" high speed " desert in an 80 series

[Jason hansen]

My experience with 80's is even if your drive very slow in the desert somthing will will probably break or need upgraded on the 20 year old vehicle. If you go at high speeds catching air you will need more than a 1 k budged just to pay for collateral damage. You might pay 1 k just to get your 80 out of the desert.

 

[Qball]

I have fox 2.0 and TJM progressive springs and here is my experience. Keep in mind the TJM springs are a little on the soft side and for the most part to run "high speed" or deal with larger bumps you need longer and stiffer springs.


Death Valley roads with wash board and some undulation is good up to 50mph.....again undulation not bumps, think rough bumpy roads.

Mojave roads with small bumps(less than 12 inch) is ok up to 20-30mph but the bigger whoopdeedoos I'm back down to 10-15 because I would bottom out on the bigger bumps.


To sum it up fox is great for smaller stuff, slow to medium speed and great on the road, leisure expedition style? But it feels very linear and really isn't great if you decided to be more aggressive/faster it's not as well suited, granted its probably outside their design specifications so I won't call it weakness. At 120 dollar a shock it is untouchable by anything else remotely in that price range. btw don't be fooled by the resi, that only increases the oil capacity and really nothing else so don't spend your hard earn money on just cool looks.

 

[bug616]

please be reminded that the OP specifically said "need" to do 45-50mph on non paved roads! doing 55-65mph feels a lot different than doing 35mph!

Yep, specifically what the Koni HT Raid is built for I beleive

 

[Qball]

So much like the title says is what I am looking for. I have searched and found very little. I want to be able to travel at 45-50 mph across the desert in my 80. More specifically, I NEED to be able to travel 45-50 mph in my 80 at king of the hammers on the desert loop sections.

I am the crew chief of the #49 Mistress Racing TTB equipped 4400 class race car and really need to be able to keep a reasonable rate of speed in order to not be even further behind the race car than I already am during pre running. I'm not lookin to build a race truck, or even an all out pre run truck. I am looking to put something together that is still able to daily drive, and here is the big one... Something that still fits in the garage... Yup, must be no taller than 7' max.

Currently the truck has the 50mm lift with shocks from iron man, and on the street it's great, wheeling it isn't bad at all and I don't really have any complaints other than perhaps the shocks are a bit on the firm side. I have sliders, a front bumper and winch, no roof rack, no boxes in the back, no giant swing out bumpers. A fullsize spare and 20lb co2 will be located inside the rear area where the 3rd row seats go.

I know someone has done what I'm looking to do, just curious the best step forward. I have a (in my opinion) smaller budget of around 1k that I would be willing to spend before February. But I don't want to have to spend twice. By that I mean I don't want to buy some shocks now, then next year switch to coil overs and or bypass shocks and end up tossing what I have.

View attachment 1309314 View attachment 1309315

So 1k budget like many said will kill the deal because the speed you are looking for cost far more than that. that said you could dial up the compression if you have TJM adjustable shocks, rebound will be lacking so you really need to watch out for uncontrolled body motion. Just remember for normal linear shocks if it's good for one thing then it's terrible at another, if you could dial up the compression for bigger bumps at faster speed the ride would be terrible for the smaller stuff, you probably know that if you are involved in the off-roading business.


That said i would suggest Tribe slow and save your pennies up for a custom set of King shocks.

 

[Qball]

$1k budget isn't going to touch that.

I would look into the Fox and Icon 2.0" shock options.

Doh, sorry I missed the 1k budget part.

 

[scottryana]

Like others have said it's going to be really tough with a $1k budget to get to 55mph in rough desert running, without really pushing the 80 harder than stock components can handle.

Some of the things I would recommend will come off as slightly counter intuitive to 90% of what we try and do with our trucks on mud. Unfortunately that might translate to not working out so great for your purposes after you get out of the desert. So do you get it to run great in the desert but sacrifice other off road aspects?? With that said here is what I would likely do if I had to try and get an 80 to tackle prerunning like that.

- Clean house.
Get inside and under the truck and yank out every piece you don't need. I would take the sliders off, the front bumper off and build a winch plate, pull all the glass but the windshield, full interior out (you'll thank me later during clean up, lol). Anything you can do to lighten the truck up. Just make sure if you're running tires and tools inside that you have good tie downs.

- Change things to get more up travel. (The 80 has big wheel wells but the tire has no where to go with the fender liners in):
Go to a 4" lift spring (get the truck weighed at your running weight and find appropriate rate)
Go to a 33" tire (more up travel less mass to control)

- Step up to better damping
The King 2.5" reservoir setup is great with your running weight (from your spring setup) call Joey with that weight and what you're going to do so he can have King valve the shocks appropriately.
King bump stops. Anything to gently slow that truck from crashing down on those axles

- Control the top of the truck.
Get with the Aussies and order their swaybars. Whiteline has heavy bars but there is a guy on mud that has them produced for him up to 38mm. In the desert you're not so worried about articulation since the right and left sides don't see massive differences, you're more worried about controlling the body in a 50mph corner on dirt.

I am not sure how long the desert sections are, but if you have to run at speeds for more than 15-30 min I would look at welding reinforcements on the front axle bells, the axles, and the suspension mounting points.

Good luck and have fun!

 

[chap79]

I have fox 2.0 and TJM progressive springs and here is my experience. Keep in mind the TJM springs are a little on the soft side and for the most part to run "high speed" or deal with larger bumps you need longer and stiffer springs.


Death Valley roads with wash board and some undulation is good up to 50mph.....again undulation not bumps, think rough bumpy roads.

Mojave roads with small bumps(less than 12 inch) is ok up to 20-30mph but the bigger whoopdeedoos I'm back down to 10-15 because I would bottom out on the bigger bumps.


To sum it up fox is great for smaller stuff, slow to medium speed and great on the road, leisure expedition style? But it feels very linear and really isn't great if you decided to be more aggressive/faster it's not as well suited, granted its probably outside their design specifications so I won't call it weakness. At 120 dollar a shock it is untouchable by anything else remotely in that price range. btw don't be fooled by the resi, that only increases the oil capacity and really nothing else so don't spend your hard earn money on just cool looks.

This pretty much sums up my exact experience with the fox 2.0's as well.

 

[jtwopark]

I would probably be more willing to spend my money on the Kings and up my budget than running the Fox or Icon stuff. We have all King suspension on the car also.

Still wanting to know some actual part numbers and or what others have used and done.

I'll get you some part numbers, later tonight

 

[Golgo13]

Have you tried doing this in stock condition? I might be willing to bet it doesn't do too bad...

 

[nukegoat]

Hydraulic bump stops are going to be critical along with heavy rebound damping. The 80 gets pretty pitchy out there IME.

@jtwopark - you should consider lowering your bumps.

 

[nukegoat]

Have you tried doing this in stock condition? I might be willing to bet it doesn't do too bad...

Lol... no.

 

[Mieser]

I blew 2 fox shocks just recently! Don't do fox for high speed! They blow seals!

What version of Fox shock did you blow a seal on? What seal was it?

Saying Fox shocks don't work for high speed is a pretty broad statement....

 

[Mieser]

I have fox 2.0 and TJM progressive springs and here is my experience. Keep in mind the TJM springs are a little on the soft side and for the most part to run "high speed" or deal with larger bumps you need longer and stiffer springs.


Death Valley roads with wash board and some undulation is good up to 50mph.....again undulation not bumps, think rough bumpy roads.

Mojave roads with small bumps(less than 12 inch) is ok up to 20-30mph but the bigger whoopdeedoos I'm back down to 10-15 because I would bottom out on the bigger bumps.


To sum it up fox is great for smaller stuff, slow to medium speed and great on the road, leisure expedition style? But it feels very linear and really isn't great if you decided to be more aggressive/faster it's not as well suited, granted its probably outside their design specifications so I won't call it weakness. At 120 dollar a shock it is untouchable by anything else remotely in that price range. btw don't be fooled by the resi, that only increases the oil capacity and really nothing else so don't spend your hard earn money on just cool looks.

Why would you want a stiffer spring rate? Springs hold the vehicle up. They do not have any ability to damp energy. If you run a stiffer spring thinking it will help with 'larger bumps' you are going to have to deal with that extra stored energy with the rebound valving?

The J80 chassis can be a heavy pig, but it would be interesting to see how common springs shape up to most common coil-over spring rate theory. I'm guessing that a lot of the aftermarket coils have almost no preload at full droop either.

I'm curious, is everyone running the Fox IFP stuff with 'factory' valving? As anyone tried valving them for their own use? I'd be curious to know what Fox is sticking in them 'stock' for bleeds and valve stacks. They seems to be running a pretty normal 2.0 piston with a 5/8" shaft. The oil volume is down a little bit without a separate reservoir, but they still aren't an emulsion with the gas piston. I wonder what the pressure rate curve is with the small gas volume. For $125 I think they show a LOT of promise.

 

[jtwopark]

What version of Fox shock did you blow a seal on? What seal was it?

Saying Fox shocks don't work for high speed is a pretty broad statement....

The 2.0 body was the one that blew and the part numbers were for the 3-5" lift!

I just wanted to see what the big deal was about the 2.0 body....a $500 dollar spur of the moment....waste of my time and money

Fox bypass and high end stuff is top notch but hate seeing that brand on bicycles!

 

[jtwopark]

Hydraulic bump stops are going to be critical along with heavy rebound damping. The 80 gets pretty pitchy out there IME.

@jtwopark - you should consider lowering your bumps.

I am not going to touch what KING did! They did the install and prototyping for the kit. In the video I was only doing 35 in the desert. Around 50-65 mph is where I started to bottom out on big whoops and dips and jumps.

That is why I am in search of bypass shocks and coilovers to find room to put both on there

 

[jtwopark]

Have you tried doing this in stock condition? I might be willing to bet it doesn't do too bad...

My stock shocks fell apart where the shaft pulled out of the body! Not a good idea!

 

[Mieser]

The 2.0 body was the one that blew and the part numbers were for the 3-5" lift!

I just wanted to see what the big deal was about the 2.0 body....a $500 dollar spur of the moment....waste of my time and money

Fox bypass and high end stuff is top notch but hate seeing that brand on bicycles!

So what 'blew'? Shaft seal extrusion? Physically broke something? Any specifics?

Since it was for a 3-5" lift I am guessing it was the IFP line? 2.0 aluminum body with the IFP piston in the shock body.

 

[Mieser]

One interesting thing I found out about the J80 chassis building my new hybrid project, is that the REAR suspension is actually lacking about 1.5" of uptravel compared to the front. The rear suspension also runs a dual bumpstop system with a rubber overload 'spring' in the coil. I think that can cause a very steep increase in spring rate for the last few inches of uptravel....that increase in spring rate can cause bucking since the rebound valving in the shock can't deal with it. I'd like to look at adding another 1-1.5" of uptravel to the rear suspension, try some more modern foam bumpstops, and a few other little tricks to see what happens. Stepping through the design of the suspension from stock should be interesting. Since I am building a bit of a hybrid....I don't have to deal with some of the standard J80 problems like tons of weight, needing lift for larger tires, etc....

 

[jtwopark]

So what 'blew'? Shaft seal extrusion? Physically broke something? Any specifics?

Since it was for a 3-5" lift I am guessing it was the IFP line? 2.0 aluminum body with the IFP piston in the shock body.

I don't have any pics but fox will not warranty it due to misuse! So I'm okay with it because I deliberately tried to break them and abuse them. also to see what its limits were! What I was doing with kings I did the same with the 2.0 body foxs but they just did not hold up so well. I am just trying to give my experience with the parts and I am no way stating that fox or any other brands are no good.

The king 2.5 with res and standard valving rides more comfortablely than the 2.0 fox shocks if anyone is interested on how the road feel is. There are compression adjuster so one can firm it up if needed.

If anyone gets any sort of shocks for the 80 just know that there will be fade on the passenger side due to the extra heat given off from the exhaust manifold.

I would opt to get a finned type reservoir if anyone experiences this.

 

[mingles]

While I don't have a lot of technical input on this topic, this thread reminded me of a video I had seen a while back of the Flat Out Racing team off road racing an 80. The truck is not stock by any stretch of the imagination, but it shows what 50/60mph suspension travel looks like over rough roads. The undercarriage shots begin at the 1:37 mark.