3P's TCCS Disassembly/Analysis

Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
Yes. I have a few modified ECUs out with beta testers. Have made good progress fixing issues uncovered by them. Have also put together a complete model of the fuel calculations which has allowed us to modify the stock program for the Lexus AFM/550 injector to retain the original ignition timing and fuel enrichment. More to come.
 

73tlc3fe

New Member
Aug 3, 2011
4
0
0
Southport, NC
3p141592654;1911873 said:
I do not have any more reader boards available. The design files are available on Assembla for this board, and you can have dorkbots make it for you fairly cheaply. Alternatively, you can desolder the MCU chip and send it to me and I can read out the code for you.

I was able to find a spare ECU, is this offer still open?
 
Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
Was able to read the code in an ECU from France and found it to be mostly identical to USDM code, except for ignition timing which is significantly more advanced for low load/low rpm region. Likely due to higher minimum fuel octane (92 vs 87 AKI). Plots are show below comparing the two.

US Ignition Map
Imageus.jpg

EU Ignition Map
Imageeu.jpg

Difference between EU and US
Image3.jpg
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
Lots of progress over all. Very stable hardware and firmware. Just Peeling back the layers on all the math Toyo used to make a+b=c. Lots of variables!
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
2,477
0
0
Perkasie, PA
I know how that can be. I strongly suggest the algebrator. It saved me boatloads of time while completing the ME degree. Short of calc and above it will handle everything you throw at it.

Sent from my SAMSUNG-SGH-I337 using Tapatalk
 

Rollus

New Member
Jun 2, 2011
593
0
0
Paris, France
3p141592654;1982410 said:
Was able to read the code in an ECU from France and found it to be mostly identical to USDM code, except for ignition timing which is significantly more advanced for low load/low rpm region. Likely due to higher minimum fuel octane (92 vs 87 AKI). Plots are show below comparing the two.

Good job, and "vive la France" :p

BTW, maybe it as something to do with turbo spool instead of knock? (even if I propose knock first, I can't stop thinking :))
I mean, is EU more advanced or US more retarded? (speaking of ignition obviously..)

Have a nice time

Reynald
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
Jon is the human form of an algebrator. If only he had more ram..

The EU map has more timing advance. Do you guys have emissions in France?

That area is the cruise, and light load region. The changes in timing on the low end make a noticeable difference in throttle response and take off. Observed through a manual trans. 7m loves timing. The JDM knock retard may offer some insight..i hope
 

Nick M

Black Rifles Matter
Sep 9, 2005
8,871
37
48
U.S.
www.ebay.com
3p141592654;1959897 said:
Yes. I have a few modified ECUs out with beta testers. Have made good progress fixing issues uncovered by them. Have also put together a complete model of the fuel calculations which has allowed us to modify the stock program for the Lexus AFM/550 injector to retain the original ignition timing and fuel enrichment. More to come.

What about raising the threshold for "abnormal turbocharger pressure", to match the 550's. I would like to screw in the adjustment on the Lex meter further. I have not kept up on all of your 630 pages.
 
Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
An interesting question that I have been working on recently. The current fuel cut happens to coincide with 100% injector duty cycle at 6500 rpm.

That means raising the fuel cut is only going to create a lean-out at redline, assuming you can actually hit 100% VE at 6500 rpm. My guess is that is unlikely with most setups. I guess you could back off on the enrichment a bit at redline to buy back some margin. Also, the auto tranny shifts around 5500 rpm so people with them can raise fuel cut a little and stay out of (theoretical) trouble.