1992 F150 4 Link Valving Advice

[ricky.vazquez]

Looking for some guidance. Went from a single 2.5 coilover on the rear of the truck to adding a 3.0 4 tube bypass. Before with single coilover I was running double stack .020 shims and it felt very good only problem was thur very big gouts I would slam bumps. That’s the reason I added these bypasses. I Lowered the compression in the coilover to 0.015 and the bypass had a 321 .015 stack in it for the first test. It was super harsh with all tubes open. So now I took out the 3 biggest shims 2.000 diameter and only left the 1.800 and on. Now I’m thinking I lost all my bump zone. (Haven’t yet to try). I’m taking it out to hammers next week for the week. Going to do some testing and valving. Thinking about putting 0.012s or even 0.010s in the coilover and adding shims back into the bypass to get a good bump zone in. Does that sound about right or am I all fucked up. I’ll figure it out just the thought of driving my truck at hammers with a shitty valved rear is driving me crazy.

 

[theycallmeWALLY]

Rule of thump on shims from my understanding:
Biggest shims are flow low speed
Smallest shims are for high speed.

So you want all of those shims in place but you can adjust how many. Luckily we have @ADSRACINGSHOCKS on here that has helped with a lot of great information so far!

 

[mobil1syn]

coil over should be .010 on compression, .008 on rebound.

2,2,1 on the bypass. you said 4 tubes, but the tube layout is not clear.

do you have pictures or the pistons?

 

[ricky.vazquez]

coil over should be .010 on compression, .008 on rebound.

2,2,1 on the bypass. you said 4 tubes, but the tube layout is not clear.

do you have pictures or the pistons?

That’s exactly what I was thinking on valving too. I was in a time crunch so I did what I did. So I’m going to try it out tomorrow in Lucerne for KOH for the week. If it sucks balls I’ll definitely try out that. One thing nice about the valving I have right now is there is no bypass noise on the road before it did when it was rock hard

 

[Cleandezert]

did i read it right that you took out the 2.0 shims completely? so when you look at the piston you can see through the compression ports? You need those 2.0 shims to block the flow and then use the 1.8 and so on to back up the 2.0

the bypass noise is because the stiff valving was forcing fluid through the bypass tubes, if you had those wide open there is very little spring pressure on the poppets, so any movement will crack those open and start the clatter clank sounds. lol close those tubes some to increase the crack pressure of the popets

 

[ricky.vazquez]

did i read it right that you took out the 2.0 shims completely? so when you look at the piston you can see through the compression ports? You need those 2.0 shims to block the flow and then use the 1.8 and so on to back up the 2.0

the bypass noise is because the stiff valving was forcing fluid through the bypass tubes, if you had those wide open there is very little spring pressure on the poppets, so any movement will crack those open and start the clatter clank sounds. lol close those tubes some to increase the crack pressure of the popets

yes I took out the 2.0 shims completely due to not having enough time + correct thickness of shims in time for tomorrow. I ordered .010 and 0.08 from kartek so should be here when I get back. So yes the 2.0 shim is gone allowing fluid to bypass the piston leaving the bypass tubes not to work as much because of fluid bypassing from the piston. Sloppy mistake on my end realizing you want the bump zone as hard as can possibly be. So that being said once I get back from KOH I’m going to 0.010 in the coilover and back up to 221 0.015 in the bypass to get a hard bump zone.

 

[Cleandezert]

looks like you have a good plan together. I once too my ranger out with brand new bypasses that i had no idea what valving was in them and slapped them on the front.... front was so stiff it felt like my fillings were about to fall out. I was on a trail going to a popular spot to watch races and had a bone stock f150 pull up next to me and laugh he was faster than my race truck..... i promptly went back to the trailer and pulled those shocks off and tried to regain my ego. lmao

 

[ricky.vazquez]

Little update for you guys. Truck ran phenomenal at koh. Was able to hit everything I believe the truck is capable of. Minimal bypass clicking due to taking out the 2.0 shim. I do notice the coilover temp is hotter than the bypass but for now I think I’m going to leave it until I finish my swing steering hopefully before the more race on the 25th (I think that’s the date). Once I finishing the steering and drive it one more time I’ll probably revalve the rear again to get a better bump zone but like I said it sucks because it works so well hahaha

 

[theycallmeWALLY]

Stoked it worked well but it's for sure off if you are heating up your coilover more then bypass.

With that said. Run it.

 

[Giant Geoff]

First, I start with weighting it down completely. Get the spring rate right until you have 9/16" of space between each coil. I would start with 10/8 in c/o, 20/12 in b/p. Put a Zip-Ty on the shaft to see how much travel you're using. Adjust until you have a good balance front to rear.

 

[ricky.vazquez]

First, I start with weighting it down completely. Get the spring rate right until you have 9/16" of space between each coil. I would start with 10/8 in c/o, 20/12 in b/p. Put a Zip-Ty on the shaft to see how much travel you're using. Adjust until you have a good balance front to rear.

I’ll give that a try for sure thanks Geoff

 

[theycallmeWALLY]

First, I start with weighting it down completely. Get the spring rate right until you have 9/16" of space between each coil. I would start with 10/8 in c/o, 20/12 in b/p. Put a Zip-Ty on the shaft to see how much travel you're using. Adjust until you have a good balance front to rear.

Why are you looking for 9/16" between coils? Is that combined on each coil spring or is that on the main spring?

 

[Giant Geoff]

Why are you looking for 9/16" between coils? Is that combined on each coil spring or is that on the main spring?

I figured out an easier way to get the spring rate right and its by how much the coils are crunching at ride height. 1/2" space is too light of a rate and 5/8" is too stiff. It works will on 2.5" shocks but not on 3.0".

 

[ADSRACINGSHOCKS]

I figured out an easier way to get the spring rate right and its by how much the coils are crunching at ride height. 1/2" space is too light of a rate and 5/8" is too stiff. It works will on 2.5" shocks but not on 3.0".

it would really change between spring manufacturers wire diameters and pitch of spring change between all of them, a blue coil or betts is different than in an eibach or hyperco i can see the generalizing for eyeballing but there are alot of variables

 

[ricky.vazquez]

I figured out an easier way to get the spring rate right and its by how much the coils are crunching at ride height. 1/2" space is too light of a rate and 5/8" is too stiff. It works will on 2.5" shocks but not on 3.0".

I’ll definitely see where I’m at

 

[Giant Geoff]

I’ll definitely see where I’m at

It's a great way to get you very close. You can get more detailed if you're racing but this will make you perform at a great level.