Hydro Bumps

AssBurns

will wheel for beer
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#1
Who's running hydro bumps? I know a few of us are running them at the moment and wanted to start a topic about them. So people can get an idea if they are worth the cost to them or not, and help others with picking the right set for the right application. Also tips on tuning them.

Post up some info and pics of your setup


Here is my setup.
I have Sway-A-Way 2.0 x 4" bump stops. I need to destroke them down to 2 or 3" though, since I am only about 2.5" from hitting them at ride height now. I have the nitrogen pressure set for 110 psi. It works pretty well for the setup I have but I will need to increase the pressure once I destroke them down to 2".
I absolutely love them. They are such an improvement over the stock bump stops or the daystar comp bumps that I had before.

IMG_8859.JPG IMG_8848.JPG IMG_8735.JPG
 
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#2
I run SPC Jounce bumps on the front. They are ultra short 1.5" stroke which is well suited for IFS. I'm not running any front end reinforcement so bumping off the lower twisted the frame quite a bit. Performance at speed is killer, but I don't really need them. I never got around to adding rears and I don't really plan on it.

 
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#3
I have 2.0x4.0 Fox’s on my front end. Shortened to 2” travel till I do more work to strike off the spindle.

They’re currently in the same position but chopped and welded about 2” higher now that the front is LT.

Works great just a little noisy since they strike so early in the travel so they tap tap tap a lot.
 

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AssBurns

will wheel for beer
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#4
I have 2.0x4.0 Fox’s on my front end. Shortened to 2” travel till I do more work to strike off the spindle.

They’re currently in the same position but chopped and welded about 2” higher now that the front is LT.

Works great just a little noisy since they strike so early in the travel so they tap tap tap a lot.
That's what I noticed with my rears. They are 4" bumps so they touch way too soon. I need to destroke them down to 2". Was gonna do that this weekend but couldn't find my spacers. What is nice is they act like sway bars when cornering haha
 
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#5
You probably won’t find a specific spacer, use a DOM tube machined to whatever length inside to limit it. There’s a write up somewhere on RDC about it.

Found a youtubes that shows you.

 

AssBurns

will wheel for beer
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#6
You probably won’t find a specific spacer, use a DOM tube machined to whatever length inside to limit it. There’s a write up somewhere on RDC about it.
I had a buddy make some 1" spacers for me to bring them to 3" stroke. I need him to make me another set to bring it to 2" stroke, since 3" will still probably be too much with 6.5" of up travel at ride height.
I was gonna put them in Saturday night but looked all over the garage with no luck. Then Sunday morning I happened to open a drawer to find them sitting there. Story of my life... :rofl:
 

AssBurns

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#7
You probably won’t find a specific spacer, use a DOM tube machined to whatever length inside to limit it. There’s a write up somewhere on RDC about it.

Found a youtubes that shows you.

But you can buy some shaft spacers for the SAW air bumps here. I'll probably end up getting a set of these instead of asking a buddy to machine another set. For $5, it's not worth having someone make them one off.
http://www.offroad-engineering.com/52709-001.html
 

whippersnapper02

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#8
Even in stock form, I've wanted to run a set out back. OEM pogos over stuff and the Wheeler's bumps leave no room for uptravel. I'm all stock out back now so just pogo again.
 

AssBurns

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#14
I keep saying I'm going to make a new kit so I can bump off the spindle to do it right the first time. Figure just to get hydros in there to hold me over until that stage.
Get whatever length bumps you would use when you get a new kit, and just make them work in the meantime. It'll work now and later, so no point in holding out.
 
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#15
Get whatever length bumps you would use when you get a new kit, and just make them work in the meantime. It'll work now and later, so no point in holding out.
Still plan to bump 2" at the spindle. Might need to shorten down to 1.5" at the lca. You can really only get 14" of travel out of a 5 lug unless you design a new steering setup.
 
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#16
I've run a couple hydro setups on two vehicles, one being my 4runner with LT and one being my 4500 solid axle Land Cruiser. Couple of points before I get into specifics and for people who are tl;dr: I HIGHLY suggest hydros, I have yet to see a situation besides packaging where they are not vastly superior to a normal bump. You can change the length, change the compression easily and on the fly, take it apart to heavily change the internal valving, rebuild them, etc. The mere ease of tuning them which anyone with a compressor or nitrogen can do alone makes them a worthwhile investment for someone who doesn't want to tear their shocks apart and valve their suspension. Everyone bottoms out at some point, hydros give you lots of control and arguably the best way to slow the suspension down before hurting yourself or your truck.

On the 4runner I ran 2" 2.0 FOAs up front off the lower arm. I ran them around 300psi which worked great, I honestly can never say I heard or felt them engage--the transition was very seamless (though I had lots of other shit making noises). I also got a set of 4" 2.5 FOAs for the rear which I then shortened to 1.5", this was a huge band aid because I thought bumps would help with shitty shocks when I should of gotten good shocks and left the stock bumps. I shortened them with a PVC spacer, which worked fine and fit really well (I wouldn't do that again, but if you don't have access to machinery it worked fine). I ran from 150psi which was very clanky as some people mentioned, down to 60psi which I couldn't hear engage and still served itself well. I tried bumping them to 150psi with a CO2 setup a few times but that didn't seem to do much if anything, though that might of been user error or a phase transformation of the CO2 under the high pressures of the bump (?).



On 4508 I applied what I learned from my 4runner and went with 2" 2.0s. Anything more than 2" for low travel numbers (ie sub 16" probably at the tire) starts to have too much effect with the suspension when you don't want it too. Figure a 4" bump with 16" of travel is a quarter (25%) of your entire travel range is just bump travel, which means your suspension is now heavily pushing back the tires and trying to keep you from slamming down so if you had only another inch or two of that whoop left, well now your compression stroke is slowing down and the whole chassis is getting pushed upwards a lot more than if the shocks alone were allowed to do their thing. Likewise, a 2.5 is an absolute monster of a bumpstop and not worth the weight and size on anything except maybe TTs and Rock Bouncers and Monster Trucks.

On 4508 I ran the hydros straight to the axle. The whole time I ran 100-150psi iirc, I think I started at 125psi and bumped up to 150psi while tuning at KOH since the suspension was feeling really dialed but I was bottoming the hydros out a hair more than I wanted. My current opinion is the "ideal setup" is where the hydro CAN get used for normal stuff, but not fully used ever. That allows that last inch or so of bump travel to only come into play when you are really pushing the truck more than usual or hit something unexpected. I used to be of the opinion you should never use any of the bump unless you hit something gnarly, but after a bunch of tuning it felt good to me when about half the bump was frequently used. This was for larger whoops, and barely kissed if used at all for normal whoops, and then like I said a bit left in reserve for unexpected stuff.



My new 4800 buggy build will run the same 2.0 2" hydros from 4508, and will obviously be a solid axle car. I may increase the rear to a 4" bump since the rear will ideally be pulling 20" or more of wheel travel but we'll see.

My buddy Cartzo has some hydros on his front LT setup on his 1st gen 4runner and they bump off the upper arm uniball cup (it runs a horizontal upper uniball) which I think is one of, if not the best way, to bump off a IFS setup since you can tune it a lot better since there isn't a huge lever arm acting against the bump plus the bump loads are transmitted straight through the spindle instead of applying a bending moment like if you bump off the arm. And since there's no lever arm, it's not like you're running a tiny stroke bump to get the bump travel at the tire you want.
 

AssBurns

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#17
I've run a couple hydro setups on two vehicles, one being my 4runner with LT and one being my 4500 solid axle Land Cruiser. Couple of points before I get into specifics and for people who are tl;dr: I HIGHLY suggest hydros, I have yet to see a situation besides packaging where they are not vastly superior to a normal bump. You can change the length, change the compression easily and on the fly, take it apart to heavily change the internal valving, rebuild them, etc. The mere ease of tuning them which anyone with a compressor or nitrogen can do alone makes them a worthwhile investment for someone who doesn't want to tear their shocks apart and valve their suspension. Everyone bottoms out at some point, hydros give you lots of control and arguably the best way to slow the suspension down before hurting yourself or your truck.

On the 4runner I ran 2" 2.0 FOAs up front off the lower arm. I ran them around 300psi which worked great, I honestly can never say I heard or felt them engage--the transition was very seamless (though I had lots of other shit making noises). I also got a set of 4" 2.5 FOAs for the rear which I then shortened to 1.5", this was a huge band aid because I thought bumps would help with shitty shocks when I should of gotten good shocks and left the stock bumps. I shortened them with a PVC spacer, which worked fine and fit really well (I wouldn't do that again, but if you don't have access to machinery it worked fine). I ran from 150psi which was very clanky as some people mentioned, down to 60psi which I couldn't hear engage and still served itself well. I tried bumping them to 150psi with a CO2 setup a few times but that didn't seem to do much if anything, though that might of been user error or a phase transformation of the CO2 under the high pressures of the bump (?).



On 4508 I applied what I learned from my 4runner and went with 2" 2.0s. Anything more than 2" for low travel numbers (ie sub 16" probably at the tire) starts to have too much effect with the suspension when you don't want it too. Figure a 4" bump with 16" of travel is a quarter (25%) of your entire travel range is just bump travel, which means your suspension is now heavily pushing back the tires and trying to keep you from slamming down so if you had only another inch or two of that whoop left, well now your compression stroke is slowing down and the whole chassis is getting pushed upwards a lot more than if the shocks alone were allowed to do their thing. Likewise, a 2.5 is an absolute monster of a bumpstop and not worth the weight and size on anything except maybe TTs and Rock Bouncers and Monster Trucks.

On 4508 I ran the hydros straight to the axle. The whole time I ran 100-150psi iirc, I think I started at 125psi and bumped up to 150psi while tuning at KOH since the suspension was feeling really dialed but I was bottoming the hydros out a hair more than I wanted. My current opinion is the "ideal setup" is where the hydro CAN get used for normal stuff, but not fully used ever. That allows that last inch or so of bump travel to only come into play when you are really pushing the truck more than usual or hit something unexpected. I used to be of the opinion you should never use any of the bump unless you hit something gnarly, but after a bunch of tuning it felt good to me when about half the bump was frequently used. This was for larger whoops, and barely kissed if used at all for normal whoops, and then like I said a bit left in reserve for unexpected stuff.



My new 4800 buggy build will run the same 2.0 2" hydros from 4508, and will obviously be a solid axle car. I may increase the rear to a 4" bump since the rear will ideally be pulling 20" or more of wheel travel but we'll see.

My buddy Cartzo has some hydros on his front LT setup on his 1st gen 4runner and they bump off the upper arm uniball cup (it runs a horizontal upper uniball) which I think is one of, if not the best way, to bump off a IFS setup since you can tune it a lot better since there isn't a huge lever arm acting against the bump plus the bump loads are transmitted straight through the spindle instead of applying a bending moment like if you bump off the arm. And since there's no lever arm, it's not like you're running a tiny stroke bump to get the bump travel at the tire you want.
All good points. Thanks for sharing. I think you are right about running a shorter stroke bump so that it truly is a bump zone, rather than it taking place of your shocks performance. However, having dialed shocks, and preferably bypasses to help keep off the shocks in a smooth progressive manner is also very important. I am in major need of tuning my rear shocks. I need to give Bilstien a call and see what they can do to help with a better shim stack.
(Word of advice to anyone reading. If you are buying shocks that are rebuildable and plan to tune them, don't get Bilstiens. They have almost no support or tech info to help.)
 

PCTaco

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#19
Hey I was looking for this thread..

So the consensus is what, around 2" of stroke in the front for non long travel?

Any reason to go longer in the rear?
 

AssBurns

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#20
Hey I was looking for this thread..

So the consensus is what, around 2" of stroke in the front for non long travel?

Any reason to go longer in the rear?
I wouldn't go more than 2" unless you had like 16 inches of travel. I'm at 3" with about 13.5" of travel and it's too much. I think 2" would be perfect for my situation. I need to stiffen up the valving in my rear shocks while I'm at it too.
 

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