stock maf tweecer tune for 24punders

just use a jaj1 cal file to start off with its the 95 cobra calibration same maf as a gt but just set for 24lbers

Nick

If not....you just change your injector slopes...but I think the first Idea is better.

RC

type911 said:

I was thinking of that but wasn't sure if it was the same maf. Thanks for the help.

Click to expand...

I was using the stock maf with my 30# inj's for quite a while.

All you gotta do is plug in your t4m0 curve in the j4j1 cal file.

One thing to watch for is that as your combo grows you could peg the stock maf. The combo in my sig was right at the limit of the stock maf at about 4.9 volts.

Good luck and let us know how it turns out for you

Later
Grady

I just did this/asked this question last week or so, the J4J1 has a diff. MAF transfer than the T4M0 program. You will have to go into the utilities and copy from the T4M0 to the J4J1, also if you want to use the T4M0 program as most say it is a better perf. tune to start with you will need to copy the breakpoint, inj. slope high and low (you might want to try the 1.2 multiplication, for the one that needs it, cant remember if its high or low slope without looking at it), as well as the fuel vs batt offset from the J4J1 to the T4M0. THis is the advise I got from Clint 86gt on the forums last week.

type911 said:

I am still new to the tweecer.so from what I get from all this is. If I run the jaj1 binary I can copy the maf curve from my wh40 binary to run the 24#'s.
I was hopeing it was as simple as running the jaj1 binary..

Click to expand...

I'm gonna try to keep this short.

j4j1 inj slope values are different to be sure but batt offsets are very different, breakpoint is different cause it is null & void due to same high/low slope values, min pulse width is different also. Slopes, min pw, batt offsets, and breakpoint (all four of them) play into getting your inj's dialed in for good cl operation.

IMHO, until you get a better understanding of how the pcm works, I would just keep things simple. The j4j1 cal file will work really good for a combo with 24 & 30 pound inj's with only the slope values adjusted to match the inj's you are using. As for the other three inj settings I would not hose with them at this time.

Load by hand (not import/export, copy/paste or anything automated kind of thing) the two parts of each maf transfer point (volts & kg values) of your t4m0 into the j4j1. You must check each entry after your final save and make sure all values are corect.

Your inj high/low slope and maf curve loaded into an original j4j1 cal file will produce very good drivability but the power will be somewhat soft. The power will be restored with various tweecs like spark tables, fuel tables, spark tip in, etc.

A few final thoughts based on my findings.

Your first objective when tuning is a safe tune with good cl drivability.

The second objective is improving max power at mid to wot opration.

Fuel changes

A wide band is a must for dialing in your af ratio correctly.

Fuel adjustments should be made with CAUTION when first learning and keep the changes small. Verify the results of that change in your datalogs before making more changes.

Dial back the spark when working with fuel as too much spark and too little fuel is not a good thing.

Later
Grady

final5-0 said:

I'm gonna try to keep this short.


Load by hand (not import/export, copy/paste or anything automated kind of thing) the two parts of each maf transfer point (volts & kg values) of your t4m0 into the j4j1. You must check each entry after your final save and make sure all values are corect.

Click to expand...

I had to copy from utilities, by checking the box in funtions that was the MAF transfer, when I loaded them by hand every time I tried to save it the numbers reverted back to what they were orig. I tried this 4-6 times. I am using 1.30A9 so that may be why, thats why I said to do it threw the utilities since that worked for me.

type911, also has 24#inj. not 30's some one else mentioned they were running 30's.

blksn955.o said:

I had to copy from utilities, by checking the box in funtions that was the MAF transfer, when I loaded them by hand every time I tried to save it the numbers reverted back to what they were orig. I tried this 4-6 times. I am using 1.30A9 so that may be why, thats why I said to do it threw the utilities since that worked for me.

type911, also has 24#inj. not 30's some one else mentioned they were running 30's.

Click to expand...

I use V1.20 and have not moved up to the latest version due to the data drop outs other bugs that so many others have posted about on the Tweecer sites.

I have seen some say the maf curve will have hosed values when you import/export with the newer version.

As for values changing back to original values, some times it has to do with hex values that the pcm uses. I have found that sometimes if that happens you have to enter a value slightly different. Example: you want 2.256E-5 but you get something less that that after a refresh or save. Try to enter a value of 2.258E-5 followed with a refresh or save.

Later
Grady

I have seen that in the scalers, and yes there are the drop outs from what I have heard as well.

I think I read that if you import from 1.20 to the 1.30A9 the values get hosed, as in if you import a MAF transfer file from 1.20 to the MAF transfer of 1.30A9. BUt I went from the ccf (or whatever the file names are) of 1.30A9 to 1.30A9 I just have a copy of the j4j1 and t4m0 in there to copy from instead of having to go into 1.20