Project: Midnight Panic

Genuinely curious, what is the cause for most supercharged engines to have a cyclical idle pattern?
 
I think that is generally due to the blower being overdirven.
 
Genuinely curious, what is the cause for most supercharged engines to have a cyclical idle pattern?
There are multiple reasons that a guy can start getting blower hunt at idle,
I’ve heard of everything from “fuel puddling” to improperly adjusted butterfly/throttle shaft from side to side allowing movement from one side to the other,

So far I‘ve never had one I couldn’t fix by opening the throttle blades a couple thousandths & leaning out the fuel a touch,

Personally I think the hunt is kinda cool, but there’s applications, like a drag car trying to stage, that I’d prefer a more smooth idle,
I’ve seen some cars get pretty rowdy trying to get them to the line.
 
most of the monster jam trucks were lopey enough that they surged several inches at a time when staging. I assumed they were either set up to lope as much as possible because it's cool, or it was somehow a consequence of maximizing throttle response. Tuning something like that isn't anything I've ever come near.
 
Not really an update on the truck itself, but this last weeks work is truck related,

With the new trailer & having to constantly swap tires on whatever rig I'm hauling there was a need for a better jack system,
Last year I simply used a standard floor jack, however it comes up a few inches short of reaching the hight needed to go from a 35"ish tall tire to a 50+" tire, so normally there's a block of wood or two in play, wich can be sketchy, plus there's must be 60 reps or so on the handle to get full stroke of the jack,

I've seen purpose built jacks used by monster truck guys for years, & after looking into it I even found there is a company that builds them,
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I noticed on their page "Financing available" so I figured a turn key jack is out of my price range,
Besides, I had a pile of useable parts here that could be used to build my own,
The list of stuff I had on hand included,
A nearly new 12 volt pump left over from a rear steer job,
Four good 1.25 heim joints left over after swapping the buggy over the EMF joints years ago,
A couple 3/4 heims,
Some 1.75" 7075 aluminum link material,
A 3" diameter, 18" stroke hydraulic ram that came out of the trailer project,
And a good sized sheet of 1/2" 6061 aluminum,

A quick trip to the eBay shopping center for some 1.5" 6061 round bar, a couple more 3/4 heims, & a pair of front hubs, tires, & wheels for a chinese kids ATV pretty well rounded out the parts I was short,

After eyeballing pics like those posted above, & pulling a few measurments from the cylinder I had, I set down & did a little 2D work with the pasmacam program to see what I could make work,
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The first issue I ran into was port orientation on the cylinder, combined with it's clevis style mounting, it just wasn't going to work, I considered buying new, for about 3 seconds until it remembered I had a mill & lathe that I had just spent hours cleaning a couple day prior,

So changes were made,
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Also a new rod end was built to get away from the clevis/pin setup,
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As you can see, changing the cylinder mounting changed the length of the cylinder (over all, not stroke) so I had to revamp my drawing,
Eventually I settled on a plan that looked like it would work, then last week I took a DXF file & my 1/2" aluminum to the waterjet guy in town,

While waiting for him I went ahead & built the link bars, & finished up the cylinder,
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Then my first day off this week I got a call that my parts were done,
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If you look closely the smaller triangular shaped parts are 3/4" thick, & cut from left over 7075 aluminum I used for wheel centers,
These parts are where the cylinder attaches,

Through the whole planning stage I knew I did not have enough welder to burn this thing together, so bolting it all into an assembly was my best option, some of the design reflects that,

Setup for machine work on some parts got a little creative, but nothing to crazy,
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Some where around 50 holes were drilled & tapped, then 60 or so were countersunk for flush head bols,

The bottom pads are held to the main frame rails with 1/4-20 fasteners, then the 3/4" pin boss plates are bolted using 3/8-16 bolts,
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I also had the axle mounting plates cut on the waterjet out of 1/4" steel plate, The axle itself was a hard old pallet racking pin I found in dads pile of good usable stuff, :laughing:
After machining it down from a crusty 1.5" to a usable 1.25" where it passes through the side frames & mounting plates, the ends were fit to the china ATV hubs, & the center cut down for weight savings.
Then just enough weld to keep the shaft from moving around,
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Next was a battery box that doubles as a pump mount,
This was cut on the plasma table after figuring out exactly what I needed, then welded together,
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The battery box was then welded to the axle mounting plates making all the steel components one piece,
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If you look closely the smaller triangular shaped parts are 3/4" thick, & cut from left over 7075 aluminum I used for wheel centers,
These parts are where the cylinder attaches,

Through the whole planning stage I knew I did not have enough welder to burn this thing together, so bolting it all into an assembly was my best option, some of the design reflects that,


You know you can make multiple passes, right? :flipoff2:
 
The battery box/axle assembly was then powdercoated, followed by final assembly of the main frame of the jack,
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In the above pic you can see how the 3/4" 7075 tabs are used for pinning the cylinder, plus the pin extends the full width of the unit & bolts passing through the side frames thread into the ends of the pin, tieing the whole assembly together even more,

For moving this thing around I'd need a handle, or, something to grab & muscle the thing around,
Everything I had looked at was similar to a wheel barrow, & was a fixed part of the unit,
I had something else in mind when I drew mine up,
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The parts above slide over the axle, then one of the 4 axle mounting bolts pass through the main frame plates from the inside out, both holding the axle in place, & acting as a stud on the outside, the curved slot around the pivot hole will go over this "stud" which with make the handle adjustable,

Before final assembly of those parts I built a couple support bars for the battery box,
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And a pair of retainers to keep the hubs on the axle,
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Here is everything in place before installing tires/wheels,
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I didn't take a single pic of assembling the pad end, or link bars, Which I should have, the pad end (part that goes under what's being lifted) also uses 3/4" 7075 for attaching to the cylinder & link bars,

In a couple of the pics previously posted you can see the axle mounting plate has an extra hole that lines up with a hole in the main frame plate, these are actually the mounting holes for the upper links, So not only is there a big bolt passing through the side plate it also passes through the steel plate, tieing the link to the axle (passing through the side frame) which is also bolted through the side frame,
And if that wasn't enough, the bolts that pass through the side frame plates, axle mount plates, & through the heim, thread into a 7075 aluminum rod that spans the width of the jack, so both left & right sides are all tied together,

(Definately should have took a pic)


Here is the whole unit assembled after dropping in a battery & bothing the pump on.
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Next up was wirng & plumbing,
Nothing special here, couple power leads, couple diodes, a fuse, & a few wires going to a 3 pin plug,
A cheapo winch controller works for up/down control, & since in just plugs into the unit, a guy could posibly set it up wireless pretty easily,
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Completed unit
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And with the handle folded down,
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I run out of time before finalizing & setting pressures, but I did get a couple videos of testing it out,




 
Thats awesome, they definitely are an awkward machine to move around on dirt. I've worked MJ and privet shows for the last 15 years in my area as track crew.

What does the front slide/rest on when used? I believe most have a pad of sacrificial material?
 
What does the front slide/rest on when used? I believe most have a pad of sacrificial material?

Just a 12x12 aluminum plate currently,
I could see MJ jacks being used on pavement a lot & causing wear,

Mine will be almost strictly dirt or smooth concrete,
A nylon or other form of plastic would be easy to add if needed. Good suggestion.
 
Just a 12x12 aluminum plate currently,
I could see MJ jacks being used on pavement a lot & causing wear,

Mine will be almost strictly dirt or smooth concrete,
A nylon or other form of plastic would be easy to add if needed. Good suggestion.
That should work out great. Get it pinstriped to match the truck ;)
 
Just a 12x12 aluminum plate currently,
I could see MJ jacks being used on pavement a lot & causing wear,

Mine will be almost strictly dirt or smooth concrete,
A nylon or other form of plastic would be easy to add if needed. Good suggestion.

That would suck to scratch your new $9k Jack. :laughing:

Great job on everything man, you truly have the mad ninja skills :smokin:
 
So I have to slide this project over to the other side of the shop for a bit again,
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I've been talking about a new engine for the buggy for about 3 years now, it needs to happen this year,

Before moving the rig off the rack I did get some limit strap mounts tacked in place,
The front is pretty straight forward, a couple tabs on the axle housing, & a longer mount with a few holes to select from up on the chassis,
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The rear I decided to try using the sway bar arms & links, keeping the straps up out of the way since on this end of the truck the bump stops are contacting the axle housing,
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I've been using the poly performance quad wrap straps for years on the buggy, if they end up being a little light in this application everything is built to accomodate a second set of straps pretty easily,


At this point the truck was moved & the buggy positioned for tear down,
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Fortunately it doesn't take long to tear this thing apart,
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And not a lot longer to have a fwe parts swapped over & the new engine set in place,
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The down side is I have decided to completely replace my accessory drive setup (Part of that can be seen with the change from a mechanical to electric water pump) which also means the fuel cell will probably need redesigned & rebuilt, (it was needing attention anyway)

So thats where I'm at, back to work & waiting on a couple new steering pumps, The good news is once the engine swap is complete & tuning is done, I'll be getting very close to pulling Midnight Panic completey down for finish work.
 
I ended up short a little material for finishing the accessory drive this days off,

Lots of aluminum chips were made,
This alternator mount started as a nice chunk of 1.5"x2" 6061 about 9" long
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Not sure what application the crank pulley was for, looked like a power steering pump, but after boring the center & putting the 4 bolt patter in it, the application is not big block Ford.

I had a couple stamped steel idlers on hand, but the diameter was a little big, so I pressed the bearings out of them & built new ones the diameter I wanted,
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The idler on the right will see more load, so it has 2 bearings,
The single bearing unit is on the slack side of the belt, & is only there to increase wrap around the crank pulley,
Also, there will be a turnbuckle from the top of the new alternator mount to the threaded boss on the alternator case for tensioning the belt,
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On to the steering side,
Since this rig was built I've run some form of P-pump, usually a stock parts store unit for the rear steer, & a high volume deal for the front,
This time I am going to switch over to the Saginaw TC/Type2 pump,
Both pumps are supposed to be better than stock, (circle track application), with integrated reservoirs for packaging,
I did have to swap pulleys to get better bolt access from the front,
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Both pumps will bolt to a single plate that will bolt to the front of one head, (opposite the alternator)
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The mount actually bolts flat to the back of the pumps,
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On the front side of the pumps another bracket was built to tie everything together, & also provide a mounting point for the second idler,
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Next week I should have the material to build the stand-offs & get this unit bolted to the engine,
 
It's been a real busy couple weeks trying to button up this engine swap,

I finally got the accessory drive all wrapped up, literally,
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With the front of the engine sorted I could get the rest of the parts put back on, (upper intake, exhaust, wiring, cooling system & steering plumbing, etc)
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The next project to tackle was a new fuel cell,
For years I've been using a modified RCI unit, we all know their reputation with cracking, & this one was no different,
Mine has been in & out of the rig to repair cracks 3 or 4 different times, to get it out of the chassis I had to pull the shocks off one side to get enough room to pull the tank out, so it was no small task,

For those that do not know, I run nitrous on this rig, & for the most part it runs on pump gas, but when using the bottle I inject 110 octane race fuel with the nitrous, So, the rig actually has a complete secondary fuel system dedicated to the nitrous system only, (separate tank, pump, filter, & regulator) All of this mounts in/on the main fuel cell,
The fit & attachment of this secondary system is another reason to upgrade the main fuel cell,

So the goals for the new tank are,
1) More robust, less cracking
2) Better fit in the chassis, easier removal
3) Fit the nitrous fuel system to the main system cleaner/better
4) a little more capacity would be a plus

1) Most off the shelf aluminum fuel cells are .090" thick (I believe all RCI units are advertised using this material)
I happened to have a half a sheet of .125" 6061, so after a little measuring & coming up with a design, the main body of the new tank was cut to size,
The front & sides of the tank are one piece with two bends,
2) At two inches narrower this tank can roll out the back of the chassis without removing the shocks,
4) The back is the second piece bent in four places in a way that allows the tank to extend back between the bump stop cans, (gaining a couple gallon capacity,)

The bottom makes up the third piece & after it was cut to fit, those 3 parts wer tacked together,
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3) The top makes up the fourth & final piece, this is where merging the two fuel systems together takes place, since the nitrous system tank fits inside the main tank,

On the old setup the top of the tank had threaded inserts that held everything in place, The nitrous tank had a flange, & would drop through a hole in the top, resting on the flange, & sealed with a gasket,
On top of that flange is a billet aluminum top, this is where the inter pump & filter mounts, pressure & return ports pass through, & pressure regulator mounts on top of, That billet top is sealed to the flange with an O-ring,
Here's what that unit pooks like outside of the small nitrous system fuel tank,
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A similar setup is used to on the main tank to hold the main fuel pump,

With the new tank I wanted to get away from threaded inserts going into a thin aluminum top, & get rid of that gasket sandwiched in there,

So I started with a chunk of .390" thick aluminum plate, & after many setups & hours of machining, I had a billet top to tack onto the new tank.
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The majorty of the top was cut down to about .200" thick, leaving the mounting threaded areas the full .390,
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Now O-rings will seal both sides of the auxillary tank flange,
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After a quick test fit, the tank was finally welded out,
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