PDA

View Full Version : Useful Shock Travel



BD-VX99
11/27/2005, 02:28 PM
Has anyone ever unhooked their torsion bars and then raised and lowered the suspension, stop to stop, to measure how much of the available shock travel is actually being used in the stock setup?

Front 15.35” extended x 10.24” compressed
Rear 19.25” extended x 12.54” compressed
(by the way, are these correct for the stock KYB’s?)

Presumably there must be some small amount of extra unused travel at each the compressed and extended limits to prevent the shock from being damaged (thanks Joe). If this is the case then how much? Obviously, you guys know where this is leading. I’m preemptively searching for shock options and would like to know the TRUE required compressed/extended lengths rather than what is actually available on the stock KYB’s. I’ve tried to search for this but have come up empty. I’ve read many posts about what fits and doesn’t, and what works and doesn’t, but in this case I might go to custom mounts and/or end caps. What I’m really after is what the actual travel measurements, and mount to mount distance at full compression would be if the shocks were removed. Another thing (more of an opinion question): How much “unused” travel would you guy recommend leaving at either compressed/extended limits to avoid damaging the shock?

Thanks

SPAZZ
11/27/2005, 08:12 PM
be carefull!!!


If you get too much travel with the rear shocks, with articulation your springs will come out of the seat and then when your VX comes back down it will crush wiring and who knows what else when the springs gets pressed wrong. Also, just by disconnecting ONLY ONE SIDE of the front and rear swaybar you will get more articulation/travel.

If you get too much travel in the front with too much angle the cv's start breaking. The axle dropdown brackets help, but it would be nice to put an Atomic axle in there or better shafts with ujoints instead of the cv castle/bearing setup Isuzu uses. Also, if you have a lifted VX make sure you flipped your upper balljoint to mount underneath instead of on top.

So....these are the reasons your travel is limited. Get beyond these weak points and then you can start the other extreme mods. I personally am going solid in the front with a Dana 44. I want to do the extreme wheeling I do with my VX and not have to worry about the front axle breaking.

Joe_Black
11/28/2005, 12:33 PM
Check your PM box, I forwarded some info from a few PM's between Reg Hinnant and I while considering the Bilstien 7100 motorsports shocks. I had found an eye-to-rod shock mounting adapter at the time, but have since decided to follow the rally VX example of dual-shocks at each corner.

Swordy
11/29/2005, 01:43 PM
Your front travel is limited by your bumpstops. Changing your front shock length alone will not give you a significantly different travel.
Also you really need to be careful about the angle of your cv's at full A-arm droop since at 45 degrees, as much torque is being absorbed by the cv joint itself as is being transferred to the wheel.
As far as needing a little more shock travel than your suspension allows, yes, you do need that for about 95% of the shocks that are produced. Bottoming or over-extending shocks can damage the seals in a relatively short time. Stock there seems to be maybe a three quarters of an inch extra (at full droop) but its not extremely important how much. There just needs to be some.
Once you know exactly what you want, if you can't find it, Bilstien and Doetsch both have a custom shop and can build what you want, and its not as expensive as you might think. I already know what I would like to replace the fronts with, I just haven't gotten around to doing it yet.


I have already replaced my rears and love them, but I think maybe Bilstein BE5-6252-H5 might have been an even better choice
The Vx, and IFS vehicles in general usually need very stiff valving.
Hope this helps. Andy

BD-VX99
11/29/2005, 04:35 PM
Thanks guys.

My intent is not to look for more travel. I'm only trying to find options to better use the travel that we do have (and have a real cool setup as well). So I'd like to fab a stem style end cap to fit some of the rebuildable eye/eye shocks that are available. If the stock shock has a compressed length of 10.24" then I need to find an aftermarket shock with the same. However, if the bump stops restrict the shock from using the last say 1/2" of travel then I would only need a shock with a compressed length of 10.74" (minus the extra travel needed to prevent the shock from bottoming). So, for example... a fox 2.0 shock (5.10" travel) has a compressed length on 10.65" and an extended length of 15.75". Enough travel (5.10" to 5.11"), but too long when compressed (if only by a small amount). If that small amount isn't being used, then would I be fine not accounting for it when I fab the new end cap? In the rear, (using a fox 2.0 for example again) 6.69" of travel is available in the stock shock. Fox has a 6.5" shock. Close, but is it close enough? as the compressed limit the Fox shock would be fine, but it is almost 1/2" short when extended. If I really need that extra 1/2" (to prevent damage) then I could always fab a longer end cap for the rears aswell, but I'd rather not have to. Any thoughts? At this point I'm just fishing for options.

Swordy
11/30/2005, 12:28 AM
For our rear shocks, the extended length of the shock is actually what limits the travel. I "believe" the Fox shocks are good enough to handle that type of abuse. Alternatively you can use limiting straps to limit your extended length.
I have noticed that the specs on Fox shocks show longer compressed lengths for a given travel than other brands, or I probably would have used them myself.

There are stem converters avaibable commercially if you'd rather just buy them. I assume you must have some reason for not just using a rebuildable stem/eye shock?

As you know, For the front shocks, your compressed length needs to be slightly shorter than the distance between the shock mounts when the Lower control arms are bottomed out, and at least slightly longer when th the upper arms are on the droop stops. (including any adapter/cap you might want to make) It seems that the best way to do that is with an external reservoir shock since the shock bodies can be made shorter when the resevoirs are remotely located.
Too much travel won't be much of an issue for the front shocks, as unused capacity will just keep the shock operating cooler. I really liked the fox shocks too, but you might want to look into another brand that has the specs you need.