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Dust Buggy

Used pretty much all the shock and bump travel.
Bumps are at 100PSI
Dented the driver bump pad which I figured was going to happen with 3/16” mild steel wall. Fix is either a custom Domex strike plate from Goatbuilt or a 1/4” 304SS plate.
It is super cush riding at speed on 12” berms but the 18-24” berms at low speed are pounding on the bumps.
Front looks like full bump compression. Rear looks like 3/4” left to go.
Springs appear to be just right with a little squirrelyness at high speed with jerky steering input. Otherwise stable. Also running 1/2”-1” preload and don’t want the ride height any higher. Softer would only be worse as far as I know.
Keep in mind, no rear passengers, half tank, no gear, no skid plates.


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JB shifter pin yeeted itself at some point in time. It could have been me or probably was me but I no longer have faith in the spring loaded clamp to hold it from rotating and falling out. Will be replaced with locknut and bolt.
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Oil pressure Autometer guage was bouncing around at idle from low maybe 15 PSI to 25 or 30.
The mechanical guage on the oil accumulator was a solid 35 PSI at idle with hot synthetic oil.
The oil fill is at mark when engine is just over idling and overfilled when accumulator has dumped.
Maybe bad sender or ground on sender?
Or do the gauges drop off at low pressures.
 
HYDRODYNAMIC said:
Oil pressure Autometer guage was bouncing around at idle from low maybe 15 PSI to 25 or 30.
The mechanical guage on the oil accumulator was a solid 35 PSI at idle with hot synthetic oil.
The oil fill is at mark when engine is just over idling and overfilled when accumulator has dumped.
Maybe bad sender or ground on sender?
Or do the gauges drop off at low pressures.
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Probably bad sender or ground. If it's new id lean towards ground, as I've got gauges from them well over 10 years old and never had a sensor fail.
I've currently got an Autometer GS in an engine with low oil pressure (maybe 10 psi at idle) and it reads nice and steady.
 
How did it feel and what are you thinking about how it handled?
 
Very cool! Very impressive! Please keep updating us during testing. (Which I guess is forever, lol) Sounds like it’s not too bad right out of the garage.

How is the steering at high speed? One thing I’m courious about is “high speed, high rpm” . On my truck, my whole rpm range is 1500-2500, (diesel) so I can’t tell much difference in the steering. On your project, I assume you can be at 50 mph with the rpms at 1500 or 5000. Is it drastically different steering through that range?
 
WaterH said:
How is the steering at high speed? One thing I’m courious about is “high speed, high rpm” . On my truck, my whole rpm range is 1500-2500, (diesel) so I can’t tell much difference in the steering. On your project, I assume you can be at 50 mph with the rpms at 1500 or 5000. Is it drastically different steering through that range?
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that's the whole point of a flow regulated pump. No changes in steering volume based on rpm.
 
Bebop said:
that's the whole point of a flow regulated pump. No changes in steering volume based on rpm.
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Excellent, I was wondering if he had something like that. Is that a specific pump or an add on device?

Edit, is it adjustable?
 
Bebop said:
time to add bleed in the rear and heavier compression stack in the front.
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i disagree.

hes living in the land of piston plunge right now, any changes he makes are based on bad information since he doesnt have 200psi in the shocks.

i will say if i was him id be ordering a 9-hole
piston for the rear.
 
HYDRODYNAMIC said:
Way back when ordering for first go around only the front needed the 9 hole.
The rear being on trailing arms was OK? with 8 hole.
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its is my opinion that an 8-hole has no business on anything in rock sports. there is too much flow, so you have to add valving to get the bottom out resistance, but the get harshness, if you valve for comfort, you have no bottom out resistance. 9-hole is the best flowing off the shelf piston in the game.
 
mobil1syn said:
its is my opinion that an 8-hole has no business on anything in rock sports. there is too much flow, so you have to add valving to get the bottom out resistance, but the get harshness, if you valve for comfort, you have no bottom out resistance. 9-hole is the best flowing off the shelf piston in the game.
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So the 9 hole flows the best, but the 8 hole flows too much? I feel like I'm missing something here in what you are saying.
 
Confirmed the fronts are at 150 PSI
Ideally I would like to make a change before testing again as it a a pain to get the trailer and load up.
What is the next setup?
9 hole rear with what bleed?
Bump both comp valve stacks up one or two brackets?
 
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Ghetto Fab. said:
So the 9 hole flows the best, but the 8 hole flows too much? I feel like I'm missing something here in what you are saying.
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the amount of oil coming through the large ports of the 8-hole make controlling flow a challenge to get bottom out resistance AND comfort. the 9-hole flows better allowing bottom out resistance and comfort.

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mobil1syn said:
the amount of oil coming through the large ports of the 8-hole make controlling flow a challenge to get bottom out resistance AND comfort. the 9-hole flows better allowing bottom out resistance and comfort.
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Sorry, good post though.

Flows better and flows the most to me sounds like the same thing. I think what you might be trying to get across is the 9 hole flows a more proportionate amount or appropriate amount, whereas the 8 hole just flows too much? Is there an issue with the 8 hole flowing too much in one direction?
 
Ghetto Fab. said:
Sorry, good post though.

Flows better and flows the most to me sounds like the same thing. I think what you might be trying to get across is the 9 hole flows a more proportionate amount or appropriate amount, whereas the 8 hole just flows too much? Is there an issue with the 8 hole flowing too much in one direction?
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The 9 hole has 6 compression ports vs 4 on the 8 hole. The 9 hole can flow more with less resistance allowing more valving. The more valving allows better tuning for high and low flow rates. The 8 hole starts to build too much resistance at high flow rates creating harshness instead of flowing and doing work quickly.
 
Blase said:
How did it feel and what are you thinking about how it handled?
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It has plenty of power to get up to speed and break things if not careful. I assume this will be the same in the rocks.
Trans and torque converter appear to be just right.
Still getting used to the gate shifter. Cruising around is super comfortable as the ergonomics are dialed.
Steering is smooth and fast.
Sway bar could be a little stiffer as at speed it does feel squirrely. When steering quickly and or when the drivetrain torque rolls the chassis.
Shock tuning is not there yet. Slow speed is too comfortable but gets harsh when the bumps engage. Need to trade some low speed comfort for the heavy hits.
 
HYDRODYNAMIC said:
The F550 brakes will only clear a 20" wheel and I wanted to be able to run a 17" to keep things standard. I first adapted a set of Willwood Dynalites and through more research found out they would flex and not provide the stopping power and also have a soft pedal due to the flex with the spacers needed for a wide rotor. I then thought about narrowing the rotor to 3/8 width and taking out the caliper spacers. Then I remembered that I didn't want all these one off wear parts, or under powered brakes. I ended up using F250 2000 rear wheel calipers and 13"x1.18" rotors. The rotors needed the flange mounting ID opened up a little. The caliper brackets and adapter did need some machining to sit true and flat and some sanding for clearance and a new bolt pattern to clear the knuckle. The piston size 1.75" Dia = 4.8" area and will be the same in the front and rear now. The Willwood AT6 which is their go to caliper for Ultra4, SCORE, BITD is a 5.4" area, so the Ford rear caliper at 4.8" is 89% of that so pedal and line pressures should be ideal. The wheel clearance is great. A bent wheel or small rocks will not get jammed between the wheel and the caliper. All the wear parts are available off the shelf and the brake pads are larger with more material and different pad compositions are available. The pistons are sealed for dirt and water ingress. The calipers are stiff for minimal flex. The rotors are thick vented so I don't have to worry about overheating. The pedal is a Willwood 7:1 swing mount tru bar for dual master cylinders.

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Did you make the brackets yourself?
 
wizbang said:
Did you make the brackets yourself?
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I had to check the calendar to make sure it was really Tuesday before I could fully enjoy your first post. IYKYK
If you are for real like Santa, Easter Bunny, and Boogy Man then yes, I made the brackets.
If I was to do it all over again would I do the same thing. Yes, I can brake check my kids out of their seats to see if they are belted in or not. Safety first.
The only downside I am not crazy about is that I had to mill and tap the caliper brackets to make everything fit. I don't like the idea of having a custom part although it is not a custom wear part. The caliper is stock but the caliper mounting bracket has been modified. Not talkin about the silver bracket I made but the cast black slide bracket that comes with the caliper. Also had to open the ID of the disk to fit the hub, this is a simple task and one that could be done with an angle grinder so not so worried about this wear part so much.
Enjoy the rest of your Tuesday.
 
Custom Crow Safety Gear belts showed up for the rear bench.
The rear bench is a big deal to me. I tore down the old buggy because I wanted a four/five seater so the whole family could ride and eventually I could ride in the back bench and let the boys pilot the ship. The whole buggy was designed around me being able to sit in the rear bench comfortably. Crow harness's were chosen because that is what I originally had on the Hydro buggy along with the Timbuk2 shoulder pads. The 1/4 scale tractor I worked on at Cal Poly in 2004 also had the same harness so I have a sentimental attachment to the setup. Crow did a custom build to use the kid friendly aircraft buckles with the clip in ends as I used eyelets to connect the harness. The center doesn’t get the shoulder pads as they are discontinued, but more so because we should be taking it easy if all 5 of us are belted in. Once it’s me and the boys, two on the bench then it will probably get wild enough that we will need some padding.
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No 5 point harness is a big problem IMO.
Especially with kids that aren't as focused on keeping their bodies straight and planted in the back of the seat.
 
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