Completed Project My 98 super charged EX

[CDW6212R]

it is exactly the same and thats probably what killed mine and why after being the only V8 two door with a 4406 e shift i swapped in a manual 4406

That brings up the 4WD operating system as I was deciding how to do it years back. I wanted the A4WD but I knew the internal clutch might be a issue with unknown power levels. In my research I found out that the 98 Expedition uses a GEM and different 4WD switch that provides locked 4WD(mechanical), and not use the TOD/clutch parts. Those control the shift motor to obtain 4WD Hi. I have a 98 Expedition GEM, and the 4-position switch(2WD,A4WD,4WD H, 4WD L), but making use of those isn't easy, maybe not possible. But I got them thinking maybe I could figure out how to utilize the GEM 4WD circuit.

If the Explorer A4WD system was reliable, I'd rather go that simple route. Dissecting the Expedition GEM and making that work might be way over my head. But I did find that the Expedition switch can mount to the Explorer bezel, it would be slick to have the 2WD position just to the left of A4WD, and not labeled.

 

[4pointslow]

I race in automatic 4WD and love the system and how it works.
I would not have it any other way. If you go WOT off the line it locks the front wheels in from the start.
Years ago I had one of the transfercase speed sensors fail, it is a hall effect and wired to the GEM module which controls the transfer case on my 1998.
When the sensor fails it shorts out and causes the power going to it to drop to 0 volts and I can not launch the truck, it just sits there and spins the rear tires.
It wastes my time and money going to the track when I can not launch so I put a voltmeter on the power wire coming out of the GEM module that goes to the sensors. Now if one shorts out I will see 0 volts instead of 10 volts in my center console. I posted pictures of it a while back.
Also when I changed the gears to 4.88's it threw off the MPH readings coming from both transfercase speed sensors. They read mush faster than the vehicle speed sensor coming off the ABS module and that pissed off the GEM module and it would turn off the auto4WD after one launch.
That day I had to keep restarting the truck to be able to launch.
I cheated and got one signal changer and put it between the ABS module and GEM. It is basically lying to the GEM saying the vehicle speed is higher than it is to match the transfercase speed sensors.
I love the system, it really does work well. Even my stock 1998 and supercharged 2004 have it.

With all that said I like the sounds of the Expedition one having two wheel drive but don't know how that system works off the top if my head.
Sounds like something to swap to for the V8's as another option to the manual Tcase.

 

[4pointslow]

I forgot to mention I got a spare transfercase years ago, I couldn't pass it up as it was already removed at a upullit junkyard.
For $60.00 I took it home thinking I was going to destroy my original one.
Later I stole the speed sensors off it to replace mine.
Guess where that transfercase is now?.......
It is in my 1998 4 door that has 286,000 miles on it. hahaha
The 4 door transfer case was leaking even after installing a rear seal in it so I just swapped it out the last time I put a transmission in the truck.
LOL.
I need a new 4 door with no rust, and now the rear main seal is leaking on that 4 door too. I replaced that years ago so I don't know what is up with that.
But 286,000 miles, I cant expect it to last forever I guess. lol
Really wish I could find a new 4door 1998, I really like driving that truck as a daily.

 

[CDW6212R]

Thanks for the endorsement of the A4WD system. I've liked it in my 99 truck, so I expect the BW4406 to work about the same way.

If you are wanting another 98, try searching south in areas where you could drive to, and a member might be able to look at for you. Lots of members here have discussed how their market is for 302 trucks in that 98 model range. It looks like $1500-$2500 should get you a nice truck, if you can identify the condition before going to see it.

I found my 98 Limited in Spring 2016, and my condition was to have no rust. I found this in NC, but seven years before came from GA. I paid $500 more than I could have, but I didn't want to barter and maybe have to keep looking. I was happy to see no issues, besides some minor damage to the radiator support(fenders and hood don't line up well).

 

[vroomzoomboom]

have you ever thought of swapping it for a manual case?

 

[ahodges]

I've been doing 4wd launches with the 4406e without issues. My thought is that the clutches have to be bigger in the 4406 over the ones in the 4405 anyhow, and I worry about the strength of the front axle anyhow. At the drag strip I launch in 4WD with just the brown wire mod and once I'm off the line, I turn it back off. If it was locked manually in 4WD, I wouldn't be able to disengage the 4WD at WOT. I'm sure it is possible to scab the GEM from the Expedition onto the Explorer somehow, but I never felt like pursuing that one (lots of custom wiring involved with that).

I actually did find the limitations of the 4405 when I had my stock OHV 4.0 in it. I was doing some vibration trouble shooting so decided to remove the rear drive shaft and drive it around only with the front driveshaft/ axle. I tried to be cute and do a FWD burnout. Instead, the transfer case clutches slipped and sent nasty shutters through the truck. That was the last time I did that.

 

[4pointslow]

have you ever thought of swapping it for a manual case?

Never.

 

[CDW6212R]

I've been doing 4wd launches with the 4406e without issues. My thought is that the clutches have to be bigger in the 4406 over the ones in the 4405 anyhow, and I worry about the strength of the front axle anyhow. At the drag strip I launch in 4WD with just the brown wire mod and once I'm off the line, I turn it back off. If it was locked manually in 4WD, I wouldn't be able to disengage the 4WD at WOT. I'm sure it is possible to scab the GEM from the Expedition onto the Explorer somehow, but I never felt like pursuing that one (lots of custom wiring involved with that).

I actually did find the limitations of the 4405 when I had my stock OHV 4.0 in it. I was doing some vibration trouble shooting so decided to remove the rear drive shaft and drive it around only with the front driveshaft/ axle. I tried to be cute and do a FWD burnout. Instead, the transfer case clutches slipped and sent nasty shutters through the truck. That was the last time I did that.

That's good to hear Andrew. I like the thought that the TC clutches may hold the front well enough to not slip at take off. If it can do that strongly, the higher power may not affect it long term.

 

[4pointslow]

So today we got snow so my race season is over.
I am bummed that it came to such a quick end being that it had only just started for me in November.
At least nothing broke including me.
So next year I am planning on installing a wet nitrous kit, I believe it is the only way I am going to get this thing into the low 12's where I want to be.
Since I have a GT500 supercharger I am planning on going with one of the plate kits made for them.
I have looked at Nitrous Express and Nitrous Outlet kits so far.
There are clearance problems near the wiper motor so I don't know which one would be better or if another brand will work.
I want to start out with the smallest jets possible, just to cool the intake air charge down. So I will have to order jets smaller than the ones in the kit.
Was also thinking of only spraying after the 3-4 shift completes, that's where the truck seems to loose power.

I have to read up on the regulations of having a bottle in the passenger compartment since the explorer is like a station wagon or hatchback.
Don't want to be told that I can not race because it doesn't conform with regulations.
There are also lots of options like bottle openers and heaters etc. Don't know what I will need.
After seeing pictures of destroyed vehicles due to bottle rupture, I also want a new bottle from a reputable place like Summit or Jeggs.
Bottles do come in kits like the GT500 kit so maybe that is the right way to start out.

I would appreciate any info or feedback as I have never had nitrous before.

Here is a picture of my engine compartment. I circled the area where the plate kit will go.
There is no room behind the supercharger which is a shame because it has two ports that could have been used.
The plenum has been modified since this is a stage 7 port with snakebite overdrive gears added, so I would not feel comfortable with putting a jet into that plenum. That is why I am leaning towards the GT500 plate kit.

 

[4pointslow]

I should also add I am going to switch to the Ford Racing throttle body.
Here is a picture of the throttle body setup.

 

[4pointslow]

Here are the two plates I am looking at. They have different hose attachment locations.
Not sure which one would fit better. With my luck I will probably buy one and then have to order the other one due to fitment issues.

 

[Dono]

Your going wet kit so you can just shut the bottle off and disarm the system? I keep looking at nitrous, and wonder what a small dry jet would do, other than crack my block in two...lol.

 

[4pointslow]

One thing I know I will need to add is a blow down tube.
This would make sure the nitrous vents outside if the bottle pressure gets too high.

 

[4pointslow]

Your going wet kit so you can just shut the bottle off and disarm the system? I keep looking at nitrous, and wonder what a small dry jet would do, other than crack my block in two...lol.

LOL, yes a wet kit.
Probably crack my pistons.
Dry kits seem safer when you see a nitrous backfire with fire coming out the intake or the intake blowing to pieces.
But then you have to richen the mixture up only when spraying the nitrous.
Since I only want to spray in 4th gear the wet seems the way to go.

 

[4pointslow]

I think I will need a purge kit too, doesn't seem to come with the GT500 kit.
I would like something like JD has with blue LEDS !!!! That looked really cool when he was purging.
Maybe I should go with green though since everything else is green like my under glow lights.
Is there rules about where to spray the purge, could it be under the vehicle or does it have to come out the top?
Lots of things to look into.

 

[CDW6212R]

If you can put it inside, would it be at the very back? You could weld in a metal shield/box if it's in the corner, even cut the floor out for pressure release, or access maybe. I have a large 12v air compressor mounted to the frame under the left corner, but only mean to run a line up into the cab.

 

[4pointslow]

I would put it at the very back if allowed to have it inside.
What do all the Mustang Hatchback guys do? I wonder if they have to have in a metal box?
When I have time to search the almighty internet that is one of the questions I need an answer to.
Placing it underneath would be secretive but I don't think there is room anywhere since my mufflers are where the spare tire used to be.

 

[CDW6212R]

I think it might vary by sanctioning rules, the hatchbacks do use that rear space. There's decent room back there, but I wouldn't want a compressed tank of gas behind the rear tire, or have a strong barrier between them.

 

[4pointslow]

Looks like a 5 lb bottle would fit back there real easy too.
I will probably start with 10 lb bottle since that's what comes with the kits.
The bottle should have the knob facing towards the front of the vehicle and tilted up since there is a straw in the bottle going to the bottom.

 

[4pointslow]

I have this storage box bolted down in the back of the truck.
I sure would like to have the Nitrous tank inside of it so it can not be seen except at the track where I want to show off everything.
Will need to do some measuring and test fitting and still got to find out if it would be OK with the local tracks.