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Discussion Starter #1 (Edited)
Here is a link to the Pinouts of the '00-'03 Spyder 1zz,'00-'02 Celica 2zz and Corolla 2zz

http://s312.photobucket.com/user/CapWeir/library/Toyota ECU PDF

Go to Page 4.. post 63 for MAF MOD work

I have herd all the Reasons why it's 'Wrong' to run the Wrong Engine On the 'Wrong' ECU.. and I understand why it's 'Bad'.. The injectors are Smaller on the 1ZZ.. the 'Same' MAF is Calibrated Differently between the Two ECU's.. and a Different size Pipe.. Ignition Advance is Different..
But what happens when it Really Happens.. Lets See..
Thanks to Curt, I've had an Opportunity to play with some 2ZZ Stuff, and 2ZZ documents.. BUT he did not send me a 2ZZ, So I'm Stuck playing with a 1ZZ Motor!.. I'll work up to a 2ZZ.. It'll just take time..

I was trying to Troubleshoot some of the 'Idle Learn' the ECU's were doing.. as it turns out, from what I've been able to gather.. The 1ZZ is Really Stupid, as far as Idle is Concerned... It just runs through it's 'Programmed Steps' for water temp, and engine Speed.. I have not been able to see any 'Learning' taking Place..
Now I needed to see the 2ZZ ECU Idle learn.. So I plugged in the 2ZZ Swap harness, and a 2ZZ ECU, fired it up. Started and ran Fine.. I watched the Engine get to temp, and watched the Ignition advance as the engine warmed up.. But I still did not see any real Smarts of what was happening..

Time for a Drive..
I took the Car for a Slow Drive down the Street, with LogWorks recording, and Displaying all the Info.. the Ignition advance was OK.., and the ARF's were good..
I then came back and let the Car Cool Down, and did a Restart on the 2ZZ ECU.. ( 2 Trip Logic )
The car started right up, and Idles Fine.. after It got warm, I took it for another ( Longer ) drive.. What I noticed was the 'Deceleration Fuel Cut' is NOTICEABLY louder!.. This is where ( apparently ) the Fuel is Cut as the Engine tries to Idle down to about 1200 RPM.. What I herd is a 'Sucking' like a really small turbo blow off valve Poping.. I have not herd that Noise before.. But I Figure it's the IAC Doing Something.. and the Engine almost Died.. It stumbled at about 600 RPM before it Caught.. So I did the Run again.. Out and Back same Road, came up to the Stop, and this time the 'Noise' was as loud, but not as long, and the car 'Stumbled' at 800 and Caught..
Did it again.. Same run.. This time the Engine Idles down to 900.. It still did the 'Noise' ( That I had not herd the 1ZZ Do before! ) but it Smothed Idled at 900.. It Learned!..
Next Time I do this Experiment, I'll have the 'Scope hooked up to the IAC Valve, so I can See the Pulses going to 'Make it Move'.. I'll need to install an Inverter, cauze my Scope is 110!.. I want to See this thing Learn.. and I want to see that it is really Learning.. ( Watch the IAC Pulses get Wider as it Tries to 'Up the Idle' )..

Now the Next Step, is to Run the 2ZZ ECU at full Load, and See how all the O2 Feedback Stuff has Done on it's 'Two Trip Logic'..

I took a look at the ( One and Only ) Fuel Trim and the LTFT was +6.2..( adding Fuel Because the Injectors are Smaller ) the STFT was about 1.. ( No 'Big' Correction to what it has Learned about Fueling Long Term )
Hooked up the Lap Top, and headed for the Freeway On Ramp!!.. Do or Die

Here is the 2ZZ Log from LogWorks.. If you haven't seen a Log Before.. It takes a While to 'See what Your Looking At'.. Black Line is RPM's



And just For Comparison, here is the 1ZZ Log of the Same Freeway On Ramp.. Eariler in the Morning.. 2 Months ago..



The 'Blue Line' is the TPS Voltage.. as you see, when I accelerated on the 2ZZ ECU, I was 'Chicken' and was backing out of the Throttle a Little, as the R's came Up.. It felt like it Came up Quick.. But then I was Woried!..

The Orange line ids the Air Flow Off the MAF. The Air Flow was not as high with the 2ZZ tracing as with the 1ZZ.. I think this has to do with the Temp of the Air.. Warmer day when I ran the 2ZZ ECU..

The Really Important stuff is the Air Fuel Ratio.. ( Red Line ).. The 'Up and Down' is the Fueling the ECU does in Closed Loop.. When it Goes to Open Loop, the Line Gets Stable.. Looks Good..
The Next Important thing is the Ignition Advance..( Green ) This is hard to read, and I really need to 'Overlay' the two PDF's on each other to see the Differences.. My 'Old School Eyes' does not see any Danger Zones.. But the Advance is Less with the 2ZZ ECU that what the 1ZZ is Normally Running.. This could be a Function of the 'MAF Calibration', as this is used to Fugure Engine Load.. and this will be Wrong on this Install.. If I removed the 'Vanes' in the Air Box, and Redid the Run, it should be Closer.. ( I think.. )

Cap
 

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very interesting. i too would like to see an overlay
 

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You are only using two of the three O2 sensors when you have a 2ZZ ECU and swap harness plugged in. Stock Spyders have 2 O2 sensors in the header and 1 after the cat. Stock Celica GT-S have just one sensor before the cat and one after.

2ZZ ECU has simpler idle settings than 1ZZ, at least in the PowerFC world so I think this also applies to the stock ECUs. As long as you didn't have the A/C or defroster on, both would be using one set of upper/lower limits, though, so we can ignore this.

I would not rev above 5800 RPM because VVT, fuel, and timing all change in a way that would probably be inappropriate at best for a 1ZZ engine. The 2ZZ ECU will also allow you to rev far past the safe limit for a 1ZZ. Ooops. There goes the engine.

Fuel, VVT, and ignition timing will be different... what's good for a 2ZZ isn't very good for a 1ZZ and vice versa. I guessed at one point that idling would be safe, though, and you've proven that. Would I drive it down the street? Probably not! But it's your engine, my friend.
 

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Discussion Starter #4
The Idle Circuit

I installed an Inverter, in my 'Test Bench' Spyder.. And did some more testing.. This time it was the Idle Air Control Valve ( IAC ). I put my Scope in the Spyder and went for a Drive.

The IAC is sort of an 'Electro-Mechanical' Dash Pot.. It keeps the 'Intake Runner Vacuum' from getting too High..
As you open up the Throttle, the IAC will also open, in a Ratio of the Engine Load. As the Load on the Engine increases, so does the Positioning of the IAC.. While you are Driving, and you Accelerate, the IAC will Open Wider.. Even though you are not Even Close to Idle Speed. If the Engine Speed, is High when the Throttle is Closed.. the IAC will Close. As the Engine Speed aproaches 2K Or so RPM ( and the Throttle has not been opened by the Driver ), the IAC will 'Snap' to full open. The IAC will then gradually start to close as the Engine Speed is aproaching the 'Targeted Idle Speed'. This speed is < Apparently > set by a Function programmed in the ECU and uses the Coolant Temp Sensor to figure out.
I have not seen any 'Change Idle Speed' by the ECU, other than the A/C Idle up speed, that is 'Invoked' when the A/C compressor is running.. This appears to be a 'Position Offset' to what ever the IAC 'Was' going to do, but the A/C system told it to 'Offset a little More'. This 'Offset' also happens to the IAC while Driving.. the IAC will reposition itself when the A/C comes on and Off.. So the IAC is ALWAYS moving..
The only 'Idle Recovery' I have Seen, is when the Idle Speed drops below 500RPM.. ( Like when letting out the Clutch ) then the IAC will 'Snap' full open to try to recover the Idle. When the Idle is Above 500, the IAC will 'Snap Back' to the 'Programmed Position'.
I have seen a Little Different behavior in the 2ZZ ECU ( Running a 1zz Motor ), and that was the 'Blow Off Noise' I herd on my first Post.. This is the ECU correcting the Deceleration Rate of the engine when it's approaching Idle. The IAC will 'Snap Open' when the engine is almost at Idle Speed, and it's correcting the Deceleration rate, as the Engine would 'Possibly' stumble and Die.. This 'Snap Open' is the Noise I herd. As the ECU 'Apparently Learns' the Different Idle Down Rate of the 1ZZ motor, it no longer needs to 'Fix It'..
I have not seen this Behavior in the 1ZZ ECU, but then it's running an Engine it's Designed For!..

Cap
 

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Cap, are you testing this stuff just to satisfy for your own curiosity? In any case, thanks for sharing the results with us other nerds. :cool:

What I find interesting about the IAC is that the test procedure published in the BGB is wrong in regards to the IAC's start up test sequence.
 

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Discussion Starter #7
Kevin:
I'm thinking the IAC is 'Pre-Positioning Itself' For the possibility of the Driver Closing the Throttle too Quickly.. This will prevent the wide open throttle to Closed throttle 'Stumble and Dye' that can occur. My thoughts any way..

Kingspyder: Curt gave me the Opportunity to use some of this 2ZZ stuff, and I like to figure out how stuff works.. So this is a Two for One Special..

Cap
 

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Please forgive me as I am a complete engine management rookie (suspension is more my thing) but what software/hardware is used to make the logs posted on the first post?

If not too difficult, I would like to log what the stock ecu is doing, just for my own learning purposes.
 

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Discussion Starter #10
This is where 'We' Learn.. That's why you ask..

For my Stock Configuration, I chose to add hardware, that can be Read by a Lap top. My thinking on this was I could Plug in ANY ECU or Engine Computer in to my Spyder, and Not have to Worry about a Compatibility issue with the recording software.. And all the Logs are the Same Values.. No 'Scaling'..
This way the Car is reporting what the Engine Computer is doing, rather than the Engine Computer, reporting what it is Doing. So the Car is now a 'Test Bed'...

Here is the Link to the Install of the Hardware/Software.. 'Bout $800. Possibility it was more, and I just don't want to admit it!..

http://spyderchat.com/forums/showthread.php?t=31615

Cap
 

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Cap just to let you know from my own personal experience the 2zz has a rock solid idle. The 1zz when I had it would fluctuate a few RPMs low every now and then.

The 2zz engine probably because of the ECU is better ruining on the whole which I cannot explain except to say that its smoother and more precise.
 

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I think knowing what the stock ecu is doing now is pretty powerful. I ordered two books on EM so I will be educating myself. So from your 1zz ecu logs, were would you look for power?

I don't want to go PFC, b/c I think I am eventually building the car for STR (scca), which does not allow replaceing the ecu with a standalone, but does allow reflashes and piggybacks.

With a piggyback (say emanage for example) that leaves me with fueling and timing. How much do we feel there is to gain with timing? What about AFR, in open loop would it need to richened up or leaned out for max power? It seems like it is already running pretty rich in open loop (full throttle).

I am not looking for a 20 hp increase, but if you could gain 8-10 hp that would be great.
 

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Discussion Starter #13 (Edited)
MAF Voltage Vs CFM Flow

My Testing has now brought me to checking the MAF Voltage VS CFM air flow of a Stock Spyder Intake. I also have the opportunity to test a PPE CAI
I've noticed that usually when someone is having problems with a Spyder.. they have an 'Intake' on it.. And if the Stock Intake is Placed back on the the Car.. it Runs Better..

I've been trying to figure out the reason why.. My Theory is, because the 'Calculated Load Value' of the Engine by the ECU is off, because the MAF signal is Greater or Less than what would be Expected for the Actual Load the Engine is under.. and the Ignition Advance is 'Wrong' for the Actual Load.. because the ECU has no way of Knowing the Actual load.. The Load is Calculated by the MAF/RPM=Load ( Or Something like this ).. So if the MAF is Wrong, the Calculated Load will be Wrong.. and the Ignition Advance will also be Wrong.. and the Knock sensor could also be playing a Factor in the 'Drivability' issue, as the Knock Sensor will not Pull Timing 'Smoothly' , so the Car will 'Stumble' a Little.


What I want to achieve is a 'Base Line' as to the Spyders Air Flow Vs MAF Voltage of Stock Spyder.. then Look at the Various other intakes, and what they do to the MAF Voltage, and relate that to how that would affect the Ignition Advance.. or any 'Hunting' that might be introduced.. ( Knock Sensor at Play? )

The Spyder does not have a 'Unrestricted Intake'.. as it has a form of 'Vanes' in it.. and they will affect the Air Flow Properties of the MAF Voltage VS AirFlow..

Here is the Spyder 'Mask' before the MAF


This is a Pic I Snapped from NewCelica of an Aluminum remake of the Celica Mask..



As a side note.. LR posted in Newcelica, about the MAF Voltage not being 'Scaleable' to a Different size intake.. he ran through a few tunes he did on a Car and Different sized intakes showing how a Tuned Car set up for One Sized Intake, can not just be Swaped over to another size intake, and a 'Correction Factor' Used.. the Tune was actually Different.. I've always wondered how accurate that is.. or at least what factors might be at play..

I have the opportunity to test a 'Smaller than Stock' PPE Intake.. The PPE intake is Smaller than the Factory Stock intake.. It's inside dimension is 2.360 inches, as the Factory intake is 2.570 inches..

The Center of the MAF in the PPE intake is 39% up from the Bottom, and the Center of the MAF on the Factory intake is 36% up from the Bottom.

The PPE intake Should cause a little greater than an 18% increase in the MAF air flow Signal going to the Engine ECU, and this will cause the ECU to effectively 'Pull' Timing advance on the Engine.. Because the MAF is a little higher ( Percentage wise ) from the bottom of the PPE Tube.. And the Area if the PPE tube is smaller, the Signal should be higher than 18%.. If you look at the Chart.. the MAF Voltage is Actually LOWER for the same air Flow than the Stock Intake.. The factor that must be in play here is the 'Maf Center Offset Distance' to modify the Ar Flow Curve, else the PPE intake would have a Greater MAF Signal per CF of Air than the Stock Intake.

The JPG is a copy of the Graph I made of the PPE Intake, Stock Spyder, and Spyder with no Vanes..



I went back to some of my Chartings of the Spyder running down the Road, and got the MAF Voltages, and put the Arrows on the Chart at the Proper Spots.. My Test Bench runs out of Air at 180 CFM. so thats where the Testing Stops..

I ended up using a Celica ECU wired on the Bench, to power the MAF..




The MAF is powered by 12 Volts .. and Somehow the ECU has electronics that are working with the Internals of the MAF to make the 0-5 Volt Sig.. I was not Expecting that.. So it just took a few Days to set all that Krap Up.. I'll figure out that stuff later..

Here are the Various Test Configurations ..

PPE Under Test



Stock Air Box Under Test



I checked to see if the Air Cleaner by itself was OK or whether it needed the Bottom Box.. 'Bout the Same!



The PPE "Electrical Data" was more stable than the Stock Air Box.. I would have to set up a 'Charting Test' to track that.. < Later > that data is not represented here.. but might play a Factor is future testing/Mods

Cap
 

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Nice setup! Wheee.

I imagine the stock ECU calculates load exactly like the Power FC. If so, it is

Load = Correction * 16384 * AirflowLookup(MAFSV) / RPM

Correction comes from a table of 8 numbers used to scale the whole thing up/down. We can just forget about that for now.

The 16384 is 2^14 and is just there to scale the overall output for a 16-bit number. Load can be greater than 16384 but it is always less than 65536 (what will fit in a 16-bit word).

The important part is the AirflowLookup function. That returns a number based on the MAFSV input (0.0 - 5.12) and the airflow curve you have selected for use. In the Power FC, you can have several curves defined, but you select one of them. The airflow curve is an array of 32 points. Each point is (Voltage, Value). Curves are pretty simple and look just like that graph you posted. I've posted a picture before in the Copilot topic.

It makes sense that the PPE output is higher. The tube has a smaller diameter, so the same amount of air (CFM) will be moving faster. Faster moving air affects the sensor more. It also makes sense that removing the vanes from the stock tube (which I've done, and also filed them down) would cause the MAFV to be higher. In that case, it is just because the tube does not have that restriction in it. The vanes are there to smooth out the airflow, which is important for relatively slow moving air... at idle. It makes the idle smoother and prevents bogging that can happen when the airflow changes rather suddenly by reducing turbulence.

A different intake - and airflow curve - can either help or hurt the performance with a stock ECU, depending on multiple factors. You are at the mercy of what the ECU will do in response to that input. It causes the fuel, ignition timing, even VVT to change for any given situation because all the maps are addressed by RPM and Load. With a Power FC, you can change all the maps and the curves if you want.

What I'd really like to see, Cap, is a comparison of curves for different diameter intakes, all using the same air filter. I'd be particularly interested in seeing

Stock vs 2.75 O.D (1/16th" wall) vs 3.0 O.D (also 1/16" wall)

Then I could build the curves in Power FC format and make them available in mr-s.org. I've been wishing for this for a while now, ever since LittleRocket clued us into his homemade flowbench. He said he'd do it, but as always, he's just too busy.

Now where are those green dots for Reputation when I really need them?
 

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Oops... forgot to mention why I would want the air filter to be the same (just for testing). A filter may direct more air towards the center of the tube, which is where the sensor is. So we'd like to compare intakes with all their characteristics as they really are (apples to oranges) but also compare diameters, say if someone just wants to change the diameter of the intake (homemade intake). It should also make it easier to come up with a simple formula (coefficients for a polynomial). Then we'd know what any diameter tube would do to the output.
 

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Discussion Starter #17 (Edited)
Nice setup! Wheee.


It makes sense that the PPE output is higher. The tube has a smaller diameter, so the same amount of air (CFM) will be moving faster. Faster moving air affects the sensor more. It also makes sense that removing the vanes from the stock tube (which I've done, and also filed them down) would cause the MAFV to be higher.


Kevin..

Lets look at this Chart, and Get some Terminology..

I see the MAF output LESS for the PPE intake.. at 100 CFM of air flow, the Stock air Box will give you a 3.42 volt Sig.. The PPE will give you a 3.25 Volt Sig. and If I Pull out the Vanes out of the Stock Box, I'll get a 3.12 Volt Sig..

That says to me that all the Configurations I tried,( 3 ) the Stock Intake will give me the Most Sig per Air Flow ( It's the Baseline ) .. I was expecting the Stock Box to have a Lower Sig, when the Vanes were removed.. and that Happened.. But I was not Expecting the Smaller PPE intake to have a LOWER sig per air Flow than Stock.. As you said, it's a Smaller Intake, and the Air Flow is Faster.. I was expecting MORE Maf Sig.. The Only thing I can relate it to is the 'Off center' Maf Placement..


What I'd really like to see, Cap, is a comparison of curves for different diameter intakes, all using the same air filter. I'd be particularly interested in seeing Stock vs 2.75 O.D (1/16th" wall) vs 3.0 O.D (also 1/16" wall)
That is my Next Step.. I had actually threatened to do this before in a Conversation with Dev.. But things got Busy.. Now I have the Air Flow Test Bench ( On Loan from my Head Guy.. ) and I can Do the Experiments and not have to mount it on the Car.... I have the PPE intake Set up, and the Air Filter for it.. So I can make the Comparison Chart for that Air Filter..

But one of the other dimensions that must be plotted is the MAF center Distance on the Intakes AND the Different Diameters of the Intake Tube.. More Variables..

If the Flow Bench was Mine, I could hack into it and get the Air Flow Measurements up to about 360 CFM, as the bench really is Two Benches.. One for Suck, and one for Blow.. If you reconfigure the Entire bench to either Suck or Blow, than you actually have Twice the Air.. But I told 'Harry' I would not Screw up his Bench..

Cap
 

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I see. I was reading that wrong.

Smaller intake: faster airflow, but not more CFM. I thought the MAF sensor would be fooled by faster airflow, but it looks like it does a good job of measuring the Mass of air like it should.

No vanes vs vanes is really interesting. The MAFSV is lower with no vanes.
 

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So....

with a PPE intake and a 1zzfe PFC, how I should modify the airflow curve????....
Cap gave us CFM but Power FC deals in "Load", so we don't have the same units. However, I can come up with a formula relating CFM to Load and use Cap's raw data (what was used to create the Excel graph) to make a new Power FC airflow curve for the PPE intake. Actually, Cap could do that if he was so inclined. He has the numbers.

Very nice. Very, very nice. Cap is the man.
 
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