Fox top out washer?

osidepunker

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So let me start by saying I'm a complete n00b when it comes to shock tuning, but I've been running my truck for years and I'm starting to learn a few things. I have a question about the top out washer:

Is there a reason why someone would remove the top out washer in a bypass?

Background:

2013 Tundra weighs 4100 lbs on the front axle, 3900 rear axle. Shocks are Fox
Front: 16" travel, 2.5 coilover and bypass, stock rubber frame bumps
Rear: 17" travel, spring under axle, 2.5 bypass, 3" fox bump

The suspension used to be plush and I could still take decent whoops, but I was having problems with the leafs sagging and my 700# coils were binding. So I had deaver make me some custom 3" wide leaf pack (stock are 2.25" wide) and I switched the coils to 800#. Now I have more than 50% uptravel at all 4 corners and its pretty even all around.

I also switched the pistons in all 4 bypasses to "low flow" pistons (coilover wasn't touched, some kind of aggressive flutter stack). The guy who switched the pistons, changed the stacks as well. Formerly all 4 were a form of 4.3.2 stack with a single flutter. The guy removed the flutter and also removed the top out. So now I have 4.3.2 stacks with a low flow piston and no top out.

It drives very well over the big stuff but its a little rough over the chop. Also, I am blowing through the bottom zone a little more than I was before the changes which makes me think I need to put the top out back in. I am considering dropping down to a 3.3 stack and putting the top out back in, but I am curious why the last guy removed it. The work was subbd out so I don't know who it was that did it. Plus I am going to stop letting others do my revalves as I want to learn how to do it myself.

Here are a couple videos:



 
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I'm so old I remember when those trails were smooth and Cinder Lake was flat except for the NASA digs.

Give RaceShock's Lee Bob a ring at (602) 505-3700 and ask him.
 

gwizz

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not real sure about that top out washer.. as far as i can tell its there to protect the compression valving from getting hammered at full extension, not real sure why someone would take it out especially if they went low flow piston. as far as the other changes uh every shock guy (including this one) who isnt physically tuning your truck is just guessing. my guess with the bypass is you would want to go more aggressive with the valving thats in it and tune out the negatives of that using the tubes since your already blowing through your bump zone more than you want to and there is no tube for that. its probably what your tuner guy was trying to attempt by changing the pistons to cut orifice size tho this doesn't make sense for 1:1 ratio set ups like your leafs in the back. (or he was stealing the high flows cause im pretty sure those 9 holes cost extra) as far as low speed ride, tune that with your C/O. easiest done by going real light on the big low speed stacks, or with a flutter but again its all a guess. your best bet is to buy a bottle/regulator and get a couple stacks that give you a decent range of shims. tools arnt that crazy. soft jaws for the shaft and spanner wrench.
 

osidepunker

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not real sure about that top out washer.. as far as i can tell its there to protect the compression valving from getting hammered at full extension, not real sure why someone would take it out especially if they went low flow piston. as far as the other changes uh every shock guy (including this one) who isnt physically tuning your truck is just guessing. my guess with the bypass is you would want to go more aggressive with the valving thats in it and tune out the negatives of that using the tubes since your already blowing through your bump zone more than you want to and there is no tube for that. its probably what your tuner guy was trying to attempt by changing the pistons to cut orifice size tho this doesn't make sense for 1:1 ratio set ups like your leafs in the back. (or he was stealing the high flows cause im pretty sure those 9 holes cost extra) as far as low speed ride, tune that with your C/O. easiest done by going real light on the big low speed stacks, or with a flutter but again its all a guess. your best bet is to buy a bottle/regulator and get a couple stacks that give you a decent range of shims. tools arnt that crazy. soft jaws for the shaft and spanner wrench.

Thanks man! This is good information. I understand this is all guesses, but that is what I am looking for prior to doing my first change. My goal here to learn about valving and get my truck dialed in myself. I already have N2 and I will be getting the rest of the tools in a couple weeks after my Baja trip.

You confirmed what I was thinking about the top out. I am going to put that back in on all four corners and go back to the correct Fox stacks as a starting point. I am hoping that putting the top out back in will keep me from blowing through the bump zone.

For the front my low speed compression feels good in the coilover, if I open the bypasses, I get a nice smooth ride that is still somewhat controlled. Its the bypasses that introduce harshness on the chop, but yet I was still blowing through the bump zone. So I will put a 3.3.2 stack with the top out and keep the low flow pistons in the bypass and see what happens.

For the rear, same thing. The bypasses are harsh on the chop. I am not blowing through the bump zone as bad as in the front because I have separate bumps. I have them set at 250psi, I'm using all the travel on the really hard hits and it feels pretty controlled. But in order to have a decent ride I have to have the 1st and 2nd zone opened up a lot so I'm basically relying on the bump zone for the high speed compression. So I am thinking to put in a 3.3 stack with the top out and keep the low flow pistons.

Do you think I am on the right track here?
 

partybarge_pilot

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At that size shock, low speed harshness is not coming from the BP, The CO has to much, this is hampering the BP's ability to do it's thing. The top out washer also limits the shims travel and will really increase the high speed damping. This will help with the big holes. BP's should almost never have flutter stacks.

If it's still harsh in the chatter, time to open up the CO's and pull a bleed screw.
 

gwizz

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also i take back what i was saying about the shock guy stealing the high flow pistons. i get what he was trying to do now.


i wouldn't drill bleed holes. you need as much dampening as you can get.

also if you going to post a vid do one where its doing something you dont like vs smashing baby whoops.

 

osidepunker

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eh lurked your vids, your to heavy. you need bigger shocks.

Yes I agree, I'm too heavy haha 8000lbs, 4100 in the front, 3900 in the rear. Buuut I can't afford bigger shocks at this time so I'm gonna have to make do with what I have. I understand that bigger shocks will be easier to dial in the valving, but I'm pretty close with the 2.5s and I am not overheating them. The fronts never get too hot to touch. The rears do, but my guess is not more than 200 degrees. Although I did just buy an IR thermometer so I can track the temps.

also i take back what i was saying about the shock guy stealing the high flow pistons. i get what he was trying to do now.

i wouldn't drill bleed holes. you need as much dampening as you can get.

also if you going to post a vid do one where its doing something you dont like vs smashing baby whoops.

Well I didn't post this video because when I did that run I was on softer coils and the leafs were totally different; 2.25" wide and only 4" uptravel. I've since corrected my spring problems and changed pistons and valving. I went from 700# to 800# coils in the front and 3" wide leafs in the rear and now sitting on 8" uptravel
 

osidepunker

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At that size shock, low speed harshness is not coming from the BP, The CO has to much, this is hampering the BP's ability to do it's thing. The top out washer also limits the shims travel and will really increase the high speed damping. This will help with the big holes. BP's should almost never have flutter stacks.

If it's still harsh in the chatter, time to open up the CO's and pull a bleed screw.

Well like I said, if I open up the bypasses all the way, the coilovers are nice and soft, low speed is good on the coilovers. I believe they have a single flutter, down south sent me a stack and I had someone else throw them in so I don't know exactly whats in there. But my plan is to open them up and measure them.

Thanks for confirming what I was thinking with the top out washer. That is what I would like to do, put the top out washers back into the bypasses so I can increase the high speed dampening for the really big stuff.

and yes, I will not have flutter stacks in the bypasses, I will do 3.3.2 stacks in the front and 3.3 in the rear as a starting point.
 

gwizz

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Yes I agree, I'm too heavy haha 8000lbs, 4100 in the front, 3900 in the rear. Buuut I can't afford bigger shocks at this time so I'm gonna have to make do with what I have. I understand that bigger shocks will be easier to dial in the valving, but I'm pretty close with the 2.5s and I am not overheating them. The fronts never get too hot to touch. The rears do, but my guess is not more than 200 degrees. Although I did just buy an IR thermometer so I can track the temps.
its not about the heat, its about the dampening ability of the 2.5 piston vs a 3.0 for the rear and what its doing free flow. have you done an air bump on the rear yet? if you haven't do a 2.5. or just save up for the 3.0s or bigger. as you go harder with the valving youll see a noticeable difference in temp in the shock.
 

osidepunker

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its not about the heat, its about the dampening ability of the 2.5 piston vs a 3.0 for the rear and what its doing free flow. have you done an air bump on the rear yet? if you haven't do a 2.5. or just save up for the 3.0s or bigger. as you go harder with the valving youll see a noticeable difference in temp in the shock.
Yes, I have 2.0 3" air bumps in the rear set to 250 psi. My bump zone in the rear is good, I'm just trying to put stacks in so that I can close the tubes a little without it getting harsh. Right now they're halfway open so I can keep it soft over the chop but I don't really feel the middle zone
 
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