AEM, Christuned, bother?

[Root Moose]

Yeah, it takes me forever to do anything these days...

I've got the Banks header, 2.5" exhaust all the way out and enough parts to build a custom cat converter with O2 port that I can tap with a wideband. Also have a cheap Chinese knock off Airflow snorkel to act as a form of CAI.

Is this enough mods to bother with a custom tune? If it's worth the effort I'll pursue but if it's a big time sink for marginal gain then I'll leave it till I have more time.

How reliable is the AEM? I want something truly install and forget once it is sorted. This is my gas-n-go overlanding rig that I've focused on. Makes a case for a Christuned OEM computer?

What say you?

Thanks.

 

[Boostwerks.com]

I wouldn't bother.

Save the $ for a rainy day.

 

[NorCalChris]

What's christuned?

 

[Talyn]

The tune isn't only good for changing AFR and timing. He can do several other items like disable torque management and some other thing that relates to the transmission. It makes quite a bit of difference.

However, given your little bit of mods I wouldn't spend the money until you do a stroker.

 

[O-Gauge Steamer]

I run an AEM F/IC8. Once I was happy with the tune, it has not been touched since. It just does the job which is all anyone can ask of a piece of hardware...

The purpose of a F/IC is to manage fuel injectors that have significantly greater flow than stock. It is also used to retard the spark in Forced Induction installations.

Torque management is applicable to XJs that have the AW4. The PCM retards the spark during the upshift in order to soften the shift. It is a passenger comfort thing... And though you will feel a difference in the shifting of the transmission, I would need to see dyno proof of a performance increase.

I am in the process of reprogramming my PCM, so I have a fair idea of what can and can not be done with the PCM. I am not stating an opinion based upon reading stuff on the internet, I am reading the codes in the PCM...

IMO, there is no compelling reason to change the tune of your XJ. Very little, if anything, would be gained from it.

So, unless and until you make a significant change to the engine by either building a Stroker, adding forced Induction, or both... Save the monies for use on something worthwhile.

A side note here.
There is no way any piece of additional hardware can advance the spark past what the stock PCM does. If you need/want a more aggressive spark, the Crankshaft Position Sensor must be relocated. See the thread that Talyn posted. The XJ has the timing "fully advanced" mechanically by the relative positioning of the CPS. The PCM then retards the spark to meet the conditions present at the moment. When forced induction is added into the mix, the spark must be retarded more in order to prevent detonation. And, more fuel must be added in to go with the additional air being pumped into the engine. This is why a F/IC.

As to the spark, if you think about it, it makes sense. In order to advance the sparks to fire before it should, the external device would need to fire before receiving a trigger. I guess it would have to be clairvoyant in nature to do that...

 

[Root Moose]

The other thing I was planning was one of child9's shift kits. I tow a lot and close to capacity so perhaps that is a better use of the money? We are planning a big trip this summer (~12k kms) and I am wary of changing too much in the transmission since it is original and neglected with 250,000 kms on it. Thoughts?

 

[Talyn]

yes, go with a FringeXVO valve body now.. then tun later

 

[O-Gauge Steamer]

I am, not too surprisingly, in agreement with Talyn. Until and unless significant work is performed on the engine, do not bother with the expense.

Monies better spent elsewhere.

 

[GrimmJeeper]

What's christuned?

there's a guy named chris that tunes ECUs, and he's one of a very small number of people that has cracked the late model chrysler ECU programming code

 

[O-Gauge Steamer]

As it turns out...

I am possession of the requisite hardware/software to reprogram the JTEC PCM. What I have covers years 1996 - 2004 so that includes the JTEC+ as well as the original JTEC.

This has proven to be an interesting set of discoveries. Whereas most of the world rates the fuel injector flow in pounds/hour, Chrysler uses grams/second.

I am not in a commercial operation at this point but.....

One never knows what is around the corner...

 

[hexdmy]

Yes, the need for tuning varies depending on the level of modifcations . The AEM FIC is a useful tuning device, but it does not accomidate all engine modifications. The more agressive you get with camshaft duration, the more benifits you will see with proper ecu calibration. From my experience, if the tuning can be done without a FIC, the end result is better drivability.

Chris aka christuned

 

[bjoehandley]

there's a guy named chris that tunes ECUs, and he's one of a very small number of people that has cracked the late model chrysler ECU programming code

How "late model"? There are people who want somebody to crack the computers for the Pentastar baaaaaad!

 

[hexdmy]

How "late model"? There are people who want somebody to crack the computers for the Pentastar baaaaaad!

My speciality is with JTEC and SBEC2'S, although I can tune NGC3/4 and GPEC. Or are you suggesting that there is a diy way to tune Chrysler ecus ?

 

[bjoehandley]

My speciality is with JTEC and SBEC2'S, although I can tune NGC3/4 and GPEC. Or are you suggesting that there is a diy way to tune Chrysler ecus ?

I was just curious about the current Pentastar computers, the lack of a programmer has been driving those of us so interested within the 3.6l V-6 JS body Avenger and 200 community just about batty..............some more literally than others:confused1

 

[Talyn]

Until and unless significant work is performed on the engine, do not bother with the expense.

While I am not saying that a tune on an engine with little mods won't help I would advise to wait until you go stroker or FI. If you never do then spend it later on a tune. Personally I loved the way the tune made the shifting feel more solid, aside from other factors.

the 3.6l V-6 JS body Avenger and 200 community just about batty..............some more literally than others:confused1

Why do you feel the need to bring up your Sebring in 80% of your threads?

 

[O-Gauge Steamer]

By removing the torque control, the shifting of the automatic will appear to be firmer. IMO, the cost for that PCM modification is high for that alone.

I add the italics because unless or until the transmission itself is modified, the shifting is exactly the same. Only the perception has changed. I recently had the Transgo shift kit installed and that definitely firmed the shifts.

I am debating on whether or not turning off the torque control will add, substantially, to the actual performance of my rig.

To be fair, I would need to compare the performance of my transmission to one that has the Child9 valve body installed. I suspect that the Child9 version will perform equal to or better than the Transgo version.

I will be altering my shift points to take better advantage of the supercharger. There is no longer any need to upshift at the near 5000 rpm point.

 

[Root Moose]

The Fringe VB or even just the Transgo kit is attractive to me. Firmer shifts and being able to have 1-2 stay in 1 are the two big things really on my bullet list. As much as I like the idea of the RA controller or similar I'm a fire and forget kind of guy for this kind of vehicle. Stick it in D and go, stick it in 1-2 and have it in stay in 1... that's all I need. I don't need a bunch of extra buttons/switches in the cab for just that functionality.

I kind of wish there was an easy way to retrofit the WJ's 5 speed auto into the XJ. Now that my Jeep is fully built I'm up around 9000 lbs when towing and the extra gear could come in handy. There's been a few times where I wish there was an extra (different?) gear when climbing the hills up in Québec.

Thankfully I haven't been wanting for brakes (WJ) and an extra 1000+ lbs in the Jeep itself helps control the load no problem.

Probably should have started with a WJ. LOL Live and learn.

 

[O-Gauge Steamer]

As is always the case, everyone has an opinion and all that really mater is that you are happy with how the rig operates. IMO, there is no one absolutely right way to go about this.

What would have been nice is if Chrysler had fitted a modern transmission to the 4 litre prior to it's demise. At least then it might have been possible to get more than 4 gears in the automatic...

 

[Talyn]

I'll take the AW4 any day over a Chrysler POS transmission.

 

[Alexia]

What would have been nice is if Chrysler had fitted a modern transmission to the 4 litre prior to it's demise. At least then it might have been possible to get more than 4 gears in the automatic...

I'll take the AW4 any day over a Chrysler POS transmission.

They did, A 42RLE. It's a giant POS that I am stuck with in my LJ.

Now, with the AW4 in my MJ I plan to just do a valve body change along with built up internals. Changing torque management in the PCM would be nice, but it feels fine to me right now.