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Getting Started with tuning

12K views 71 replies 12 participants last post by  vetteoz 
#1 ·
So I thought it would be kinda neat to start a thread that maybe could benefit everyone that wants to tune.

If your gonna tune one of the first steps is to datalog.
A great site to start with for some free datalog software can be found here. You'll also find directions on that page to build your own OBD1 connector

http://winaldl.joby.se/

You can also find free tuning software at
tunerpro.net

trial software, they also carry datamaster
tunercat.com

Tunercat and datamaster is what is most often used when your getting a prom done by a mailorder company

If you prefer to tune yourself then you may need to look into burning your own proms.
Most common place for us guys to get the prom burning equipment and chips are through
moates.net

Hopefully this will get us all started on a thread that can end up with some good information and a place to discuss the early stages of tuning.
 
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#35 · (Edited)
Sorry, I'm learning this as I go a bit too. SV and I mentioned on PM we need to get this going again.

If anyone sees I say something off, CORRECT ME.

OK, the basis of all tuning is the IDLE. If you can't get the idle right, the rest is kinda meaningless.

To do this remove the IAC from the air circuit, cover the IAC hole in the throttle body with duct tape. Dial in your idle from that point.

Then reconnect the IAC and remove the tape.

the idle should adjust from there.

At this point when you put it in gear, or start the AC, the car will SURGE then level down to where it is supposed to be idling. MOST ECUs have an adjustment for that condition, how high it will surge.

There is something called a "LEAN STUMBLE" if you make the car idle too lean. Idle air fuel ratio is relative to the cam. Some like 13.X others can go to 15.X.

If the idle is too lean, when you come off idle the car will want to stall, and studder.

MOST ECUs have an adjustment for that so that it works as an "accelerator pump" to push gas as you are just off idle. There is a setting there.

So the trick is to get the idle to a point where it's as lean as you can go, but still adjust the "accelerator pump" feature so that you can leave the stop light without studdering.

This is very basic, very elementary stuff. There are people better than this than I am.....I'm sure they can chime in...:D
 
#36 ·
I'm gonna get back on this as well. I've been swamped with work.
 
#38 ·
Thanks for the comment, makes it worth my time to write.
 
#40 ·
We got the general idea of whats going on with some inputs and outputs so far. Naturally the thread isn't intended to start a tune from scratch and build a .bin. What we want to do is assume that the car were tuning is something thats already existing and basically running or you've just done some mods on it.

Before you want to do anything with the tune we need to see whats going on with the engine. So we need to start with a datalog. This records and you can analyize whats going on with those inputs and outputs.

Doesn't matter which datalog program you decide to go with they basically all give you the same information but may look a bit different.

Here's a screenshot of my datalog program



So what your looking at is the basic infomration of your inputs and outputs.

RPM,MAP,TPS,SA,CTS,IAT,Injector PW,GMS sec,
INT,BLM,WB02,IAC

Don't expect to now everything with one datalog. Unfortunetly you'll never stop datalogging as long as your tuning.

Here's another look at my datalog program. this is what I have up while driving and it gives me an overall look as to whats going on. Theres more screenshots I can show you and will later. Just trying to give you an idea of what the datalog is showing. The program I use also allows me to playback my datalogs. I can bring the computer inside and play it back as if it were live
 
#41 ·
Great Reply. Let's take a look at what is going on with ed's car and see if we can make some determinations.

1. He's at idle
2. He's pulling about 55 KPA which indicates light load on th emotor.
3. He's idling a little on the lean side which is no biggie
4. Looks like he put it in gear around time stamp 00:00:35 and the IAC compensated
5. He's in open loop. (that is why the BLM is pegged at 128)

So what does all this mean?

To me, looks like he has a happy idle at a decent AFR with a working IAC.

Not ALL ECUs program this way. I'll get some screen shots of mine tonight so you can see what is happening.

That is a good place to start the process.
 
#42 ·
Exactly. All ECU's are different but you will have the same basic information.
You can tell what state the engine is in just by looking at a few simple things.
RPM
Open Loop or Closed Loop

What I have found out the first thing you need to do once you start datalogging is pay attention to your inputs. Make sure they are all working correctly. The datalog program will only work as well as the information that its been given.

To give you an idea of how to look at this .bin lets try this:

First line of the datalog
825 RPM
MAP 56
Say you want a bit more fuel because the AFR is 16.6

Open you .bin in your editor, find the table that is used for the VE. In my case its called VE Low Speed. here's a shot of it. I've highlighted the 825 RPM area @ about 56 Kpa



Let say I want to bump my fuel a bit. You can do it one of two ways in my case. Either type in a new number and go with that or (what I do) is pull up the graph. Select that same area 825 RPM 56 Kpa

Then pull it up. Naturally this is an extreme but wanted to give you a good idea of what it does
 
#44 ·
Don't think your off topic at all. IMO I think that once you make your change and to get the best performance out of your engine (if thats was your looking for), then yes. A tweak to the tune would be in order
 
#45 ·
This is a great thread and I'm learning a lot about tuning. One question I do have is can someone expand on this?
To do this remove the IAC from the air circuit, cover the IAC hole in the throttle body with duct tape. Dial in your idle from that point.
How do we dial in the idle from that point? It looks like the IAC controls the idle and the ECM controls the injectors and timing. Aside from plugs and wires, isn't all the control given to a better faster smarter computer?
 
#46 ·
This is a great thread and I'm learning a lot about tuning. One question I do have is can someone expand on this?

How do we dial in the idle from that point? It looks like the IAC controls the idle and the ECM controls the injectors and timing. Aside from plugs and wires, isn't all the control given to a better faster smarter computer?
Use the screw on the throttle body to move the plate in and out, or move the idle up and down. Set it where you want, then reconnect the IAC and take the tape off the holes.
 
#48 ·
Thanks guys. This helped me out because I think the Vette is idling to high. I'll try to bring it down this weekend. I'm pretty new to this Corvette stuff so this is a great learning experience for me. I don't want to ask to many questions because this may be covered latter.

The program you guys are using is called WhatsUp? Correct? Why do you prefer whats Up to WinALDL and where can you get the application Whatsup? I did do a quick internet search and nothing came up under the Whatsup application with obdii in the search engine.
 
#50 ·
The program you guys are using is called WhatsUp? Correct? Why do you prefer whats Up to WinALDL and where can you get the application Whatsup? I did do a quick internet search and nothing came up under the Whatsup application with obdii in the search engine.
WinAlDL is a datalog program. You can find a link to that within the first few posts of this thread

Whats Up is another type of datalog- that came with my new ECM. It can't be used with any other type of ecm. Only the EBL/Flash from dynamicefi.

DataMaster is another type of datalog. theres a link for that as well in the beginning.

I know .... a bit confusing.
 
#51 · (Edited)
on the topic of injectors to me there is a lot more to the concept of injector flow than flowing at a static pressure of 43.5 or whatever psi. thrown at the injector.
In tuning and application the most critical area of the injector pulse width occurs below 6ms. and .02 fuel mass (gr.). When comparing injectors or doing swaps this is were the differences between injectors can be seen.
If swapping from an early type ev1 to the later type ev6 that flow the same lb. rating @43.5 the result using stock gm offsets is an air mass calculation that is approx. 12% off all the time. This 12% airmass error can get carried over to the idle control strategy, making it that much more difficult for the ECM to precisely control idle speed with the IAC motor or electronic throttle control system. The solution is to command the ECM the new injector characteristics that will result in an injection time of 3.1ms in order to deliver the fuel mass target of 0.010g to the cylinder. This means giving the ECM more info than just the offset and linear flow rate. The same would apply to using higher than rated psi for an injector. The truth is that the increase in
pressure also affects both the opening delay and the nonlinear flow region of injection.
Ford racing has been kind enough to make there injector information public. The problem for most here is using the ford logic/description of "intercept of the high slope" low slope" etc. is than converting it into gm description.
 
#52 · (Edited)
HEY MICK, your name just came up in another thread. http://www.smokinvette.com/corvetteforum/showthread.php?t=42587

I hate to hijack, but I gave up with the stock ECU.. Not that it isn't a better solution if you know what you're doing, it's just SOOOO HARD these days to find someone who does.

I am carrying a line by Motorvation. This is TJ Tracey's company :



TJ was with Hypertech for years and Mike, was the primary tech guy for FAST for years. These guys know their stuff. It's what they run on their cars, both track and hot rods. Mike is running it on a mild Ford Galaxy that he uses for a street cruiser.

I put one in my car as I just simply couldn't get the stock ECU dialed in. I attribute that to 3 things:

1. Lack of experience
2. Complexity
3. Lack of local support that has been doing it on the on going basis

It's running much better now with the new ECU and has allowed me to actually UNDERSTAND tuning and not just get frustrated.
 
#54 · (Edited)
The MOTORVATION system is set up before it leaves the factory for the basis of your car. They set the injector flow, RPM range, etc.. etc... etc... By doing this a lot of nuance is buried, and this is done by design to keep it simple. Because you don't see it here, does not mean it's not capable, just means it was buried from the UI so you can more eaisly tune.

Here's how the Motorvation tunes, and why I decided to use it. The FUEL Screen.



This is the primary tuning screen, a box shows up where you are running. The information regarding the engine is in the box that is always on top.

What you see in the screen is the PULSE WIDTH.

You want it richer, you multiply it by 1.XX

If you want it leaner by .XX

It is adjustable to 2 decimal points, many systems only one. So it is more granular.

The pulse width is adjusted until you get the desired AFR you are seeking. Pretty simple.

You can select a range of numbers, single box.

Also on this screen you can adjust the fuel bump, for example when you put on the AC or put it in gear, the RPM will go down and come back up. You can control the response time of the IAC and the fuel delivery as to how fast the pump reacts when you put your foot down.

The choices are multiply range, fill, interpolate using formulas in the software either vertical or horizontal. You simply drive and adjust the number in this box to the get the desired AFR. The software guides you as to where you're at, so it's easy to follow. The box where the car is operating turns red.
 
#55 ·
With their system, the second screen is pretty self explanatory, SPARK. You set your timing curve here.



On the bottom you will see starting timing, you just throw that in there. And a rev limiter.

That's easy enough.
 
#56 ·
O2 sensor screen sets target AFR. You can see on the bottom it allows idling in open loop and the parameters are set for when closed look kicks in. TPS position, RPM, and temp.

 
#57 · (Edited)
The IAC screen sets your idle:



Simple...the RPM rev limit is one element of taking it out of open loop. if you exceed that limit, you're in closed loop.
 
#58 ·
The offset screen changes fuel delivery on the global basis by either water or air temp. So under certain conditions if you want it leaner or richer you can dial that in.



The system will support up to a 5 bar sensor. It says 3 on the bottom, but can be unlocked for 5.
 
#59 ·
And finally single or dual stage NOS settings:



Don't think too many here are worrying about that.
 
#60 · (Edited)
Mick will tell verify, he's been giving me help for 2 years trying to get my tune right. The guy who I had helping locally, I think was over his head.

The Motorvation ECU was tuned in 3 hours for a perfectly good street tune (just starting is a little hard but I only get one shot a day at that).

Faster chips, better technology, and native PC interface have made tuning MUCH easier. The stock ECU is a lot more granular, however, it is pretty complicated.

I understand the theory of the stock ECU, putting it into practice on a stock ECU was REALLY time consuming and I just wanted to DRIVE the car. Now it is running stronger than it ever did with the stock ECU and doesn't have all the pops on deceleration, hesitation, etc.....

Seems to me that the Motorvation worked for me. Easy to install, easy to tune, and easy to modify on the fly.
 
#61 · (Edited)
Mick will tell verify, he's been giving me help for 2 years trying to get my tune right. I've been working with the stock ECU a long time. It was GOOD just wasn't GREAT! The guy who I had helping locally, I think was over his head.

The Motorvation ECU was tuned in 3 hours for a perfectly good street tune (just starting is a little hard but I only get one shot a day at that). And the car is running FAR BETTER than it was two months ago.

Faster chips, better technology, and native PC interface have made tuning MUCH easier. The stock ECU is a lot more granular, however, it is pretty complicated. The whole point of tuning is to get the amount of fuel you need into the car, to get the AFR you desire, and match it with the correct spark timing. It's not really magic, but it IS complicated. Mick is one of the smartest guys I spoke to regarding the stock ECU. The reality is, there aren't many of them around anymore. I think the MOTORVATION solution is a great solution for the novice tuner.

I understand the theory, putting it into practice on a stock ECU was REALLY time consuming and I just wanted to DRIVE the car.

Seems to me that the Motorvation worked for me. Easy to install, easy to tune, and easy to modify on the fly.
 
#64 ·
Showing some troubleshooting

I wanted to share this with you guys so you can see how to do some troubleshooting using a datalog program.

Here was the problem

Car started to act as if it were misfiring / skipping.

so I did a quick datalog. On this screen shows my problem.

Before I post what was wrong I figured I'd have you guys take a look and tell me what you think?

 
#68 ·
I wanted to share this with you guys so you can see how to do some troubleshooting using a datalog program.

Here was the problem

Car started to act as if it were misfiring / skipping.

so I did a quick datalog. On this screen shows my problem.

Before I post what was wrong I figured I'd have you guys take a look and tell me what you think?



So we know the problem is a misfire/skipping problem and has gotten worse.
So the first thing naturally we look into plugs,wires,distributor cap,etc.

Now look at the first few lines and what do you see?

MPH= 0
TPS= all different %'s

Remember .54 volts = the butterflies are closed?

Why is the TPS opening up and telling the ECM that it is?

TPS sensor came loose or the voltage is not set correctly. 5 min fix problem solved, 0 dollars invested
 
#65 ·
If that WB is correct, your AFR is all off.
 
#66 ·
Nope... WB is disconnected for now. Had to send the controller out for repair.
 
#69 ·
That's a little more troubleshooting than tuning......here's where I'd like to go, and I'm working up to it.

The goal of tuning is getting the right AFR that the motor likes. My car seems to like 14.0 in general.

The direction I'd like to take is to understand how the sensors relate to AFR.

For example why is there a temp sensor and a water sensor? What do changes in those sensors mean in terms of needing to be more rich, or more lean? What does the vacuum indicate? Why does 50KPA require less fuel than 60 KPA.

I'd like to go to generalities about what the inputs are telling the ECU (in general) and what the ECU has to do to compensate. AND what you have to do as a tuner to compensate for the different conditions picked up by the sensors.
 
#70 · (Edited)
That's a little more troubleshooting than tuning.
Yes it was, and was the point of the post. To understand what "we" are seeing in a datalog an why its important.
Sure we can all go out and "buy" a tune. But if we don't understand the basics of what to look for how do we know that something is wrong.
With a purchased tune that simple error we could have easily blamed on the "tuner" and in reality it would have been the "customers" error.

I've seen way to many times over the years people who have gone out and bought a tune. Gotten there chip and because they don't understand what to look for in there datalog have ruined there engine. Then naturally put the blame on the tuner. When in fact if they had understood the basics of when to know to shut the engine down and get in touch with the tuner to figure out whats going on.
So if you have purchased a chip my advice would be to understand the basics of whats going on so you can report to your tuner. Just because one tune works on another car doesn't mean it what your car wants.


There are some really good tuning books out there to help us as well. Greg Banish has written some really good books for people like us that want to understand whats going on. The can be purchased at most of the bookstores. I'll get some titles to post, but do not have them handy right now.
 
#72 · (Edited)
What hasn't been mentioned is what is needed to tune stock ECM's

This device lets you adjust tune from a laptop even while you are driving
http://www.moates.net/product_info.p...roducts_id=169

You will need this adapter also
http://www.moates.net/product_info.p...products_id=32
It replaces the factory chip ( used up to '93 ) and allows the Ostrich cable to be connected to the ECM

Using a tuning software program like TunerPro RT
http://www.tunerpro.net/
http://www.tunerpro.net/features.htm
http://www.tunerpro.net/screenshots.htm

You adjust your tune using the software on your laptop and upload it to the Ostrich.That holds the tune and runs the engine .You can remove the laptop until you want to adjust tune again

You need to download the program
http://www.tunerpro.net/downloadApp.htm

and the correct definition files for the ECM in your car
http://www.tunerpro.net/downloadBinDefs.htm
 
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