my front brake lines are just long enough to not be a problem. The front shocks seem about right, the rears might be a bit to long, we’ll see how they do. Ill have a big lift update/pic dump in my build thread real soon covering all the things i did along side the lift. I dont want to clog this thread with that, but we may have some idea bouncing to do.
New Dobinsons VT series dual rate coils
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Jason Andrews
Modaholic
Tha
Thanks for all the info. I’m trying to figure out how to get more down travel. I’m 6” up and 4” down right now with the 4” shocks. I’d like to flip that. I planned on making a spacer for the shock but it seems like I’m going have to extend a couple other thing too! This helped a ton
Did you verify the front is actually using the amount of travel that is there to use and when it uses it?
In my testing I could only get my unmodified Slee arms to stuff 3.5" up and 2.75" down when stuffing/drooping one side at a time like what happens on the trails. It would only use more up/down when both left and right sides flexed/drooped together like what happens at high speeds on road. @Squeegee have you flexed the front to see that it uses all 4" of down travel the current setup offers?
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Here’s pics of my front install. I have extended brake lines. I also changed 4” Ironman foam cell pro to 6”. The axle is fully drooped out here to where I could pull the 4” Flexi out with no resistance.
Install of the longer 144’s I could do by hand on the driver’s side and using my normal trick of a 4’ leverage bar under the coil on the tighter PS side.
Just get it part way on the perch and kick it over. This is way more droop than a 6” shock and I still have 6” of up travel in the front.
Nothing else here is special except the extended brake lines and nothing is disconnected except the shocks that don’t allow anywhere near this much droop.
Just get it part way on the perch and kick it over. This is way more droop than a 6” shock and I still have 6” of up travel in the front.
Nothing else here is special except the extended brake lines and nothing is disconnected except the shocks that don’t allow anywhere near this much droop.
lumbee1
Native American
For the rear also using 6” Foam Cell Pro, I’m now at 5” up and 6.5” down. I’m not able to use all of the up travel with 38’s but it’s close as the dirt line sho
Also installed Timbren bumps in the rear. These act as high speed hit stops like a hydro, and then are super squish at full flex. They compress a lot, almost the same as my 3” extensions with factory hard rubber.
I would not use a ~10” travel shock (4” lift) on these coils unless you have enough weight to really compress them. Noting again that I am 26” hub to fender at all 4 corners.
The resistance to high speed bottoming out with these coils is unreal. There is no reason for a non-racer to be driving as fast as you can over heavily rutted and big hit and drop terrain as you can with these, you’ll scare your passengers to death.
Also installed Timbren bumps in the rear. These act as high speed hit stops like a hydro, and then are super squish at full flex. They compress a lot, almost the same as my 3” extensions with factory hard rubber.
I would not use a ~10” travel shock (4” lift) on these coils unless you have enough weight to really compress them. Noting again that I am 26” hub to fender at all 4 corners.
The resistance to high speed bottoming out with these coils is unreal. There is no reason for a non-racer to be driving as fast as you can over heavily rutted and big hit and drop terrain as you can with these, you’ll scare your passengers to death.
You figured it out - you bought shocks that are too short, and shocks set travel on a coil suspension unless you have link bind (like we do up front). That’s why I didn’t bother looking at those shocks.
I’m not sure why supposed 4” shocks are really for 3” lifts and 6” are for 4-5”, but you have to get the actual spec numbers of the shock to tune it right.
Here’s the specs on my shocks in 4” (LFE) and 6” (LFE1) in mm extended and compressed, first set is rear and second is front.
Compressed length increases by 30mm between 4” and 6” and droop by 60mm. The. 4” lift shock is 10.25” travel and the 6” is 11.5”. Tune on these numbers with your actual measurements.
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Great information in this thread. I am currently running 4" flexy coils in the front and rear with 20mm and 30mm spacers. 37" tires. I will have to get some measurements once I get the rig out of the garage. With the 4x4 labs bumpers I have coming, I have a feeling these new coils will come in handy.
lumbee1
Native American
I should have clarified, the limitations were experienced while both springs and shocks were out of the front.
I was shooting for a 60% up and 40% down. The Tapered coils lifted the Cruiser much higher than expected and while I haven't measured, my guess is shock travel is closer to 75% up and 25% down or worse.
Everyone will come to their own conclusion, what I have found the 80 series front suspension does not allow enough articulation to use up the extra length of the 6" shock.
At full droop with the 6" shocks everything is maxed out, from the DS to the panhard bushings, coils rub the inner bump stop on the front. On and on
With a tall lift they could work but you will have things address.
At full droop with the 6" shocks everything is maxed out, from the DS to the panhard bushings, coils rub the inner bump stop on the front. On and on
With a tall lift they could work but you will have things address.
it has nothing to do with flex, an 8” travel shock is about enough for the front f you could get it 50/50. It just doesn’t make sense to have say 7” up and 3” down.
I could tell with the 4” version I was getting a bit of down travel flex limitation in the front so I fixed that.
I don’t think it’s a good idea ever to just add a bunch of down travel, but at >5” of lift you just need a bit longer shock.
Like I said everyone will have the own conclusion
And it has everything to do with articulation
Jason Andrews
Modaholic
Maybe not with the rear, but with the stock front control arms binding and making the rear doing 90% of the work on most 80's, I think it's a great idea if you have the right parts to compliment it. Adding "a bunch of down travel" to 4" isn't exactly overkill. Did you measure to see how much down travel you actually use in front?
I took off my front 6" lift (28.75") Foam Cell Pros for a 7"lift (30.5") shock. Insanely better on road and much more stable off road. Disclaimer: it's only because of the design of the control arms I'm running that I can take advantage of the extra travel available.
IMO the rear doing most of the work is what makes the truck want to flop on it's side. I'd rather the front stay the most stable, level, and do the lions share of the work since that is where most of my weight lies.
@Nay The 11.5" listed for the rear FCP's includes the 1" bump stops on the shock. You have closer to 4.75" up and 5.75" down from what I can see in the photo.
This is at 30” with .5” left of droop. 1.25” more droop than the average 6” lift shock offers. Still has 1” more of up travel it’s not using on this test and another 1” that I can’t use because of my larger bump stops. I could grab the rear bumper and teeter it back and forth. No fear of suspension unloading and it rolling on its side. Rear FCP’s only using 4.25” of down travel on this test.
The older style c97-144vt did unseat a little bit at this point. The driveshaft was not even remotely close to being at a bad angle or to end of the splines. Edit: I guess I would need to droop the passenger side tire to really see how bad it is...
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What I meant was the stock arms can’t really use a long travel shock given the restrictions. Longer shocks up front just ensure there isn’t a droop side restriction. The 80 front flexes better than people think it does, but a lot of setups are so biased to up travel that they don’t work properly. That front won’t compensate for a droop limiter on one side the way a 4 link can do at least partially.
OME designs their 0-3” lift with the same shock. People have been walking into that trap forever and wondering why their suspensions don’t work.
Would love to hear feedback from anyone who has gone from the OME 3.5" lift and shocks to the Dobinson lift, particularly the new VT coils? Trying to gather if it's a major difference and what you noticed... Is it worth the upgrade? Thanks!
Sorry for the bad picture! It’s about 6” from the pad to the bump stop and I was fully riding on it in the picture. Yesterday I went on my first spring run and I got the shock to fully droop out. If I measured it correctly ride height to full droop was about 4”.
One thing I have done is to mark the shocks with one inch increments and the half inch marks in between. You can then easily see Ride height, full stuff and droop. You can also see if you hitting you bump stop before your shock bottom out.
This is important with the VT springs as you can see in the picture you can get it to fully stuff.
For me in the past with a lighter Rig running OME it was hard to get it fully stuffed in the front like you have it (higher rate/ stiffer spring) at the same time the OME did not bottom out on the high speed dune bashing like the C97-146 Vt are doing.
In short it's all a trade off, unless you have the cash to build a Ultra4 Car it's really hard to build your 80 to be good at everything!
Touching on a couple of points here, I agree it would be ideal to have the rear more planted with front flex than what we have stock. I’d leaf the rear if I really wanted to mess with it and then open up the front, but I don’t want to mess with it.
In a stock config I’ve always focused design on not creating too much rear flex and forcing the front to work more. The 4” FCP were well balanced in the rear at 4.5” lift but short in the front. Since I added lift I went 6” version noting it’s in my preference to dump a bit of travel in bump stop to stay closer to 10” usable than 12” for the rear.
For the front, I hadn’t initially measured (not following my own guidance) and I could tell from wheeling vids that I’d limited front droop articulation slightly. Not enough to really affect how it wheeled, but I needed to fix it adding more lift.
Damping is maybe the most interesting personal preference. I don’t like high rebound damping on a 4x4 or a mountain bike. One of the reasons I’ve stayed away from a suspension redesign is noting the ongoing focus on off camber feel of floppiness for people who have done it (you included, not a critique, just an observation) and a resulting focus on beefing up swaybars, etc.
With the Flexi coils, I’ve felt way more confident in seriously off camber stuff and I don’t run swaybars. Hoping that continues here as it’s a major performance benefit of a good dual rate coil in my experience and in the literature generally. I think this may be one of the key benefits for people who are still hyped up about tapered coils vs dual rate.
The sooner we can get “Slinky” out of the hive mind the better.
I just drove “The Gap” construction zone on I-25, which may gone down as one of the most poorly executed highway expansion projects of all time. Unless having a ton of crashes in there was part of the design.
The new coils are much firmer as we’ve noted. I can’t say I thought it went through that not really a modern road section more smoothly than the Flexi, but certainly more…directly.
Not much more to say until I get a good wheeling comparison that’s technical crawling, other than I do not think these coils replace the 4” Flexi automatically for anybody with a lighter rig. I like them better, the stability gains are big, but they are right in the edge of stiffness for a closer to stock weight rig. Somebody valuing plushness more would still be well served to consider the Flexi.
OTOH, I have no idea what the residual value of a heavy duty tapered coil would be here, unless “slinky” is a fetish word for you. Although these are still called “variable tapered”, which is code for slinky, so maybe that gets the job done
.
The new coils are much firmer as we’ve noted. I can’t say I thought it went through that not really a modern road section more smoothly than the Flexi, but certainly more…directly.
Not much more to say until I get a good wheeling comparison that’s technical crawling, other than I do not think these coils replace the 4” Flexi automatically for anybody with a lighter rig. I like them better, the stability gains are big, but they are right in the edge of stiffness for a closer to stock weight rig. Somebody valuing plushness more would still be well served to consider the Flexi.
OTOH, I have no idea what the residual value of a heavy duty tapered coil would be here, unless “slinky” is a fetish word for you. Although these are still called “variable tapered”, which is code for slinky, so maybe that gets the job done
.
I’m going to get that done today! I have a date with a forklift tonight
