Mazda Rotary Club

Anyone do their own tuning? There\'s a fairly big DIY scene in the states, but I\'ve not seen anyone on the forums here talking about it. I\'ve got a fair bit of experience myself, having worked on a few of my cars and mapped a few project cars for other people. I\'ve done a couple of MK1 MR2\'s, an E30 BMW drift car with a 2.7 turbo engine (300bhp) and a 2.0 T28 turbo scirocco (280 bhp + nitrous) running high 12\'s on the strip.
I\'m going to do the tuning on my forthcoming FD track project, and while I could talk to the guys in the states, it would be nice to get something going here.

Ian

Me and DaveHG do quite a bit of mapping using Datalogit on the Apexi PowerFC, there are a couple of others on here doing the same

I\'ve just started dabbling in this, all be it with a piggy back unit (emanage) so I am starting with someone elses work as a base, but finding information is as much or more of a chore than actually getting the laptop connected and tweaking the tables.
 
As you say, there\'s much more info on the forums abroad - US and AUS sites - about how to get started and for advice.  Might be nice to get something started here.

I am using a PFC and Datalogit, together with a Innovative LC1 wideband and Excell spreadsheet for AFR tuning.


I have a bunch of maps (search rx7club.com for member \'hwnd\') to compare with and use base maps.

I also have the Chuck westbrook tuning notes which are pretty handy to get to understand all the different features and their use

Quote from: Speedworks;617215I am using a PFC and Datalogit, together with a Innovative LC1 wideband and Excell spreadsheet for AFR tuning.
 
 
I have a bunch of maps (search rx7club.com for member \'hwnd\') to compare with and use base maps.
 
I also have the Chuck westbrook tuning notes which are pretty handy to get to understand all the different features and their use

I found 2 good discussion threads - one on timing and one on AFR\'s for rotary\'s - which I printed out - can\'t remember if that was on RX7club.com or one of the other FC sites, but ironically I found them whilst browsing the rx8club.com for emanage info.  I\'ll dig out the papers tonight and post the links up - some good reading.

Quote from: Prof;617222I\'ll dig out the papers tonight and post the links up - some good reading.

Please do, ive always wondered how this mapping stuff works :D

I\'ll be doing mine once I\'ve finished building it. Will be calling Blitzboy for help ;)

Excellent, we\'ve got a few then :) I looked into the datalogit option, but it\'s fairly pricey compared to the plain old serial cable I use with the megasquirt. What\'s the tuning interface like with the datalogit? Do you get a 3d graphical representation, or just the figures?
I\'ll have a look at maps later on and the papers once prof posts them - thanks for the info. I\'m really interested in the spark advance table for the rotary, and how its needs differ from a piston engine. Fuel mapping\'s always a breeze with a wideband anyway, and once the timing\'s right I never find it takes very long. I have a techedge WB myself, which I built from a kit.
I\'ve got no experience on the rotary yet, but if I can help anyone with general tuning info I\'d be happy to pass on what I know.

ok,
 
found the docs, they are on an FC3S site, but the timing is applicable to FB / FC / FD and even the RX8.
 
This one is for timing:
 
http://forum.teamfc3s.org/showthread.php?t=41915
 
This one is for AFR\'s:
 
http://forum.teamfc3s.org/showthread.php?t=38317
 
I\'ve some other bits and bobs somewhere as well, but these 2 are a good place to start.

Can this thread be made into a sticky hopefully there will be some valuable info as the thread progresses

I\'ll sticky and move to engine and tech section Lee.

Cheers Kev

Could you leave the timing map alone with say street port , single turbo and power fc and just do a/f ?

The timing will come from a base map - which will be enough to get the car running before it goes to a tuner to be mapped properley.  If you\'re doing the tuning yourself then you\'ll probably need to make changes to the timing.  The thing is, changes you make to timing will affect AFR\'s and vice versa - so you\'ll almost certainly end up needing to make some adjustments.
 
It could be something silly like the plug types you use - may require more advance or retard to run smoothly.
 
The stock ECU I am using is chipped and has very different timing maps to the stock ECU I had before.  I\'ve run both with the eManage so that I could see what the differences were.
 
The chipped ECU has considerably less split (between leading and trailing plugs) in the non boost part of the map which gives much better response low down in the map.  It pushes the advance out as far as is safe when off boost, then quickly pulls timing back as boost is made.  About the only changes I had to make to the timing were a little bit more retarded towards the top end of boost in the mid revs, as that\'s where the most likelyhood of knock will be.
 
I am guessing that a base map will not be optimised for your particular engine so it would pay to set that up first, then once done you can sort out AFR\'s for best power with safety.  Timing will not be as advanced as it could be, and that\'s for safety.  So if you want the most power and torque from the engine then you\'ll need to do the timing.

Quote from: Prof;617492The timing will come from a base map - which will be enough to get the car running before it goes to a tuner to be mapped properley. If you\'re doing the tuning yourself then you\'ll probably need to make changes to the timing. The thing is, changes you make to timing will affect AFR\'s and vice versa - so you\'ll almost certainly end up needing to make some adjustments.
 
It could be something silly like the plug types you use - may require more advance or retard to run smoothly.
 
The stock ECU I am using is chipped and has very different timing maps to the stock ECU I had before. I\'ve run both with the eManage so that I could see what the differences were.
 
The chipped ECU has considerably less split (between leading and trailing plugs) in the non boost part of the map which gives much better response low down in the map. It pushes the advance out as far as is safe when off boost, then quickly pulls timing back as boost is made. About the only changes I had to make to the timing were a little bit more retarded towards the top end of boost in the mid revs, as that\'s where the most likelyhood of knock will be.
 
I am guessing that a base map will not be optimised for your particular engine so it would pay to set that up first, then once done you can sort out AFR\'s for best power with safety. Timing will not be as advanced as it could be, and that\'s for safety. So if you want the most power and torque from the engine then you\'ll need to do the timing.

 i did get a map from rx7club which takes you through the pfc with a datalogic and using a wideband on a to4e tubby,he said that hes not going for as much power as he can get so is leaving the ign map as it comes on the pfc and just doing the a/f ,so what hes doing isnt safe or healthy for a good map ?

I don\'t know how good the timing maps are on the basemaps for PFC - I think if you\'ve got a basemap for most of the same mods it\'s going to get you close, but even a little bit out on timing makes the engine quite unresponsive and if it\'s advanced rather than retarded it could land you in trouble :(
 
At the very least make sure the timing at idle is set correctly as per the service manual - at least you\'ll not the starting point is spot on.

this is a really interesting thread, ive always wanted to get into mapping but dont have a clue at mo and dont really know where to start, great thread guys :Thumbsup!

hopefully some of the more experienced guys can chip in with some info to help us less experienced guys

yep would be great :yes

I\'ll do my best with what I know.

Lets start with timing:
We have a matrix with RPM on the X axis, and manifold pressure on the Y axis. I believe the apexi has a 20x20 map, but my example uses 12x12. In the screen grab below the RPM is represented as usual, and manilfold pressure pressure is represented in KPa, or Kilo-Pascals. 0 being a complete vacuum, and 100 being atmospheric pressure (or thereabouts) Anything about 100 is obviously boost, which you\'re probably used to seeing stated in bar. Bar uses the same units as KPa, but is normally stated as pressure above atmospheric. So running .8 bar boost will give 180 KPa.
In our map below, (from the \'rocco turbo btw) the figure in each of the bins represents ignition advance. It\'s that simple. So the idle area of the map is in the bottom left, at low RPM and KPa. We don\'t need much advance here. Moving to the right you\'ll see the cruising area. Here you\'ll see that we\'re building advance quite rapidly up to 3000 rpm. After this we level off the advance through to peak torque, then add maybe a couple of degrees after that up to redline. Moving up the map towards atmospheric, or full throttle on an NA, and the \'transistion\' area on a turbo, you\'ll see that that we lose some advance overall, but we keep roughly the same curve up and down the RPM. Moving into the boost area, we lose timing fairly rapidly. THis is dependant upon compression ratio, combustion chamber shape, and a whole bunch of other factors I won\'t go into now. You\'ll find some great info on making a good base ignition map for the rotary in the posts Prof gave us earlier.

As it goes there\'s no black magic or voodoo here yet. The trick is obviously what to put in the bins, but the rules are fairly simple once you get to grips with them!
The megasquirt tuning software also gives us another neat way of changing the map. You can get it to generate a 3D map, with advance on the Z axis. The little red X can be navigated around the bins with the arrow keys, and the advance value can be modified up or down with the Q and W keys, and when running a green blow moves around the map with RPM and load, so you can tune realtime. I\'ve no idea if the apexi software gives you something like that though. Maybe someone can shed some light here?
I\'ll cover fuelling tomorrow when I get some time.

great info, my boost controller reads in kpa, i just let my mapper set it up, i never bothered touching it as i dont understand it

Thanks. Lol, just realised how many typo\'s I made, and can\'t edit them now. Sorry about that!

Quote from: Prof;617759I don\'t know how good the timing maps are on the basemaps for PFC - I think if you\'ve got a basemap for most of the same mods it\'s going to get you close, but even a little bit out on timing makes the engine quite unresponsive and if it\'s advanced rather than retarded it could land you in trouble :(
 
At the very least make sure the timing at idle is set correctly as per the service manual - at least you\'ll not the starting point is spot on.

cheers prof i will try and find the thread its got a complete apexi guide with a datalogic

Hi Ian link for the Megasquirt forum on the US rotary site
http://www.rx7club.com/forumdisplay.php?f=153

Thanks, I haven\'t been on there for a while and it looks like there\'s some interesting stuff going on. Anyone here played with Megasquirt? I think that\'s the way I\'ll go for my project, but I\'d like to see what the Apexi or Emanage are like to tune. Would any of you guys who have the software and live reasonably close mind letting me have a quick look over it sometime?

So, belatedly on to fuelling. On the FD we have a MAP (Manifold Absolute Pressure) sensor for measing airflow into the engine. It doesn\'t do this directly - we have to tell the ECU how much air is flowing at a given RPM and manifold pressure, and we do this by building a map. Just like the spark advance table, we have a Volumetric Efficiency (VE from here on) table which is used for calculating how much fuel to inject.

Cribbed from Wikipedia: "Volumetric efficiency in internal combustion engine design refers to the efficiency with which the engine can move the charge into and out of the cylinders. More correctly, volumetric efficiency is a ratio (or percentage) of what volume of fuel and air actually enters the cylinder during induction to the actual capacity of the cylinder under static conditions. Therefore, those engines that can create higher induction manifold pressures - above ambient - will have efficiencies greater than 100%."

So, to walk through the fuel map as we would when \'mapping\'...
Starting at idle makes most sense, so we\'re in the bottom left of the map. Low RPM and low manifold pressure - the throttle will be shut and the engine has to work hard to move air through the tiny gap left past the butterflies, and we\'re left with a partial vacuum in the cylinders, or chambers in our case, and hence a low volumetric eficiency. It depends on the engine - compression, porting, air cleaner, exhaust and even ignition timing all have a big part to play in determining the VE. Still, a low value here is sensible.

On to the no load range of the map. A slight crack open of the throttle and we\'ll start to build RPM. Volumetric efficiency won\'t be much more so the map will remain fairly flat as we move up the rev range, but will increase slightly if the throttle is opened more.

Time to give it some load. We\'ll look at the cruising area of the map next. This means 2500 - 4000 RPM and low to medium pressure. You won\'t find the VE increases much with RPM under cruise, but the VE map will start to ramp up sightly as the pressure builds towards atmospheric.

The fun part is always Wide Open Throttle. On an NA motor it\'s pretty simple - WOT yields 100KPa, and close to, but not neccesarily complete cylinder filling - 100% VE - and this will be the highest line on your map. Generally you\'ll find it increasing with RPM up to peak torque, and might drop off a little after that.

On a turbo motor it\'s a little more tricky. The 100KPa line is called the transition area - the point at which you actually start making boost. The volumetric efficiency obviously ramps up from here as we\'re pushing more air in than you\'d get if it was at atmospheric pressure. More boost = more air = higher VE.

So, the great question is, how the hell do I know what the volemetric efficiency is to start filling in the bins??? The answer is a wideband lambda sensor. If the lambda is showing lean (greater than 14.7:1) then you\'ve got too low a value in that area of he map, and you\'ll need to increase it. Too rich, and you\'ve overestimated cylinder filling and you\'ll need to lower that part of the map.

I should mention here that target Air Fuel Ratios (AFR) will be different for the vairious parts of the map I\'ve listed above. At idle and cruise you\'ll want to keep it pretty lean for good fuel consumption, so look for the magic 14.7. Some engine will run leaner, others won\'t run lean at all and you\'ll have to keep it slightly rich to keep it smooth. Under higher load up to 100KPa look to make it richer, maybe down to 13 or 12.5 - this is where you\'ll get best power. Under boost I normally go for 12 to 11. Any more and you\'re just wasting fuel. Further than 9.5 will yield a massive cloud of black smoke! If you have to run this rich under boost to stop detonation something else is wrong. Don\'t get tempted to use the fuelling as a band aid for other problems.

I should mention over-run too. Coming down form high RPM with throttle shut will yield the lowest manifold vacuum and lowest VE. If you fancy some lovey pops on over-run, aim for over 16:1 above 3000RPM. Trust me, it\'s good. Th E30 drift car has a straight-through side exit exhaust, and convincingly scares the bejezus out of anyone lucky enough to be on that side of the car. It\'s like a shotgun going off. Looks mighty impressive at night too :Giggle

good write up there Ian

Quote from: ianelvar;618251Thanks, I haven\'t been on there for a while and it looks like there\'s some interesting stuff going on. Anyone here played with Megasquirt? I think that\'s the way I\'ll go for my project, but I\'d like to see what the Apexi or Emanage are like to tune. Would any of you guys who have the software and live reasonably close mind letting me have a quick look over it sometime?

If you are coming to RS6 I can let you have a look at the Emanage stuff. :Thumbs-up
 
If not, you\'re not so far away.
 
The biggest issue with the Emanage is finding out what you\'ve got in the stock or chipped ECU - as you can only tune on top of that as a starting point. Getting a log of the ECU before making changes let\'s you see what the ECU is doing as regards timing and fuelling - and then you can tweak the maps about a bit to compensate for the modifications made.
 
Because of that, you pretty much have to get things logged and build replacement maps for stuff like the airflow meter before you take them off, so using an Emanage on a peripheral port will be virtually impossible without some big guess work. To use it on a street or bridge ported motor where you can take off the AFM once you\'ve built a replacement map is more doable, and the map\'s available will allow a wide range of adjustments to be made allowing for quite a lot more boost or using a MAP sensor for speed density tuning for instance.
 
I tried the AFM replacement and whilst it ran reasonably well, the car was always a little lumpy compared to running with the AFM - a lot of that is down to the more accurate fuel metering at low air flow volumes (where the AFM is changing it\'s signal the most). It would also appear from some research I\'m doing into replacing the AFM with a MAF (hotwire) type sensor, that the overswing of the cone/flapper in the AFM is used to provide enrichment during rapid acceleration - it\'s not possible to do that with the AFM replacement map, so that leaves you having to use the table in the Emanage provided for that.
 
My plan is to program a little PIC microcontroller to spot the rapid Aiflow change and temporarily spike the output signal, where it would normaly just provide a straight lookup from the MAF signal output and translate to the expected voltage from the AFM.
 
That would leave the only other problem being the air temperature compensation. The stock AFM has a thermistor to let the ECU know how hot the air is so it can calculate air mass. The hotwire sensor adjusts it\'s output automatically for air temp - colder air is more dense and cools the wire more. The big question is would the MAF provide the correct adjust ment if a fixed resistor were used to let the stock ECU assume the temp was say 20 C - or would the air temp need sampling as well to provide additional correction - these are unknowns at the mo ;)

Thanks, I hope it\'s informative.

Cheers Prof, but I can\'t make RS6 unfortunately, already booked up :( Would be good to meet up sometime though, they\'re some interesting ideas you\'ve got. I\'ll give you a rundown of the MS stuff too if you want.
What do they give you on the Emanage for acceleration enrichments? Megasquirt uses the TPS, and you just have to set up an injector pulse addition for 5 x volts/microsecond bins. Implementing that in a PIC should be pretty easy though.
The hot wire idea is particularly intriguing. I\'m tempted to say that running a fixed resistor to lock the temp signal would work fine with the self compensating nature of the hot wire system.
A trick I\'ve used on MAP systems with lumpy idle vacuum (throttle bodies) was to add a little canister before the sensor. It averages the vac a bit and makes it much more manageable. Doesn\'t help if you\'re not making much vacuum in the first place though ;) What setup are you running?

Emanage enrichment map uses Throttle opening % against RPM, and then has a seperate time to decrease row (back to standard map) along the bottom (default 20ms).
 
The engine makes about -0.5 ~ -0.7 BAR of Vac according to the gauge (on idle), but I think the issue is that the 3 BAR sensor is only operating over 1/3 of it\'s range in the vacuum part of the map, whereas the AFM covers 70% of it\'s voltage swing in that area of the map, with the top end of boost resulting in hardly much change in AFM signal - in fact the stock AFM bottoms out at around 11 psi - so additional fuelling has to be done on the MAP sensor from then on.
 
As for the hotwire trick - I am going to try a fixed resistor first, but will run with both AFM and MAF on a dyno to get the table setup, then I can just change the plumbing over - slap in my little PIC box and it should work straight off (famous last words).  I\'m hoping for slightly crisper throttle response and spool up from the turbo.

i have pretty much 0% understanding on mapping but just wondering, when you map a car. how do u map it for say when you doing 100+ mph?
ie, is the map based on the rev range unloaded and loaded or does the speed play a factor with the map?

sorry if its a really dumb question!
just thinking if u map on the road you cant really take the car to 130+mph to map it lol

Quote from: L18M;627377i have pretty much 0% understanding on mapping but just wondering, when you map a car. how do u map it for say when you doing 100+ mph?
ie, is the map based on the rev range unloaded and loaded or does the speed play a factor with the map?
 
sorry if its a really dumb question!
just thinking if u map on the road you cant really take the car to 130+mph to map it lol

It\'s not a dumb question.
 
Clearly the top parts of the rev range and higher gears really need to be done on the dyno - where you can do any speed you like.
 
You tend to hit higher boost in higher gears anyway, as there is more load on the car from drag and wind resistance.  However, you can get a fairly good tune in 3rd gear pulls up steep hills and then tweak it on a dyno later.  As long as you tune conservatively - so keep it on the rich side of safe, and check your boost controller for spikes by checking peak boost reached after any \'ragging it\' runs.
 
The other thing a dyno will let you do is sit at given RPM or boost for as long as you want - not possible to do that on the road.

Anyone already tried to remap the stock ecu.? maybe if we gather knowledge we can find the correct maps/value in the bin and then the need for a piggyback or standalone is gone..
 
I\'ve readout a tuned ROM, and asked Prof for a original file, so I can spot the differences..
 
the main problem is I do not have experience with these 8 bit FC ecu\'s, so I do not know the factors used in these maps and the axis locations, as I usally map 16 bit Bosch diesel ecu\'s for VAG TDI\'s (msa15, edc15 & edc16), and I have little experience with petrol ecu\'s, altough I know the principles of the working of these engines quite well..
 
(http://users.telenet.be/rub87/rest/fc.jpg)
 
Here you see some of the changes made in the maps..

That\'s definately worth a go I reckon. I\'ve got a spare jap spec ECU I can pull apart, so I\'ll have a look. I just found this from a quick google search: http://www.16paws.com/ECU/index.html
I might get in contact with the guy to see how he\'s getting on.

I got also a N374 RE-Amemiya C-type ecu, when you plug it in car with oem boost control system it settles nice at .8 bar midrange and tapering off towards redline, this is a feature the other remapped ecu I have doesn\'t do, so with those you need to run a separate boostcontroller..
 
Altough it seems the RE-Ameiya ecu is the superior ecu, it is much more responsive off boost, and seems to have more torque with equal boost..
 
Too bad the eprom is epoxied on the board :/

Interesting. Epoxied chip doesn\'t have to be a problem. I do a lot of work with surface mount EEPROM where I just mount a chip clip on top and read it while in the board. I\'ll have a quick look inside my spare and see what I can come up with, then maybe we can start comparing ROM images

I tried to read it thru the backside of the board, so I slided a socket on there and that in the eprom reader but the file doesn\'t seemed like correct at all :/ can it be that it\'s corrupt because of reading it on the board? a bad connection is also a ....bility as it used to be covered in epoxy too on that side :D

I wonder if it\'s possible to make a daughter board using a surface mount pic that would replace the processor and ROM, as long it has the same inputs/outputs to the logic board, you can then provide facilities like USB connection or serial port direct to the board, so you\'ve got programmability.  I presume some of the ROM space is just tables, and some is code - might have another look at my spare ECU and see what\'s possible to achieve.
 
The other posibility is to replace the digital board outright - as all the ECU sockets are on the analog board :)  This would make the choice for processors quite wide.
 
I like what that guy\'s done with the ECU tester - that was something else :Thumbs-up  
 
Give the A to D chip is 16 channels but 8 bit (256 values), the tables can not be bigger than 256 cells.  Quite likely they are smaller.
 
Just out of interest Ruben, what was that software that displays the mapping tables.  I presume were are looking at timing, but what\'s the other table ?

i cant see the web page that you linked to prof
it just says ip banned and when i click contact administrator it brings up a program that i cant use does anyone have the email address for the admin of the site??

Quote from: stocky;628164i cant see the web page that you linked to prof
it just says ip banned and when i click contact administrator it brings up a program that i cant use does anyone have the email address for the admin of the site??

The links on the FC3S site ?

Quote from: Prof;628161I wonder if it\'s possible to make a daughter board using a surface mount pic that would replace the processor and ROM, as long it has the same inputs/outputs to the logic board, you can then provide facilities like USB connection or serial port direct to the board, so you\'ve got programmability. I presume some of the ROM space is just tables, and some is code - might have another look at my spare ECU and see what\'s possible to achieve.
 
The other posibility is to replace the digital board outright - as all the ECU sockets are on the analog board :) This would make the choice for processors quite wide.
 
I like what that guy\'s done with the ECU tester - that was something else :Thumbs-up
 
Give the A to D chip is 16 channels but 8 bit (256 values), the tables can not be bigger than 256 cells. Quite likely they are smaller.
 
Just out of interest Ruben, what was that software that displays the mapping tables. I presume were are looking at timing, but what\'s the other table ?

I think those 2 upper ones are timing, trailing/leading, and the others are probaly fueling related.., problem are the factors/offset with these 8 bit ecu\'s, this is much less of a problem with 16bit ecu\'s and when you have to possibility to log every in/output
 
I use winols to work with the bin\'s..
 
a good way to learn things is when you have a emulator, so you can view in realtime the places where the data is being read, like for instance you can do with motec ecu\'s and probaly most of the standalone\'s, and have the possibility to change data in realtime
 
anyone has a 27(c)256. emulator.. prof..? :)

Just starting to have a look round my current map using datalogit with pfc. Im completely new to this so bare with me. the pfc uses a 20x20 screen the horizontal numbers being rpm which is fine got to grips with that. What im trying to understand is what values the vertical numbers represent.I presume these values will change dependant on how much boost you are running but for example if you were running 1 bar what would these values represent.

Quote from: Rub87;628169I think those 2 upper ones are timing, trailing/leading, and the others are probaly fueling related.., problem are the factors/offset with these 8 bit ecu\'s, this is much less of a problem with 16bit ecu\'s and when you have to possibility to log every in/output
 
I use winols to work with the bin\'s..
 
a good way to learn things is when you have a emulator, so you can view in realtime the places where the data is being read, like for instance you can do with motec ecu\'s and probaly most of the standalone\'s, and have the possibility to change data in realtime
 
anyone has a 27(c)256. emulator.. prof..? :)

I built the 27256 Eprom emulator in Elektor -  but the board is quite large and it\'s loaded via rs232 - I am looking to find a usb based eprom emulator that has a footprint not much larger than the eprom chip, that would be the ideal tool for this sort of job.
 
I\'m interested in any feedback from folk who have built and or used either the Megasquirt or VEMS ECU\'s on a rotary engine.  In particular any issues that you had.

Quote from: lee mills;631479Just starting to have a look round my current map using datalogit with pfc. Im completely new to this so bare with me. the pfc uses a 20x20 screen the horizontal numbers being rpm which is fine got to grips with that. What im trying to understand is what values the vertical numbers represent.I presume these values will change dependant on how much boost you are running but for example if you were running 1 bar what would these values represent.

Have a quick look here bud, page 14 deals with fueling. They represent manifold pressure, and via some clever calculation, air flow. The post I made a couple of weeks back on fueling should give you a bit more info, but I think the apexi has the axis swapped compared to the system I use.

http://www.mazdarotaryclub.com/general/apeximanuals/RX7Tuning.pdf

Quote from: Prof;631508I built the 27256 Eprom emulator in Elektor -  but the board is quite large and it\'s loaded via rs232 - I am looking to find a usb based eprom emulator that has a footprint not much larger than the eprom chip, that would be the ideal tool for this sort of job.
 
I\'m interested in any feedback from folk who have built and or used either the Megasquirt or VEMS ECU\'s on a rotary engine.  In particular any issues that you had.

I\'ve found a few schematics for emulators. None of them look hard to build, and all work off a parallel port.
I\'ve also found a few commercial products, but they\'re expensive and no smaller than the DIY versions, and all have a ribbon cable from the box to the \'chip\' connector. I can make up one of the circuits given time though.
If you want it really small it\'d have to be SMT, and that\'s no so easy though.

Quote from: ianelvar;631866I\'ve found a few schematics for emulators. None of them look hard to build, and all work off a parallel port.
I\'ve also found a few commercial products, but they\'re expensive and no smaller than the DIY versions, and all have a ribbon cable from the box to the \'chip\' connector. I can make up one of the circuits given time though.
If you want it really small it\'d have to be SMT, and that\'s no so easy though.

I remember seeing a device in one of the electronic magazines - it was about the same footprint as a 28 or 32 pin chip but a bit taller - and had a USB connector on it.  Can\'t seem to find it now.

This?: http://www.progshop.com/shop/epromemulator/emulator.html

is there any software in which you can see which parts of the bin are actually used by the ecu?

Quote from: Rub87;631885is there any software in which you can see which parts of the bin are actually used by the ecu?

If you can find a dissassembler for the DSP that\'s used in the ECU - you can dissassemble it - some of the dissassemblers are able to work out which is code and what is probably tables (based on it not making sense as code) and will give you some assembler output with labels and such.
 
I didn\'t find much on it - and it\'s not the same as the S4 ECU\'s either - so that excellent link on 16 paws site doesn\'t give us much info - except perhaps the algorithms used for fuelling and timing.

you don\'t need to idssabemtle the file, it works like this
 
you look at the file, you\'ll find most of the mapping as I showed in some pics, then you mark those in the file, then you load the file in the emulator, then when an adress is read by the ecu it is marked in the hexdump, so where you marked the maps in, this way you can easily find the axis value etc
 
I once used an OLS300 emulator from a friend with winols, you can trace live in the maps/file where data is being read, and make on the fly adjustments with engine running

What sort of RPM and AFR\'s have you got yours idleing at BlitzBoy and with what size injectors?

great thread :) ive been looking at tuning my car in the near future once ive got some more knowledge on it, i found this online if anybody is interested.
http://http://www.innovatemotorsports.com/resources/FCedit_tutorial.pdf

I cant get your link to work, but i bought an innovate guage, and a DIYPNP for a S5 13bt.
 
I\'ll be using tunerstudio which has AFR/VE seek for fine tuning - will let you know how I get on.

ok, doesnt work my end neither, ill tell you how i found it instead :) on google search engine type in tuning with a power fc, should be the 4th one down ,pdf file

http://www.innovatemotorsports.com/resources/FCedit_tutorial.pdf
Thats the link

I haven\'t read through the whole thread but, I have always done my own mapping. Usually tune on the street, but have used dyno before. I prefer street tuning as it puts more load on the engine and allows you to tune cruise maps.

Right now I\'m running datalogit + PFC + lc1. I\'m tuned up to 24 psi with water injection on pump fuel. My general rules in tuning rotary is keep it conservative and let the boost make the power.

Leading timing should be under 15* at 15 psi (1 bar)

Split under boost is between 8-15* split depending on where in the map I\'m at. Vacuum is 0 split and idle is -12 split (negative)

AFR\'s are 10.8:1 - 11.3:1 from 24psi down to 15 psi, below 10 psi they are 12:1, vacuum cruise is 16:1 low speed cruise under 50 mph is 14.7:1 and idle is 13:1

I haven\'t had the car dynoed but it\'s in the 525-550 RWHP area, smokes the tires in 1st 2nd 3rd and 4th gear at over 120 mph.

What are the effects of negative split at idle? I will be mapping my first rotary soon, it\'s a renesis 6port we put into a miata for circuit racing.. it\'s is running on a MS2, and I will try to keep the "3 stage" inlet manifold operational to maximize area under the curve.. I have a good idea about a starting point for afr\'s, but little about what timing/split I should run..
 
I plan on running around 12:1 at WOT, and around 13:1 or a little leaner at light load, but the engine will spend 90% of the time on full load or no load..

Just makes the idle smoother on some setups. I\'ve only tuned turbo rotaries so I have no ideal whats ideal for NA engines. The dyno is the best way to figure that out.

Anyone got any more insight into trailing split settings? Especially those at 100kpa / 0psi / WOT n/a kinda range.

I\'m fairly happy I\'ve got my leading timing fairly well sorted and my AFRs. I\'m running an n/a s4 FC engine on stock ports with full exhaust, basic throttle body mods and a megasquirt ECU.

Idling at ~16 BTDC & 14.7:1.

Light cruise/ high vaccum at ~20 BTDC from 1.5k through ~30 BTDC at 4k to redline & 16:1

Normal cruise at ~22 BTDC at 1.5k through ~28 BTDC at 4k to reline &14.7:1

WOT at ~22 BTDC at 1.5k, up to 25 BTDC at 3k through 5k, then leading up to 27 BTDC at 7k & ~13.3-13.0:1 across the range.

Can post screenshots of my maps, inc trailing split, later but thought that would give a vauge idea of my approach.

But I\'ve just used the megasquirt base settings for trailing split and not touched it. This is where my rotary knowledge fails me a little. How much do I stand to gain/loose with trailing split tuning? Any tips on the basics from which I can experiment? and finally how \'dangerous\' is tuning the trailing split? as in if I were to experiment with it, how likely am I to cause det/other problems and ruin my engine :P

Hello chap. Sounds like you\'re heading in the right direction. If I remember correctly, running with less split has a similar effect to advancing the lead timing. There\'s a massive write up on rx7club.com that gets really technical. It will answer all your questions if you can find it. Good luck! Will post if I do find it.

http://www.rx7club.com/showthread.php?t=809261

I don\'t think this is the thread, but I remember now that BDC is the guy to look for posts from. He really knows his stuff. Again, good luck dude

This is what I know from tuning with the emanage and looking at other peoples data (try teamfc3s for some good writeups on timing and afr\'s - there\'s 2 threads in particular on there which are long runners and include input from people like BDC, Judge Ito, Dragon (Ross?) and others that explain the timing quite well).
 
Seems that you can have virtually no split in the vacuum part of the map, so before you see any boost, and then bring split to around 15 degrees as you start to see boost and towards your peak torque point, reducing the split again after the peak torque.
 
The engine will run fine on just the leading plugs, so provided the split isn\'t massive, you aren\'t likely to cause det by playing with the split much - provided leading timing is right.  I\'ve even seen on the chipped ecu\'s for the FC, and some of the maps for the RX8 tuned with emanage that they use negative split in the cruise/idle parts of the map - this is an area I really don\'t understand too well - and no one seems to want to let on why/how to use negative split.

I will keep it short and simple,
0 degrees split  on idle and light cruise
Then 10 degrees split on cruise and WOT
not much gains to be had with a figure less then this

Cheers guys. I\'ll have a play with the split on my way to work tomorrow. Will try various things and see how I get on :) I\'ll report back!

Well I had a play on the way into work (50 miles or so).

The base MS map had 15 degrees at idle, dropping to 8 for cruise cells, and back to 12 for WOT and into boosted cells.

After reading what you guys had to say and on rx7forum etc, I\'ve made some fairly big changes.

I\'m running 0 degrees split for the majority of the map. After a bit of experimentation I\'ve gone for -3 degrees split in idle conditions. Seems to have given more a more stable idle than ever, though I did have to fiddle with my idle valve settings as it was idling high. Then for 90kpa I\'ve gone for 1 degree and 3 degrees at WOT. I\'ve made that 2 degrees and 4 for peak torque of 3kish and the gone for to 0 and 2 degrees above 6k.

Overall the engine seems a bit keener. Its running cleaner at light cruise and idle, especially where I\'m running it lean (16:1). I guess with 0 split it just means its got double the chance of igniting the mixture properly.

Next question then....

I\'m running premix, OMP is removed as I cant use 13b pump with 12a front cover. Because of this, in combination with my 2 stroke motorbike experience, I\'ve not activated the overrun fuel cut. I figured its not got for the seals to be spinning at high RPMs with no oiling. (The pops and bangs running a slightly lean mix on the overrun also sound awesome and make me feel like I\'m driving a race car :P)

On the downside to even get a 17:1 AFR on the overrun@ 3k rpm I\'m using 8% duty cycle or so on the primaries. 8-10% is about the same as I\'m using cruising at 30mph in 4th. Idle is using around 4%.

I\'m doing all I can to try to improve my fuel economy as this car is my daily. Any opinions of the safety/non safety of using the overrun fuel cut?

Or any other tips for fuel economy? As I said in the previous post I\'m cruising as lean as I dare and I\'m using as little cold enrichment as the engine seems happy with.

Quote from: ianelvar;717792http://www.rx7club.com/showthread.php?t=809261

I don\'t think this is the thread, but I remember now that BDC is the guy to look for posts from. He really knows his stuff. Again, good luck dude

BDC is a full on c0ck wash! read here for graphic proof of that > http://www.rotarycarclub.com/rotary_forum/showthread.php?t=11528 (you need to sign up and post 20 times to have access but it\'s WORTH IT! JUST TO READ ABOUT THIS CERTIFIED IDIOT and AVOID HIM AT ALL COSTS!).

Take advice from him? sure if you want nobodies who have blown more motors that Paris Hilton has c0cks then go for it :mmmm

I recently read these resources and found them extremely helpful.

https://docs.google.com/file/d/0B_jE2-IDoVTfSGZhZEhsM0ZNRk0/edit?pli=1
http://www.wrex-racing.com/docs/fd/tuning/fd_tuning.doc

Not tried any of it yet, still reading to learn how it all works.

Quote from: BlitzBoy;617202Me and DaveHG do quite a bit of mapping using Datalogit on the Apexi PowerFC, there are a couple of others on here doing the same

Blitzboy do you still do mapping of FDs? If so how can I contact you?

Jamie next time you have Insomnia read this tntead from the start

Sent from my SM-N950F using Tapatalk

I would look for Blitzboy on FDOC