Author Topic: Shock Help - PLEASE (Read 2337 times)

BlackYJ · « **on:** December 11, 2006, 07:05:20 PM »

Alright he is my story, I have ordered some custom 3" lift leaf springs for my YJ as well as some 5/8" lift shackles and I am trying to figure out what length of shock I will need. I know the best way is to get the lift installed and then measure but I would like to try and figure it out before hand.

So my main question is should a shock have equal amounts of up and down travel or are shocks usually proportioned for either more up travel or more down travel?

ornamental · « **Reply #1 on:** December 11, 2006, 07:34:56 PM »

sounds like a trick question.

i dont think it matters as a shock is valved to travel in 2 directions. rather than only 1 direction and a resovoir of some sort.

i think travel distance may be more important to a jeeps application.
up travel would need to be restricted by bump stops and clearance, how ever i think the more droop, the beter...
regardless, does Your YJ flex lol

BlackYJ · « **Reply #2 on:** December 11, 2006, 09:35:07 PM »

I should with these new springs. I have just trying to figure out how the shock should setup while at ride height. If it is a 50-50 split or 60-40, 40-60, etc. I know the bumpstops should limit the upward travel and the spring should stop the downwards travel

Brink · « **Reply #3 on:** December 11, 2006, 10:18:44 PM »

It'll depend on the stance you are going for. What tire size on that lift? How far will the tire be from the fender at ride height? No reason to have any more up travel than there is room to go up.

Lower the better IMHO. I'm running mine severely biased towards down travel. And actually plan to tweak it even more so this winter.

Down travel is far more usable travel than uptravel for us. Unless you are a prerunner or jumping the jeep all the time that is. Those would be the only 2 examples I can think of that would benefit from extra uptravel.

BlackYJ · « **Reply #4 on:** December 12, 2006, 07:14:59 AM »

I will be staying on 33s with this setup.

So Eric you are saying probably a 60% down and 40% up would be a good starting point?

Bnine · « **Reply #5 on:** December 12, 2006, 07:48:04 AM »

If you lift amount is constant, then your uptravel decreases as you increase tire size.

So if you went from 33-35's, you would need to bumpstop another inch or so. Meaning by stopping uptravel sooner, you could afford a slightly longer shock.

And vice versa. Reduction in tire size allows room for more uptravel.

I have Denis's tuned to about 60/40, but that is with really long shocks, and custum shock mounts that are raised from stock.

Easiest way to find your longest shock allowable.

Get fully stuffed, measure your shock from eye to eye, minus half an inch. That is the longest compressed length you can run, regardless of what suspension you run, since its tire clearence and bumptops that are the limiting factor.

As in, you dont need your lift in, you just need that length when the tire you are going to run is stuffed right into the fender.

Hope that helps Scott.

BlackYJ · « **Reply #6 on:** December 12, 2006, 09:35:31 AM »

No that did not really help me much

. I will definitely go measure and see what I come up with

Hey Bill, you did not happen to measure these long travel OMEs you installed on the guys YJ did you

Bnine · « **Reply #7 on:** December 12, 2006, 09:46:25 AM »

I have in the past but dont remember the exacts. Im pretty sure they are around 27 inches extended, with 10 inches of travel, meaning right around 17 inches compressed.

Bnine · « **Reply #8 on:** December 12, 2006, 09:47:08 AM »

I have another set coming in this pallet, I can measure them then to be sure.

BlackYJ · « **Reply #9 on:** December 12, 2006, 05:01:59 PM »

I talked to Modern today and they gave me the measurements for the extended shocks, but thanks for the offer

Brink · « **Reply #10 on:** December 12, 2006, 06:20:09 PM »

Bill's right about not needing the springs in to measure for the shocks compressed travel. Set it up so the tires are almost rubbing. Then measure the shock. This won't change with any spring you want to install. Say that's 15"...... now you do need to take a good guess at your new ride height. Then take that measurement. Subtract the 2 and that's the max uptravel you can fit. Now just multiply that by whatever ratio you feel like your suspension should have (your 40/60 up/down is in a pretty good ballpark IMHO)

So using some easy numbers that could be.....

15" shock at full comp.
20" shock at ride height
5" uptravel
40/60 = 5/7.5 = up/down travel

That leaves you with a shock length of 15" compressed and 27.5 extended.

It's a simple example with easy numbers but hopefully it makes sense. It does depend on you having an idea of ride height the springs will provide though.

BlackYJ · « **Reply #11 on:** December 13, 2006, 08:24:44 AM »

Thanks for the insight guys, I when definitely be measuring this weekend

TrappersJeep · « **Reply #12 on:** December 13, 2006, 10:37:31 AM »

It's been good reading this post, I've been "piggy-backing" along and getting all the tips along the way too, as I'm also looking at getting some longer shocks for the newly upgraded lift and tires and wasn't exactlky sure how to go about getting the correct size. Looks like I'll be doing some measuring this weekend as well. :lol: Thanks. :lol:

BlackYJ · « **Reply #13 on:** December 14, 2006, 07:20:56 AM »

Geez, those E-towners piggy backing off the Calgarians again

.

Well I took the punged and ordered some OME LT shocks, so I will see how they turn out. I measured my dads last night and his shocks were sitting at about 22.5" with 3" of lift, so the LT should be just right, I HOPE!!!! :? :?

Also the funny thing is that the YJ OME LT shocks have MORE travel than the TJ ones, I guess it shows that leaves flex more than coil and need more travel.

TrappersJeep · « **Reply #14 on:** December 14, 2006, 08:56:26 AM »

Quote from: "BlackYJ"

Geez, those E-towners piggy backing off the Calgarians again .

It's easier that way...kinda like management - let someone else do the work and then reap the benefits :lol: