Shock valving on heavy rigs.

[blistovmhz]

Really? You've brought it up in every post.

There's a line somewhere between spending money and wasting it. I try to stay on the left side of that line. Here in Canada, that line is a big thick neon pink line, guarded by bees so you can't accidentally cross it without knowing. When you lay down $100 for a set of the shittiest Chinese wheel studs that break off before they're even torqued, you know you've 1. crossed that line and 2. shopped at Lordco (essentially our Pep-Boys). Same goes for when you hand over a grand for a brake line you can fab yourself in 15 minutes for about $10, even if you've never built a brake line before and don't own a flaring tool.

If your'e going to pay someone to work on your vehicle in Canada, you may as well just pay them double to NOT touch your vehicle. You'll end up ahead that way.

I just do the math. What's my time worth, how long will it take me to do it myself (better than any shop will do here, even if I suck at it), and what's the shop charging. I think back to the previous owner of my first XJ, who spent $4500 or so trying to solve a problem that took me 2 weeks of "just sorta thinking about it" and 3 cents of wire to solve. Sure, I could try throwing another $4500 at the problem even though the first $4500 didn't count for shit, but that's 2-3 weeks of work for me. Why in the **** would I work at a job I don't want to be at for 3 weeks, to pay a guy for an hour or two of his time to NOT fix my Jeep?

 

[blistovmhz]

The other factor which I find is equally important, is that I want to know how my shit works. I've never found a shop here that will actually fix the problem you wanted fixed. Most do nothing and claim it's fixed. Others at least try, fail, and say it's fixed. You can only take your car in for an alignment so many times before you get pissed that the paint marks you'd put on everything before bringing it in, still line up where you left them.
Besides which, we enjoy figuring this shit out. If everything was free, I'd still be doing most everything myself, just so I know how.

 

[StinkyFab]

So buy some good shocks and start shimming. At least you'll have the equipment, if not the knowledge. Who knows, you could get lucky.

Main thing everyone is telling you is that there is no off the shelf solution. If you don't wanna find someone qualified to do the job throwing off the shelf parts at it isn't gonna fix anything either. At least if you buy quality shocks that can be revalved you can do the research and try to do the valving yourself. After many years building race cars and rebuilding hundreds of shocks and going to dozens of shock tuning sessions I can confidently say that I can sometimes get into the ballpark of decent, but to get it right I have to also get lucky. Maybe you'll get lucky, and maybe after tearing your shocks apart a few dozen times you'll actually get good. Either way you'll be ahead of your current plan.

FYI, opening up any of these shocks and changing valving is NOT hard. Knowing what to change it to however......

 

[blistovmhz]

So buy some good shocks and start shimming. At least you'll have the equipment, if not the knowledge. Who knows, you could get lucky.

Main thing everyone is telling you is that there is no off the shelf solution. If you don't wanna find someone qualified to do the job throwing off the shelf parts at it isn't gonna fix anything either. At least if you buy quality shocks that can be revalved you can do the research and try to do the valving yourself. After many years building race cars and rebuilding hundreds of shocks and going to dozens of shock tuning sessions I can confidently say that I can sometimes get into the ballpark of decent, but to get it right I have to also get lucky. Maybe you'll get lucky, and maybe after tearing your shocks apart a few dozen times you'll actually get good. Either way you'll be ahead of your current plan.

FYI, opening up any of these shocks and changing valving is NOT hard. Knowing what to change it to however......

And that's a good answer. Probably my plan at this point. I just wanna make sure I'm going to end up with big enough shocks on the first try, which is why it'd be nice to find someone else with a rig roughly my size and find out what valving they ended up at to get their ride less terrifying

 

[MoparManiac]

I think you're going to hard pressed to get people to just "give up" their shim setups.

Most people that did it themselves, have invested a ton of time into getting in the right ball park. Others are professionals and require payment for that kind of information. Nevermind that how your suspension is setup, front/rear weights, sway bar or lack of sway bar, and a host of other variables play into this. No two XJs are going to be similar. One little difference in a characteristic can require a different approach completely.

I would suggest, as others have, to research a bunch of shock theory, and figure out what you're trying to do. Race? Cruise down some trails? Sorry, don't know if you discussed that but I'm not re-reading all of this.

 

[ROBZ95Xj]

how much crap do you have in the back of your xj that the rear weighs 200lbs more then the frt

 

[blistovmhz]

I think you're going to hard pressed to get people to just "give up" their shim setups.

Most people that did it themselves, have invested a ton of time into getting in the right ball park. Others are professionals and require payment for that kind of information. Nevermind that how your suspension is setup, front/rear weights, sway bar or lack of sway bar, and a host of other variables play into this. No two XJs are going to be similar. One little difference in a characteristic can require a different approach completely.

I would suggest, as others have, to research a bunch of shock theory, and figure out what you're trying to do. Race? Cruise down some trails? Sorry, don't know if you discussed that but I'm not re-reading all of this.

Never understood the obscurity thing. I've got a lot of different backgrounds, but open-source software development had a big influence on me. I've always released everything I learn publicly. I'm sure there are other guys who'd be happy to share their valving. Yea, if it's your job I can understand why you would feel like releasing the secrets of your trade seems like a bad idea, but I'm pretty confident it would only benefit you in the long run. On the rare occasion that I pay someone to do something for me, my decision is always strongly influenced by how willing to share information they are. Again, from my strongest background (software/IT), secrets are scary. I will never recommend black box solutions to any of my clients because if I don't know what's in it and I don't know how it works, I have no reason to trust it. Paying for a black box means you're blindly trusting someone at their word (scary stupid IMO) or in some cases in their reputation (a little better, assuming you've heard good things from people you trust not to be retarded).

In my field, I'm not worried about making things so open and simple that I put myself out of work. Most IT people are awful (thus why everyone hates them) so when a client tells someone about me, I like to know there will only be good things said. Generally when I work myself out of a job, it lands me 3 or 4 new opportunities through word of mouth.

Besides which, when it comes to 4x4 junk, people are usually pretty open. It's all fine and good to be the baddest ass rig on the road, but then you have no one to wheel with (I have a hell of a time finding people in my area who can keep up, so I end up just building their rigs for them so I've got wheelin' buddies).

how much crap do you have in the back of your xj that the rear weighs 200lbs more then the frt

Fuuuuu! I have no idea how that happened. When I add up everything I've done to it, it doesn't make sense. I probably lost around 100lbs off m y ass recently as I've better organized my trail tools, but still no idea how I'm that rear heavy. I've got the same plating front/rear, roughly same weight in bumpers. The only thing in the back that adds a lot is the swing out carrier and 35" spare, but no amount of math seems to add up to the numbers I'm seeing on the scale. I'd rather lose a few hundred off the rear to balance things out than add it to the front, but as it stands, when I'm climbing out of a mud hole, my weight transfer kills me. My roomies sas'd k1500 usually has less issue pulling out of ruts than I do, and he's on bald 37's.

 

[cal]

XJ's from the factory are pretty even weight front to rear. It doesn't take much to make the rear weigh more.

The race jeep's heaviest corner is the front left, but the 2nd heaviest is the right rear.

Its the steering box and the jack. remove those and we're pretty close to even in all 4 corners.

 

[sidewaysstarion]

Its the steering box and the jack. remove those and we're pretty close to even in all 4 corners.

Racing without those would be rather interesting.

 

[rockclimber]

XJ's from the factory are pretty even weight front to rear. It doesn't take much to make the rear weigh more.

The race jeep's heaviest corner is the front left, but the 2nd heaviest is the right rear.

Its the steering box and the jack. remove those and we're pretty close to even in all 4 corners.

solution: spare steering box mounted to passenger uni-frame rail.

 

[cal]

solution: spare steering box mounted to passenger uni-frame rail.

Not until we can figure out how to make them active-active and delete the ram.

 

[ashmanjeepxj]

Shock valving will not replace the need for a sway bar. I raced KOH13 4,600lbs on an antirock sway bar rear only, it was too light and scary through woops at 60MPH and stepped up to a PAC 7/8in bar with ~16in arms, made a world of difference.

Antirock size 3/4in bar front and rear would do you good.

ADS shocks make a cherokee bolt on race shock, 2.125 in shock body ~$700 a pr. They keep a log book for each customer's custom valving. Talk with Brian he can go through his log book and get you close to a similar customers happy place, they will give you a free re-valve if you ship the shocks back. This would be a good entry level shock you could turn.

Shocks are not simple or math like your thinking. It is trial and error to match valving to your rigs geometry and driving style. There are low speed and high speed valving adjustments and linear or progress valving stacks. These extremely dynamic adjustments can not be measured by a simple compression/rebound number.

 

[blistovmhz]

Oh yea. So here's what I'm talking about with my shocks.


It's not horrible, but definitely not great. On the street it handles fine (nice even). On the trails it's not too bad, but on the rocks, you can definitely see it bounce around a few times before settling.
I'm thinking to confirm that I need something a bit stiffer, I'm going to see if I can find another pair 255/75 shocks to bolt into the stock rear location, to assist the bilstiens mounted through the floor. I figure if a set of 255/75 mounted at 45 degress helps things, that gives me a pretty good idea of my overall compression/rebound damping should be (255/75 + 50% for the second set at 45).

 

[DieselSJ]

Oh yea. So here's what I'm talking about with my shocks.


It's not horrible, but definitely not great. On the street it handles fine (nice even). On the trails it's not too bad, but on the rocks, you can definitely see it bounce around a few times before settling.
I'm thinking to confirm that I need something a bit stiffer, I'm going to see if I can find another pair 255/75 shocks to bolt into the stock rear location, to assist the bilstiens mounted through the floor. I figure if a set of 255/75 mounted at 45 degress helps things, that gives me a pretty good idea of my overall compression/rebound damping should be (255/75 + 50% for the second set at 45).

Yes, that is exactly it. Ignore all the great advice about having someone who knows what they are doing help tune your shocks and just bolt another improperly valved (for your rig) along side the current improperly valved shock. I'm sure throwing additional shocks on there will be a great solution and solve all of your problems.

 

[blondejoncherokee]

255/75 is just way too soft. You will need at least a 280/80 or something 300/100 or 300/90 I bet. but it requires some testing/tuning. Just like building a bastard pack.




my rig on 60/14b , 40s, 3 linked, is literally bottoming out the front 7100s (12" short bodies) just driving on the road( O ring hits all the way on the bottom of the shaft just driving to the trail)
I was running 10.5" prothanes with a 1" air gap. I am now adding some 1.5" DOM into them, since I think they are compressing way to much.

and I am blowing them out on the trail ripping out all 3 or 4 of the bottom seals on the trail therefore no front shocks driving home.

I am running 275/78. So that is too soft for me. And its getting a cage over winter so it will get more top heavy.

I ordered a custom set of shims after some research about heavier rigs since I carry so much weight and its only getting heavier, I am going to try 360/100 to start, since I don't think a small jump will do enough since its so soft as of right now.

and if that is too stiff for the trail, ill maybe bring it down , or vice versa , bring it up.

I just built a bastard pack for the rear and pulled the deavers, PAC 250LB progressives up front which actually seem pretty soft .

 

[blistovmhz]

That's sorta my thought as well.
An extra 255/75 at a 45 angle translates to roughly 127/37 for a total (combined with my vertical shocks) of 382/112. That may be a bit stiff, but it'll at least give me a second set of numbers at the other end of the spectrum, so I'll have an idea of roughly where I want to be.
Now to find shocks that'll fit in the stock location, without either bottoming or topping out with half my travel .
Given I'm running 12" vertical, I should be able to fit a 10" in the stock location I think.

 

[LEVI_KING]

how much crap do you have in the back of your xj that the rear weighs 200lbs more then the frt

chances are a 5.3 is lighter than a 4.0L by quite a bit.

oh ya, and Hasta

 

[rockclimber]

255/75 is just way too soft. You will need at least a 280/80 or something 300/100 or 300/90 I bet. but it requires some testing/tuning. Just like building a bastard pack.




my rig on 60/14b , 40s, 3 linked, is literally bottoming out the front 7100s (12" short bodies) just driving on the road( O ring hits all the way on the bottom of the shaft just driving to the trail)
I was running 10.5" prothanes with a 1" air gap. I am now adding some 1.5" DOM into them, since I think they are compressing way to much.

and I am blowing them out on the trail ripping out all 3 or 4 of the bottom seals on the trail therefore no front shocks driving home.

I am running 275/78. So that is too soft for me. And its getting a cage over winter so it will get more top heavy.

I ordered a custom set of shims after some research about heavier rigs since I carry so much weight and its only getting heavier, I am going to try 360/100 to start, since I don't think a small jump will do enough since its so soft as of right now.

and if that is too stiff for the trail, ill maybe bring it down , or vice versa , bring it up.

I just built a bastard pack for the rear and pulled the deavers, PAC 250LB progressives up front which actually seem pretty soft .

even with soft valving you shouldn't be ripping apart seals. you may want to invest in some limit straps and make sure you aren't getting bind in the shocks.

you should also probably step up to a larger shock. chances are the d60+40"s combo is just too heavy for those shocks.

 

[blondejoncherokee]

Its not droop but compression.
Made some inserts for the prothanes to make a hard stop so no more than 5" of up travel now. Which will fix the bottoming out part. Now the too soft part will be fixed by the new shims .


Adding a second set of shocks seems silly. Just buy the right shocks and be done . Play with valving until you dial it in.

 

[N20Jeep]

i don't believe that building a new mounting setup and installing a secondary pair of shocks is the answer.