I have read a few posts on here talkng about BLM and INT. I have done about 10 chips for my car hammering down the BLM's to get them as close as possible to 128. I have done pretty well getting my BLMs down from around 145+ across the board to between 121-135. But the thing that I don't understand is even when my BLM is at 128 my INT maybe at 117 for instance. So whay is the INT not at 128 when the BLM is at 128??

I am experiencing some knock so I tried taking out some timing in the higher MAP region between 80-100 MAP and 2400-3400 RPM. Still getting some knock though but not as much since I took out the 2 degrees or so out of the park advance in those cells.

I use the moates data logging software and it shows 14.1 fuel ratio all the time never changes is this normal?

The only other question I have is I read about tuning WOT AF Ratio 12.8 how do I do this?

If anyone has time and could have a look at my data log I could send it and maybe give me some advice. I want to get rid of the knock and then get as much spark advance as possible for most performance. The file size is about 400kb of my data log.

Mike

 

The INT is a short term change, it's normal for it to move around and depending on conditions, vary. It's not worth worring about, if you BL's are close to 128 your more then close enough.

Detonation takes time to happen, actually for the temps to build for it to occur. You need to look in the areas just before it occurs as well as the areas where it's occuring.

What code are you working with?.
There should be a PE vs Coolant temp correction. Or just PE AFR table.

 

Grumpy thanks for clearing that up on the INT and the spark advance and what tables to look for.

I am working with WinBin but I should change to Tunercat makes life a little easier using that program.

 

IMO, it's hard to beat Tunercat, for being about to walk thru a calibration, and get to the frequently used stuff.

I would suggest thou, that you surf around, and find a hac, of what your working on and snag a copy of HexEdit. Once your familiar with all the TC can afford you, and be able to dabble in obscure stuff, your to the stage of doing oem level work.
One of the big benefits of tuning is being able to sharpen ones logic. While alot of the easy stuff, is easy, as you get to seeing how things interact, and sit down with your notes and make real sense of things, is something that's not at all lost on just tuning. The better you are at tuning, the easier diagnostics become, and figuring out who to pay at the end of the month,

 

Find a hac, you kinda of lost me there what is the hac and what does it let me do or what is it for? I have heard that word all the time in postings but never really thought about it that much.

 

a hac is commented code from the ecm.

you can get the ANHT hac (ANHT is a $8D mask, from a vette '727 i think, and is very useful for working on any $8D mask such as AUJP, but keep in mind that all the code is offset by a few bytes)

http://www.diy-efi.org/gmecm/papers/

 

WOT is the last place to tune. My AFR /WOT was confirmed on dyno. two runs 11.9/1/ 12.1/1. i was told by dyno guy to tune for 11.5/1??? now i hear that is too rich per this forum. i left it at 12.1/1. From what i hear the 02 sensor will not provide you with WOT tuning help. a wide band is the way to go and i will be ordering 1/1/04 once i check the hole in the budget as not being too deep. is there a post (stick?) as to what i shouold be shooting for in PE from 800 rpms to 5500rpms as far as air fuel ration for max TQ/HP? i believe once in PE it would be about 12.5/1 but unsure what rpm it should first see 12.5/1? I also assume it would be a linear progression from say approx 15/1 to 12.5/1 and then stay at 12.5/1 ?

 

to quote grumpy, give the engine what it wants.

There is no magic rule....sure, 12.5:1 may be right for a lot of engines, but some will like 12:1 or some will like 13:1. do the plug reads, drag strip testing, and do whatever goes fastest.

as for transferring from 14.7:1 to PE AFR, I think this is pretty much instaneous as soon as you hit PE (maybe someone else could comment), but I can't imagine that, even if you could, you'd want to roll the PE down slowly...that would just mean the motor is running leaner than its best power for a certain period of time.

 

thanks that makes sense. i will look at my dyno run again. i assume i was PE right from the get go. i think the dyno guy entered PE 1/2 way through 1st gear. will look at the function of time over the run and recheck those A/F ratios. not practical to go to dragstrip for me. maybe i will lean out a bit and rerun the dyno next year. i added a lot of pump shot after dyno as i had a bog i feel was from lack of PS and that may affect the numbers i will see.