Thread: Can we make my rock crawler faster in the whoops?

id use poly bushings, if you use a heim you need to make sure the shock mounts below center link of the links or else it will twist and try to bend a shock shaft. you probably knew that though.

I'll probably go with a bushing and see if it's capable of handling the articulation on the rocks. I'm going build for the heims and switch later if it's what I need to do. I did know about mounting the shocks lower than center. Thanks.

johny joints for the links flex great

WOW. those #'s are so close to mine. haha. That orange chevelle in the back ground shacks house window when he is idleing. Unreal car. Nice meeting you last month.

Originally Posted by sullyman

WOW. those #'s are so close to mine. haha. That orange chevelle in the back ground shacks house window when he is idleing. Unreal car. Nice meeting you last month.

Looking at your truck gave me a lot of direction for what I want to do. I'm working on making the Chevelle quieter now. I drove it to Corona on Friday and I'm barely getting my hearing back today. I'm just extending the exhaust over the rear axle and out the sides. I might have to sell my HIDs so I can pay for the rest of my build.

What HID's do you have. Allways interested.

cool f-toy i thought about adding a few goodies like that to mine but havnt yet..

Originally Posted by sullyman

What HID's do you have. Allways interested.

You have a PM.

I'm planning on putting bushings that fit into the scrap 2"x.250" wall tubing I have. These will be on the forward end of the lower links. So the bushings are 1.5" with a 2" shoulder and 1.5" long. I'll be able to use a .5" bolt through the mount and bushing. Here's the Poly Performance part # PPM-4301-200. Does anyone see any problems with this set up?

I'm also ready to start building the upper shock mount. It will go where the bungee cord is in this picture. It will go all the way across the rear seat. After it's in I'll have to making gussets to tie it into the rest of the cage.

I'll be lucky to have this thing ready for KOH. I've been working, getting the ready for next years drags, and my vacation. Here's what's been done recently.

looks good!!!

How much shock shaft should be showing when I initially set up the shocks and springs? I have 16" shocks.

depends on ride hight .. up travel ect ,.. drums on a rock crawler ?

It's sitting at ride height now. My shocks are just mocked up now. The shafts are set at half their travel now (in the picture). I've always had drums at the rear of my crawlers and most of my friends have the same.

Here's what I've been able to accomplish lately. Finally have a shock mounting bar that I'm happy with. I still have to put some plating between the two vertical tubes above the shock mount. I don't know how much more bracing I'll need but it's a start. At full compression the shocks are 90* to the links. They're also tilted in 5*. Tomorrow I'm going to do my upper link mounts. That way I can fully cycle my suspension. Next weeks I'm going to fully box my lower control arms. I calculated that I need 200 lb springs over 350 lb. I'm looking for some 3" id x 14" long 200 lb springs.





Do you see any major mistakes in what I have going so far? I still have to figure out what I'm going to do about that missing piece of frame.

Whats the shock angle at bump?

id cut off the whole back section of frame and tube it in, its really just unneeded weight back there. this is how we did it on a jeep i built.

just cut the shit all out and run tubes inward and back, then you can build wings off the rear section if you have a cell or whatever you need? what id do looks pretty basic maybe a little more angle on the c.o. so its as close to 90* at bump as it can be. im still learning but i feel good about my suggestions! good luck!! looks fun!

guess no one reads these days, he said they are 90* at bump.

lol my bad i read the bottom line didnt see the top one plus im a few beers down lol my bad!

i would remove the two vertical bars that are above the shocks looks like a head ace to me other then that looks good
better hurry up and get it done the season is here to crawl

why not do the shock like /\ like most crawlers cause your shocks will not be running straight up and down most of the time so just less you have to worry about binding

Originally Posted by shane1617

why not do the shock like /\ like most crawlers cause your shocks will not be running straight up and down most of the time so just less you have to worry about binding

because that is about the worst thing you can do when you are trying to go fast.

And you are thinking of shocks off the axle, not on links.

I was thinking about cutting out all the frame from the back of the lower link mounts. That will definitely make it easier to mount the bumps. I don't want to inboard the top of the C/O anymore. They're already close to the back seat. The two vertical bars will be padded. My son and I sat back there and they aren't as close to your head as you might think. If it's a problem I'll take them out and put some new ones with a little bit of bend in them. The only think I need to worry about mounting in the back is some tools and my propane tank. Not too much weight.

Thanks

Everything is tacked in except for the upper link mount on the axle. I'll have to build that tomorrow, along with some bracing for the axle. If I can get all this done I'll try cycling the suspension.

According to the 4 link calculator I'll have 71% anti squat and 4* roll over steer.

If you want it to go through whoops "good" then Id suggest cutting the front knuckles off the axle tubes and building in 10* of caster and 10-15* KPI. That alone drastically helps the KOH rigs in the go fast sections

How will that help? Those mods are not in my plans.

i wouldnt worry about that to much, suspension travel and tuning will make it worlds better then what you had before. other mods would help you keep it straight at high speeds, but i dont think you plan on doing 100mph do you? lol

I hope he plans to go 100mph =)

100mph is a little out of my range right now. Maybe on flat land.

I mocked up the upper link mount and cycled the suspension. The only problem I have is the drive shaft is pulled out pretty far. I'm going to shorten the lower links and inch and that should take care of that problem. I may also bring the lower links 8" closer together at the frame. That will cut my roll over steer in half.

Originally Posted by 84prerunner

guess no one reads these days, he said they are 90* at bump.

Just like magazines, all I do is look at the pictures and sometimes the sentences associated with them.

looks good. whats the reason for the links on top of the axle? just for extra groumd clearance?

Originally Posted by ovrebo1

Just like magazines, all I do is look at the pictures and sometimes the sentences associated with them.

Sounds like me too.


The links are on top of the axle just for clearance. I'm concerned with the link hanging down too low and dragging on the rocks.

It's finally standing on it's own.







There's still 4" of up travel in the shocks but I need to make some room for my drive shaft to take advantage of it. Total so far it's getting 17.5" of travel. I still need to finish the link mounts on the axle, finish boxing the links, and shorten the links up an inch. I also think that my spring rates are too high (250 over 300).

Here's the latest progress. I still need to finish mounting the rear seat, the tank mount, the axle truss, and the lower links. I'm also thinking about selling the rear seat and just putting a single seat in between the shocks.

Will these springs "settle" at all? I keep thinking that the buggy looks too high in the rear but it's actually sitting level now. I was too used to seeing it sagging in the rear with my old leaf springs.

Some updates:











My only concern right now is if I need to add some more support to the bump stop cans and if I need to put a bolt through the upper shock eye of the (converted airshock) bump stop. Next week I'm going to finish boxing in the upper link mounts and trussing the axle.

run two tabs and run a bolt through the bump stop and it will be really strong that way should be fine the way it is but for an hour or so worth of work it would give me a piece of mind

I got the bump stop cans reinforced and my rear lights working. Two red tail lights and brake lights, one amber tail light and brake light, and one reverse light. Tomorrow I'll have my rear rock lights done. It's almost ready.

Everything in the new four link worked better than I thought it would. Here's a long boring video of the rear suspension (and up my son's nose). I didn't go too fast because the wife was in the buggy. If you look close you can see that the upper spring wasn't doing any work. I found out that I put the secondary spring stop too low and I was only on the lower spring. Even with that mistake it's a million times better than my old leaf spring set up on the rocks and going fast. Once I made some adjustments it felt even better. Now I really need more power and front suspension work.

GOPR0255.MP4 - YouTube

looks good!