Any Updates?
Interest in Tuning for Boost with the Stock ECU
- Thread starter sr5guy
- Start date
Matt,
In post 77 you go into some detail about how it may be possible to get around fuel-cut/CEL when ECU sees more then 3v from the MAP sensor...and having a no-boost/boost flag to tell the ECU to reference separate "boost tables" for fuel/timing.
What does it take to get from this lovely Christmas gem you dropped to this land of tuning for boost with the stock ECU? Is this mechanism you speculated about at an early stage (post 77) still the way to go? Something else likely more-viable? What are the difficult pieces that stand between someone taking this info to a tuner knowledgeable about TunerPro and getting tuned for boost?
Thanks again.
It appears that an AEM/Honeywell 5 bar sensor will do the trick. Using this sensor will get you approximately 2.5-3 bars of range. I have yet to test this in car but it works on paper.
We confirmed 2 things at DDozier's shop in September.
#1 . The ECU will never be able to see over 2.8volts on the map sensor channel.
#2 . The ECU clips the lower end of the MAP sensor voltage and you must use a MAP sensor that doesn't go below .5 volts at full vacuum. The 4 bar map sensor we were using was around .07 volts at full vacuum and this is why couldn't get it to work
The issue is in the ECU's hard coded, un-modifiable MAP sensor volts to internal LOAD translation routine. It not only clips the upper end of the MAP voltage (~2.8volts), it also clips the lower to .5 volts. (I don't have my notes with me, so those aren't the exact #s but they're close). Here is what happens:
Engine LOAD is specified as a percentage. Engine LOAD is not direct representation of MAP sensor voltage since some filters and delta's are applied to it but for most purposes it's damn close to it. The stock load % value also translates approximately to KPA.
0% LOAD = 0 BAR / 27 inHg = .5 volts
50% LOAD = .5 BAR / 13 inHG = 1.4 volts
100% LOAD = 1 BAR (Atmosphere) = 2.8 volts
With the AEM 5 bar:
0% LOAD = 0 BAR / 27 inHg = .5 volts
50% LOAD = 1.2 BAR = 1.4 volts
100% LOAD = 2.9 BAR = 2.8 volts
There are literally 100's of parameters in the ECU and they all need to be re-scaled to match. So if a parameter was for instance, set to engage the ejection seat at 100% load (atmosphere) it now needs to be set to 48% LOAD since that is the new map sensors value for atmosphere.
The fuel, ignition and other LOAD referenced maps also need to be scaled. Depending on your preference for resolution (the stock ECU's tables are 16 LOAD x 20 RPM) you modify the load scale appropriately. This is a bit complicated to explain so I'm going to use 10 columns for simplicity's sake.... let's say you wanted to allocate 4 columns for boost.
Stock Columns:
10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100*
Add 4 Boost Columns with 5 bar sensor, tuning up to 2BAR of boost
8 | 16 | 24 | 32 | 40 | 48* | 53 | 58 | 65 | 70
Add 4 Boost Columns with 5 bar sensor, tuning up to 2.9 BAR of boost
8 | 16 | 24 | 32 | 40 | 48* | 68 | 78 | 88 | 100
*= Atmosphere
-Matt
We confirmed 2 things at DDozier's shop in September.
#1 . The ECU will never be able to see over 2.8volts on the map sensor channel.
#2 . The ECU clips the lower end of the MAP sensor voltage and you must use a MAP sensor that doesn't go below .5 volts at full vacuum. The 4 bar map sensor we were using was around .07 volts at full vacuum and this is why couldn't get it to work
The issue is in the ECU's hard coded, un-modifiable MAP sensor volts to internal LOAD translation routine. It not only clips the upper end of the MAP voltage (~2.8volts), it also clips the lower to .5 volts. (I don't have my notes with me, so those aren't the exact #s but they're close). Here is what happens:
Engine LOAD is specified as a percentage. Engine LOAD is not direct representation of MAP sensor voltage since some filters and delta's are applied to it but for most purposes it's damn close to it. The stock load % value also translates approximately to KPA.
0% LOAD = 0 BAR / 27 inHg = .5 volts
50% LOAD = .5 BAR / 13 inHG = 1.4 volts
100% LOAD = 1 BAR (Atmosphere) = 2.8 volts
With the AEM 5 bar:
0% LOAD = 0 BAR / 27 inHg = .5 volts
50% LOAD = 1.2 BAR = 1.4 volts
100% LOAD = 2.9 BAR = 2.8 volts
There are literally 100's of parameters in the ECU and they all need to be re-scaled to match. So if a parameter was for instance, set to engage the ejection seat at 100% load (atmosphere) it now needs to be set to 48% LOAD since that is the new map sensors value for atmosphere.
The fuel, ignition and other LOAD referenced maps also need to be scaled. Depending on your preference for resolution (the stock ECU's tables are 16 LOAD x 20 RPM) you modify the load scale appropriately. This is a bit complicated to explain so I'm going to use 10 columns for simplicity's sake.... let's say you wanted to allocate 4 columns for boost.
Stock Columns:
10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100*
Add 4 Boost Columns with 5 bar sensor, tuning up to 2BAR of boost
8 | 16 | 24 | 32 | 40 | 48* | 53 | 58 | 65 | 70
Add 4 Boost Columns with 5 bar sensor, tuning up to 2.9 BAR of boost
8 | 16 | 24 | 32 | 40 | 48* | 68 | 78 | 88 | 100
*= Atmosphere
-Matt
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sr5guy ... Matt
I've discovered this thread rather late in the piece, and just read it again in slow time. I'm that old school electronics engineer who did this stuff back in the 70's and 80's ... so I truly appreciate how much you've done and I really admire your work. Reverse engineering is no mean feat! If this project is part of why your new employer took you on... they've got themselves a damn good deal.
I'm contemplating what is needed from here on. Like many I'm very keen to get OEM tuning capability and real time data logging and reporting for my NSX (and anyone else who's interested)
I've just donated to Mark Mansur and will install TunerProRT as soon as the registration key arrives. I will also get the Moates Ostrich V2 emulator. Is this enough to read and compare ROM contents? If you have been using other equipment any chance you can post a parts list?
Also I imagine you have a good collection of datasheets for some of the chips on the NSX ECU board - any chance of bundling them up and sharing?
I have assembly code experience, although to be honest I'm more hardware than software. Are you prepared to share your assembly code discoveries so far?
I would enjoy developing detailed ECU circuit diagram if that proves necessary, starting with whatever you and Eddy have already. But perhaps much of this has already been done in the Legend community?
Did you ever get to the point of burning replacement 27C256 ROMs? If so where did you get the chips and EPROM burner?
(curious - why did Eddy's markup of the 'Address, Data and Chip Select Signals' diagram attached to post 94 show a 27C512? Perhaps the Legend has double the ROM capacity of NSX?)
Happy to discuss any of this by PM if appropriate, also happy to share with all and sundry
I've discovered this thread rather late in the piece, and just read it again in slow time. I'm that old school electronics engineer who did this stuff back in the 70's and 80's ... so I truly appreciate how much you've done and I really admire your work. Reverse engineering is no mean feat! If this project is part of why your new employer took you on... they've got themselves a damn good deal.
I'm contemplating what is needed from here on. Like many I'm very keen to get OEM tuning capability and real time data logging and reporting for my NSX (and anyone else who's interested)
I've just donated to Mark Mansur and will install TunerProRT as soon as the registration key arrives. I will also get the Moates Ostrich V2 emulator. Is this enough to read and compare ROM contents? If you have been using other equipment any chance you can post a parts list?
Also I imagine you have a good collection of datasheets for some of the chips on the NSX ECU board - any chance of bundling them up and sharing?
I have assembly code experience, although to be honest I'm more hardware than software. Are you prepared to share your assembly code discoveries so far?
I would enjoy developing detailed ECU circuit diagram if that proves necessary, starting with whatever you and Eddy have already. But perhaps much of this has already been done in the Legend community?
Did you ever get to the point of burning replacement 27C256 ROMs? If so where did you get the chips and EPROM burner?
(curious - why did Eddy's markup of the 'Address, Data and Chip Select Signals' diagram attached to post 94 show a 27C512? Perhaps the Legend has double the ROM capacity of NSX?)
Happy to discuss any of this by PM if appropriate, also happy to share with all and sundry
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I'm interested in same answers. The Christmas eve posting left me under the impression that with TunerProRT and the Ostrich v2 one could flash a modified BIN to stock ECU...but maybe I misunderstand and ones needs to install a ZIF socket and flashable EPROM.
Is your NSX modded in any way right now?
Let's take this 2BAR example...someone implements...gets car tuned for this, etc. I assume anytime the car sees above 70% load (all the way up to 100%) it will just use the fuel map values for 70%. So if someone a) puts a smaller pulley on a positive-displacement SC or b) cranks up or has malfunctioning regulator on a turbo or centrifugal-type SC orhappens to drive or c) exceeds boost levels tuned for in some other way...Kaboom. Right? Or does the ECU, despite not bumping up against the 2.8v limit and resulting limp mode, know in some way that things are off, or for this kind of safety does someone need to bolt on safety in some other way (some device that if it sees MAP signal greater than threshold, will send 3.5v to ECU to force it into limp mode or some other mechanism)? In more simple terms, any good/best options for re-creating this "I'm not tuned for any MAP higher than x" safety ceiling?
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I think the point of the different sensor is that it fits a greater pressure range into the existing voltage range. Thus you need to retune the ECU so that it responds as desired for the same pressures, which are now at lower voltages. And that frees up the upper end of the voltage range for pressures that exceed atmospheric.
See this wiki:
http://www.acuralegendwiki.org/index.php/G2:_FAQ:_ECU
Reply in RED
- - - Updated - - -
First questions answered above ^
This is why you choose a good tuner and/or set up your tune with a margin of error. You would always tune the last column very rich and with retarded timing. The table will read to the highest column and stay at that value if LOAD exceeds that value.
Just need a good tune and proper plan. No OEM or aftermarket system that I know of has any type of protection like that.
-Matt
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Yes definitely need to pull your current EPROM and install a 28pin socket (I don't think has to be ZIF). This is so the Ostrich emulator can be connected, and (later) re-tuned ROM inserted
I've been studying moates' related products (moates.net products for Honda/Acura) and now I'm contemplating their 2TIMER product. It piggybacks a 27SF512 chip (64K) into same socket and provides ability to switch between two programs / tunes. Looks like this will allow switching between two 32K segments (i.e. two whole tunes), where 32K is size of our standard 27C256 ROM. Also need to ensure it will sit inside our ECU box.
In any event we'll also need a EPROM burner - to program the 27SF512 chip (e.g. Moates BURN2 or others mentioned by Matt above), so we can drive the car with the new tune but without a PC in the passenger seat!
I would not consider my engine "modded", it's all stock NA1 other than RDX injectors, GTLW exhaust and Top Speed Headers, with wide band AEM O2 sensors. Although this is the FI sub-forum my interst is NA for now. FI with tuned OEM ECU is appealing down the track (maybe).
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Thanks Matt ... yet another good resource. And I'll keep an eye on your google drive for those datasheets
I completely understand why you're holding assembly code and datalogging solution close to your chest for now, but do keep us posted on any developments. I am running several other projects using Arduino (ATMEL MCU) to "instrument" my NSX. I already have RPM, GPS, O2, temperatures etc displayed on LCD, and will soon be looking into interfacing Arduino <=> Android via bluetooth so I can display output data on Android screen. Clearly an overlap here.
What do you think of using moates 2TIMER as I described above (with 27SF512) to provide quick access to 2 complete tunes ?
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I've used the Moates 2 timer a handful of times and can confirm that it works and fits within the NSX's box. I suggest a low profile socket installed in the NSX ECU. FYI: the stock 32k chip is split into 2 16K sections, low side = manual transmission, high side = automatic transmission. Only one side is ever seen by the ECU and it's selected by the absence (M/T) or presence (A/T) of R4. So, with a 64K chip you can run 4 programs if you wire and program it correctly by making duplicates of the appropriate M/T or A/T program.
The Ostrich 2 has been installed in my PCM for the last 4 years without issue and without a laptop hooked up. It has taken quite a bit of abuse, and so far the only issue I have had is with the ribbon cable wearing out due to this abuse. If you were to de-case the Ostrich you can fit it within the NSX ECU case.
-Matt
Very useful info. Is R4 the only difference between M/T and A/T ECU?
Cool, so Ostrich 2 is not just an interface to PC - it has internal flash?
I assume PCM = Programmed Control Module = ECU?
Still exploring the moates site:
Just spotted Bluetooth install for Ostrich 2. Have you tried this?
Is the EmUtility a necessary or useful tool?
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R4 is the only difference.
Never tried the bluetooth interface, IIRC they were never able to get it working.
The Ostrich is a stand alone flash module. IIRC it has a backup battery good for 20+ years.
-Matt
Matt
Back in post #44 of this thread you included a video of your test bed running NSX ECU with TurnerPro showing tracing. I'm pretty sure this was well before you got the data comms working, my question is how do you get TunerPro to show tracing without data comms and an associated ADX datastream definition file?
thanks
Back in post #44 of this thread you included a video of your test bed running NSX ECU with TurnerPro showing tracing. I'm pretty sure this was well before you got the data comms working, my question is how do you get TunerPro to show tracing without data comms and an associated ADX datastream definition file?
thanks
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Are you talking about address hit tracing with the Moates Ostrich 2.0? If so, simply press the "A" button on the table.
-Matt
Dear Matt, I hope you and your family had a good Christmas and wish you all the best for the New Year!
Do you think 2016 will be the year in which datalogging becomes possible in OBD-1 NSXs? If there's anything I can do to help like paying, being a guinea pig, etc., just let me know.
Do you think 2016 will be the year in which datalogging becomes possible in OBD-1 NSXs? If there's anything I can do to help like paying, being a guinea pig, etc., just let me know.
- Joined
- 18 March 2017
- Messages
- 3
Wasn't sure where to post this, but wanted to give a huge shout out to Sr5guy on helping with my build. So I figured, why not his tuning thread to show what he has accomplished!?
Build Specs:
91 Legend 5mt
RL C35 swap
SPEC 3+ clutch
Socketed stock ECU
Moates Ostrich Emulator
Soldered 4 pin header for tx/rx
TunerPro RT software
Vortech V5 (f-trim)
CX Racing W2A cooler
Innovate MTX-L wbo2
AEM 5 bar map
MFactory LSD
Timing Adjuster delete
RDX Injectors (resistor delete)
Dimpled stock fpr, I think it's at 50ish psi? (AEM one sprung a leak on me)
S2K electronic power steering
Walbro 255 fuel pump
93 pump gas
Anyway back to Sr5guy. I socketed and installed the Moates onto the ecu, soldered on a 4 pin header to a later model obd1 ecu (earlier models didn't have the header spot). Almost did it correctly myself, but he had to fix a broken connection from my overheating the board. Lol
As stated previously we had to use the 5bar map because of the voltage restriction built into the ecu. So a little testing to find out the MAP and AEM voltage line variance (multiplier).
To get datalogging he made some magic that I cannot explain. But we spliced in the MTX-L wbo2 into the timing Adjuster port in the ecu and just deleted the timing Adjuster altogether. If he wants to explain it he can.
Everything was stock except for the supercharger, and map sensor at this point. Fuel injectors and clutch weren't upgraded to see what the stock system could handle.
The first road tune session was a success. We were able to get the MAP sensor to read correctly (or close enough). Datalogging was working like a charm. Here's a quick vid of the day after the first tuning session.
https://youtu.be/it5PG7MMIv4
We quickly found out that the stock Injectors were not going to be enough for anything above 5psi (to be expected). And my old clutch just didn't have it in it, heh. So I put her back on stands and went to work.
RDX Injectors installed, FPR increased, resistor box deleted, and spec 2+ clutch.
On the next trip down we were able to dial in a safe tune with retarded timing. Zero knocks in the full map range. Running 14.8-15 AFR from idle to part throttle, 12.1 AFR in full throttle. Was cut a little short due to weather and me being called into work, but that's life. Was definitely impressed with his attention to detail and ability to troubleshoot on the fly. More impressed with his ability to deal with my ADD, lol. I still am running the same tune until I become more familiar with the timing tables as that is my next move. Definitely room for improvement, but until I get more miles under it and a few small things knocked out, it is still a blast.
The next weekend I came across a traveling mustang dyno in town for a local classic cruise/show. I still had clutch slip with the Spec 2+. Also had 190*+ intake temps. 5k rev limiter because it was all still fresh to me.
https://youtu.be/8jIRxPBuhC4
276.5whp/266.4wtq on a dynamometer. Which run 12-15% lower than dynojet. I was ecstatic. My original goal of 320whp on the little V5 seemed definitely attainable.
Since then I've added a 3+ clutch that finally doesn't slip. Increased rev limiter to 6500. Introduced a BOV to the atmosphere since we don't use a MAF. Installed a CXRacing water intercooler with small reservoir for now. Prototype MFactory helical LSD (first non clutch LSD for Legend ever). 235 Gmax tires (really need to invest in some legit tires next season). The next step is to go a plug colder than stock, and dial in the timing. I think with those additions 320 should be easy on the C35.
Anyway, enough about the specific build. I wish I could speak the same language as Sr5guy when it comes to the tuning capability. What I wanted to show is that he was able to do it, and it all seems to be working out rather well. Both Tuning and Datalogging were achieved on a stock ecu [emoji106][emoji106][emoji106]. Great job man, excellent work!
Sent from my iPhone using Tapatalk
Build Specs:
91 Legend 5mt
RL C35 swap
SPEC 3+ clutch
Socketed stock ECU
Moates Ostrich Emulator
Soldered 4 pin header for tx/rx
TunerPro RT software
Vortech V5 (f-trim)
CX Racing W2A cooler
Innovate MTX-L wbo2
AEM 5 bar map
MFactory LSD
Timing Adjuster delete
RDX Injectors (resistor delete)
Dimpled stock fpr, I think it's at 50ish psi? (AEM one sprung a leak on me)
S2K electronic power steering
Walbro 255 fuel pump
93 pump gas
Anyway back to Sr5guy. I socketed and installed the Moates onto the ecu, soldered on a 4 pin header to a later model obd1 ecu (earlier models didn't have the header spot). Almost did it correctly myself, but he had to fix a broken connection from my overheating the board. Lol
As stated previously we had to use the 5bar map because of the voltage restriction built into the ecu. So a little testing to find out the MAP and AEM voltage line variance (multiplier).
To get datalogging he made some magic that I cannot explain. But we spliced in the MTX-L wbo2 into the timing Adjuster port in the ecu and just deleted the timing Adjuster altogether. If he wants to explain it he can.
Everything was stock except for the supercharger, and map sensor at this point. Fuel injectors and clutch weren't upgraded to see what the stock system could handle.
The first road tune session was a success. We were able to get the MAP sensor to read correctly (or close enough). Datalogging was working like a charm. Here's a quick vid of the day after the first tuning session.
https://youtu.be/it5PG7MMIv4
We quickly found out that the stock Injectors were not going to be enough for anything above 5psi (to be expected). And my old clutch just didn't have it in it, heh. So I put her back on stands and went to work.
RDX Injectors installed, FPR increased, resistor box deleted, and spec 2+ clutch.
On the next trip down we were able to dial in a safe tune with retarded timing. Zero knocks in the full map range. Running 14.8-15 AFR from idle to part throttle, 12.1 AFR in full throttle. Was cut a little short due to weather and me being called into work, but that's life. Was definitely impressed with his attention to detail and ability to troubleshoot on the fly. More impressed with his ability to deal with my ADD, lol. I still am running the same tune until I become more familiar with the timing tables as that is my next move. Definitely room for improvement, but until I get more miles under it and a few small things knocked out, it is still a blast.
The next weekend I came across a traveling mustang dyno in town for a local classic cruise/show. I still had clutch slip with the Spec 2+. Also had 190*+ intake temps. 5k rev limiter because it was all still fresh to me.
https://youtu.be/8jIRxPBuhC4
276.5whp/266.4wtq on a dynamometer. Which run 12-15% lower than dynojet. I was ecstatic. My original goal of 320whp on the little V5 seemed definitely attainable.
Since then I've added a 3+ clutch that finally doesn't slip. Increased rev limiter to 6500. Introduced a BOV to the atmosphere since we don't use a MAF. Installed a CXRacing water intercooler with small reservoir for now. Prototype MFactory helical LSD (first non clutch LSD for Legend ever). 235 Gmax tires (really need to invest in some legit tires next season). The next step is to go a plug colder than stock, and dial in the timing. I think with those additions 320 should be easy on the C35.
Anyway, enough about the specific build. I wish I could speak the same language as Sr5guy when it comes to the tuning capability. What I wanted to show is that he was able to do it, and it all seems to be working out rather well. Both Tuning and Datalogging were achieved on a stock ecu [emoji106][emoji106][emoji106]. Great job man, excellent work!
Sent from my iPhone using Tapatalk
- Joined
- 18 March 2017
- Messages
- 3
I had a huge post with pics and a wonderful story, but I guess it either didn't post or it was deleted. Shame.
Short story. Matt was able to not only tune my Supercharged Legend, but was able to get datalogging to work also.
Great job Sr5guy!!![emoji106][emoji106][emoji106]
Sent from my iPhone using Tapatalk
Short story. Matt was able to not only tune my Supercharged Legend, but was able to get datalogging to work also.
Great job Sr5guy!!![emoji106][emoji106][emoji106]
Sent from my iPhone using Tapatalk
A little confused why not just use a proven aftermarket ecu such as aem....considering the cost of a potential mistake, at least with an nsx
