those of you running 12" travel shocks with a under the bed shock mount; is there any compression travel left in your shocks at full bump?
If you have pics of your mounting locations on your axles could you post a few?
Reason I ask is I'm planning to use a 1-1.5" aluminum body lift ( I already have a thread on this so if you have a comment please post there. ) then run a longer shacklet to gain more up travel. It I can use mouting locations that are higher up in the axle and a 12" travel instead of running a 14" travel shock I think that would be best.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Sat Jan 10, 2015 2:47 pm
by BDKW1
dtbback wrote:then run a longer shacklet to gain more up travel.
Shackle has nothing to do with uptravel. your frame is in the way of that. The only 14's you can get under the bed are Bilstien weld tops and maybe Swayaways.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Sat Jan 10, 2015 6:25 pm
by dtbback
Oh, I thought that with a longer shackle it would be an inch or so higher up before reaching the 0 arch point.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Sun Jan 11, 2015 9:43 pm
by Travisfab
12's are really pushing it, you will sacrifice bump travel with 14's.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Sun Jan 11, 2015 9:52 pm
by dtbback
Thanks for letting me know. I think I am going to be looking for set of raptor take offs.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Mon Jan 12, 2015 9:43 am
by LvSteve
The raptor rear shock work but you need to add damping , call Joe Moore at Fox , He did a complete service reseal and added damping for 100 plus shipping
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Wed Jan 21, 2015 12:26 pm
by agavelouis
dtbback wrote:For those of you running 12" travel shocks with a under the bed shock mount; is there any compression travel left in your shocks at full bump?
If you have pics of your mounting locations on your axles could you post a few?
Reason I ask is I'm planning to use a 1-1.5" aluminum body lift ( I already have a thread on this so if you have a comment please post there. ) then run a longer shacklet to gain more up travel. It I can use mouting locations that are higher up in the axle and a 12" travel instead of running a 14" travel shock I think that would be best.
I have the Solo underbed mount and 12" Fox triple bypass p/b shocks. Full stuffed, shocks bottomed, I am just kissing the stock rubber bumps. I didn't get any pictures of it as I got it all pretty much done in a few hours over 1 evening.
I did not add the shackle drops to the rear with my Q80's and Solo shackles, as I wanted to keep the ride height down. This shouldn't effect the measurement from the axle to upper mount for your shocks though. I just go less negative on my springs at full bump.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Wed Jan 21, 2015 10:47 pm
by SteveG
With my Autofab upper rear shock mount, 12" travel Swayaways we're not bottomed with the bump stops removed and the axle metal to metal on the frame. 14's would require going up into the floor.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Thu Jan 22, 2015 1:46 am
by dtbback
Steve thats with a spring under? Do you have any pics of your rear set up cycled at bump?
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Thu Jan 22, 2015 7:29 am
by SteveG
No. That's with a stock spring configuration. I have photos on my computer. I'll try to get them up in the next day or two.
My rear suspension was very conventional but worked exceptionally well. Good leaves, stock shackles, upper shock mount, 2-link kit and 2.5" shocks... never felt like I needed more.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Thu Jun 11, 2015 10:31 am
by Hauls Assington
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?
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Thu Jun 11, 2015 11:22 am
by PaulW
get your shocks revalved
Start Your Go-Fast Build-Rear Suspension
Posted: Thu Jun 11, 2015 1:37 pm
by birdco85
Dido. Mine did the same thing but I'm running nationals. I have bypasses but my rebound tube is only open half a turn. I have fox 90 stack on rebound. I think it's a .015 stack. It might actually ride better for me if I close the tube all together.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Mon Jun 15, 2015 5:54 am
by yikes
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.
Re: Start Your Go-Fast Build-Rear Suspension
Posted: Mon Jun 15, 2015 6:04 am
by yikes
birdco85 wrote:Dido. Mine did the same thing but I'm running nationals. I have bypasses but my rebound tube is only open half a turn. I have fox 90 stack on rebound. I think it's a .015 stack. It might actually ride better for me if I close the tube all together.
I was running .020's on rebound for a few years and thought it might be too much due to the touchy bypass adjustment; however, it worked awesome on the hard hits. Last time I had the shocks apart I put a .015 stack in. It was a bad move. Control on big hits and g-outs went away. Made the Bronco much more challenging and occasionally scary to drive at the speeds I'm accustomed to. Almost lost it recently out at Ocotillo when it launched sideways off of a big hit. Skinny pedal saved the day again.
Start Your Go-Fast Build-Rear Suspension
Posted: Mon Jun 15, 2015 9:52 am
by birdco85
Skinny pedal always helps. I'm thinking of going to a 100 or 105 stack for rebound. That's just a hybrid .015 and .020 stack. I just don't want to pull them out and revalve AGAIN!