Re: Thread for those of us who tune our own cars
 

Idle is perfect. Looks like low timing, adjusting the IAC through the tune, and dashpot decay was the trick. I also needed to adjust the idle adder for startup as it was only set for 1 second, making it want to stall on startup trying to drop to 700rpms immediately after crank.

Need to replace a bad front o2, do some mild tweaking of the MTF, and it will be WOT tuning time! Can't wait to see how it runs with my timing ideas to help low-mid rpm power. Then it will be e85 time! I have a free hour of dyno time at my old tuners shop, so I'm going to show up and get it dyno'd on e85 and surprise him that I tuned it myself. Maybe do a little tune tweaking on the dyno as well.

Re: Thread for those of us who tune our own cars
 

When u get on the dyno b sure to alowly add timingon the way up and monitor knock. Also try and let the car cool between runs to make your starting point the same. IAT ECT. on e85 i would think 18 degrees to start and fo from there. How much boost you running?

Re: Thread for those of us who tune our own cars
 

What does re-scaling the tune mean? I read about it a little in the tuning guide but still don't fully understand it. How soon do you guys hit the 63#/min air flow cap in the MTF? My projection hits it at ~800 MAF counts so my remaining points just flat line. Pretty amazing how much more air flow the car sees with boost and how quickly load increases.

The BP Modifier method seems to be the preferred method? So you double the BP modifier values manually, then cut the MTF in half, and then? Just retune the MAF and you are good to go? This seems like the best way to go.

Well seems like the BP modifier method works. I'm going to need to adjust the points on the MTF to have more even gaps between data points because now my low end is more sensitive to minor adjustments. But once I get it dialed in this should fix any WOT worries.

Boost is about 9lbs, once it warms up it will drop to 7ish.

Re: Thread for those of us who tune our own cars
 

Misinformation!!!! The base fuel table does set the desired lambda at wot conditions. The idea is to make your actual lambda closely match the desired lambda. The desired is coming from the base fuel table, which in most strategies is a function of RPM and load.

Re: Thread for those of us who tune our own cars
 

Yup^ as for rescaling the tune I also did this to mine. By your post i assume you figured it out?

Re: Thread for those of us who tune our own cars
 

How is the desired lambda read, with the o2's correct? So when you go WOT and switches from closed loop to open loop the o2's are no longer being in use and your car is going only by what the MTF is set at. You can have your base fuel set at whatever you desire and once you go into open loop at WOT the table is irrelevant. What you are saying is if you don't go into open loop your A/F ratio is being controled by the base fuel table and controlled by the front o2 sensors and yes that is correct and your computer will make adjustments to the MTF to reach desired lambda. But like I said earlier once you go into open loop it takes the o2's out of the loop and uses only what is programmed in the MTF.

The o2 sensors just read the ratio of oxygen to fuel in a given sample. So the computer adjusts fueling through stft so the sample of exhaust reaches 14:1 in closed loop. The mtf predicts the what flow of air through the maf will ultimately translate to that ratio after combustion. Once it knows the fuel needed for that ratio, that the base fuel table can be used to determine the fuel added to reach the lamba desired in the base fuel table. Forcing open loop and changing the bft across the board will prove this theory if the mtf is accurate.

Re: Thread for those of us who tune our own cars
 

I tell ya what if you truly belive that set your base fuel table to 17.0 afr above 500 TP and go out and go WOT and report back to us what happed!

Re: Thread for those of us who tune our own cars
 

Very well written. But i would state the maf reads the incoming air predicts it

Re: Thread for those of us who tune our own cars
 

I can set it to whatever i want since my car is tuned in open loop only and doesn't use the o2's at all. That being said the tune will not change.

Re: Thread for those of us who tune our own cars
 

Yes i know this and how it works in closed loop. I was talking about open loop. I know the base fuel table is used in closed loop and at WOT untill you go into open loop which the mtf should be set to where the BFT would be calling for if it is set right. So yes i know how the BFT works and what it does

I mapped my entire mtf using open loop and 14.7 afr ratio with the base fuel table at 1.0. Of course projected the counts over 500ish and set the base fuel table at .75 for high load. I saw 11.0 Afr throughout my WOT pull within 5%. Barely had to tweak it. I changed before 4k to .8 in the base fuel table without changing the mtf so we will see if my afr changes when I do more testing tomorrow.

Do you all disable your knock sensors? Mine was pulling max retard at 11.0 afr, 40 degree iats, and 10 degrees max timing with them enabled. So I just shut them off under 5k for now.

Re: Thread for those of us who tune our own cars
 

Im eaton swaped so i have them turned off as they are no longer there

Re: Thread for those of us who tune our own cars
 

So by what you say then why wouldnt the base fuel table just be set at stoic then and you could use a power/boost enrichment table like gm does? Please post a screnscreen shot of your fuel table i would love to see what your doing.
If thats the case then set the base fuel table to 17.0afr @ wot and be sure to datalog it and post it up for us.

Re: Thread for those of us who tune our own cars
 

I'm not sure what GM does I don't tune GM cars. I tuned my car in open loop because I was having issues with the o2 sensors not reading correctly and wanted to take them out. They were causing extra fuel to be commanded because they were showing a leaner then commanded a/f ratio then what was being commanded with the BFT. So I tuned my car using the MTF in open loop to insure that the motor was getting exactly the amount of fuel at the different load ranges and maf counts that I wanted. from idle at 160 counts all the way to full load and boost seeing over 960 counts on the MAF. So like I said with my car being in open from idle to full boost it doesn't use the base fuel table and the computer doesn't makes adjustments from what I have command in the MTF.

Now my car is mainly a track car and is one of the fastest on this site and if it was a mild modded car or a car that is driven on the street a lot I would use the o2's and tune the car using the fuel tables to control a/f ratios. the way I tune mine might not be the same as the way others would tune their car but the drivability is excellant all thru the different load ranges and at WOT. Tuning a car with 160lb injectors with a BW S482 billet turbo isn't too easy when the boost kicks in and you go from 500 counts to 900+ in a little of a second.

Re: Thread for those of us who tune our own cars
 

I also have the knock sensors turned off and not hooked up. Don't need the computer pulling timing when I'm trying to win a race at the track.

Re: Thread for those of us who tune our own cars
 

Any fix as to why it was throwing a lot of fuel at one bank? Mine is doing the same thing. I replaced the o2 sensor and it was great for a day, and now it is throwing 25% fuel at the drivers side so it starts to run like trash. I guess I could limit the closed loop stft correction to 5%, or just leave it in open loop like I've been doing. I think it has a slight leak from the primary but nothing that bad. The location on the collector is less than optimal, and its at 9 o'clock.

I think the tuning guide mentioned that it was challenging to tune large turbo cars because the maf counts will flatline even though the car will continue to make power, so it will start to go lean. And you had to use the fuel multipliers or the base fuel table to get more fuel.

Re: Thread for those of us who tune our own cars
 

Major exhaust leak before the o2 sensor, bad o2 sensor, bad connector anything like that will cause it to read wrong. This is a good example of why I run my car in open loop all the time if your tune is correctly done you won't have an issue running it in open loop. From what you are saying it sounds like a lazy o2 sensor and they do go out. Are you using OEM Ford o2's or aftermarkert? I'd only run the ford ones they seem the last the longest and work the best.

Re: Thread for those of us who tune our own cars
 

If your only seeing it on one bank then its not a maf error its a exhaust leak, bad/lazy o2 is it Adding fuel i assume?

Re: Thread for those of us who tune our own cars
 

Glad to see others tuning their cars as well.

I purchased the PRP softwre from lasotta with his tuning guide. It has been helpful but I have already learned a lot from this thread. I gotta do a bunch of work on my MTF since when I start the car up cold it idles in the 18-20 af range lol.

BTW car is down because I think I have a vacuum leak where the lower manifold sits between the heads.

Bosch sensor. I just replaced it. I should have picked up motorcraft ones. Yes adding fuel stft is 1.25. Maybe the leak is worse than I thought.

Welcome to the tuning party SLOWHITE.

Re: Thread for those of us who tune our own cars
 

It's crazy how these parts can be sub-par compared to motorcraft, but still make it in the market. COP's are like that too. I only buy them from Ford.

Re: Thread for those of us who tune our own cars
 

Sounds like u have a vacuum/exhaust leak.

Re: Thread for those of us who tune our own cars
 

Is it still 1.25 after you replaced the o2 with the Motorcraft one?

Re: Thread for those of us who tune our own cars
 

Doing what you describe is likely completely screwing up your load calculations, amongst other things. Let's presume that for the factory NA calibration your commanded lambda at 5000 RPM and 750 throttle counts (or say a load of 0.899) is 0.879 (12.3 AFR on 14.1 stoich). Now you come along and really want something more like .799 (11.24 AFR on 14.1 stoich). If all you do to drive it to that .799 actual lambda is increase the airflow in the MAF table then you have fictitiously skewed that actual airflow measurement because the ECM is still calculating the pulsewidth based on the original .879 lambda. The actual airflow through the engine hasn't changed. Its the same now as it was originally, you just want to run at a different lambda at those same conditions. Your load will be higher, spark taken from a different point in the BDL table, etc. What you really want to do is change the commanded fuel point. This is done by changing the base fuel table at that point where you desire the change. The fuel needed to deliver that commanded lambda is then calculated based on the original UNCHANGED mass air curve; you're just asking for and receiving a longer pulsewidth from the injector. Load hasn't changed and the airmass entering the engine remains true. Does this make sense?