paul_dezod

I have been doing a lot of tuning, side project stuff and R&D lately, and I would just like to share a few of my findings, which may help some of you. Some of this I have known for sometime, but I feel it would be a benefit to the community to provide the knowledge.

First off, I would like to say that the stock ECU is quite a different animal than I have ever depicted. The more I am working with it, the more I am learning about it. I was just thinking that I was pretty close to managing most of it's inter-working, but I was dead wrong. I am at the tip of an iceberg. Let me elaborate a touch on some stuff.

1) TPS on this car is actually measured in two fashions. Pedal positon (which is what the pedal is doing) and TPS (which is how far the plate is open on the TB). The TB plate only opens about 85% even when the pedal is floored to a 100%. You can verify this by pulling off your intake pipe and pressing the throttle down to the floor. Notice is does not open 100%.

2) Commanded AFR in closed loop and open loop is going to be very contingent upon fuel injector latency and injector offset being properly input. (this mostly applies to standalone ECUs). I have been playing with several of the Deatsch Werks injectors and found that having correct battery offsets and latency allows for better fuel control overall. So, if you can, contact the manufacturer to get this data to make your tuning life easier. (The latency part is used in the AEM FIC)

3) Cam sensor problems can arise from use of the Brian Crower cams. You will need to adjust the dowel pins closer to the sensor to ensure this does not happen. Standalone and in-line ECUs will have the most sensitivity to this. Piggybacks can be effected and everyone should take precaution when installing them. (Rob and Alex can attest to this for sure)

Side note on this one: The car will run on a stock ECU, but may not run at all on any aftermarket system. This is due to the fact that the stock ECU has adaptive strategies around the sensor failure based upon other sensor feedback and switching to a wasted spark design to band-aid the problem.

4) The stock ECU relies heavily on the primary O2 sensor. So if you are running any type of piggyback or in-line ECU this sensor's health and performance is a must to help guide in closed loop feedback and O2 skewing. So do not disconnect it (unless you want to be in open loop all the time and have a CEL for it) and make sure it works and is healthy

5) The secondary O2 sensor (which everyone seems to space out from their exhaust stream) if spaced out to prevent a cat failure code, can cause a CEL for bank 1, sensor 2 voltage errors of such. (I forgot the code ) This code will cause a few odd things to occur to the adaptives, which can alter your tune. This sensor "switches" back and forth and reads the catalyzed mixture coming out of the cat and tells how the next combustion cycle should read.

6) Knock control on the 2AZ, using the factory knock control, is always ridin the threshold of knock. It will constantly test the boundaries by adding in 1-2 degrees of timing, seeing if there is knock, then pulling it out. It's quite an active system and is always on the fly. So, make sure those ignition curves and EGTs stay in check. I have noticed that at close the MBT value of ignition timing that the ECU will still continued to test the threshold of knock and advanced until it detects detonation. The EGTs I have seen at full WOT have been around 1600 F max. This of course is dependent upon tuning, but this is running 8 PSI at 11.1:1 AFR WOT with ignition timing running around 13-15 degrees of advance.

7) Part of the stock ECU's logical path for fuel delivery and the MAF's calculations are only a small part of the logic Toyota actually input into the tC's fuel and ignition delivery. The MAF's diameter (pipe it sits in), charge temp, cam timing, lift, intake manifold volume & runner length (why some IM's have issues idling etc) etc...They are TONS of parameters that directly or indirectly effect the entire performance of the ECU and system overall. So please, keep this in mind when putting together a setup. All of the parts must work harmoniously and be taken into account for the plans and budget of the car.

The stock ECU is super smart and well equipped with that stock primary O2. It is VERY accurate. Do not be fooled!

m6ar2cel6oTC

If the factory knock sensors pushes the limit in timing then why on the piggybacks do you take timing off then?

3min3m2

If I remember correctly they pull timing in open loop normally and the ecu pushes it in closed loop.

But I know nothing compared to Paul.

cburglb34

^^^ x2

paul_dezod

I have seen values as high as 36 degrees of advance cruising on the highway and average WOT timing before any retard from us is about 22-23 degrees.

m6ar2cel6oTC

So what is timing at wot? And what should it be on full boost?

paul_dezod

Too contingent upon your setup. The AFR, the ignition timing, turbo efficiency, intercooler efficiency, fuel used, iat, coolant temp all play rolls in that answer.

cburglb34

paul send me ur car ill make 600 hp with 33degree advance at WOT 0 detonation

with a 12.5:1 afr

paul_dezod

vented window in block included free of charge?

cburglb34

only if it appears withing the first hour of tuning =] anything later and its gonna run u 200 doll hairs

paul_dezod

Chuck and Larry


For example
Cruising doing 65mph. 10% throttle, 3532RPMs we where seeing 35 degrees of advance.

Yet at 6609 RPMS, 100% TPS, we where running 24 degrees of advance. This was about 5-6 PSI at this point.

Also, our stock duty cycle on an 850cc injector, walbro 255 on a returnless system was a mere 44.7% peak

m6ar2cel6oTC

Come to Miami and tune my car Paul.

crush02342002

iTrader: (2)

fwiw im sitting on 32% idc w/850cc big reds @ 8psi with my dinky garrett t3/t4b, last time i had over 80%idc at 11psi on the same turbo. so im just guessing i got a ways to go before i reach 80% idc. still will need to raise the fuel pressure and volume at some point otherwise that 80% idc will come real quick

crush02342002

iTrader: (2)

paul what was the airflow of the turbo you guys used?

RusWolf

iTrader: (3)

As far as cams go, Paul does this mean that i need to pop my valve cover and adjust the cam to what you are saying ? or were they properly adjusted when Don installed everything there ?

3min3m2

Using my scangauge I've seen values up to 36 like u guys. Amazing really.

my06tc

iTrader: (2)

so the throttle only open at %85 at WOT, i wonder if theres a good reason for that,but i have a throttle controller that suppously open's it %100 or close to it at WOT...

paul_dezod

It was a 54 trim, .63 A/R

paul_dezod

If you are running on a Hydra and BC cams already, the air gap was already addressed Yev. We have had a few customers where their car would not start after installing cams. Since your car is already running, you have nothing to worry about.

paul_dezod

I'd be curious to see how well or at it works. I know most of those simply change the ramp of the TB opening. For example, it feels faster because at 40% throttle, it opens the plate 60%....