RE: Suspension.Is this really true?

[comtn4x4]

#700 gets stiff real quick when you start adjusting preload. At first I thought they were, of all things, too soft.. but a few twists ramped up the front fast. I’m running a steel bumper, steel winch rope, and two batteries, if that helps. I’m not a fan of the valving I’ve got, but 700# coils seem right.

If you want it truely dialed in have your truck weighed and let the suspension shop, whichever one you’re going with, calculate the appropriate spring rates.

What suspension are you running? I have a 650# coil now and it's not sufficient. And my nose is lighter than yours. Aluminum bumper, synthetic rope, only one battery. I'm not aware of a shop that has that capability.

 

[CF_Machete]

And all this being said now I want my stock suspension back to see if my 285/75's will fit! It's hard to imagine that they would

fyi, you can run 285/70/17's on a stock suspension if you push your fender liner fwd and trim your bumper, though I would not take it off road. I did this with my tires before my lift. Minor rubbing at full lock in reverse.

You can disagree. But it's still correct physically. It's just geometry. Everyone tells you the same thing because it's just a physical property of the system. If we could change it we would.

If you add a longer bump stop you can have less suspension travel and possible keep from rubbing in some cases - but that makes it worse off road. I'm not sure why you'd want to do that. You'd be better off with a smaller tire and full suspension travel.

totally agree with the physics, lifts do not add travel(long travel excluded), they just change the travel midpoint. But bigger tires do increase total clearance and a lift will increase angled clearance.

 

[Jetboy]

Ok this is really insightful. So if you don't mind let's talk the specifics of my situation. I started with my truck lift 2.5" in the front and very little extra weight. (650# Coil) As time went on, more weight was added. Sliders, aluminum bumper winch etc. You can see in my signature. So after the bumper and winch the front was too low. I cranked up the adjustment collar significantly to get back to the same lift height. The ride became much harsher. Now I am ready for new suspension front and rear. What coil should be used to better account for the additional weight that was added?

This is sort of a typical scenario. What you probably really want is more compression dampening in your shocks.

The front coils have about a 2:1 leverage ratio. So a 650lb coil means approximately 325lbs per inch of suspension compression. And that's on each side. So half of the combination of both 650lb springs means that each inch of suspension compression requires 650lb of force. If you added 350lbs of winch and bumper you'd expect the front to drop about 1/2" The coils on each side would need to be adjusted by 1/4" to regain that static ride height.

So hypothetically let's say you've done that and now you're back to where you started height wise, but the ride seems rougher. The most likely reason is that you're vehicle is now heavier and you have 350lb more force pressing down on the springs at the same ride height you had before. The rebound dampening is pretty important to ride quality. And you're not something like 15% change in force but the shock is the same. So you are probably feeling the difference in rebound dampening compared to spring force at the new weight.

Also I'd guess it's possible you've over compensated and now set the ride height taller. We all have a tendency to go just a little higher each adjustment. The higher you go the rougher the ride. The increase in angle of the control arms as you lift means that more of the road bumps are transferred through to the chassis regardless of spring or shock choice.

All that said- 700lb springs are probably about right. That's typically on the heavy end of the spectrum. Assuming they are the same unsprung length, going from 650 to 700lb springs will raise the front end about 1/3 of an inch. It's not a huge difference.

Someone like Accutune can re-valve your shocks depending on what you have and often improve ride quite a bit with the shock valving. It's sort of a question of budget and how much it's worth to get the extra bit of ride quality. Or go for a shock with adjustable dampening like the Old Man Emu setup that has compression and rebound adjustability.

 

[comtn4x4]

This is sort of a typical scenario. What you probably really want is more compression dampening in your shocks.

The front coils have about a 2:1 leverage ratio. So a 650lb coil means approximately 325lbs per inch of suspension compression. And that's on each side. So half of the combination of both 650lb springs means that each inch of suspension compression requires 650lb of force. If you added 350lbs of winch and bumper you'd expect the front to drop about 1/2" The coils on each side would need to be adjusted by 1/4" to regain that static ride height.

So hypothetically let's say you've done that and now you're back to where you started height wise, but the ride seems rougher. The most likely reason is that you're vehicle is now heavier and you have 350lb more force pressing down on the springs at the same ride height you had before. The rebound dampening is pretty important to ride quality. And you're not something like 15% change in force but the shock is the same. So you are probably feeling the difference in rebound dampening compared to spring force at the new weight.

Also I'd guess it's possible you've over compensated and now set the ride height taller. We all have a tendency to go just a little higher each adjustment. The higher you go the rougher the ride. The increase in angle of the control arms as you lift means that more of the road bumps are transferred through to the chassis regardless of spring or shock choice.

All that said- 700lb springs are probably about right. That's typically on the heavy end of the spectrum. Assuming they are the same unsprung length, going from 650 to 700lb springs will raise the front end about 1/3 of an inch. It's not a huge difference.

Someone like Accutune can re-valve your shocks depending on what you have and often improve ride quite a bit with the shock valving. It's sort of a question of budget and how much it's worth to get the extra bit of ride quality. Or go for a shock with adjustable dampening like the Old Man Emu setup that has compression and rebound adjustability.

You’re absolutely right about over adjusting to compensate. Initially I adjusted too far up and had to bring it back down. It was awful at first then more tolerable once I got it lowered.
I’m hoping the 700# spring will be ok.
I don’t recall any other shock than the OME with both compression and rebound
Adjustment? And considering I’m going to a whole new suspension is it worth looking into custom valving?

 

[Jeremy556]

You’re absolutely right about over adjusting to compensate. Initially I adjusted too far up and had to bring it back down. It was awful at first then more tolerable once I got it lowered.
I’m hoping the 700# spring will be ok.
I don’t recall any other shock than the OME with both compression and rebound
Adjustment? And considering I’m going to a whole new suspension is it worth looking into custom valving?

All rebuildable, race type shocks are adjustable on compression and rebound via the shim stacks. IME, most shocks with external adjusters aren't worth the cost of entry. The adjustment range is usually quite limited and worthwhile changes require tearing down the shock.

ETA: And yes, the person you were talking to is correct. When it comes to the 120/150 platform front end, you are generally just changing ride height in the same range of suspension motion. Bracket lifts and real long travel are different, but uncommon on this platform. Aftermarket UCAs can get you a bit of extra caster to help clear the body mount, but in general, if you actually use it off road a "lift" on this platform doesn't help your tire clearance at all.

 

[Throwback]

Interesting. So what does a lift using stock LCAs actually improve for off roading these things, assuming you need to run stock size tires for clearance under full articulation?

This forum is full of photos of sweet lifted rigs with big tires. Surely they're significantly more capable than stock suspension and tire size... right?

 

[bimrunner]

Interesting. So what does a lift using stock LCAs actually improve for off roading these things, assuming you need to run stock size tires for clearance under full articulation?

This forum is full of photos of sweet lifted rigs with big tires. Surely they're significantly more capable than stock suspension and tire size... right?

With the exception of LT or SAS it is looks and approach angle. Tires aren't dependent on lift unless you want 35s that don't always eat fenders. They still will with stock fenders on LT fyi. This is why when you go to big tires you are doing some cutting of liners, pinchwelds and body mounts. Moving the castor forward with new uca helps with clearance. After market bumpers or trimmed stock bumpers help too. The lift height is for the gram. :guitar3:

Upgraded shocks and springs also can perform better with other mods because they can also be more specifically valved for a specific setup and ride characteristics.

 

[wfo9]

Interesting. So what does a lift using stock LCAs actually improve for off roading these things, assuming you need to run stock size tires for clearance under full articulation?

This forum is full of photos of sweet lifted rigs with big tires. Surely they're significantly more capable than stock suspension and tire size... right?

The 3 keys of typical offroading.
- Traction
- Stability
- Clearance


The 4runner has poor clearance stock and is in desperate need of a lift to deal with technical terrain.. . By clearance I mean all types of clearance.. not ground clearance alone.. it in itself is not near as important as approach departure and break over which are all miserable on these things in terms of dedicated off-road rigs. The lift gives it help, but the body and other low hanging parts still get in the way pretty much no matter what you do.

Also, most lifts do add travel (especially in the rear where it is most needed). The front is just limited by the design unless you start really chopping it up.

 

[JSparky]

What suspension are you running? I have a 650# coil now and it's not sufficient. And my nose is lighter than yours. Aluminum bumper, synthetic rope, only one battery. I'm not aware of a shop that has that capability.

Radflo 2.5's with OW valving and 700lb coils, from Metaltech. Rear are their matched Radflo shocks, Dobinsons heavy coils. http://www.toyota-4runner.org/5th-gen-t4rs/236107-wampa-jr-build.html

I'll be swapping out to ADS front and rear, I'm running heavier and taller than initially planned so it's not really a fair comparison for the Radflo stuff.

Race/Custom shops should be able to work with you on both springs rate and valving. I know Slee out of Colorado works with ADS, perhaps consider talking with them. My 80 on Slee's ADS suspension runs smoother than my 4Runner, which is a big reason I'm swapping over.

Lots of good info being covered in this thread.

 

[honda250xtitan]

You can disagree. But it's still correct physically. It's just geometry. Everyone tells you the same thing because it's just a physical property of the system. If we could change it we would.

If you add a longer bump stop you can have less suspension travel and possible keep from rubbing in some cases - but that makes it worse off road. I'm not sure why you'd want to do that. You'd be better off with a smaller tire and full suspension travel.

I understand the geometry of what is being said i just don't understand it when i see stock ride height vs 3" ride height. But i get it, you're pushing all the components down, BUT the tires still need to clear the fenders at bump travel. I guess my hangup is coming from the titan IFS we ALWAYS added taller bump stops when adding a leaving kit, 5100's, and even coilovers. Limit bump travel so you don't blow out your shocks at full compression. Leveling kits kill travel, but everything else was a longer shock and with uppers you gained back the loss in droop travel by changing the ride height...to a certain point.

 

[wfo9]

I understand the geometry of what is being said i just don't understand it when i see stock ride height vs 3" ride height. But i get it, you're pushing all the components down, BUT the tires still need to clear the fenders at bump travel. I guess my hangup is coming from the titan IFS we ALWAYS added taller bump stops when adding a leaving kit, 5100's, and even coilovers. Limit bump travel so you don't blow out your shocks at full compression. Leveling kits kill travel, but everything else was a longer shock and with uppers you gained back the loss in droop travel by changing the ride height...to a certain point.

I agree that limiting up travel to clear more tire is not necessarily a bad thing overall. It mostly depends on what you are doing and what your goals are. For most general use situations.. the sacrifice required to run more tire is worth it..

For trail use and slow speed.. sacrificing up travel to gain down travel is generally fine up to a point. For speed oriented stuff the up travel is critical to have. The uptravel is also nice to have for tails, but it very much depends on independent vs solid axle in terms of the impact of increasing bump... ON a solid axle you can bump it much lower and still get plenty of articulation due to the geometry and leverage change of more down travel on the other side. The shock itself does not really need to compress more to get the wheel in a similar position when articulated. However... you still sacrifice vertical travel, so you need dampening changes to stop a harsh bottom out (ideally a bypass of some sort or hydro bumps)

In an ideal world.. the fender wells on the 4runnner would be setup for much larger tires. It's just not made for that unfortunately... in contrast the new JL takes 37s no problem at all with just a small lift.

It's a mind twister to get one of these Toyota pigs set up to run a decent sized tire (35+) and be ideal in all situations (speed, trails....) I don't think it has been done yet to be honest. You can make it moderate trail worthy pretty easy, but to also be able to do the speed stuff is not easy at all. Then to do the extreme trails and the speed is almost impossible.

For most people who want to go big... Save your money and just buy a JL and enjoy it. Extreme offroad with these trucks requires a real passion to fit the square into the round...trailblazing and cutting...

 

[JSparky]

I agree that limiting up travel to clear more tire is not necessarily a bad thing overall. It mostly depends on what you are doing and what your goals are. For most general use situations.. the sacrifice required to run more tire is worth it..

For trail use and slow speed.. sacrificing up travel to gain down travel is generally fine up to a point. For speed oriented stuff the up travel is critical to have. The uptravel is also nice to have for tails, but it very much depends on independent vs solid axle in terms of the impact of increasing bump... ON a solid axle you can bump it much lower and still get plenty of articulation due to the geometry and leverage change of more down travel on the other side. The shock itself does not really need to compress more to get the wheel in a similar position when articulated. However... you still sacrifice vertical travel, so you need dampening changes to stop a harsh bottom out (ideally a bypass of some sort or hydro bumps)

In an ideal world.. the fender wells on the 4runnner would be setup for much larger tires. It's just not made for that unfortunately... in contrast the new JL takes 37s no problem at all with just a small lift.

It's a mind twister to get one of these Toyota pigs set up to run a decent sized tire (35+) and be ideal in all situations (speed, trails....) I don't think it has been done yet to be honest. You can make it moderate trail worthy pretty easy, but to also be able to do the speed stuff is not easy at all. Then to do the extreme trails and the speed is almost impossible.

For most people who want to go big... Save your money and just buy a JL and enjoy it. Extreme offroad with these trucks requires a real passion to fit the square into the round...trailblazing and cutting...

Well said. I think I’ll add that, in terms of practicality, the point where I (personally) would need 37’s would be far beyond the point where I’d be willing to take a 40-50k vehicle. Everyone’s different, but the margins for major body damage on a trail like that are just so much higher. For a universal jack of all trades/master of none type vehicle I think the 4Runner works great, especially on rough washboard where solid front axle rigs really bring the suck.

Edit: I say this because I’ve been impressed with some of the stuff I’ve been able to get the 4Runner through.

 

[comtn4x4]

Radflo 2.5's with OW valving and 700lb coils, from Metaltech. Rear are their matched Radflo shocks, Dobinsons heavy coils. http://www.toyota-4runner.org/5th-gen-t4rs/236107-wampa-jr-build.html

I'll be swapping out to ADS front and rear, I'm running heavier and taller than initially planned so it's not really a fair comparison for the Radflo stuff.

Race/Custom shops should be able to work with you on both springs rate and valving. I know Slee out of Colorado works with ADS, perhaps consider talking with them. My 80 on Slee's ADS suspension runs smoother than my 4Runner, which is a big reason I'm swapping over.

Lots of good info being covered in this thread.

In your build thread it says you are running the Dobinson's C59-701V.
That's for 600#+ I think it says? You are quite a bit heavier in general than I am. Obviously from your thread that works well for you. Which did you have before that? I was considering either the C59-677V or the OME 440 constant weight. Any thoughts on those?

 

[honda250xtitan]

I agree that limiting up travel to clear more tire is not necessarily a bad thing overall. It mostly depends on what you are doing and what your goals are. For most general use situations.. the sacrifice required to run more tire is worth it..

For trail use and slow speed.. sacrificing up travel to gain down travel is generally fine up to a point. For speed oriented stuff the up travel is critical to have. The uptravel is also nice to have for tails, but it very much depends on independent vs solid axle in terms of the impact of increasing bump... ON a solid axle you can bump it much lower and still get plenty of articulation due to the geometry and leverage change of more down travel on the other side. The shock itself does not really need to compress more to get the wheel in a similar position when articulated. However... you still sacrifice vertical travel, so you need dampening changes to stop a harsh bottom out (ideally a bypass of some sort or hydro bumps)

In an ideal world.. the fender wells on the 4runnner would be setup for much larger tires. It's just not made for that unfortunately... in contrast the new JL takes 37s no problem at all with just a small lift.

It's a mind twister to get one of these Toyota pigs set up to run a decent sized tire (35+) and be ideal in all situations (speed, trails....) I don't think it has been done yet to be honest. You can make it moderate trail worthy pretty easy, but to also be able to do the speed stuff is not easy at all. Then to do the extreme trails and the speed is almost impossible.

For most people who want to go big... Save your money and just buy a JL and enjoy it. Extreme offroad with these trucks requires a real passion to fit the square into the round...trailblazing and cutting...

yea i mean 37's fit on my f250 bone stock lol. :fish:

 

[wfo9]

Well said. I think I’ll add that, in terms of practicality, the point where I (personally) would need 37’s would be far beyond the point where I’d be willing to take a 40-50k vehicle. Everyone’s different, but the margins for major body damage on a trail like that are just so much higher. For a universal jack of all trades/master of none type vehicle I think the 4Runner works great, especially on rough washboard where solid front axle rigs really bring the suck.

Edit: I say this because I’ve been impressed with some of the stuff I’ve been able to get the 4Runner through.

Yea, it's a good for a general utility, overland, moderate trail. family truckster.... It is not ideal for a hard core off-road machine. You really can take a JL, slap 37s on and go do things that would scare the living crap out of the avg person.. and not put a scratch on the body... It's engineered with that use case in mind... The 4Runner is not even close to that. The JKs had so many other issues, that it required a ton of mods to run 37s reliably and they still sucked on the road. I think the JLs just took out of the box hard core to a new level. I have still not driven one. But watching them on trails.. I'm blown away.. and I'm not easily impressed.

My friend who has an 80 on 40s all chopped up to clear plus tons of mods thinks his stock JL with a lift and 37s can do more. BUT it's still a dime a dozen jeep.