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Completed Project My 98 super charged EX

Use this prefix for completed projects that are not "How to" articles or threads asking for help.
1998 Explorer 4.0 SOHC
Bought it with a melted alternator/wiring harness from a junkyard for $1,000
Fixed it, drove it for two weeks, then I boosted it.
Started with an M90 supercharger kit from
Upgraded to an M112 Lightning supercharger that was a prototype kit.
Next was the M122 off a 2012 GT500
I have reached 20 lbs of boost (with ARP head studs) and a 12.83 in a quarter mile.

1. How it looked when I brought it home.
2.The M90 supercharger installed
3.The GT500 supercharger installed
4.How it looks now
green ex.jpg
Lowered Rear.jpg
Exploder wheelie.jpg

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Yes, I think the 4x4 was the hardest since I had to file a little plastic away and solder. But all in all it wasn't too bad. Making sure the LEDs were in the right way an important step, I was checking and rechecking to make sure they would light up. I didn't want to get it all back together and have to take them apart again to reverse the LED for correct polarity.

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Secret Water Methanol Switch

While redoing my center console I ended up not having a place that I wanted to put my Water Methanol Injection enable switch. I decided to try a temporary custom alteration to the rear defrost switch after looking at the wiring diagrams. I would have liked to do it to the rear wiper switch since I don't have a rear wiper any more but the rear defrost looked easier and I don't use it either since I barely drive the truck when its crappy outside. I will most likely change it at a later point.

I found that you can take the switch cover off the switch so first thing was putting a rear defrost switch cover on a spare fog light switch. Then I found that the back of the switch comes off so I swapped them so I could use the connector for the rear defrost switch that was already in the truck. This prevents me from plugging in the wrong ones to the wrong switches.

I did not cut any wires either, I just removed two from the back of the connector and taped them up. Then I installed two new wires with the same terminals (spare DPFE or TPS sensor connector has the same terminals) in the back of the connector then going to my water methanol relay.

After playing with the switches for a while I decided to change the LED that lights when the switch is on. The amber color was not noticeable enough so I went with red. Turned out pretty cool looking.

Just a note about the switches, the regular rear defrost is a momentary contact switch and the fog is a on / off switch. My new custom switch has the rear defrost picture on the front of it but is now an on / off switch that enables my water methanol system. This is completely reversible since no wires were cut, when I find a better place for the switch I will re-enable my rear defroster. The second picture down shows where I shaved a little plastic line down so the switch housing would fit in the defrost position in the radio bezel (you normally can not change the position of the two switches). I also plan to change the LED in the fog light that tells you the switch is on, to blue.


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this was what i did when i was doing my l.e.d.'s so i didnt screw up the polarity. i found which was the + and - sides, then took a black sharpe and ran it up and down that lead. then when you put it together, one side was black and the other side wasnt. it would also melt away if you had to solder them so contact wasnt affected.......but now that you have done yours, i guess this is useless info....
as for your meth kit, its not armed all the time? the aem controller i have is set by boost. if you dial it to come on a 3 psi, thats when it turns on. same with how fast it comes in.

LEDs and switches

That's a great tip for installing LEDs, I may use that when I do the window switches.

My meth kit is not used all the time, I have two tunes so I can drive on the street without spraying water methanol and then spray at the track when needed.
You would be surprised how fast you can empty the bottle.

The snow performance kit I got can use boost or a MAF reading, I am using the MAF. It is progressive too so it ramps up the higher the MAF output goes.
I have it starting approximately 600 counts of the MAF, at that number the rpm is around 4,000. My lowest drop in RPM (3rd - 4th) is to 4,000, setting the controller the way I did makes sure that the Spray doesn't stop when the auto trans shifts.

Blue LED

I put a blue LED in the fog light switch.


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Tinted Plexi-glass

I put a piece of tinted Plexi-Glass over the hallpower monitor.
Looks better in person.


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Everything is looking great!

1/8th mile


Next weekend I should be racing at MapleGrove Raceway.
The track was half concrete and this year they decided to concrete the rest of it. It wont be completely finished by next weekend so the race will only be
1/8th mile. I should be able to get the truck on the scale to check the weight.

I was wondering when you were going to get back there.
There really hasn't been much going on lately, with Tim's drive-train out, and me waiting on my bottom end.

1/8 mile


wow. 13.4 in a quarter mile! nuts. and that thing sound soooo bad ass from the inside!

online calculators

Yea, according to an online calculator I was anywhere from 13.10-13.40 today
I wish it was really a 1/4 mile today for accuracy's sake.
Right where I figured it would be with the warmer weather etc. Should be back in the 12's in November/December.

Impressive! I love how often it shifts with that 5 speed vs. my 4 speed. That extra gear range might be keeping you in the power band better.


The 5R55E is definitely an interesting transmission.
Yesterday it was shifting around 5400 (1-2), 5500(2-3), and 5600(3-4) according to the datalogs. I am using the X4 to datalog and tune now.
I will be playing with the shift points to see
1. What the effects are in the 1/4 mile,
2. If I could go with a smaller diameter tire
3. To see if I have eliminated spark blowout
I have adjusted my spark plug gaps down to .035, and yesterday there were no signs of spark blowout at all. Of course the tune was short shifting the transmission around 5500 so further experimentation is needed up to 6250(stock rev limiter). I need a good test and tune night at the track.

A side thought about nitrous, you don't want any ignition problems at all. If I were to install it I would have to have all signs of blowout or any other ignition problems eliminated. Still would like to try a small shot by the end of the year.

The air fuel was on the rich side, I thought I adjusted to compensate for the water/methanol that richens up the mixture but I may have adjusted the wrong way and made it worse rather than better.

Here is a screen shot of a datalog from yesterday.
I am using my on board PC to datalog in pass-through mode with Livelink GenII and the X4. You can not use Livelink 6.5 with the X4 but you can open the datalogs made with GenII in LL6.5 and I am doing that for clarity.


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Truck weight

I forgot to mention, I filled the tank and drove to MapleGrove Raceway. After the first time trial I got on the drive on scale. The truck with me in it weighed 4410 so it is down 95 lbs since the last time I weighed it when it was 4505.

looks like i have to find a way to shed some on evil. it weighs 4340 with 3/4 tank without me in it.

1/4 miles runs

I got some track time at Atco Raceway and did some 1/4 mile runs.
Video's will be posted soon.
It was nice and hot outside and I expected 13.40 or 13.50 in a 1/4 mile.
My first run was a 13.47@100.36 mph with the transmission being short shifted 1-3 at 5200 rpm and the PCM deciding to skip second gear (WTF?). 3-4 was at 5500 rpm.
See first picture.

I changed the shift points a little to hang out first, second and third gear longer.
The result was a 13.19@101.65 mph with 1-2 happening at 5900 rpm, 2-3 at 6188rpm and 3-4 at 6188.
See second Picture

Later with the same tune the PCM decided to skip 2nd again. I have some investigating to do to find out why it is doing that. There is a "PID" named commanded gear and it goes right from 1 to 3 sometimes, so I have concluded it is a tuning issue. Maybe something with allowed time to shift gears or something.

No spark blowout with the gap set to .035

Also I believe the switch to shift by rpm and mph is backwards in my tuning software. I may be wrong but I think when it is set to shift by both it doesn't and when it is set to shift by MPH only, it shifts by both (whichever comes first). More testing is required, darn, guess I will have to go back to the track again. lol.
I forgot to lean out my mixture again, I was having so much fun.

I will be doing an exhaust back pressure test at Idle and wide open throttle soon. Probably next weekend after taking two ASE recertification tests. Then on the 27th I have an appointment to drop my truck off and have some custom exhaust work done. I am having 2.5 inch pipes with high flow cats put on. I am retaining the dual inlet, single 3 inch outlet flowmaster for the time being. I will be testing exhaust back pressure again afterwards.


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And what?