Building TURBO system for YJ

MikeGyver

UtahWeld.com
Location
Arem
I'm baaack! :eek:

I found a way to "fix" this thread and allow the photobucket-linked pics to show, so as I find time I will continue (slowly) updating the thread with new pictures to get to current.

If you download the "Photobucket Hotlink Fix" extension for the Chrome browser, all the pictures linked to Photobucket will display as normal(!)
This is a good extension to have anyway...


A lot of really good stuff has happened since the last post so get the Chrome extension here and lets continue the journey of boost.
https://chrome.google.com/webstore/detail/photobucket-hotlink-fix/kegnjbncdcliihbemealioapbifiaedg


A random teaser pic from summer 2018:
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MikeGyver

UtahWeld.com
Location
Arem
Ok, I just graduated with my bachelors in mechanical engineering and now I finally have enough time to finish this build thread that I've put off. I feel bad about leaving everyone hanging for so long, so lets do this.

The FMU and MSD box are gone and we're going all out with a proper method for controlling fuel and timing under boost.
As the teaser wiring harness picture above alludes to, we're going full standalone fuel injection and throwing away the crap factory computer.
I used a Megasquirt 2, which is kinda a DIY open source dillio which uses some really powerful tuning software, which we will get into later. You can control anything from a turbocharged weedwacker to a 16cyl sequential fuel injected motor with variable valve timing and a turbo with launch control and nitrous. The computer comes as a circuit board and a bag of components you solder on to it for around $300. Wire it into your vehicle and define your sensors in the software then start tuning, what could be easier, right?

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After an evening of following the manual to guide me for the setup I used, we have this. I'm going to but putting my MS2 in a GM LT1 Camaro PCM housing because it's waterproof and every square inch of the jeeps interior and exterior is potentially exposed to water.


Adapting the MS plug to the LT1 PCM plug. Onboard MAP sensor visible on board.

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Same mounting location as the stock computer.
 
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MikeGyver

UtahWeld.com
Location
Arem
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You can go with any number of different ignition timing systems, like 24x or 58x tooth reluctors like you'll find on an LS1 using coil per cylinder. I decided to go with the Ford EDIS-4 system for it's simplicity. This system is unique in that it handles all the timing details by itself and needs only receive timing commands from the megasquirt via 2 wires for 1 degree (or is it .1 deg?) timing control. This system uses a 36-1 tooth reluctor wheel and no cam position sensor at all! If timing commands are lost from the megasquirt, the EDIS system simply reverts to a constant 10 degree of timing 'limp mode'. The EDIS parts came off an early 90's 1.9L Ford Escort and consisted of ignition module, coil pack, 36-1 reluctor wheel, and VR sensor.

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Coil pack mounting location using the weird factory mounting bracket and modifying it to fit.

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The distributor will not be used again on this engine, it's just there to plug the hole and drive the oil pump.
 
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MikeGyver

UtahWeld.com
Location
Arem
The Ford EDIS system uses a "36, minus one" tooth crank position wheel. This wheel is cast as the same piece as the harmonic balancer on the Ford Escort. I simply cut it off using an angle grinder then faced both sides on a mini lathe.
This wheel needs to be aligned correctly with the engines physical top dead center. To mount this on the Jeep 2.5L, I used the big harmonic balancer-to-crank bolt to clamp the wheel down, and a single bolt to set the rotation of the wheel relative to the crankshaft. This single bolt would utilize one of the three harmonic balancer puller bolt holes. I did not yet at the time know how the orientation of the 36-1 wheel would land, so I just made a 120 degree groove which would allow me to mount the 36-1 wheel no matter what the clocking needed to be.

The following work is from the summer of 2017.

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Drew up some CAD dimensions to guide my slot making.

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Cast iron chips.

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Ok, here's the magic part. This is going to be a little hard to explain. There's a die grinder clamped into a metal tube with a metal plate welded to it. The metal plate has a hole and you can see carbide burr sticking through it. The metal plate and the deep socket are clamped in the vise. The 36-1 wheel is free to rotate about the deep socket, which fits very well in the center hole of the 36-1 wheel. With the die grinder running this allows me to turn the 36-1 wheel by hand and route out the arc. If I need to adjust the placement of the slot slightly, I just re-clamp the vise with the deep socket moved slightly.

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Cast iron machines easily.

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Nothin to it.

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Brazed a steel spacer to the back. This spacer has a hole that fits tightly on the big crankshaft bolt; this is what keeps the 36-1 wheel centered.

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Yay. Just gotta mount the sensor now.

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Here's how I mounted the VR sensor. I cut the mounting feet off the sensor and slightly turned down the body in the lathe so it would fit in a 2-piece clamping shaft collar. This mounting method allowed me to clock the sensor so the wires were aimed optimally, and to adjust the stickout so I could easily get like a .030" air gap using a feeler gauge. This sensor needs to be attached rigidly to the engine so you don't get weird timing flutter problems. The idea is that after the rotation has been accurately set and verified with a timing light, I will tack weld a washer around the bolt head so that the clocking is preserved even if I remove the wheel for some reason (which I still haven't done yet).

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MikeGyver

UtahWeld.com
Location
Arem
These pictures are from the summer of 2018.

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This is all the megasquirt needs.

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I used this as on opportunity to consolidate all my aftermarket wiring into the factory fuse & relay box by adding many circuits from a parts box I got at the junkyard. Now my spot lights, electric seats, wideband o2 sensor, and some AUX circuits have a fuses and relays and clean wiring.

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Building the new megasquirt engine harness and integrating it into the existing Jeep body/interior wiring.

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Mostly done. The wiring is now really clean with just a single main run and wires coming off it where necessary. I still haven't loomed the wiring yet.

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If you're going to do something like this is absolutely critical you avoid ground loops and isolate electrical noise from the high voltage ignition circuit. I used a central single point ground for everything at the engine block, not the battery. Fuel injection systems typically use high impedance sensors whose signals vary from 0-5V, so if your ground is shifting even a tenth of a volt due to some current draw, your computer is going to completely freak out.

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These are the only wires going into the megasquirt computer, that's it.
 
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MikeGyver

UtahWeld.com
Location
Arem
My air intake temps were getting way too high; 250 degrees F on a long pull in the summer, so knew I either needed an intercooler or methanol injection. Every 30 degrees you can drop the intake air is equivalent to 1 psi of boost as far as charge density goes. I went with an intercooler because it's passive and has zero maintenance. Got a nice, inexpensive $130 vertical flow intercooler off eBay and got to work stuffing it in the CJ grille which I modified to fit the YJ.

This took place in the summer of 2019.

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Under the knife.

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A tight fit.

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I used this as an opportunity to upgrade the rusted out CJ blinkers to LEDS and refinish the grille.

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Intercooler bolted to the grille, about 3/8" back from touching the slots.

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Intercooler mounted just high enough to miss the winch.

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Mocking up the new piping.
 

MikeGyver

UtahWeld.com
Location
Arem
Ok time to refinish and restore some structural integrity to this poor grille from 1972.

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I spend some time rebuilding the bottom rail. All the weight of the entire front clip, radiator, intercooler, etc is supported by the single body mount at the middle of this rail.

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This part was all rusted out. I had to get some structure from the bottom rail to the side structure in order for the load to be transferred safely down to the rail and its body mount.

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Gotta clear all the power steering lines.

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Using muriatic acid to dissolve some really deep rust pitting.

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No more rust.

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A coat of self-etching primer.

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Hmm, this thing is in pretty rough shape. Let's see if we can clean it up a bit so we can run it into some more trees later.

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MikeGyver

UtahWeld.com
Location
Arem
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Cleaned up nicely.

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Wetsanding the terrible orange peel.

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Buffing and waxing the banged up piece of metal for a better finish than a new car lol. This thing is insanely smooth, reflective, and shiny now. I got a little carried away with the wet sanding as you can see on the edge on the left.

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Back on the road.

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MikeGyver

UtahWeld.com
Location
Arem
Lets talk a little about the tuning software.
The tuning program that Megasquirt uses is TunerStudio, and there's a datalog viewing program called MegaLogViewer. I believe the basic versions of both are free.

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Here's the "dashboard" in TunerStudio. I've got the program set to record 45 snapshots per second through a USB cable that comes out of the Megasquirt computer in the Jeep. The gauges on the dashboard update in real time as I'm driving. You can choose to record or not. If you record you can then later open the datalog in MegaLogViewer, which has some very powerful visualization features to make sense of the massive amounts of data. The small window that is open in the image is the volumetric efficiency table which you have to develop for your specific engine. it's essentially how much the cylinders are filling up with air for a given manifold pressure and RPM. This VE table is iteratively honed in from datalogging, or by using TunerStudio's Autotune feature which can can adjust it in real time while driving and get pretty close using feedback from a wideband o2 sensor.

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Here's some data visulization in MegaLogViewer. You can plot any 3 data channels against each other on a "2.5D" graph. I've got nearly a million snapshots displaying on the graphs from datalogs recorded in August 2019. The left side is showing RPM on the X axis, manifold air pressure on the Y axis, and the "Z" axis is the color of the cells which is manifold air temperature. You can see that boost starts building right off idle at 900 RPM, reall goes vertical fast at 1900 RPM, and hits full 11 PSI boost by around 2700-2800 RPM.
The graph on the left hand side is showing RPM on the X axis, fuel injector duty cycle on the Y axis, and manifold air pressure (in KPa) as the Z axis (color). The Jeep is running the factory 3 bar (43.5 psi) fuel pressure regulator and a 190 LPH (or whatever it is) Walbro fuel pump. I'm running some unnecessarily big 60#/hr (630 CC/min) Siemens Deka fuel injectors. The max duty cycle is 64%; using an online horsepower calculator this is about 250HP worth of fuel. This seems high and I'm guessing it's more like 230hp, which is about double the factory HP of 123. And this is all on a motor that is curiously only making 90psi compression on every cylinder, when it should be more like 120 psi at this elevation. I'll probably look into whats going on with that and see if I can rectify it and gain a nice bump in power.

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Here's MegaLogViewer again showing a histogram of RPM vs MAP, vs closed loop fueling correction based on the wideband o2 sensor. You can see that it's dialed in pretty well. I can get any AFR that I command for a given RPM and MAP by using the AFR table in TunerStudio. You can also see that I've binned the histogram's X and Y axes non-linearly. The bin spacing is based on which areas the engine spends the most time in. This was determined by loading a several million snapshots or about 2 years worth of datalogging and seeing which areas had the highest hit counts. This allows me to have greater resolution in the idle and cruising cells by sacrificing resolution near redline where the engine is just acting like a big dumb animal anyway.

Anyway, it's taken a while to get it finished since I've only had 2 months out of the summer off from school, but the Jeep drives beautifully and pulls hard. Everything has been perfectly reliable and I've just been enjoying driving it since I put the intercooler on about a year ago. The engine loves the boost and it loves to rev to redline now. Before the turbo it felt like it was going to rattle apart as it revved up and felt like it was making less and less power. This honestly the most fun vehicle I've ever driven and the looks on people faces when they hear all these crazy turbo noises is priceless.
 
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MikeGyver

UtahWeld.com
Location
Arem
I'll try to get some actual videos at some point; this is kinda all I've got for now.



The Jeep is hilariously fun to drive on dirt roads now, when the boost hits the horsepower basically doubles in a split second which just blows the tires off and puts you into a drift. You can see rocks flying when the boost hits and the tires just spin going up hill at like 40mph.
 

MikeGyver

UtahWeld.com
Location
Arem
I ordered one of these $5 barometric pressure sensors. When it gets here I'm going to put it in the megasquirt as a separate, real-time baro sensor. Currently the MAP sensor is doing double duty by quickly recording atmospheric pressure right when you key on. Sometimes this doesn't work so well, like if you key off and key on with the engine running, then the fueling is off a few percent. A dedicated baro will also ensure proper fueling if i were to say drive from Utah valley to mineral basin (4800ft climb) without shutting the engine off.

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I'm also going to be wiring in an input to enable launch control. The input will be a clutch switch which I'll have to add to the pedal. The idea is that when the clutch is pressed in the, a new rev limiter will be enabled and the ignition timing will be retarded to like 0 degrees, or even up to 10 degrees after TDC. This will cause the fuel to burn in the exhaust and spool the turbo. When the clutch is released, everything returns to normal and you leave with boost. I'll probably set it to like 4psi, should be fun and i'll let you guys know when I'll need help swapping this AX-5 out again lol.
 

RockChucker

Well-Known Member
Location
Highland
I ordered one of these $5 barometric pressure sensors. When it gets here I'm going to put it in the megasquirt as a separate, real-time baro sensor. Currently the MAP sensor is doing double duty by quickly recording atmospheric pressure right when you key on. Sometimes this doesn't work so well, like if you key off and key on with the engine running, then the fueling is off a few percent. A dedicated baro will also ensure proper fueling if i were to say drive from Utah valley to mineral basin (4800ft climb) without shutting the engine off.

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I'm also going to be wiring in an input to enable launch control. The input will be a clutch switch which I'll have to add to the pedal. The idea is that when the clutch is pressed in the, a new rev limiter will be enabled and the ignition timing will be retarded to like 0 degrees, or even up to 10 degrees after TDC. This will cause the fuel to burn in the exhaust and spool the turbo. When the clutch is released, everything returns to normal and you leave with boost. I'll probably set it to like 4psi, should be fun and i'll let you guys know when I'll need help swapping this AX-5 out again lol.
Sounds like grounds for swapping in an AX15....
 

thenag

Registered User
Location
Kearns
As always insanely clean work!

If the distributor bugs you...

The 2000ish + 4.0L with a distributorless ignition still have the gear to drive the oil pump, they have a little Cam Position sensor on top of them.

I don't know if it will swap into your 4 cylinder but it might be worth looking into. It looks like this
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