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Programming for boost questions

CanMan

CanMan

NAXJA Forum User
Location
Lake Tapps, WA
So I picked up a Thunderbird SC and have started fabbing up some brackets, mounts, and so forth. These SC's are set for 12 lbs of boost stock. Im going to have a larger pulley made(or find one) so I can run less boost(6-8lbs). The TB will be on the inlet side of the SC.

Other mods are small(bored TB, 99+ intake, no cat, flowmaster 40 series). 1998, AW4, lift, gears, 33's ect..

Ive been reading about how the Chrysler computer is not self adapting, and by adding more fuel pressure, bigger injectors, and ignition mods wont work. True?

Im seeing Kenne Bell does an Optimizer 2 computer reflash/relearn, worth the money? They also do a Boost-A-Pump, worth it over an FMU?

What to do with the single feed fuel line? No return needed?

What components will I need to make this thing run right? Larger injectors, more fuel pressure, colder plugs gapped correctly, timing retarded, piggyback computer(Apexi, Megasquirt, ect..), FMU, 3bar MAP sensor, ect..?

Any and all help would be appreciated. Id like to get this thing done in the next few months.
 
maybe2fast said:
question...

how are you going to adapt an Eaton blower to a 99+ intake? and get a belt around the snout?
Click to expand...

Removing the AC that doesnt work and mounting it on the pass. side. Similar to this, but not booty fabbed.

Pics001.jpg
 
That may be one of the better solutions to a supercharger.

are you using the jeep TB on the SC? If you want a better looking adapter to the intake, take the blade out for the factory TB
 
CanMan said:
Ive been reading about how the Chrysler computer is not self adapting, and by adding more fuel pressure, bigger injectors, and ignition mods wont work. True?
Click to expand...
They are some what self adjusting. They usually have no issue with minor bolts ons. When you get into a stroker or forced induction you need to do some work. Either upping the fuel system pressure, larger injectors, map adjuster, or a piggy back.

Im seeing Kenne Bell does an Optimizer 2 computer reflash/relearn, worth the money? They also do a Boost-A-Pump, worth it over an FMU?
Click to expand...
I don't know of anyone that runs the KB stuff, as they are mostly involved with the V8 engines.
What to do with the single feed fuel line? No return needed?
Click to expand...
no return needed. The FPR is in the tank.

What components will I need to make this thing run right? Larger injectors, more fuel pressure, colder plugs gapped correctly, timing retarded, piggyback computer(Apexi, Megasquirt, ect..), FMU, 3bar MAP sensor, ect..?
Click to expand...
The main thing is that you will need a piggy back computer that will sense boost and extra fuel (either using the regular injector, or by a 7th injector). Or you could use a hobbs switch to turn on the 7th injector w/o a piggy back. You will need larger injectors if you go without a 7th injector. You could increase the fuel pressure instead, but I don't think that would be worth it as the only kit I have seen is $300.
 
I will be VERY interested in how this turns out... I have an eaton sitting in the garage along side a 4.7 stoker already built... I was planning on 30 # injectors, a check valve in the Map sensor vaccuum hose, a hesco fpr, and maybe an apexi-II to do fine adjustments with... I looked at the bgperformance pcm reflash.. but dont think they will mess with mine b/c I have a 94 (ODB-I)... what did they tell you about it?

Please keep us informed...

PM me for my email address... I have a PLETHORA of websites to send you to for your research....
 
I have actually turbo'd an XJ. Depending on the year, the ECU will yank fuel no matter how much you add. Mine fought off a 12:1 FMU and pull all the injector pulse out. If you have a single line with no return you can't run an FMU anyway. I have a set of 36 lbs injectors for sale if you need them. I used them for 10 mins and figured out my AFC wouldn't work right. Hobbs switch with an injector won't work right.

You best bet is an AEM FIC and get some injectors and a good high volume fuel pump. This is the best option for the money period. Don't bother reading turbo XJ thread with the guys that use 2 bar maps and adjusters. They will not pull timing and will detonate. Ask the guys that have blown them up.

Get a wideband O2 in your truck before you drive it. Get the fuel in the 12.0:1 or under in boost and drop a heat range on the plugs.
 
Talyn said:
Reflashing will do you no good on a turbo as far as the PCM adding fuel.
Click to expand...

So you're saying that an ECU programmed by www.bgchrysler.com for my setup wont work? I havent called and talked with them yet, but will in the next few weeks.

I understand larger injectors, possibly a better fuel pump, colder plugs gapped tighter, wideband, ect.. is in order.
 
Thats what I said. The stock PCM is limited in changes that can be made. For your need it won't do anything. There is no way to make the stock PCM understand what boost is or what to do with it. Also, last time I talked to B&G they weren't doing older Jeep PCMs.
 
Ive been getting mixed answers on a different boards.

Just to clarify, an AEM 30-1913, larger injectors, larger FP, colder plugs, wideband o2, should get me to the right area @ 6-8lbs of boost?

Might as well do a blow through carb, something I know a little more about. :laugh:
 
CanMan said:
Ive been getting mixed answers on a different boards.

Just to clarify, an AEM 30-1913, larger injectors, larger FP, colder plugs, wideband o2, should get me to the right area @ 6-8lbs of boost?

Might as well do a blow through carb, something I know a little more about. :laugh:
Click to expand...

Here is a reccomendation from someone who is actually using an FIC on a 99 XJ:

- AEM 30-1913
- AEM ECU jumper harness
- Larger injectors (I'd go 40lbs)
- AEM UEGO wideband
- Colder NGK V power plugs

The FIC will work great. It does everything you need, and nothing you don't. The biggest hurdle is to remap both O2 banks to ensure the factory ECU doesn't throw a code. However, the FIC has dual O2 bank maps and can adjust the output in several different ways to prevent a code.

AEM's new jumper harness is AWESOME! It allowed me to wire the FIC on the bench, and also completely remove the FIC system by simply unpluging the harness. I highly reccomend shelling out the extra $ for it.

A larger fuel pump shouldn't be needed.

Some pics of my setup:

Parts011.jpg


Parts014.jpg


harness006.jpg


Parts007.jpg


I'll have a full build posted soon.
 
Talyn said:
Which part is the jumper harness? The one with all the blue wires? If so did it come with both the sockets and plugs?

Does it do anything for closed loop operation?
Click to expand...

The jumper harness is the entire ECU plug, harness plug and wire assembly (Bottom pic). If you've ever spliced into the factory harness of a vehicle you can appreiate this harness. You can now even order this through JEGs online.

The FIC can adjust closed loop operation, although it's obviously best for the ECU to remain in control of closed loop. The key in boosted applications is to enrich the closed loop to open loop overlap, which the FIC can do. There is even a tutorial video on the AEM site that outlines this.

Enjoi
 
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Im getting closer to purchasing the electronics when the tax return comes. Most of the bracketry is done, tubing is next to order when I get it on the rig. Space is tight so a cowl induction hood might be built as well.

Another question..

No reason why I cant do a blow through setup, instead of putting the throttle body on the inlet side of the supercharger?

Of course a BOV would be in order to keep the SC from backing up w/ pressure.
 
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