Stiff ride woes

[thedustyboot]

Looking for some user feedback about the 4.5” BDS long arm lift kit.

This lift kit was my replacement for the 28 year old factory control arms and sacked out 2” lift coils installed by the previous owner and the Bilstein 5100’s installed by myself. It was a decent combo and the ride was pretty good all things considered.

When I purchased this kit the buyer usually has the option to go with the Fox 2.0 shocks or some BDS brand shocks for a cheaper price. I was led to believe that the BDS NX2 shocks were valved the same as Fox 2.0’s and would experience a nice plush ride with this kit.

This hasn’t been the case at all…

I’m well aware that the majority of TJ’s out there have the mighty 4.0, but sadly mine has the 2.5 and is therefore an estimated 250-300lbs lighter than the 6-cyl relatives.

I do get great articulation which would indicate nothing is binding, and the alignment was done by a licensed mechanic.

This leaves only two things, the shocks and coil springs. The questions I’m asking myself are #1 is the spring rate of the coils too stiff for the relatively lighter base model 2.5L TJ? #2 are these shocks just complete dogshit? #3 are the shocks also too stiff for the weight of my rig? #4 is it a combination of both springs and shocks being meant for a heavier 4.0L TJ.

I hate having to throw money at a problem.. the Fox 2.0’s are $1480CAD but that’s what I see 90% of people use, especially with this particular kit.

Kinda stumped, kinda pissed off, kinda bummed out…..

Cheers

 

[jjvw]

The coils create the ride height. They have no impact on the ride quality. This most likely is a shock problem.

 

[mrblaine]

The coils create the ride height. They have no impact on the ride quality. This most likely is a shock problem.

Don't overlook that while you are correct, the problem is exacerbated by the overly tall lift height changing the shock bias. If he posts up some ride height pics to show exposed shock shaft length, we'll probably see more than is prudent.

 

[macleanflood]

Put 300 lbs in the Jeep and see if it drives better. Try 600.

-Mac

 

[thedustyboot]

*Can’t figure out how to tag members while using my phone*

To all the experienced individuals who have replied, I’m coming here for info and insight to this conundrum in an effort to make an informed decision on how to proceed without wasting anyone’s time or my money.

Mrblaine: you are correct and I do acknowledge your expertise. At the time of writing this reply and making the original post I lack detailed ride height photos. I will say that the amount of shock shaft exposed is damn near 50/50 based off having seen the shocks at their compressed length in the box as well as their full length when installing them. Factory coil spring rate is somewhere around 160, and the spring rate for the BDS coils is unknown to me at this time. The forum Excel doc lists them but lacks the spring rate info. I might email bds on Monday and ask them directly.

Jjvw: I do agree with you as well, shocks can make or break a ride. My personal experience of switching from a rough country shock installed by the PO of my jeep to a bilstein 5100 made a substantial difference both on the street and off. This experience in my own opinion confirms your advice as valid.


Macleanflood: yes that’s a sound suggestion to test. Myself, some tools, my recovery gear, air compressor, and my father as passenger easily make up at least 450lbs of weight. Are you suggesting adding an additional 300lbs of weight? If that’s the case I lack the displacement (2.5L) to achieve this and quite frankly doesn’t seem like a good time to me, poor old jeep already struggles on hills.

In conclusion I’m feeling pretty let down by some of the components of this kit, mainly the BDS NX2 shocks that “allegedly” were valved the same as the Fox 2.0 IFP shocks which cost $330CAD.

 

[jjvw]

....

In conclusion I’m feeling pretty let down by some of the components of this kit, mainly the BDS NX2 shocks that “allegedly” were valved the same as the Fox 2.0 IFP shocks which cost $330CAD.

You are assuming that the Foxes are valved in a way you would find acceptable.

 

[jjvw]

...
Mrblaine: you are correct and I do acknowledge your expertise. At the time of writing this reply and making the original post I lack detailed ride height photos. I will say that the amount of shock shaft exposed is damn near 50/50 based off having seen the shocks at their compressed length in the box as well as their full length when installing them. Factory coil spring rate is somewhere around 160, and the spring rate for the BDS coils is unknown to me at this time. The forum Excel doc lists them but lacks the spring rate info. I might email bds on Monday and ask them directly.
....

A tape measure and knowing the full travel of the shocks will tell you what you need to know about the current travel bias.

 

[thedustyboot]

You are assuming that the Foxes are valved in a way you would find acceptable.

Yea it is an assumption for sure. Internet surfing for info on those shocks has indicated that they’re a bit softer than the bilstein 5100 which I have experience with.

 

[thedustyboot]

Just a brief update the my situation, it’s been challenging trying to find spring rates for the 4” bds coils that came with the lift kit. A quick email to the dealer I bought it from was able to answer my question thankfully.

The guy says the front coils have a 175lb/in spring tate and the rear coil is 240lb/in spring rate.

Now for someone with a 2.5L base model with a light rear bumper and no back seat that seems a bit too stiff. It’s difficult to say if there much take to the ride height, if anything it’s negligible. But after being pretty mean to it on some pothole ridden FSR’s coupled with the bds brand shocks the rear end likes to buck as it takes its turn going through the rough sections of the road.

Adopting the buy once cry once mentality and the good review from the lift kit dealer/TJ owner I have some Fox 2.0’s coming very soon. Will update again after they’re installed and tested.

 

[Imagineer]

Whereas I'm no where's near as knowledgeable on suspensions as most members here, I noticed you didn't mention what tires you're running?

On my prior TJ (also a 2.5), I swapped from the OEM alloy rims with P-rated tires, to JK steel rims and LT- rated tires. The LT tires were like concrete and we felt every little bump.

 

[MountaineerTom]

If you want to see how stiff your springs are, pull all your shocks and drive around some. I did on mine and it was like driving a pogo stick. Not even close to being stiff.

 

[lBasket]

I have the BDS NX2 shocks. They're firm AF

 

[TheBoogieman]

I have the BDS NX2 shocks. They're firm AF

I had those for a month. I thought they were equal to RC and Bilsteins. I was not happy.

 

[lBasket]

I had those for a month. I thought they were equal to RC and Bilsteins. I was not happy.

Yeah they're kinda ass. Been running them for years and didn't really realize how bad they were til this year in Moab when I actually rode along in a lot of other jeeps for once. I need some of them tuned shocks Josh is always talking about 100%

 

[thedustyboot]

Whereas I'm no where's near as knowledgeable on suspensions as most members here, I noticed you didn't mention what tires you're running?

On my prior TJ (also a 2.5), I swapped from the OEM alloy rims with P-rated tires, to JK steel rims and LT- rated tires. The LT tires were like concrete and we felt every little bump.

I’ve got a 33/12.5R15 K02 load C running 15psi. I could run 20 to get better mileage on the street but 15 is soft enough for the dirt roads. Sometimes I’ll air down to 10psi for the dirt.

 

[thedustyboot]

If you want to see how stiff your springs are, pull all your shocks and drive around some. I did on mine and it was like driving a pogo stick. Not even close to being stiff.

Gonna do this when the new shocks come in just for science.

 

[thedustyboot]

The SPRINGS give you a ride height based on weight. The shocks make it ride good or bad, depending on your intelligence to get the correct length/brand ones.

Yes yes between you and jjvw you both preach the same thing. “Depending on weight” is what you said in your reply. A 4.0 tj with 35’s, full doors and tire carrier is clearly going to feel different on a 240 spring rate coil compared to my stripped out base model with half doors stock front bumper, light rear bumper, no rear seat, no fkn carpet. I can’t make this any clearer to you bud….. my lighter rig is gonna sit at a different ride height and react differently than a heavier tj that MOST of this group own.

The goal of this thread is not only solve my issues and get an agreeable ride quality but also help anyone out in the future who may experience this.

The4bangertj has had some cool spring conundrums himself too, getting more lift height than what the coil was “supposed” to give BECAUSE his jeep is lighter than most.

And circling back to having mismatched spring rates with this lift, the most weight I ever haul in the back is about 120lbs split between a 70lb dog, tools, recovery gear, and a chainsaw. The lift coil I had in the rear prior to this lift was a OME 2942 that was only 160lb/in.

Shock maybe be responsible for 85-95% of ride quality but the coils certainly do contribute.

 

[jjvw]

Yes yes between you and jjvw you both preach the same thing. “Depending on weight” is what you said in your reply. A 4.0 tj with 35’s, full doors and tire carrier is clearly going to feel different on a 240 spring rate coil compared to my stripped out base model with half doors stock front bumper, light rear bumper, no rear seat, no fkn carpet. I can’t make this any clearer to you bud….. my lighter rig is gonna sit at a different ride height and react differently than a heavier tj that MOST of this group own.

The goal of this thread is not only solve my issues and get an agreeable ride quality but also help anyone out in the future who may experience this.

The4bangertj has had some cool spring conundrums himself too, getting more lift height than what the coil was “supposed” to give BECAUSE his jeep is lighter than most.

And circling back to having mismatched spring rates with this lift, the most weight I ever haul in the back is about 120lbs split between a 70lb dog, tools, recovery gear, and a chainsaw. The lift coil I had in the rear prior to this lift was a OME 2942 that was only 160lb/in.

Shock maybe be responsible for 85-95% of ride quality but the coils certainly do contribute.

Adding a bunch of weight to the existing coils changes the ride height. Changing the ride height will change the shock travel bias. Change the shock travel bias enough and the ride quality will change enough to be noticable. This is now a shock problem because the ride height changed.

 

[AWayne]

To reiterate the weight = ride quality.. I loaded up nearly 300 square feet of vinyl plank wood the other day and it's the best the rear of this shitbox has felt since before the lift.

With no spare, low on fuel, no backseat, it rides like a log wagon in the back. With hardtop, rear seat, packed full of camping bullshit.. not too bad.

If I were you, I'd do some reading on which shocks provide the cushiest ride not only on a jeep, but on some light trucks. Do some forum searching. Get the measurements on what you need for your lift as far as extended/compressed, and sort through some online catalogs. Rancho, Skyjacker, KYB, whatever. I planned on doing this for the front of mine and found a YJ front shock was close, and a 90's explorer was close with KYB Gas-A-Just, which I love on my Comanche. Ended up saying fuck it and sticking Skyjacker Blackmax all the way around it because they were cheap.

Or just talk to Fox and have some made.

 

[jjvw]

To reiterate the weight = ride quality.. I loaded up nearly 300 square feet of vinyl plank wood the other day and it's the best the rear of this shitbox has felt since before the lift.

With no spare, low on fuel, no backseat, it rides like a log wagon in the back. With hardtop, rear seat, packed full of camping bullshit.. not too bad.

If I were you, I'd do some reading on which shocks provide the cushiest ride not only on a jeep, but on some light trucks. Do some forum searching. Get the measurements on what you need for your lift as far as extended/compressed, and sort through some online catalogs. Rancho, Skyjacker, KYB, whatever. I planned on doing this for the front of mine and found a YJ front shock was close, and a 90's explorer was close with KYB Gas-A-Just, which I love on my Comanche. Ended up saying fuck it and sticking Skyjacker Blackmax all the way around it because they were cheap.

Or just talk to Fox and have some made.
View attachment 636550

You changed the ride height and that change in ride height affected the shock travel bias in a way that improved the ride quality. You have a shock problem because they are sized inappropriately for your normal ride height.