MAP Problems

[thebucky84]

Well i've been having some issues tuning my map. I know this is a hot subject as i also have the TVS Harrop with 80# injectors. Been following the other threads, but haven't helped much.

Basically this what i have been doing. First i pasted my High Octane table into my Low Octane table. Then set my PE table at 100% across the board. Set my MAF Fail Freq. at 0. Then after all of that i went into the scanner and reset my fuel trims. I went for some nice long drives with my LTFT table up hit a lot -60's in each cell. I then went to my VE table (which is what i may be doing wrong) after highlighting the LTFT on the scanner and special pasted add so it would subtract from the VE values. Now that is what i have been told to do, is this wrong? Now i have gone for numerous drives and at this point every cell on LTFT is at -60. What am i doing wrong here or not doing at all?

Mod List:

TVS Harrop 3.15"
80# Injectors
Intake
Heat Exchanger
Exhaust w/ Cat.

[umrjmac]

Be sure that you've turned off things like DFCO and COT, which will skew your data.

Getting the LTFTs to stabilize will take a bit of driving, so you may be ahead of the hounds to disable LTFTs and log and tune using the STFTs instead.

You mentioned it at the top, but just in case, be sure to reset your fuel trims after each adjustment that you make.

[Japeatr]

when you mention PE 100%, do you mean on all the time?

[skatinboarding]

Why would you be tuning the ltft only? I didnt think that trims read over 20%. If they are all a constant 60 something might not be logging right in your car. I.E. sometimes my iats read at -40* and I just have to restart my scanner. Isnt there an issue with the ve tables with fueling boost over 17lbs or something like that?

umrjmac- I thought you were not supposed to reset the trims everytime, just the first time.

[umrjmac]

I suppose, technically, it doesn't matter either way. LTFTs will take a fair amount of driving to settle in to their final level anyway. If you reset your fuel trims, then they start off at 0. If you don't, then they start off whereever you left them at (up to +/- 20).

The important thing is to not make a change, take a 5 minute drive, and assume that your LTFTs are "good".

I think you're still better off disabling LTFTs and just doing STFT logging/tuning until you get it dialed in because those react almost instantaneously. (You still need to ensure that the car gets up to operating temperature before logging still).

Also, I am NOT a veteran tuner, but I limit my changes to 5 or 10 percent max before re-logging, just so I don't overshoot and cause a problem. If you go with that, then the +/-20 max values for LTFTs are no biggie.

[thebucky84]

hmm ok, well i wanted to tune for STFT first. I was only familiar with tuning the LTFT and not sure how to set up to tune for STFT. How would i go about setting up to tune for STFT? Newb question i know, but its the only way i'll learn.

when you mention PE 100%, do you mean on all the time?

100% as in i have to be on throttle 100% to enable the PE table

[umrjmac]

you just need to ensure that STFTs are enabled and that LTFTs are disabled...you can set the min LTFT temp setting to the max to ensure that it wont try to learn LTFTs. Do that, reset fuel trims, then log both LTFTs and STFTs for one drive to ensure that STFTs are changing but LTFTs stay at 0. Then you can drop the LTFTs from your list of scanned items.

[thebucky84]

once i get a good log on the STFT, what do i special paste by on my VE table?

[chris07ss]

Tune the MAF and then re-enable the VE if you're having drivability issues.

On my 07, 42# 3" M62-powered car, I am using a MAF-only tune and I couldn't be happier.

[thebucky84]

well im back at this again after getting all my parts in. I had to get a spacer between the intake and s/c. Well that obviously raised the s/c and is awfully close to the frame for me to get the belt on. I currently have the stock 3.15 pulley on now with the 2.8 pulley waiting. What would happen if i were to put the 2.8 pulley on and then tune?

[thebucky84]

anybody have some input on the pulley question?

[thebucky84]

bump ^

[Marca34]

you will have to richen it up with the smaller pulley.