Hey guys, I just got TunerCat a few days ago as well as datamaster...my mods are in my sig.

According to datamaster when i go WOT it is showing between 35 and 39 degrees of advance, 39 degrees up around 5400-6200...but i have the timing in the main and extended table topping out at 34.5 about 90kpa on the map sensor

Where is this extra timing coming from???...there is no spark correction vs. coolant temp at the operating temp...so am i missing a table where it adds timing?...the base tune im working off of is from bryan at PCMforless. I tweaked my fuel to get the O2s steady thru the RPM range WOT (.870-.900)...i even tried taking out some timing from the main tables but it still shows as much as 39 degrees up top but then showed that it was pulling 1 degree of retard...i dont understand this, please help

 

Is it possible that there is a table of timing offsets vs. inlet air temp? I thought someone said that is where up to 3deg of extra timing comes from. That would be the basis for the alledged power gains from the SLP "timing tricker" IAT sensor mod.

Not sure though.... haven't used the stock PCM for almost 5 years.

 

Possibly but i cant find it...i kno there is a table to add timing with a low engine temp...but didnt see one for the IAT....

Anyone else???

 

I think someone asked tunercat if there was an air inlet temp vs. timing table.
Pretty sure they were told that there wasn't.

Has someone on here actually broken down the code or not?
I know I don't have the knowledge to do it....

 

anyone else??? someone has to have an idea on this...

 

This question has been asked and discussed multiple times on this board, and I don't think anyone has an answer or reason.
I think we've all just learned to tune around it.

 

well that kinda sucks...does anyone kno if the amount added is constant...or does it change with temprature and conditions???

 

I've found it to add (at wot were talking, right?) 2 degrees up to 4500rpm, 3 degrees from 4500 to 5500, and 4 degrees above 5500rpm.
Might want to do a search to check if I'm remembering that right though. Should be in one of my old posts somewhere.

Hopefully someone will figure out where this timing comes from someday.

 

I have never seen this mystery timing in my car. Countless logs in all RPM/MAP ranges and not a single noticable degree is off. I am most concerned with WOT and the timing displayed in datamaster follows the chart I made in tunercat perfectly. Are you guys using the newest version of tunercat with the lastest def. file or LT1edit?

 

I don't think it has to do with the version of software used, but I don't know. What I do know is that after hundreds of tunes this one time I had a tune in my car (not registered vin) that whatever timing I would put into the tables, that is what would show up, so maybe a sertain year/model or a tune from a sertain tunner runs around out there that actually goes by what the tables show, otherwise I get the exact same compensating valves for the RPM ranges mentioned by "Dan K". But I'm kinda stuck if I want to tune using the lastest version of LT1 edit as well not just Tuner cat.

 

Thanks alot DanK and Bunker...i would love to get the numbers in the table to match the actual timing, but i guess knowing the differences is better than nothin...i seem to have the same offset as both of you, bunker and dan...

One other question a little off topic, Do you guys have any expert tips on how to tune part throttle, or get my blms at part throttle closer to 128 without messin up my WOT...also please explain how to/ if its worth calibrating the MAF...i have the mods in my sig now, but will have the xe224/230 in soon since i have everything i need for it...should i just wait???

I am very happy with the responses to this post, i think this is the first time ive posted somthin and didnt get stupid responses or flames...thanks for the inteligent reponses