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Shock Advice, Moving from 2.0 to 2.5

triple_fcked

triple_fcked

Member
Joined
Nov 9, 2023
Member Number
7072
Messages
23
I currently have a set of old Fox 2.0 race series that I’ve been playing around with tuning on my leaf spring 4Runner. I feel like I’m pretty close to dialed in on them, and I’m happy with the performance.

Problem is, given the high amount of desert driving I do, I keep overheating the shocks, so I wanted to move to a 2.5 shock to help with this.

My question, if I move up in size, am I going to have to start from scratch tuning, or can I base the tune on what I have in the 2.0s. Super new to tuning shocks, but would love more experienced folk’s input!
 
Yes your valving will be different.

Post up the specs on the truck and we can give you a ballpark guess. Which means you'll get 10 different answers from 10 different people.
 
mobil1syn said:
what makes you think you are overheating them?
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Mainly getting leaks after 2 trips in on them, and they perform great for the first half of the day, but once they get hot they fade quickly. I get talked into doing literally hours of desert driving and razr burn by the guys I camp with, the shocks get so hot I can’t even put a hand on them.

I admit I could be getting my bleeding procedures and rebuilds wrong, but I think it’s just that I’m asking too much of them.
 
Front shocks are 12’s comp / 8’s rebound and an air bump, these seem to stay cooler than the rear. No stickers melted yet; I think the hydro bumps take some of the load off of them.
Rear shocks are 12’s comp/15’s rebound. These were the stock 30/90 valving when they came to me, and All I did was add a new comp stack, just trying to change 1 variable at a time.
The stickers were taken off so no melting on those either. The rear seems to leak more often than the front, and while they feel good so far, maybe the rebound is too much?

All shocks were ran at 150 PSI and Put up to 200 for a leak test for 72hrs before installation

I’m not married to the idea of spending more money so if there’s something to be optimized on my current rig I’d favor that.
 
15's are way to much rebound in the rear. How many bleed holes open?
 
bdkw1 said:
15's are way to much rebound in the rear. How many bleed holes open?
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2 holes, out of the 4 that are piloted, this style piston
 

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Rear should be an 8 or an 8-10 stack with 3 bleeds open.

Is the front still A-arm?
 
bdkw1 said:
Rear should be an 8 or an 8-10 stack with 3 bleeds open.

Is the front still A-arm?
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I should have opened with context for the truck. It’s a solid axle 2nd gen 4Runner, 22re, on Toyota axles, 40’s, caged. Basically a cookie cutter rock crawler.
But given that I mostly wheel in Lucerne and Johnson Valley I’m trying to squeeze as much blood out of the turnip as possible, and I’m having fun so far just playing around with valving and rebuilding.
IMG_2291.jpeg
 
200psi in the reservoirs, kick anyone who tells you different in the shin.

the rear sucks because you have it choked up with .015s on rebound. the .008s you took out from compression, drop those in for the rebound(pay attention to shim diameter, the compression cover shim is larger than the rebound)

if you want to polish the turd so to speak, find someone who can tig weld and put the reservoir port on the lower part of the body. this will reduce cavitation on the the compression stroke.
 
Thanks guys, I’ll try and get these more dialed in with y’all’s advice before dropping any coin on 2.5’s. Appreciate it!
 
OK, front needs another bleed open too. Resi out the bottom will change your valving. In a good way. It will gain about 15% more damping on comp. You can also run some high speed valving to help out with big hits since cavitation won't be an issue. Resi out the top needs 200 minimum. Resi out the bottom needs more than like 75psi......

Also, short resi hoses will help with heat exchange between the shock body and the resi's. More fluid in the resi also helps, setting the IFP depth can help in a lot of ways.

That being said, 2.5's mo better.......
 
bdkw1 said:
Yes your valving will be different.

Post up the specs on the truck and we can give you a ballpark guess. Which means you'll get 17 different answers from 10 different people.
Click to expand...

FIFY
 
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