NickSezz

Tuning is a very common topic because we are all a little concerned when dealing with the mail order tunes that most of us run. Some say they are hit or miss...but what is hit, and what is miss?

Today I finished hooking up my AEM wideband so I took the car for a speed run.When toppin out in 3rd gear I ranaround a 15.1 AFR at WOT!!! Holy crap!! I made a post in the 4.0 section about my day...here is the link so you can see (it is important to read to understand the rest of this post) https://mustangforums.com/m_4417980/tm.htm

The problem I have is this "hit or miss" term. If I never knew my AFR I would think this tune was a "hit" After adjusting to 14% richer and seeing a drasic improvement, now I do not think this tune was a hit...The lean condition was masked by the good throttle responce I was getting from the tune, but my top end was suffering greatly. Now that you see the situation, I have some questions for those who can answer them.

1. What should I get my AFR down to. The best I can get it right now at WOT is between 13.2-13.8.Brent is sending me the new tune zeroed out at 14% richer.I think it should be at 12.7-13.0 correct? Stock I ran 12.7 (as you should have read in the other post) Im looking for MAX power here.

2.If I changed the AFR, does the timing need to be adjusted along with it? This is something I would rather have Brent or a tuner do. I can handle the AFR, but there is too much guessing for timing.

3.If Brenspeed got the AFR of by this much, how off are my other settings? And how many other people are running the same tune as me that may be having the same issue?

Brenspeed is no doubt a great company, and Dave who helped me out today was very helpful. I will always buy form Brenspeed, but the mail tune idea just isn't the best I guess. Next time I get home from school (leaving sunday w/o my car) I am going to a dyno... afterI fix a small dent, clean her up, and get newtints.

Im just a little mad becauseI ran that lean tune for a whole year...There is probbably no damage done because im not always at WOT...but I feel as if I wasted money on those tunes.

By the way, they did kind of admit to me that the V6 testing there is not as extinsive as testing on GTs...but thats no excuse.

Any input to this topic is welcomed...this applies to you 4.6 people also.

NickSezz

Im not letting this one go!! Bump por favor

howarmat

This is a very good point....most tunes are intentially on the fat side to prevent the situation you have illustrated....not all of us can get an a/f ration after the tune so many do not know what theres is. Normally people know they have some problems when they experience pinging. I am not sure if you did or not though.

Not all cars are the same so a tune might be spot on for one car and lean on another. The email tunes are the tuners best guess from past cars. The MMR is not a mainstream CAI so tuning for it might be more of a guess than for other kits. Either way its good to get a car on the dyno to check the a/f if you can.

marcuskeeler

This is both a good example of how some tuners force higher numbers (and then claim they are the best in the game) and also the need to get modifications verified on a dyno.

A good FI A/F is around 11-12. Normally aspiratedI can't say for sure.

rmays06

This is concerning, but also the first I've heard of it or the first I've heard to have proved it. Nice post Nick I wish as many people read this as ask which is the best tune/tuner.

mygt500

I know that at idle on a N/A car with no "new" tune its A/F is about 14. I am boosted and running fat at about 6000 RPMS andI credit my 60# inj for that. At WOT my car runs about 11.2-11.5 straight across the board until 6000 RPMS and she gets a little rich. I prefer that esp since I am boosted and she did get a dyno tune several times to get the numbers I am running now in the sig. Canned tunes or mailed tunes are great but have some limitations since the car is not there to be on the dyno and have a accurate A/F measurement. I do know the cars computer adjusts timing according the A/F ratio it is sensing at any moment in time to a point and then she can go lean- ping or detonate (Kaboom)! Each piece of the puzzle is just as important as the tune itself. Thetuners we have now -ex brenspeed and bama chips are great and know the S197 stang and would be the only place I get a tune from if not able to dyno it. This is my preference from what I have read on the forum. If you want max HP and TQ you should pony up the cash and get her dyno tuned.....JMO J

One Bad Stang

sorry for my lack of imput, buti just have to credit NickSezz for writing such a great thread, and for that matter all the rest of you above that have very good and useful information.

NickSezz

thanks keeeeep it comin

GT Bob

I'll throw in what I know from the few GT's I have tuned in here. I've yet to touch a 4.0, but the concepts should be the same, I just can't tell you how to get there unfortunately. I will also admit, I don't have time to read the other post righ tnow, so I will likely edit this later after I get to read it.

From the factory, the WOT AFR's are commanded to be 12.4 up to 3500 rpm's, then it gets richer to 12.0 (on the 4.6 that is... have yet to look at a 4.0 file). Non-WOT conditions are commanded to a 14.65, which is the number that all Ford PCMs use for Lambda. From my experience, an N/A car will run best in the range you said, 12.7 to 13.0.. Keep it fatter on the bottom, and then lean it some on top. My car right now, I have it running 12.6 up to 3500 and then dropping to a 12.8... but my tune is a work in progress still, and I am intentionally keeping it a few points rich as a safety net until spring when I can get some time to get it fully dialed in and spend some time on cam phasing too.

Timing should be ok as well with the extra fuel. If you were that lean an dnot getting any knock, chances are you could even get away with some more timing, but I would leave that until after you get the fuel 100% dead on. The GT's seem to make best power around 27 degrees of timing, but I have heard that they will tolerate as much as 32 degrees without detonating. Honestly tho, I find it better to keep the MBT timing slightly off peak and let the Knock Advance limit add in as much more timing as the engine will take. While it may be slightl less efficient doing it this way as opposed to just putting it all in the MBT table, it's far safer.

Personally, I feel your 100% right to be angry. The whole concept of mail order tuning has never been one I am fond of. There are too many variables that can change from one car to the next with the exact same parts list to say that if it works on one, it's good for another. It's the exact reason I spent all the money I did to get a tuner shop level tuning suite.A mail order tune is nothing more than a guess... the idea of"It worked on car A, and on car B, so it must work on carsC thru Z" and so many times, thats just not the case. I myself have tuned two identical cars, and I mean 100% identical. Car A took 5 degrees more timing to make peak power than Car B would even tolerate without detonation. Both ended up at the same power at the end, but the tunes were night and day.

For whatever reason, despite that fact that it's been standard on just about every car made in the last 20+ years, it seems like tuning fuel injection is still a black art.

2cokeman

I have never had a problem with my SCT canned tune, but I do know it is an an average tune for changes in climate and altitude and all cars will react differently