J4J1 in an AUTO?

Stanger007

Founding Member
Sep 26, 2001
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Baton Rouge, LA
Does anyone have a list of the differences between the J4J1 ECU and the T4M0/W4HO ECUs or better yet a J4J1 with the automatic functions filled in (are they already in there?)

I'm about to start tuning again since I've got some more combo additions and I am looking for a good base tune to start from - is the J4J1 a worthwhile starting point?

:SNSign:
 
You can use the engine calibrations from a J4J1 in any of the 94-95 processors, but you will have to retain the W4H0 or U4P0 processor and transmission functions for the auto tranny. You may be able to see the tranny controls on the manual processors, but the hardware to drive the various transmission solenoids and sensors are not in those processors.

Don
 
Ah that makes perfect sense - is there a program that can print out the differences between two tweecer CCF files? I'd like to know what the differences between my U4P0 and a J4J1 are so that I can research what each difference is.
 
Before I start modifing the J4J1 file I have, has anyone documented the changes that need to be made to the J4J1 tune in order to have it shift an AODE car? That will save me a load of time if it's already been done. :)
 
Stanger007 said:
has anyone documented the changes that need to be made to the J4J1 tune in order to have it shift an AODE car? That will save me a load of time if it's already been done. :)

Since no one's piped up I've started merging the automatic functions over to J4J1. I found someone's tune that had J4J1 in their auto but I'm not sure what performance mods they made so I'm taking my U4P0, the J4J1 and this third tune and slowly going through and making the modifications and documenting it all.

I'll post the results this weekend.

P.S. I loaded the "mystery tune" to my car after changing the MAF, injectors etc and it worked well. I still hate to run a mystery tune though so I'm going ahead and documenting all the changes... stay tuned...
 
Thats a nice page setup :nice:

I know a few of the tweecer peeps that have the AODE have posted some need for some info. You may want to search the threads out and touch base with them to see what they have found to be good and bad chainges as far as modding the AODE settings.
 
I ran and datalogged the J4J1 tune for a while today and have had great results so far. I got my ISC and TB airflow nailed down and have a rock solid idle and no more stalling. Next up I've got to work on the A/F ratio - I'm running rich.

So far so good! :D

blksn955.o said:
Thats a nice page setup :nice:

Thanks - I just started it this weekend to keep all the useful information I run across - I figured it was a pity to keep it all on my laptop when it may help someone else.

The main page is http://wiki.72bit.com - if you have anything you want to add, feel free. If it gets big enough I'll get a real domain name for it and see if some guys from around here want to help admin it. I've just got to get some sort of organization going for all the data - it's just thrown in there for the moment.

blksn955.o said:
I know a few of the tweecer peeps that have the AODE have posted some need for some info. You may want to search the threads out and touch base with them to see what they have found to be good and bad chainges as far as modding the AODE settings.

I'll see what I can dig up. I've also got some AODE settings on the link above that will really firm up the tranny shifting.
 
A thought or two about what you are doing that has nothing to do with the auto trans stuff :D

I took a look at your sig.

You move a bit more air than a stock GT with your intake & exhaust mods.

Some of the subtle things that can make a difference in drivability like tb airflow, neutral idle airflow, isc duty cycle, and the like will most likely be somewhere in between the two.

Some load in the GT spark tables ... I would just mod the j4j1 tables to suite your needs.

As for the inj's ... If you plan on more mods ... just make it easy on yourself and go to 24's as the j4j1 is already setup for them.

You may find the j4j1 a bit softer at wot than the t4m0 but it is easily cured with a bit more aggressive spark curve.

Grady
 
I forgot to tell you something that could really give you some grief in the other post about your pcm switch and inj choice :)

If you do use 19's ... be sure to match the t4m0 slope values to start off with. DON'T do the same slope thing like the j4j1. If you do ... the offsets and slope values won't work together all that well.

With your intake and exhaust mods ... I'd bet you'll need to drop the low slope values a bit.

You'll just have to see what your combo likes.

Use the same offsets as the t4m0 ... NOT the j4j1.

Use the break point from the t4m0 as well.

Good Luck

Grady
 
Ah you're hitting on exactly what I'm playing with right now - the injector slopes and breakpoint. Been doing some logging today and playing with EA, watching KAMRFs for CL part-throttle driving so far everything is going great. Also ordered a W/B O2 so that I can get everything dead on for WOT.

I may post up some logs tomorrow - now that the tune is roughed in I've got a few things that I'll need to pros to look at in regards to the things above.

It's good to finally begin seeing the entire EEC process and be able to interpret the datalogs - anyone new to the twEECer shouldn't give up - with a lot of research it finally starts to make sense! :)
 
Where do I go from here?

Ok, the idle is for sure 100% better, no more stalling. Now comes the question of what to tune next.

I datalogged and ran the log through EA to get the Injector Timing - the resulting new numbers were a good deal larger than what was in there. I went ahead and loaded the new tune and then ran another datalog - the numbers were a bit different this time but relatively close to what was given to me the first time.

Can someone look over my datalog/tune and make a suggestion on what to work on next? My wideband won't be in until a couple of weeks so I'm all narrowband until now which is fine by me, I'd love to go ahead and get the part throttle down pat.

So without further ado, here's...
 
I am trying to use a j4j1 tune with a u4p0 computer, but have a few questions. Under function, I changed everything that had to do with transmission to match stock u4p0 tune. Scalers I did the same thing. When I go to function trans_converter_slip_2nd y values are different

for example j4j1 bottom 3 are

16.6667
10.8333
5

u4p0 is
18.75
15
12

do I just ignore those, and match the boxes still?

I know nothing about these aode functions, even though I wish i did.
 
Stanger007 said:
I don't have a function named "trans_converter_slip_2nd" but I do have a table that looks like this. Check the name of the function again? :shrug:

How did you like your Edge convertor? I'm getting ready to put mine in.

Wes

yea, that is the table I am talking about. Did you change anything on that, or did you just leave it how it is?

The converter is really nice. It is like a totally different car, feels like it picked up 40hp (i know it didnt though)

It will be even better when I get some good tires.

my best time is 15.08 @ 93.77 but with only a 2.2671 60 foot, traction is a majro problem
 
Mustangless said:
yea, that is the table I am talking about. Did you change anything on that, or did you just leave it how it is?

That's a screenshot from the values I'm running on my current tune.

Do you have any times before the convertor? Your 60ft is much better than my last runs... 2.3 and 2.4s. :owned:
 
Stanger007 said:
That's a screenshot from the values I'm running on my current tune.

Do you have any times before the convertor? Your 60ft is much better than my last runs... 2.3 and 2.4s. :owned:

no, I never went to the track before. My first pass with the converter was a 2.9 :nonono: .