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bro stuff aka shock question.

gwizz

Active Member
#1
cummins powerd k20 with fox 2.5 14" RR's also 2.0 bump shorted to 3" travel.
springs 200/600 (lol) the 200 is basically a tender coil but i have 1-1.5" till i hit the dual rate stop with 3" pre load at ride height. with about 6" total up travel at the shock. low i know...

original "ish" compression valving.. (low and behold the shocks were not balanced lol... the other one had a bunch of .012s instead of .015s)
two bleed holes didnt check the size but they looked factory? aka had ano on the inside.
1.800 ------- .010
1.600 ------- .015
1.425 ------- .015
1.350 ------- .015
1.100 ------- .015
0.950 ------- .015
long story short the original set up workd pretty good at speed 50-60mph (my guess is full valve lift or flow or what ever so were talking about orifice flow at that point)but was easily over powered at slower speeds, like rolling into a set of whoops i would sit and pogo on my bumps to the point where trying to drive through it would get dicy. plus every time i went out i could fully bottom it out no matter what pressure i put in my bumpstops.
so i changed that to this
1.800 ------- .012
1.600 ------- .015x2
1.425 ------- .015
1.350 ------- .015
1.100 ------- .015
0.950 ------- .015

mainly im just trying to effect the slower speed portion of the valving, which is why i went thicker on the 1.8 and did the double. if i move the double stack higher to the smaller diameter shims or go thinner on the 1.8 shim is that a round about way to lessen the effects of this change?

or should i just start trying to figure a flutter stack/rate plate deal? cause given my corner weight i can probably get away with loosing some orifice? orr am i way off base here?

so i realize the double stack is a pretty significant change, defiantly can tell the small sharpstuff where as before curb sized things really just made noise. its not that bad still just makes noise but you can defiantly feel them now. realistically i need to take it to the desert and see what happens. this picture is old and the bump has been shortened since. but gives you an idea of the angle of the shock in relation to the 1:1 motion ratio.

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gwizz

Active Member
#4
the rear... nothing special. stock length leaf/shackle and "two link" 14" fox 2.0 85 compression (all .015 minus the main being .012), 35 stack for the rebound. it does alright ish.. but honestly 3.0s and coil springs are in my future for the rear of this thing.. sooo im kinda over tuning/messing with the rear.
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gwizz

Active Member
#5
should i go back to the .010 main shim, and then put the double stack higher up in the higher speed valving? tiny **** is pretty chattery :/ which was expected... but i want my cake and to eat it too.


or should i try a flutter stack, tho im pretty sure those lend them selves to higher motion ratios than 1:1
 

partybarge_pilot

Well-Known Member
#6
Strait 15 stack with a 1.8X.015 on top of the stack as a flexible rate plate (maybe 2). Make sure there is space between the rate plate and the top out washer. Also put like 300PSI in them.
 

gwizz

Active Member
#7
Strait 15 stack with a 1.8X.015 on top of the stack as a flexible rate plate (maybe 2). Make sure there is space between the rate plate and the top out washer. Also put like 300PSI in them.
how does the rate plate work? are you trying to limit the "valve lift" of the valve shims by physically stopping them as they deflect? essentially valving your orifice or total flow of the piston? also if you have dimensions/materials for a real one ill make them. im neighbors with a tool maker who has the stuff to make stuff lol.

also at what portion should it be in the stack? or just on top?

if any one has picture of one in use that would be cool. i get that moving it around effects how or when it "hits".

way to harsh with the double stack on the small chattery stuff. thats with only 200psi too. before on the original stack i ran 350psi, but that was still pretty soft on the small stuff, but pretty good for everything else.
 

partybarge_pilot

Well-Known Member
#8
Small chattery stuff is more in the bleeds. If that was the only issue with the double stack, open another bleed hole.

I do not personally like rate plates. It's a personal preference thing. I feel they make the square edge holes to harsh. Some people like them in the front to make the front pop out of a hole. I feel that make the truck feel harsh and put way to much stress on everything including the oil.
 

gwizz

Active Member
#9
Small chattery stuff is more in the bleeds. If that was the only issue with the double stack, open another bleed hole.

I do not personally like rate plates. It's a personal preference thing. I feel they make the square edge holes to harsh. Some people like them in the front to make the front pop out of a hole. I feel that make the truck feel harsh and put way to much stress on everything including the oil.
i want to do as much as i can with shims before i do bleed holes. catch is the slow stuff was really good before this valving which is why i havent done that just yet. plus im heavy soo even those tiny holes probably make an overall difference.

i went back to the .010 for the main, then .015 for everything else, but double stacked the .950 . i dunno im trying to get an idea of what shaft speed the change i make effects. the low double stack combined with the .012 main was pretty noticeable. plus i think that would get worse once i start to stroke the shock out more/drive faster.

besides bleed holes working both ends, do you loose some compression valving as well even at full lift or what ever the term is for the valving fully open? the original set up was actually decent at higher speed, just to soft between, really good slow speed, but you could drive through it pretty easily.

im probably asking bypass problems.. but cant fit em or afford them lol.
 
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