A different kind of suspension discusion

[blazinzuk]

Little back ground. My bro in law has always loved blazers and Jimmys has had a couple usually had to sell cause something broke or was going to ( usually transmissions and he didn't have money to fix em. Well he finally got himself a good ( great) job. He wants to get another one and fix it up good.

We were talking about suspension lifts. Super articulation is not a goal with this truck. It will need to be capable but it will be his mostly daily driver, so it needs to ride nice and they like to do alot of milder wheeling.

So the question I have is what do you guys think is the best lift height to get the springs off the bumpstops a bit ( more uptravel means smoother ride off road if all else is done right).

I think 3" is plenty of height.

I am not worried about tire clearance at all. I can help him mod the fenders however he wants to run whatever size tires he wants. I am just thinking pure ride quality.

So 3" 2" no lift? What do you fellars think

 

[Hogback Fabrication]

What springs is he planning on?

 

[blazinzuk]

What springs is he planning on?

We will be doing custom springs for sure when the time comes.

 

[shady]

I think 3" is perfect retains a near stock,,, or as stock should have been appearence also. Mine rides exellent by the way

 

[metalneverdies]

I would go 4 inch strictly for the ability to get custom Alcans. I have only had my truck up to 60 since the lift but Alcans and stock sway bar feel plenty stable.

 

[Blue85]

Just drop the body on a GMT900 chassis.

I think your idea is great. You have to figure that a stock 30 year old truck is sagging, so even a 2" spring will bring you like 3.5" off the bump stops. As a DD only, it will probably have a sway bar, but still - the lower the truck the better it will handle. And 35s actually look pretty beefy on a 2" lift.

I don't understand the comment about 4" for availability. A custom spring is custom, so you should be able to order a 2.75" lift if you wanted.

 

[shady]

I would go 4 inch strictly for the ability to get custom Alcans. I have only had my truck up to 60 since the lift but Alcans and stock sway bar feel plenty stable.

My 3" are custom alcans

 

[oakknight]

Rear shackle flip and custom stock (zero lift) rears. Then maybe 3 in the front with zero rate if you need it to level. then use the sway bar disconnects.

 

[Deuling]

Rear shackle flip and custom stock (zero lift) rears. Then maybe 3 in the front with zero rate if you need it to level. then use the sway bar disconnects.

Winner winner! Exactly what i was gonna say. And what im gonna do when i can afford custom stock height springs for the rear to go in my flip.

 

[jp0863]

If it's a daily driver and he wants to keep it simple, 4" Tuff Country EZ ride and Bilstein shocks. Had this set up on my old K5, before building my Suburban, and it rode very well on the highway. The plus side is if he ever want's to go off road, it will work very well off road too. For ease of install and daily driving, keep it simple!

 

[Smokinthehippies]

In theory could you not go 0-2" of lift and do the effort to raise the bump stops. Or switch to a air bump? I guess that only makes sense if the goal is to be low as possible

 

[badmix]

2" Rough country springs (ez ride, not the HD springs) and Bilstein 5150s. This has been a great combo for me. I also ditched the swaybar. I get some body roll in tight slow turns but then again, this isnt a sports car. I can hit speedbumps full speed and it doesnt buck the truck.

2" Spring lift only. Im running 33" x 12.5 x 15. With a 3" lift I maybe able to squeeze 35s. From my understanding, a 2" lift doesnt require Transfer case drop or additional steering component changes like a dropped pitman arm. I think 3-4" starts getting into those other aspects (drive shaft angles, dropping trans case, lower pitman arm or switch to cross over steering, etc etc)

 

[dyeager535]

I would *think* that running as little lift as necessary would provide the best ride, no? It certainly eliminates the problems with lifting a truck.

Really depends on how much clearance is needed...both for the wheeling that is done, and for the tire size that is run.

33's will clear with no lift, so clearance would increase X inches over present ride height just based on a tire change. Unless someone changed them, expect an easy 2" increase in rear ride height with new "stock" springs over old. Front I have no idea, I've not put new stock springs on the front, but with 2" increase with newer springs in the rear bring the truck level, it would seem the fronts don't sag. My front springs are worn out IMO, I just can't comment if there is sag involved as well.

My front springs are unknown age (at least 10 years old, if not 30) so I can't really say if good stock springs in the front would prevent bumpstop contact. I would suspect yes, that would have been horrible to try and sell new. I *can* attest to the fact that once I cut the front factory bumpstops in half, eliminating contact, ride improved measurably. And this included even the freeway, where you wouldn't expect it. Anyone that has hit the stops knows how "teeth rattling" the ride is when this occurs. It's painful.

The front axle on stock trucks doesn't seem to move that much, change in clearance of maybe 1", via the bumpstop mod, eliminated contact that was even occurring on the freeway.

 

[badmix]

Lets play devils advocate here - what is the drawback to cutting bumpstops?

driving wheels/tires up into the fenders?

over compressing shocks?

etc?

dyeager535 - someone needs to put a go pro under our rigs and see whats going on. Im intrigued by the notion of "bumpstops' coming into play on the highway and DD type driving.

 

[Stomis]

Theres a few level of options I see here. Each becoming more difficult/expensive.

First would be the 2-3" alcan route with the correct length main leaf for proper shackle angle.

Second would be 52in springs up front. Again alcans would be a good route. Now this gets iffy because if you want to retain good road driveability you NEED a swaybar with 52s. So you're either looking at being stuck with push pull or going with a torsional swaybar like currie or sway-a-way has to work it around crossover.

Third option would be the most simple total suspension re-design. Radius arms using nearly all ford parts for factory easy replacement stuff. Coupled with a pair of good tuneable shocks up front you could have the thing riding like a brand new truck.

 

[dyeager535]

Lets play devils advocate here - what is the drawback to cutting bumpstops?

driving wheels/tires up into the fenders?

over compressing shocks?

Those plus compressing the driveshaft so it is the axle travel stop. But I've checked that, and it's not, on *my* rig. Tires don't hit, so also not an issue. Over compressing shocks could be, did not check them to see. I'll break a shock or the mount if so. Granted, I'm not seeking out wheeling locations, so I may not flex it as much as others. Note that I *am* running (GM) three leaf front springs, not the standard two leafs.

dyeager535 - someone needs to put a go pro under our rigs and see whats going on. Im intrigued by the notion of "bumpstops' coming into play on the highway and DD type driving.

Hey that's a great idea! I happen to have one, why didn't I think of that?? I know mine was hitting the bumpstops because the springs were shiny where both bumpstops contact. I only drive it off-road at best twice a year, in late summer and early winter, so them being shiny all the time was proof enough for me, well coupled with the fact that cutting them (only modification done at that time) so drastically altered how jarring the ride was. The rest of the spring has the typical dirt/light rust that is to be expected. It floats like an old Cadillac going over rolling pavement at freeway speeds now.

Since I've modified the contour of the bumpstops, the contact "patch" should have changed shape as well. I'm looking forward to buying new front springs so I can check ride height.

 

[Stephen]

For pure bump travel availability, it seems like 4" is about where it starts getting good. Our '99 K2500 runs with 4 to 4.5" of bump travel and at amounts less than that I didn't feel like it had enough. Part of it's problem is that the bumpstops are striking the axle outboard of the leaf spring so they engage early on a one wheel bump making them seem more active than they would be striking on the ubolt plate. There's obviously a lot that can be done with the shock and it's tuning if you get into a shock you can tune. In the Baja I was running the compression adjusters all the way stiff and loving it. Up here I turned them all the way down. That's an expensive little knob though.

Chris's K30 truck runs at about a 12" ride height (top of axle tube to bumpstop bracket) which translates to about 3" of lift and has bumpstop room for roughly 5" of bump travel. He can't use it all because the cummins engine crossmember is lower but with a stock engine it would be fine. This is with one of our custom springs so it's a thick pack and with the D60 which adds a little height on it's own. Using this spring height on a K5 with a 8.5/D44 would drop you to 2.5" or so of lift and still net the same travel.

This seems like the winning height. I know it's what I would do if I was building that truck for myself again.

As far as cutting the bumpstop or taking it out on a stock height truck; be careful with it, they didn't leave much bump travel on the table when they built the truck. I could see cutting it off being OK since it's going to make engagement later and harder but still be stopping near the same level but that's as far as I would go without some serious measuring. And keep in mind leaf springs aren't very precise on axle path control so you have to leave wider margins than you would on a linked suspension.

 

[blazinzuk]

Thanks guys.

Stephen thanks for the input. I could care less about what fits and hits etc. It was purely a though about how much bump travel would equate to a good ride and where lift height would diminish its return for the springs in ability to make use of said bump travel.

This truck will be a very long term project and I will be doing most of the work on it.

My bro in law can do mechanical things and the truck needs to be dead simple and reliable. I have run 52s ( and 56s) and a couple other stock springs that were longer and those have no place on this truck.

Stephen we will probably be getting just some by pass shocks so every time we want to change the tune its to taking them apart. Though most of his wheeling will be very similar.

I will definitely be calling you when the time comes for springs. Probably bend your ear about what valving you have had success with so I at least have a start point.


Tire clearance is not an issue. There are ways around that

 

[blazinzuk]

Plenty of suspension cycling will be done with this truck to make sure nothing hits. I absolutely hate leaf springs ( says the guy who is still running them) but on this truck they are by far the best solution.

It won't be a hard core crawler but it will be able to crawl. It won't be a mall cruiser but will look great at the mall. It won't be an expo rig but fully capable of loading up the family for a week and hitting the back country. It won't be many things. But it will be able to do most things pretty good.

Like I said though this build is probably a year out or so. But I am going to make a plan he likes and attach prices to said plan and we are gonna stick to it.

 

[metalneverdies]

I don't understand the comment about 4" for availability. A custom spring is custom, so you should be able to order a 2.75" lift if you wanted.

I said that from my experience ordering ORD alcans. I was told 4" is the smallest custom spring they offer.