RCD measurements(very long)
#1
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RCD measurements(very long)
im gonna start this thread for myself jus as much as for everyone else to read. kinda a digest to keep track of all my thoughts and numbers besides the notebook i keep, that my daughter likes to draw in
current setup:
used RCD in front, basically straight outta the box as it comes
stock leafs and blocks, plus the RCD shackle in the rear(no AAL)
the RCD(w/swaybar) rides amazinlgy close to stock with #1 bars(w/swaybar). the suspension feels more free to move w/less binding due to the placement of the spring in relation to the pivots of the LCA.
i disassembled on of my coilovers today to get some hard numbers and find out how much these coils are sagged. the coils are maxed out and the front is still 1" lower than the rear and im not even runnin the AAL, so i know they are sagged. got the spring off and the free length is 11.5" should be 12. the wire diameter is roughly 19/32nds and there are 9.5 coils on the spring. that adds up to a bind height of 5.64". the more the springs sag, the more likely they are to get into a coil bind situation. the shocks are 19" extended and 14.5" collapsed measured center to center of the eyes. the spring is preloaded at ride height at 9.75"
i also took some measurements of the max travel available in the suspension w/o the shock installed. max up travel is limited by the LCA contacting the drop bracketry. i measured 14.875" center to center of the shock mounts and 20.25" hub centerline to the fender. max down travel is limited by the UCA contacting the frame. i measured 19.75" center to center of the shock mount and 28.25" from the hub centerline to the fender. at ride height the hub to fender measurement is 25"
so what does all this mean?
with 4.125" of travel available in the suspension at the shock and only 4.11" in the spring, i am very close to a coil bind problem at full compression. time for new springs in front.
the RCD does not inherently NEED a limit strap any more than the stock setup does. the shock is still the limiting factor in down travel.
the use of the stock bumpstop at the drop bracket/LCA interference severely limits up travel.
what am i gonna do about it?
since i am runnin the RCD w/o a sway bar now it feels a lil too soft for my liking. since i need new springs anyhow, i am gonna get 700# 12" springs. there is no possible way to fit 14" springs on these shocks. the higher spring rate should be a good compromise between ride quality and independent travel of the IFS.
i will probly add a limit strap down the road jus for good measure. i doubt that the suspension really needs it for the type of wheelin i normally do, but it cant hurt.
i am not currently runnin any bumpstop at all, but am gettin a set of pancake style, poly units for the jus-in-case contact at full compression.
for the rear i am gonna do a 2wd chevy spring swap to get rid of the blocks. i am hopin this will help out w/axle wrap as well. the slightly higher rate of the chevy springs should match up decently with the 700# springs in front.
i am happy with the rear ride height, so if the chevy spring doesnt add any measureable height, i will jus level the front to match.
comments? questions? concerns?
disclaimer: all my measurements were preformed in the driveway w/an adjustable wrench and an old stanley tape measure, so if anyone wants to get technical and look up/find manufactures numbers feel free. please report your findings to the class.
current setup:
used RCD in front, basically straight outta the box as it comes
stock leafs and blocks, plus the RCD shackle in the rear(no AAL)
the RCD(w/swaybar) rides amazinlgy close to stock with #1 bars(w/swaybar). the suspension feels more free to move w/less binding due to the placement of the spring in relation to the pivots of the LCA.
i disassembled on of my coilovers today to get some hard numbers and find out how much these coils are sagged. the coils are maxed out and the front is still 1" lower than the rear and im not even runnin the AAL, so i know they are sagged. got the spring off and the free length is 11.5" should be 12. the wire diameter is roughly 19/32nds and there are 9.5 coils on the spring. that adds up to a bind height of 5.64". the more the springs sag, the more likely they are to get into a coil bind situation. the shocks are 19" extended and 14.5" collapsed measured center to center of the eyes. the spring is preloaded at ride height at 9.75"
i also took some measurements of the max travel available in the suspension w/o the shock installed. max up travel is limited by the LCA contacting the drop bracketry. i measured 14.875" center to center of the shock mounts and 20.25" hub centerline to the fender. max down travel is limited by the UCA contacting the frame. i measured 19.75" center to center of the shock mount and 28.25" from the hub centerline to the fender. at ride height the hub to fender measurement is 25"
so what does all this mean?
with 4.125" of travel available in the suspension at the shock and only 4.11" in the spring, i am very close to a coil bind problem at full compression. time for new springs in front.
the RCD does not inherently NEED a limit strap any more than the stock setup does. the shock is still the limiting factor in down travel.
the use of the stock bumpstop at the drop bracket/LCA interference severely limits up travel.
what am i gonna do about it?
since i am runnin the RCD w/o a sway bar now it feels a lil too soft for my liking. since i need new springs anyhow, i am gonna get 700# 12" springs. there is no possible way to fit 14" springs on these shocks. the higher spring rate should be a good compromise between ride quality and independent travel of the IFS.
i will probly add a limit strap down the road jus for good measure. i doubt that the suspension really needs it for the type of wheelin i normally do, but it cant hurt.
i am not currently runnin any bumpstop at all, but am gettin a set of pancake style, poly units for the jus-in-case contact at full compression.
for the rear i am gonna do a 2wd chevy spring swap to get rid of the blocks. i am hopin this will help out w/axle wrap as well. the slightly higher rate of the chevy springs should match up decently with the 700# springs in front.
i am happy with the rear ride height, so if the chevy spring doesnt add any measureable height, i will jus level the front to match.
comments? questions? concerns?
disclaimer: all my measurements were preformed in the driveway w/an adjustable wrench and an old stanley tape measure, so if anyone wants to get technical and look up/find manufactures numbers feel free. please report your findings to the class.
Last edited by gumby; 03-31-2007 at 06:14 PM.
#2
True specs on the RCD front shocks
I have been looking for some new shocks on the front end since mine are sagging a bit, and after 29k, a bit stiff. I have been playing phone tag with RCD a bit but finally got the specs on the front shocks directly from the engineer.
They are bilstein 5100's that are obviously a special coilover style:
Extd: 19.125"
Col: 14.625"
Dia: 2.0"
Spring Rate: 600 lbs
Inside Dia: 2.5"
Spring Length: 12"
They told me to bump up the spring rate to 650lbs or 700lbs. I asked though, which is it? He said since its a 4.0L, the 700lbs would be best. Then you can back off the spanner/adj nut and have no preload on the spring. I think I'm going to get fox shocks. The 2.0 coilover remote reservoirs 6.5" with 14" Eibach 700lbs springs, but they don't make 14" 700lb springs, only 650's. So that's what I ended up with, and not too shabby at all. You can actually run 12" springs on these Fox shocks, then you could get 700lb springs. I thought it would be better to get a longer spring at a little lower spring rate, seems ok.
Just thought this might help all you out there looking for this info.
They are bilstein 5100's that are obviously a special coilover style:
Extd: 19.125"
Col: 14.625"
Dia: 2.0"
Spring Rate: 600 lbs
Inside Dia: 2.5"
Spring Length: 12"
They told me to bump up the spring rate to 650lbs or 700lbs. I asked though, which is it? He said since its a 4.0L, the 700lbs would be best. Then you can back off the spanner/adj nut and have no preload on the spring. I think I'm going to get fox shocks. The 2.0 coilover remote reservoirs 6.5" with 14" Eibach 700lbs springs, but they don't make 14" 700lb springs, only 650's. So that's what I ended up with, and not too shabby at all. You can actually run 12" springs on these Fox shocks, then you could get 700lb springs. I thought it would be better to get a longer spring at a little lower spring rate, seems ok.
Just thought this might help all you out there looking for this info.
#3
#4
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forgot one measurement.
hub centerline to fender at full droop w/shock installed = 27.25"
so wheel travel with the RCD is right at 7" full droop to full compression. id imagine you could get the last 1" out of it with a longer shock and limit strap, but IMO the risk involved for tearin up parts isnt worth it for an inch of down travel on an IFS.
ill update this thread when i have relevant info to add, but dont expect frequent updates. i have a full time project that takes most of my car related time. the truck is still my DD and as long as it is, it will be a back burner project.
hub centerline to fender at full droop w/shock installed = 27.25"
so wheel travel with the RCD is right at 7" full droop to full compression. id imagine you could get the last 1" out of it with a longer shock and limit strap, but IMO the risk involved for tearin up parts isnt worth it for an inch of down travel on an IFS.
ill update this thread when i have relevant info to add, but dont expect frequent updates. i have a full time project that takes most of my car related time. the truck is still my DD and as long as it is, it will be a back burner project.
#5
Not replacements
The Fox shocks are not said to be official replacements, but they do replace the shocks perfectly. They bolt right up, no mods. They ride nice...
Also, what happens if I get rid of my anti-sway bar up front? I mean does it drive totally different? Is it safe? Will it break or ruin anything? I drive mostly on road, but the bar kind of gets in the way of my tires...lol. Just wanted to ask cause I saw you say you don't have the bar...
Also, what happens if I get rid of my anti-sway bar up front? I mean does it drive totally different? Is it safe? Will it break or ruin anything? I drive mostly on road, but the bar kind of gets in the way of my tires...lol. Just wanted to ask cause I saw you say you don't have the bar...
#6
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wow, replies!
bigdreamer, thanks for the tech! looks like i hit it close enough for driveway work.
beard, bigdreamer here eludes to the fox replacement. AFAIK it is a complete shock that jus happens to be the same(or near enough) extended/collapsed dims as the bil. then you choose what ever spring you want to run. since the bil uses a standard eye-eye mounting, any aftermarket c/o shock could be used in its place.
and yeah, my coils are shot, but considering the weight they were carryin on the front of scottD's truck with that winch, im not at all shocked
edit: bigdreamer, no bar is safe as long as you know your drivin w/o it, IMO. there is more body roll, but nuthin you shouldnt be ready for drivin a lifted truck anyhow. ride is more compliant, and a lil softer. got any pics of those fox shocks?
bigdreamer, thanks for the tech! looks like i hit it close enough for driveway work.
beard, bigdreamer here eludes to the fox replacement. AFAIK it is a complete shock that jus happens to be the same(or near enough) extended/collapsed dims as the bil. then you choose what ever spring you want to run. since the bil uses a standard eye-eye mounting, any aftermarket c/o shock could be used in its place.
and yeah, my coils are shot, but considering the weight they were carryin on the front of scottD's truck with that winch, im not at all shocked
edit: bigdreamer, no bar is safe as long as you know your drivin w/o it, IMO. there is more body roll, but nuthin you shouldnt be ready for drivin a lifted truck anyhow. ride is more compliant, and a lil softer. got any pics of those fox shocks?
#7
i know this was mainly for front springs but you brought up the chevy rear springs so..if you have some cash to spend check out DEAVER springs.. they sell a rear leaf pack that, with a requirered shackle flip (which give better travel and free'er movement) will only lift the rear about a half an inch AND that is without the blocks. Plus theey are designed to help with axle wrap..
these are what im goin with as soon as its outta warentee, and i hopefully wont even need the traction bars. But well see.
and thanks for the info im really thinkin about this kit and have heard the front springs go out fast so its good to know we have a few choises, especially using the fox shocks.
JOSH
these are what im goin with as soon as its outta warentee, and i hopefully wont even need the traction bars. But well see.
and thanks for the info im really thinkin about this kit and have heard the front springs go out fast so its good to know we have a few choises, especially using the fox shocks.
JOSH
#9
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i would definatley get some deavers if i had the $$$ to spend, but that aint happenin right now.
the amount of lift they give wouldnt be enough to match the front in the configuration deaver wants them(shackle flipped w/o blocks), so i would either need a taller pack from them, or be right back my current situation in the rear tryin to decipher final ride height solutions.
the amount of lift they give wouldnt be enough to match the front in the configuration deaver wants them(shackle flipped w/o blocks), so i would either need a taller pack from them, or be right back my current situation in the rear tryin to decipher final ride height solutions.
#11
Well on the front end of things...I just got those new shocks with 14" 650 lbs springs right. Well we put them on and had to add some preload. However we haven't added enough preload to it yet to level the truck back out. So right now my 35's rub a bit on my bumper, even with it trimed a bit. I'm hoping that when I add the preload to my springs to level it out (god that's going to take a while) that it doesn't cause the ride to stiffen to much. I wish they made a damn 700 lbs 14" spring! That brings me to my question, would it be ok to stack a 6"
and 8" 700 lbs springs? I mean would that be close to the same as a 14" 700 lbs spring if they made it or would it be totally wrong?
and 8" 700 lbs springs? I mean would that be close to the same as a 14" 700 lbs spring if they made it or would it be totally wrong?
#12
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1) thanks for the continued follow up on the fox conversion.
2) yes you can stack coil over springs. they make collars to support the joint. many guys run two different springs for a progressive rate this way.
3) make sure to get us some pics of your truck on the snapshots board, we wanna see it! also pics of the fox c/o's can go here.
2) yes you can stack coil over springs. they make collars to support the joint. many guys run two different springs for a progressive rate this way.
3) make sure to get us some pics of your truck on the snapshots board, we wanna see it! also pics of the fox c/o's can go here.
#13
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picked up my new front bumpstops today. energy suspension p/n: 9-9132G
the factory bumpstop is roughly 1 7/8" tall.
the new bumpstops are only 3/8" thick!
they are pretty solid(as all poly parts are), so they arent gonna give much cushion. they will however give me all the available up travel w/o metal to metal contact and w/o bottoming out the shock.
the mounting hole in the drop bracket is smaller than the stud on the new bumpstop. nuthin a drill and a 3/8" bit cant take care of though.
the factory bumpstop is roughly 1 7/8" tall.
the new bumpstops are only 3/8" thick!
they are pretty solid(as all poly parts are), so they arent gonna give much cushion. they will however give me all the available up travel w/o metal to metal contact and w/o bottoming out the shock.
the mounting hole in the drop bracket is smaller than the stud on the new bumpstop. nuthin a drill and a 3/8" bit cant take care of though.
#14
Originally Posted by gumby
picked up my new front bumpstops today. energy suspension p/n: 9-9132G
the factory bumpstop is roughly 1 7/8" tall.
the new bumpstops are only 3/8" thick!
they are pretty solid(as all poly parts are), so they arent gonna give much cushion. they will however give me all the available up travel w/o metal to metal contact and w/o bottoming out the shock.
the mounting hole in the drop bracket is smaller than the stud on the new bumpstop. nuthin a drill and a 3/8" bit cant take care of though.
the factory bumpstop is roughly 1 7/8" tall.
the new bumpstops are only 3/8" thick!
they are pretty solid(as all poly parts are), so they arent gonna give much cushion. they will however give me all the available up travel w/o metal to metal contact and w/o bottoming out the shock.
the mounting hole in the drop bracket is smaller than the stud on the new bumpstop. nuthin a drill and a 3/8" bit cant take care of though.
#15
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scottyG sent me a link jus now. this guy is runnin 750x12's on his mountianeer, and loves them
http://www.explorerforum.com/forums/...d.php?t=184133
http://www.explorerforum.com/forums/...d.php?t=184133
#19
Once I get all the parts I have stockpiled onto my truck, it's gonna be time to get serious and replace those coils. Is there any way to "test" a shock, haven't looked into it much yet as I'm not to that point. All four corners seem like they have decent shock dampening but I'm not a pro.
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