how much shock?

[smokey]

hey guys,
New here, looking to scoop up some info on setting up the suspension on my truck. Technical crawling is more what I'm used to, but want to diversify my truck a little. I've searched and read a ton, and learned a lot already, but I have a few questions. First of all, I'm not looking to race. Weekend wheeling only, and theres no desert up here (BC, canada)...so no 3' whoops. All I'm looking to do is be able to haul down rough deactivated forest roads (usually max one foot corrugations and the odd crossditch/water bar) and if I could catch the odd bit of minor air without damage that would be a nice bonus.
Anyway, my trucks set up more for technical trails right now. It's based on a suzuki samurai (i know, laugh me off the desert racing board). It's a light frame and body, and the entire drivetrain has been swapped out, and the wheelbase is being stretched about 10". Given that my sprung weight is only about 500 pounds per corner, I'm wondering how much shock I need. Would a 2.0" non res be enough, or will I regret that and look to upgrade later? Right now I'm on leafs, and dont have room to run anything much over 45" long. I've thought about linking it front, rear, or both, and going to coils or coilovers, so somthing like a revalveable 2.0" swayaway w/threaded body is appealing as it could be adapted to whatever configuration I wanted to run. How much of an improvement would i see going from leaf springs to coils? And then from coils to coilovers?

Lastly, am I totally kidding myself in thinking that this is feasible? Is there any way something with a 90-95" wheelbase and a total weight of about 2400lbs can work decently for this given this much unsprung weight? (solid axles, toy 8" front and rear with 34s) I'm looking at running a tall skinny tire to keep weight down, and nothing as heavy as a swamper, probably more like a bfg, and open to any setup, as far as leafs, coils, coilovers front, rear, or both.

Sorry for such a long post, just trying to give some background rather than just saying "what suspension should I get?"

thanks for any info/advice

[steveG]

I think a 2.0" reservoir shock per wheel will work fine for you as long as it's valved correctly. Especially if all you've ever used is Rancho or other similar "lift kit" shocks.

[smokey]

another thing i was considering was something like bilstein 5100s, which would save me a bunch of cash. if coilovers are overkill for what i want to do, bilsteins with either a leaf setup or coils would be much cheaper than threaded shocks like the swayaways or simliar higher end bilsteins.
on the other hand, I dont want to throw that money at some shocks that I might upgrade soon anyway.
thanks again

edit: btw, unsprung weight should be about (total) 330 front, 250 rear...sprung weight (per corner) 400 rear, 500-550 front

[offroadaction]

Hey Smokey, I sent you a pm with some info. One of the things I mentioned is to check out the short course racing in Kamloops at www.korrbc.ca as a lot of those guys can help you out. Sorry to hijack the thread....

[WannaB-class5]

sami's are fun! and budget is always the limiting factor. Can I suggest finding some used SAW 2.0's on this web site. All SAW are threaded body giving you the option to go coilover later. A 2.0 will work great, I can tell you that from experience. A res is only important if you need that extra oil for cooling. if your shocks aren't cycling much and you can just stop for a while IF you ever experiecnce fade, then don't spend the extra money. That said most of the used stuff in the classifieds have resi's.

[smokey]

havent had anyone say im wasting my time with a 90" wb and a truck thats 25% unsprung weight....nice to hear....my eyes are blurred from all the reading ive done lately, and I think I will try to find some sway's and go coilover later.

Would you guys limit travel based on wheelbase? Or once again, limit it by budget, steering gemoetry, driveshaft angles etc. I mean, would there be any disadvantages to setting it up for max travel (say 18") on such a short wheelbase? Or would it make for a more balanced rig to go for something like 13"?

offroadaction: thanks for the heads up, i'll see if i can get in touch...and id definately be up for taking in some short course racing....I didn't even know they were running here...problem is if i watch that, I wont want to stop short of something i can launch off a good size jump...LOL

[tsm1mt]

havent had anyone say im wasting my time with a 90" wb and a truck thats 25% unsprung weight....nice to hear....my eyes are blurred from all the reading ive done lately, and I think I will try to find some sway's and go coilover later.


Consider that 30 years ago, the Early Bronco on a 92" WB was duking it out with CJ7s and Scouts in the desert.. and they were all winning overalls.

Granted, that's 30 years of technology ago.. but they used to race bob-tails and do alright.



Would you guys limit travel based on wheelbase? Or once again, limit it by budget, steering gemoetry, driveshaft angles etc. I mean, would there be any disadvantages to setting it up for max travel (say 18") on such a short wheelbase? Or would it make for a more balanced rig to go for something like 13"?

offroadaction: thanks for the heads up, i'll see if i can get in touch...and id definately be up for taking in some short course racing....I didn't even know they were running here...problem is if i watch that, I wont want to stop short of something i can launch off a good size jump...LOL

First thing to do is get in touch with those short-course guys and start reading the rulebook.. :D

This should probably be another thread, but it ties into your 5125 ideas.

Can anyone tell me what the significant difference is between a Bilstein 5100/5125 and a 7100 schrader?

I've read numerous posts about bleeding off the nitrogen and installing a schrader into a 5125 and turning it into a 7100-schrader.

Otherwise, it seems the big deciding factor is you can't buy the 5125 with as many valving options as the 7100..

Point being, the 5125 costs half what the 7100 does, and works just as well if you don't need to rebuild them often and you don't need a reservoir.

As I've been upgrading, I now run 7100 res up front, and 5125s in the rear. I have a 700lbs small-block up front, and the front has to work the hardest. I'm on a 100" WB.

[ntsqd]

havent had anyone say im wasting my time with a 90" wb and a truck thats 25% unsprung weight....nice to hear....my eyes are blurred from all the reading ive done lately, and I think I will try to find some sway's and go coilover later.

Would you guys limit travel based on wheelbase? Or once again, limit it by budget, steering gemoetry, driveshaft angles etc. I mean, would there be any disadvantages to setting it up for max travel (say 18") on such a short wheelbase? Or would it make for a more balanced rig to go for something like 13"?

offroadaction: thanks for the heads up, i'll see if i can get in touch...and id definately be up for taking in some short course racing....I didn't even know they were running here...problem is if i watch that, I wont want to stop short of something i can launch off a good size jump...LOL

13" of well controlled travel will outperform 18" of semi controlled travel by a huge margin. There's a fellow up your way already headed down this road. I'm sending him the link. Might be able to help you.

[smokey]

First thing to do is get in touch with those short-course guys and start reading the rulebook.. :D

This should probably be another thread, but it ties into your 5125 ideas.

Can anyone tell me what the significant difference is between a Bilstein 5100/5125 and a 7100 schrader?

I've read numerous posts about bleeding off the nitrogen and installing a schrader into a 5125 and turning it into a 7100-schrader.

Otherwise, it seems the big deciding factor is you can't buy the 5125 with as many valving options as the 7100..

Point being, the 5125 costs half what the 7100 does, and works just as well if you don't need to rebuild them often and you don't need a reservoir.

As I've been upgrading, I now run 7100 res up front, and 5125s in the rear. I have a 700lbs small-block up front, and the front has to work the hardest. I'm on a 100" WB.

LOL, tempting as it would be, I dont think I would ever get into competing in short course racing, I'd love to go watch a couple races though, so I dont think the rule book would be an issue...not for my DD anyway...maybe next build up...

I was thinking the same thing for the Bil's. If you don't need the valving options, 5100s seem similar for half the cash...unless you want the added cooling capacity of the 7100 w/res. I know a guy up here running 5150s on the back of a coiled sidekick w/ Dana 44s fr/rr, and 7100 res up front. He seems pretty happy with that setup.

[smokey]

13" of well controlled travel will outperform 18" of semi controlled travel by a huge margin. There's a fellow up your way already headed down this road. I'm sending him the link. Might be able to help you.

What about 18" or well controlled travel?:D
Given a link setup capable of handling 18" without running into problems with rear steer, driveshaft angles/slip length issues etc, what would make the 18" only semi controlled as opposed to well controlled for the 13"? Assuming the same shock/coilover setup for both, just in different lengths?
I expect control arms would be around 40" long, so 18" of travel would leave them at a little over 25* from horizontal, so of course antisquat would be way higher at droop, but I don't imagine that would be an issue, would it? Considering this would only occur while the truck was off the ground, I cant see A/S being a problem.

Another option is 17-18" of travel at each corner, but with a limiting strap in teh center limiting total droop, but allowing articulation for slower trails/rock crawling.
thanks for the info guys!

[tsm1mt]

LOL, tempting as it would be, I dont think I would ever get into competing in short course racing, I'd love to go watch a couple races though, so I dont think the rule book would be an issue...not for my DD anyway...maybe next build up...


Would you believe you're not the first person to say/think that? Don't worry - you wouldn't be the first to change his/her mind. :D

My trail rig sees a LOT less attention since I started racing... and the next incarnation of the trail rig will look a lot like "backup racer" :D

[Scott_F]

Have you been researching on Pirate4x4.com? You will find more kin folk over there. Look for the 4 link calculator. I suggest you link it with coilovers. Go with the long travel, and 35" BFG ATs (light) or MTs.

[cosmo]

"Converting" a 5125 shock can be done.Although it's really not recomended and there is some work involved.The most difficult part that you will encounter is that the rod guide is not made to be readily removed.The 7100 rod guide is,as it has a groove cut into it. That way you can use two flat blade screwdrivers and pry up on it,removing it.Some simple calculations also need to be done to determine the oil volume.The 5125 rod guide can be grooved to aid in removel in the future once you have removed it.In my opinion,I would buy new 7100's with Res. and that way you can revalve and rebuild them youreslf.

[smokey]

Have you been researching on Pirate4x4.com? You will find more kin folk over there. Look for the 4 link calculator. I suggest you link it with coilovers. Go with the long travel, and 35" BFG ATs (light) or MTs.

Ive spent a ton of time on pirate over the years. That was actually where I heard about this site.....i think....one of them anyway...
The 4 link concept/tech isnt really new to me. I have a pretty good understanding of that as far as everything involved with squat/antisq, instant and roll centers, roll axis etc.
Really what I'm spending the most time debating is method of resistance, ie the spring and shock involved. I'm confident that whatever link system I come up with could handle what I want to do, but like I said, the whole "go fast" suspension setup is kind of new to me.
I'm wondering, for the recreational purpose I have in mind, what the performance difference would be from a good leaf setup with decent shocks, to regular coils, to coilovers. I tend to get very caught up in the tech side of things, and enjoy the research involved, and the satisfaction of something that turns out the way i envisioned it, even if it takes 4 times as long to get wheeling as a mediocre setup. I would rather spend the money on coilovers if I was stoked with the performance, than save my money with leaves and nice shocks, if it left me wanting more....

that said, I'd rather spend less on leafs/coils and a conventional shock system if i was satisfied with that performance....:rolleyes:

Judging by how few results came up, I take it something like fox or swayaway airshocks are not a hot ticket for high speed use? Ive heard to keep them off the street anyway, so it may be a non-issue. I would imagine they wouldnt much appreciate the repeated fast cycling of high speed use, seeing as how they need a relatively constant gas pressure to maintain the desired spring rate/ride height....nice affordable alternative though.

[smokey]

oh ya, other thing about pirate....great source of info for some things, but fast driving is kind of out of their element, and most of the searches there brought up posts like "this is a HARDCORE ROCK CRAWLING BOARD, you'd do better on something like...(fill in some racing site here)....."
most of them run with very little remaining uptravel to keep cog low, tender/helper coils for maximum droop etc....the kinds of things i didnt think desert guys would bother with, so i thought i'd come hang around here for a while.

thanks for the info so far.

not too many local shops here that carry this kind of stuff...one guy whos a fox dealer. Little pricier than the swayaways, but if i save duty, shipping, any other border fees etc, it comes out about the same.... I've gathered they perform about the same....more reading to do.

[coolcruiserfj40]

dont forget if you do link it and use coilover or air shocks y our rear will try to unload on desents

[tsm1mt]

dont forget if you do link it and use coilover or air shocks y our rear will try to unload on desents

I've been thinking about this little phenomenon.

Couldn't you dial out some of the "unloading" and "unrestricted droop" of a coil-over and/or air-shock system with bypasses?

Sort of the opposite of how a desert truck wants to go hydraulic lock at full bump.. crank up the rebound as you get closer to full droop and slow it down.

[ntsqd]

You're talking about by-pass damper. That quasi hydro lock function works on both ends of their stroke.

[negro3030]

hey SCOTT, personally, I had never been on www.PIRATE4X4.com before today, but I got to tell you, I definitely liked the CHICKS&RIGS link...