Amateur Shock Tuning Hour

[DRIVE Jon]

Based off my last thread, I decided to valve the 10" SAW 2.0s for the front suspension on my Toyota Taco with greater compression valving... than rebound valving. I am using 4, .012" shims on compression and 3, .010" on rebound. From what people said before...my rebound valving might be a little light, but I have to start somewhere, and I don't have any .008" shims around. These shocks are small...but will eventually be lightly valved coil-carriers when I get bypasses. link to my last thread on the subject http://www.race-dezert.com/forum/showthread.php?t=31577&highlight=shock+tuning

I have a couple questions:

1. On these old SAW shocks, there are 2 bleed ports..and they are both open right now. How many bleed ports shoud be open?

2. What is a good torque value for the piston-bolt on the shock shaft. I went for 50lbs... Looks like a 5/8 thread...so it could probably take more...but 50lbs felt pretty good.

3. Last question...can i use teflon tape to seal the pipe-threads for the resivoir hose or should I use a liquid sealant...which-one?

Just for some vehicle info. 1998 Toyota Tacoma, 4wd, weight of the front half of the truck is about 2,000lbs(approx). Springs are dual/rate. Combined rate of both springs = about 450 lbs. Secondary rate when divider hits stops is 800lbs...for the last 20% of the travel. Suspension travel will be 13-15". Shocks are mounted a 11" out from iner pivot on a 18" long lower arm.


Also...any other ameteur shock-tuners...feel free to use this thread to share experience about tuning shocks...and anyone feel free to ask questions. It seems like the shock-tuning stuff is very specific to the vehicle/driver/terrain, but I am sure there are some general concepts that can get us started in the right direction. I plan to share my experiences as i try to tune these shocks.

[DRIVE Jon]

Anyone know if I should plug-up one of the bleed ports?

Please feel free to discuss shock tuning stuff on this thread. I get the feeling that shock tuning is one of the most secretive parts of off-road racing....so I don't know how far I will get with this thread...but it would be cool if the pros wanted to mention some fundamentals of tuning a couple types of different vehicles...maybe buggies, and trucks. Maybe there aren't really many fundamentals...its all case by case?

For instance, In a truck like mine (mini-truck, mid-travel) that it is best to have more dampening (thicker-shims) on the compression side, than the rebound side...so the wheels drop-out quickly...stay in touch with the ground. Does this hold true for all desert vehicles?

If anyone else would like to learn about this stuff, speak-up.

[Kritter]

35 ft-lbs with red loctite on the nut max. The tighter you go the more it effects your valving. 10-15 ft-lbs with a staked nut is optimal but not realistic.

will this truck be driven on the street? If so what ratio?

What's the bleed hole diameter?

Dont compare your compression to rebound valving as far as saying heavier or lighter then as its of no relevance in tuning, only compare it to itself.

[DRIVE Jon]

Thanks for the reply Kritter.

The bleeds are 6-32 holes..i'm pretty sure. So that would be about .136" dia. I will check tonight..they could be 4-40s

Thanks for the info on the nut. I will redo it...with some loc-tite.

The truck will be a daily driver, but just a few miles on surface streets to work and back. When I do go on the freeway(we usually take my wife's car), I don't go over 60...just like to chill in the slowish lanes. So I am willing to tolerate a more loose vehicle, but I wouldn't go againt advice that makes sense for my situation. I'm 31, I don't do carzy stuff on the roads..I save it for the desert. But you can't help it if someone pulls out in front of you! We tow the vehicle to the desert every few weekends during the season. i believe this is what you ment by ratio..not motion ratio...I hinted at that in my first post.

I see what you mean about how to approach compression/rebound valving. I believe what you are saying is:

The compression valving is related to the weight of the vehicle, motion ratio, the terrain/and desired handling performance(driver preference), and heat limitations...for a start!

The rebound side I believe is slightly more straight forward...meaning the force exerted is a know force (spring-rate)...the force of the spring trying to fling the suspension back to full extension. And of course there is also some handling performance effects. Too little rebound dampening...vehicle bounces back into the air after suspension is compressed...too much dampening and the wheels stay in the air after being compressed, and don't return to ride-height/full droop before hitting the next bump and lose traction. And if you increase your spring rate, you also have to increase your rebound dampening?

This is really simplified i'm sure, but let me know if I am on the right track.

This is the kind of fundamental chat I was hoping for. It helps me stay focused on the basics...and stay away from generalizations!

Thanks again,

Jon

[DRIVE Jon]

I checked the bleed holes....they are 4-40 threaded...so about 0.1" dia. There are 2...both open as of now.

[tltony]

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