Fox Shock Tuning

I would imagine that a number of people on this list are probably wondering (or unsure) what shock changes could improve their rig's handling and stability. I am going to try to use this thread to document what I have tried and what type of results I have obtained with various settings.

My opinions of the stock setup was that the rear end wanted to wander side to side a little during large whoops at high speeds. Body roll was heavy and steering was difficult. The rearend wanted to buck badly over small (1 foot tall) bumps and when taking table top type jumps where the entrance was short to the jump.

My first change was to take some nitrogen charge out of the shocks all around to make it sit a little lower. I found the stability better and the steering a little easier. Body roll was still heavy. Rear still wanted to bounce around side to side during whoops. I ran 3 races in this configuration. Placing top 3 in overall times in all 3 races. Rearend still bucked badly and jumps with short entrance ramps were SCAREY!

Second go-around I revalved and changed fluid and pressures to be as follows:
Front:
50 compression (stock = 35 compression)
70 rebound (stock = 45 rebound)
300 ccs of fluid (stock = 275ccs)
200 psi (stock = 200psi)

Rear:
90 compression (stock = 75 compression)
85 rebound (stock = 85 rebound)
350 ccs (stock = 300ccs)
210 psi (stock = 200 psi)

I ran this for one race as well as for a day at the dunes. Rearend was bucking badly, still, possibly worse than before. Handling over the whoops was better and didn't seem to have the backend bouncing side to side hardly at all, although still had just a touch. Ride height is a little high, making steering a little difficult. I placed 3rd overall, in time, with this setup. Was good in the dunes with the additional up travel when landing off of large jumps. Looked cool too.............

3rd go-around, and at my current setup. I am trying to speed up the rebound in the front in order to try to get the front end to come up faster over humps and jumps in order to match the rearend.

Front:
70 compression
30 rebound
300 cc's of fluid
175 psi

Rear:
95 compression
85 rebound
350 cc's
210 psi

I plan to test it this weekend. I will report how it works after this weekend when I get a chance to try it.

BTW: Properly setup Elkas have proven to fly straight off of table tops and such, land MUCH better, and handle small berm type of humps with ease (no bucking!!!). So this valving thread is really just leading up to me getting Elkas!

Where are you buying all the supplies to work your foxes over?

Are you using stock Fox fluid? What weight of oil?
Changing to a heavier weight of oil may help. Synthetic vers. Dino oil?

Thanks for letting us in on this info.

I found this valving info at Fox's web page.
http://www.foxracingshox.com/fox_tec...VING_SPECS.pdf

Rebuild info ...
http://www.foxracingshox.com/fox_tec...ON_REBUILD.PDF

I am buying the valving kits from Poly Performance, online. Only because I am lazy and don't feel like driving around town to find some. You can buy an entire valving kit for $250 (or so) or just buy the valve sets for $5 each. I bought several valve kits so I can mix and match to get the overall settings I want. I am about $40 into it with respect to valve kits.

I am using a 5weight syntheric racing fluid (Belray brand). It is pretty thin right now. I am considering putting a heavier weight in the rear in order to slow it's rebound even more, because I am at the max on valving. But to be honest, with a rig that weighs 1000 lbs with me in it, and only about 300 pounds per rear corner, I really shoudn't need to go so high in valving AND go to a heavier weight oil. I could understand it some if I was running a 1500 or 2000 lb sand car or something. But an 850 lb car....................I'm not sure oil weight is really the right direction. I am going to keep playing with the valving........then think about oil weight. This weekend will help me to know if I am heading in the right direction or not.

I've sent an email to Fox asking for their input. I'll let you know if I hear anything back.

I've changed oil weights in the past, with dramatic improvements. If you've reached the end of your valving choices, a heavier fluid is the next step.
You might try going back to the stock valving and use a 10w fluid.

All of the below are synthetic fluids.

Belray has a 10w in the HVI line

Redline Oil has a 10w Medium

Torco has a RSF light (5w) and Medium (10w)

Amsoil has "Shock Therapy" 5w and 10w

Went out to test the setup today. I absolutely love the front setup. I handles really well over whoops and is especially nice coming into washed out areas as the front end doesn't want to bottom and dig. Rebound seems good too and keeps the front in contact pretty well.

But the rear...........that's still a problem. The only way I could describe it is that the rearend feels "slick". It wants to wander and slip around quite a bit. SEemingly worse than before. But, the car didn't buck quite as bad as any of the previous setups. But it still bucks. I think I am going to try dropping the compression valving down to 70, keep the rebound hard, and go try it again. I think if I could get the rear a little softer (it didn't seem to want to work like the front), it might seem more solid and prevent the bucking a little more. I don't know that I will ever be able to get rid of it over a 1 or 2 foot berm, but it should be getting closer.

I will be trying to get it revalved over the next week and maybe get a chance to try it again shortly after that. AGain, I will report my findings.

But for now, the front seems right on. Just need to figure out the rear.

What was your final set up for the front?
With most of the weight in the back, its going to be harder to control.

Tire bounce is problem too. I noticed the Maxxis Bighorns I have, don't bounce, like the Carlisle's did. Big horns are 6 ply radials. The 2.0's would be lighter than the original Bighorns.

Front was as follows:

Front:
70 compression
30 rebound
300 cc's of fluid
175 psi