[ixtlan]

I thought this may be a good topic.
Seems that Tuners are the big deal for todays cars.
But information about what it is to do is very sparse.
Sure there are many "Tunes" out there but what are they really modifying?
What is safe?
What are the effects, as well as the Gains or Detriments?
What are we trying to achieve?
And most of all.
What NOT to do!!

Now this is all new to me and this topic is intended to both educate me as well as you.
So lets hear from the experience out there and let us all in on the big secrets of the Tuner World.

 

[cekim]

Sure there are many "Tunes" out there but what are they really modifying?

Generally speaking, they are modifying all the same parameters you would change to "tune" a carburated engine (and a few more) - but now you have more control.

Instead of spark advance retard based on springs and vacuum, it is a table (actually multiple tables).

Instead of modifying springs/jets/floats in a carb, you are controlling pulse width and duty cycle of fuel injectors.

Instead of "secondary" springs, you are controlling the open/close of CMCV's

Instead of manually choosing a cam angle based on the best "compromise" - now the PCM can change the cam angle dynamically...
All of these things are placed in tables to "build" a tune which ultiamtely builds yet another table that the PCM reads out of as the car runs...

The basic (simplified) operation of the PCM is (repeated many times per second):
1. read parameters - RPM, MAF, A/F, Throttle position, temp etc...
2. compute load
3. compute address into table based on all of the above
4. read data from the tables in the PCMs memory based on that computed address and drive out the controls:
- spark
- fuel injector control
- fuel pump control
- CAM angle (pressure)
5. wash rinse and repeat until the key is turned off...

What is safe?
What are the effects, as well as the Gains or Detriments?
What are we trying to achieve?
And most of all.
What NOT to do!!

The trouble with all of this - as with any "digital" control system is that the failure is not "graceful" - that is, analog/mechanical systems tend to operate on a bell curve...

At the top of the curve - everything works perfectly - go left or right and it starts to behave progressively worse...

With digital systems, the failure is often "binary" - either it works or it doesn't... your engine goes from purring to detonating and throwing parts out the side...

So, the what not to do is start change parameters without understanding what they do. The range of control you have when you buy a diablo/sct type handheld is intentionally limited to try and prevent you blowing your car up...

To access all of the features, you would need to purchase more software (Pro Racer in the case of SCT) which gives you access to all the parameters, but the catch is you need some way "see" the effect of what you are changing...

That's where the dyno comes in... It is a crude tool as it can't actually show you the full range/type of loads the car will see, but it does give an experienced tuner a pretty good idea of what is working and what is not....

What you or a tuner is trying to achieve is an "optimization" (tradeoff between spark, fuel, detonation, and in stock form - emissions)

Any "canned" tune is generally going to be designed to operate over a wide range of temperatures, altitudes etc which means that the writer of a "canned" tune will have to keep some margin on anything they do or they risk blowing up someone's car...

The short version for "most" people these days is actually a little more modular...

That is until you start heavily modifying your car, there is enough data out there that many on-line vendors can use a lego block like approach to build you a tune based on what mods you have...

A "good" dyno tune done local to where you will drive is always better IF (and only IF) it is an experienced tuner... If not, I think you will find that some of the on-line vendors can do just as well for a pretty wide range of common modifications...

Phew - I think I just typed up a novel - this is a big topic. While it might seem like the controls of your car have been locked away from you (which they have) - the flip side is that the computer and a qualified tuner have a great deal more control over your car than they once did and will be able to make a much more reliable powerful setup out any given mix of parts...

 

[ixtlan]

Phew is right.
Good Job!!!!

Questions I would start with:
1. Trans pressure raising I understand controls the sharpness of shift.
What are the indications ya goin too far?
2. My Tuner (Fuego) lists Stang GT 05&06 and also 07 Man or Auto.
What is the difference between 05/06 and the 07?
Why doesn't the 05/06 have the auto and manual selection
separated?
3. Timing? Advance about 4 from 0 to 2000, What about 2000 to
4000, then 4000 to 6000?
4. Fuel Rich or lean. How far would I dare go one way or another?
2%, 4%, ect?? And had would you tell your going too far? Temp?
If so what would be the tell tell signs?

Well there are the questions I will start with.

 

[stlwagon]

Phew is right.
Good Job!!!!

Questions I would start with:
1. Trans pressure raising I understand controls the sharpness of shift.
What are the indications ya goin too far?
2. My Tuner (Fuego) lists Stang GT 05&06 and also 07 Man or Auto.
What is the difference between 05/06 and the 07?
Why doesn't the 05/06 have the auto and manual selection
separated?
3. Timing? Advance about 4 from 0 to 2000, What about 2000 to
4000, then 4000 to 6000?
4. Fuel Rich or lean. How far would I dare go one way or another?
2%, 4%, ect?? And had would you tell your going too far? Temp?
If so what would be the tell tell signs?

Well there are the questions I will start with.

Increasing trans pressure too much is going to cause more rapid wear on parts.

I'd be careful messing with the fuel adjustments without determining first where you are with a wideband. The canned tunes tend to run a tad on the rich side for safety. Once you figure out where you're at, you could tweak accordingly.

 

[cekim]

Increasing trans pressure too much is going to cause more rapid wear on parts.

I'd be careful messing with the fuel adjustments without determining first where you are with a wideband. The canned tunes tend to run a tad on the rich side for safety. Once you figure out where you're at, you could tweak accordingly.

+1 on both fronts...

Shift firmness is a tradeoff between firmness and wear - if you go "too far", the car will seem jerky and chirp/spin the tires on the 1/2 shift or the 2/3 shift when you do not intend...

The 05/06 vs 07 is that the "image"' the tuner writes to the PCM has changed - so it needs to write something the PCM recognizes.

Generally speaking, you need good data to know how much if anything to change and that requires at least a wideband meter to measure A/F beyond the measurement taken by the O2 sensor already in the car...

If it is runnig really rich, you'll see soot build up in the tail pipe and possible smell unburnt fuel. Lean is a little harder - until it gets really bad (and knocks), you only see that in the spark plugs - do a search for diagnosing or reading sparkplugs on that...

 

[stlwagon]

If it is runnig really rich, you'll see soot build up in the tail pipe and possible smell unburnt fuel.

and if you're still running cats it's really not good.

 

[cekim]

BTW - to answer your question/comment about "not much information out there" - there are 2 main reasons I can think of for this:

1. Even if you know all about it - you'd need expensive toys (dyno for one) to do much with that information. You need a way to "measure" the result of the changes you make under load - trying to gather much data by doing pulls on the highway is dangerous and difficult...

2. "tuners" want to (and should be able to) recoup the time and effort they have put into learning how to "tune" a given car - so they have little to gain by teaching the whole world for free what it took time and money for them to learn...

What you see in that hand-held unit is just the tip of the iceberg of what is going on in "the tune"... A lot more thought and expertise goes into them than 1-5% lean or advance retard in this RPM range or that...

 

[stlwagon]

You could always buy the SCT Pro Racer Package and then you'll have full control over every parameter. But the PRP is not for the average garage tuner.

 

[Terry5357]

timing

what about small adj to timing as in +1% or one bump up of whatever the graduation is

 

[DynoJoe]

Firs thing that needs to be answered when this type of info is given out or asked for is:

What is your background on Vechiles?
If you have not done much with vechiles such as engine rebuilds or tuning of the older type (such as setting timing with a gun) Messing with things like the peramiters on the flash tool would not be a good idea.

There needs to be a decent amount of knowledge of the way vechiles act and respond to small adjustments.

Before we will sell a PRP kit, a customer must complete a questionaire before I will allow a PRP to be sold.
There is too much that can go wrong with the hit of the worng key nowadays.

 

[stlwagon]

Before we will sell a PRP kit, a customer must complete a questionaire before I will allow a PRP to be sold.
There is too much that can go wrong with the hit of the worng key nowadays.

That's smart! Everyone should do that. At least with PRP you can only destroy one car

 

[DynoJoe]

That's smart! Everyone should do that. At least with PRP you can only destroy one car

You can destroy any car with the same box code.

I use alot of the same box codes on our tunes, 03-04 Cobra's all get the same code regardless of what it is, same with alot of the 05-06 Stangs.

 

[stlwagon]

You can destroy any car with the same box code.

I use alot of the same box codes on our tunes, 03-04 Cobra's all get the same code regardless of what it is, same with alot of the 05-06 Stangs.

Wait... So it's not locked to a single vehicle??

 

[ixtlan]

Firs thing that needs to be answered when this type of info is given out or asked for is:

What is your background on Vechiles?
If you have not done much with vechiles such as engine rebuilds or tuning of the older type (such as setting timing with a gun) Messing with things like the peramiters on the flash tool would not be a good idea.

There needs to be a decent amount of knowledge of the way vechiles act and respond to small adjustments.

My knowledge of automotive is lets say EXTENSIVE!!!
I done it all as far as the mechanical side and have a very good knowledge of the EEC system and what it does and how it works.
But not the knowledge of tuning it. That is new to me.
But I do understand the effects of Rich/Lean, Fuel Injector timing, ect.... I just have no experience as to what to actually look for.
Does that make sense?
What would be my tattletale parameters and such.

 

[cekim]

You can destroy any car with the same box code.

Yeah - I was trying to convey that in the following - but it may have gotten lost in the other info:

With digital systems, the failure is often "binary" - either it works or it doesn't... your engine goes from purring to detonating and throwing parts out the side...

So, the what not to do is start change parameters without understanding what they do. The range of control you have when you buy a diablo/sct type handheld is intentionally limited to try and prevent you blowing your car up...

I also left that out of the "why you don't see more info" response which does indeed include:

1. trying to prevent people from blowing their cars up
2. emissions controls - there are those that would rather you not modify your engine's controls at all...

I thought that went without saying - but Joe is absolutely right...

 

[DynoJoe]

Wait... So it's not locked to a single vehicle??

No the PRP kit is locked to a single PCM code!

 

[DynoJoe]

My knowledge of automotive is lets say EXTENSIVE!!!
I done it all as far as the mechanical side and have a very good knowledge of the EEC system and what it does and how it works.
But not the knowledge of tuning it. That is new to me.
But I do understand the effects of Rich/Lean, Fuel Injector timing, ect.... I just have no experience as to what to actually look for.
Does that make sense?
What would be my tattletale parameters and such.

Basically what I was getting at was the fact that someone who wants to purchase a PRP kit from me, must fill out a questionaire before getting one.
Basically, they need to know how much timing a NA motor can take and the knowledge of how spark adders work in relation to IAT's.
They must also know what the proper A/F for an NA and Poweradder combo must be (in a range) before I will sell one.

There is alot of phone calls that get made when someone buys a PRP kit,and alot of time lost answering questions one should know.
Most of all, Alot of folks like to blame a tuner for the mess ups that happen to a car. I see alot of Threads that name the Tuner as the one who caused problems with their car, and not someone taking the time to fix Mechanical issues. Tuning a car only helps make the car more efficeint, it is not some Miracle fix for problems that alot of cars have.

Not saying that you could not meet or exceed my demands before selling a prp kit, but there are some who know nothing about these cars but know everything since they read it on the internet. I hope you know what I mean by this. I actually had a person call to order a PRP kit and he had no Clue as to what Timing did or what Air/Fuel was.
He even went as far as trying to convince me he has done tuning on older cars but had no idea what an Airbleed was or points were. These are the type of folks who do not need acess to the computer and to make changes.

Cekim has meet my requirements of a PRP as we upgraded his to the newer advantage 3.0, He is an Engineer but we didn't hold that against him either. He knows first hand after looking at the software how much is involved when you open up a tuning file with todays software.

I hope you do not take what I have written here the worng way. In todays world though, These cars are alot more complicated than my old '65 Mustang or even my old '89 Coupe with a 347. I could tune my older cars with my eyes closed and was so used to the sound of my car, I could get it tuned in by just listening to how the car ran, I cannot do this with todays cars. You cannot even begin to try and tune a car of today without a Laptop and an Air Fuel Gauge.

 

[zmanm3]

I personally wouldn't dream of messing with my tune at this point. Maybe someday when I learn a bit more and have a good understanding or what is going on. Right now I leave it to the experts. You just have to do your research on the tuner you use and make sure that he or she knows what they are doing. You are paying for their knowledge.

 

[cekim]

He knows first hand after looking at the software how much is involved when you open up a tuning file with todays software.

That's a big 10-4 :headscratch: ok - so carry the 1 and then add in the flux capacitor value - and viola! I have... er... cheesecake?

 

[MickMach]

the tranny shift point that can be changed are at WOT only...right? tranny still shifts the same at normal driving????