Karmen Vortex Elemination....

The 1UZFE EGR Delete Kit is available for sale here.
US$650.00 compares very well with the price of full aftermarket ECU's.

You could land it in Australia for $1,000.00, or NZ$1,150.00 (assuming you get it thru Customs) and tuning it shouldn't be too bad once we had established a base map for the Frequency side.

I wonder what you could do as a group buy?

Lambo, would you consider discussing a group buy with them to establish any price benefit.
 
Hi guys i spoke to Peter today re the map-ecu and he mentioned they were supplying Neil, he has pointed me over to the USA dealer for those of you in the USA http://www.powerhouseracing.com there is a like on the left to map-ecu and to the wiring diagrams at http://www.mapecu.com/merchant/downloads/WiringDiagrams/all toyota ecus.pdf and sample maps we could use http://www.mapecu.com/merchant/v22fuelmaps.shtml
and the !UZFE is listed, Peter is going to get the Powerhouse Guy to email me or login to Lextreme to answer any questions we may have, interestly Peter says that a Temp sensor is available that mounts in the valley and senses directly from the Pelum, he says this much more accurate, and as the KV only produces 10-13 hz at idle on our motor this is quite important as the temp difference can effect the output to the ECU by as much as a 1hz change in flow. It sounds like they have done their homework, the unit has harnesses available, and is tuned in real time via a laptop, i'll keep you posted.
Regards
Lambo
 
Making one for a given car should be pretty simple. Eg I could plug in a MAP, and datalog it for a while with the output of the AFM and the RPM. Then a bit of analysis, make a lookup table, and your done. Making it flexible for cars with dissimilar engines (ie turbos and stuff) would be a challenge. I am wondering if the one above alters the oxygen sensor input to the ECU too? That's very very tricky, and dangerous without wideband.

I am not convinced that this is a better solution than a whole new ECU. A new ECU gives you the benefit of being able to properly remap for boost. With this, you are still tricking the stock ECU. Having this thing installed still makes your car illegal anyway - anything tricking the ECU is technically illegal here.
 
Sound like a cheap microcontroller project then.
Not hard to create a lookup table.
If he needs 374 sites then a atmel AVR with a built in A/D converter (at least 9bits required) will give enough resolution and ram.
 
Zuffen,
sorry about that.
Basically you require a certain amount of resolution.
ie your map will output a voltage say 0-5volts DC.
Now the ECU is expecting to see a frequency input. The ECU has its own table which states for this frequency in I know this amount of air.

Now we need to convert the analogue voltage of the MAP sensor into a frequency. The microcontroller (atmel AVR) can do this easily.

It has a built in analogue to digital convertor (A/D) this will take in the 0-5 volts from the MAP sensor. The micro works in binary so either 0 or 1 is all it can handle (this is a single bit).
So an 8 bit device can have a 256 different numbers. ie 255 in decimal in binary is 1111 1111 it takes 8 bits to get this number. If all you needed was 3 parts then you could get away with a 2bit A/D convertor.
Binary - Decimal
00 - 0
01 - 1
10 - 2
11 - 3
For 4 sites we need to add an extra bit.
100 - 4

So the other device has a 374 sites, this splits our 0-5 volt signal into parts .0134volts each. ie part 0 is 0.0134volts part 1 is 0.0268

To get 374 different parts in binary requires at least 9 bits, 8 will only give us 256 sites.

Don't know if any of that made the slighest sense.
 
The resolution isn't linear though... there are quite a few little tricks in there.. plus in transient throttle situations you need to filter spikes and waves out of the MAP signal etc.
 
The linearity is not a problem, the lookup table will fix that. Using a table that is RPM vs MAP to give the frequency solves the problem. Same with the air temp sensor, its response is far from linear so a lookup table is used to calculate it.

Thought this may be handy if anyone is keen to make one, the GM MAP sensors output is described by these equations...
1 Bar Sensor: kPa = (0.369 x N) + 10.354
2 Bar Sensor: kPa = (0.781 x N) + 8
3 Bar Sensor: kPa = (1.23 x N) + 2.2
Where "N" is the 0-255 result of the A/D conversion.


The MAP sensor filtering is achieved in software through what’s called a first order lag filter (obviously there are other ways but this is the way most ECU's do it). What this does is calculate a value for the current MAP reading using the last value and a constant called the filter coefficient. This means that the calculated MAP reading will lag the actual reading by a percentage of the two readings (the filter coef. is the percentage) resulting in a much more stable and thus more accurate sensor reading that will ignore random spikes (the tighter the filter coef. the more stable the reading but it then becomes a trade off for sensor response time).
 
Max,
the linearity is a problem. You need very very fine resolution for this thing at each extreme, and the extremes are a long long long way apart. As noted above, at idle, the ECU is extremely sensitive to even a 1Hz difference. The output of the MAP is going to be bouncing around all over the place. Then as you near WOT, the MAP's signal becomes very very fine, and the AFM signal varies by hundreds if not thousands of Hz for a very small MAP increment. I have looked a lot at the way stock MAP ECUs work, and the problems they must be avoiding. The pulses in pressure could be a huge problem, and it would take a lot of software experimentation to fix. The AFM's design and location soak up a lot of these pulsation problems.

The reality of filtering is very very difficult. I have worked in embedded and DSP systems for quite some time... the devil is definitely in the details.

Of course, having said that, you could get it right enough first time. But then again that HKS VPC had a lot of ICs in it.
 
Group buy of ECU map

Hi Zuffen, During my phone call to Peter i did raise the question of a of a group buy and some sort of discount for bulk buying, he was quick to point out that the product was already on special to the USA market through Powerhouse, but said that he would talk to the right people to see what was possiable, so i guess we have to wait and see.From the posts since there seems to be some clever guys on our forum as far as electronics, so maybe they will come up with something,as an electronics engineer i tend to agree with Miles B that things are not always as simple to build from scratch, projects i have built over the years, tend to take much longer and there is always a Gottcha somewhere, and ultimatley i just pay up and let someone else do the R and D
I think the price is reasonable provided the product does what it claims,and the hours it takes to earn the dollars, are always much shorter than the build it from scratch option (no Time).I have not heard back from the Powerhouse guy yet, but i see they do supply harnesses for various Supras, and Peter says they are very similar to the 1uz layout

Best regards
Lambo
 
I know what your saying Miles B, nothing is as easy as first thought! This type of project is def not something that will take a couple of days to knock up, the software will be an absolute mission to get right - there would have to be a high demand for it as the hours involved would be very high to get it working properly.

You will find a look-up table will solve the linearity problem, at WOT the MAP sensor will be close to steady at 100kPa but the RPM will increase greatly and cause the point that gets looked up in the table to change at the same rate as when the MAP sensor varies close to equally with RPM (light loads) or when the MAP varies greatly and the RPM does not (idle region). The MAP sensor needs to be sampled accurately but because it is a 3D lookup table that is RPM vs MAP to give frequency the very small changes in MAP at WOT are not a problem. The picture you posted earlier shows the relationship very well, the MAP stays close to 100kPa but the RPM (say the X axis) will increase greatly causing much more airflow and hence the AFM frequency increased - the point in the table that gets looked up is going horizontally 100kPa at 1500rpm, 100kPa at 2000rpm, 100kPa at 2500rpm......and so on with obviously more resolution in RPM than that. Hard to explain in words.

As a side not a 374 point table does not require a 9 bit A/D converter, an 8 bit is fine. If you want a lookup table with 511 load points on the MAP axis then yeah 9 bits are needed, but for the 374 byte table (17x22 entries) 8 bit can be used - that means there are only 17 or 22 load points on the MAP axis in the lookup table with all other MAP readings interpolated to find the result. Not saying 9 bit wont work, but it would be a bit of over kill.

EDIT: Spelling!
 
The problem I see is that the range isn't there within the stock ecu, or fuel system to support the demands of the added airflow. What I've noticed with the ecu is that it goes into closed loop rather quickly as the airflow rises, and once the injectors are at their max cycle times, you have nothing more to tune with other than fuel pressure.
The fuel system would need to be added to for improvements in the airflow dept. as well as a fully mappable(?) set of correction values, likely different for each car,exhaust, etc.
Sounds like a new ecu to me.

I'm maxxed out at somewhere between 320 to 350 hp, and am not sure if the stock cams will support more than that anyhow.
 
OK, I've thought about this a bit, and I think it would be worth it to try making an MAF using the stock sensor in an oversize housing(or just inserted into piping like Chrisman did), slightly larger injectors, and then get the calibration using an S-AFC, or probably better w/ a SplitSecond controller.
If the injectors were to get too big, the S-AFC may not be able and get ahold of the values needed however.
I have no experience with the S-AFC; does it even have enough resolution for truly smooth tuning?
 
SCV8,

Now you're thinking like me.

If the Supra guys can go oversize (to the 1UZ-FE) AFM why can't we build a bigger AFM and do the same?
 
it is much easier and cheaper if you guys buy a microtech, cost me $900AU for a ltx8s got rid of the air flow meter and all the other limitations of the standard ecu e.g speed limit etc.
 
That's true, nothing like getting everything running right, then hitting the rev limiter.
If one were to use an MSD ignition, with a pre-set advance curve, getting away from the horrible, stock tendancy to retard the advance during shifts, you'd have one less worry, the rev limit would be nice if it were a bit higher, but without cams, there wouldn't likely be much up there.
I had thought about all this when I was using the fuel pressure to fine tune the high revs on my car, about how much better things would be if I could only adjust my Unichip/WeaponR box myself. That would allow me to swap injectors, and use a larger maf housing(tube). The nice part about my current setup, is that I can still pass smog by swapping in a bypass plug to return the car's ecu to it's own devices.

Another thing that seems all too simple; how hard would it be to create a circuit that would simulate a clamped signal at some high rpm value such that the ECU would never see the cut value, and allow infinite revs. You may even be able and create such a circuit with the additional ability to allow the cut at a higher rev.
 
You can't modify the RPM signal the engine sees. It will stop metering fuel correctly, sparks will happen at the wrong time etc etc...
 
I see, since everything is triggered from the crank sensors, how that would be a problem.
I hate stuff I can't dial in, usually find a way most of the time, however.
 
SCV8 - with your idea you are stuck on the basic premise that the ECU is "dumb" and not thinking about the speed at which it is telling the ignitors to fire, and only looking at the return signal for its algorithm to limit RPM.
All TCCS ECUs are monitoring their output to the ignitors and limiting that when the RPM limit is reached.

WIthout the ECU telling the ignitors when to fire you have no timing control... and thus BOOM.


As for this whole replacement of the airflow meter with a MAP sensor idea... its all well and good - but as state, why spend US$650 on something like this which will need tuning (thus time + $$$) and still be limited by the capabilities and uber safety style algorithms Toyota wrote into the ECU code??
An aftermarket standalone ECU does all of these things you are dreaming of, plus give complete control of ignition timing, allow for extensive modifications (forced induction etc) in its capabilities, and generally be able to do with your engine what YOU WANT (whatever that may be).

In my experience, working around the factory ECU is not ideal. There are safe-guards and controls and limitations and whatnot that you have to constantly work around that if you modify your engine more than say an exhaust and intake and mild cams you would end up with a passenger footwell FULL of add-ons, interceptors, signal converters, limiters etc etc..... all at large $ value!!!


Example:

I build a smallport 4age with a turbocharger. Simple engine, nowhere near as complex in control as the 1UZ. I decided (because i was a tightarse), that i would use the smallport 4A-GZE ecu (supercharged) as this was the SAME engine right down to cams and heads, EXCEPT for the pistons.... the 4agze uses 8.9:1 pistons and my 4age uses 10.5:1 pistons.....

So i used an Emanage to retard timing and level out fuel maps, naturally.

To get the emanage to adjust timing more than 6 degrees without the toyota ECU going into base timing protection mode... i had to CUT OFF the IGf signal from the ignitor and make a simple switching circuit that basically fed the IGt signal straight back to the ECU (so that it didnt know that the ignition timing was in fact being modified).

Then came the knock control...... the factory knock control took hold of ignition timing so ferociously that it was near impossible for my tuner to tune out any knock and get a good tune. It would get close to knock and immediately the timing would be pulled back by the 4agze ecu..... i think you get where im going with this.

If i had my time again - it would be 100% aftermarket standalone. I would have NEVER had these issues.


They are sooo worth it for a decently modified engine. Otherwise your interceptors and add-ons will do the trick for small mods.
 
You must log in or register to reply here.

Similar threads

L
Karmen Vortex Vs Hotwire
Replies
4
Views
1K
leeky
L
W
SC400 runs without Karmen Vortex meter
Replies
10
Views
3K
xirforever
X
O
Vortex AFM to MAF?
Replies
10
Views
4K
och
O


Top