Alfa Romeo Forums banner

What the stock 75 TS Motronic can and cannot do.

298K views 816 replies 48 participants last post by  Milanoguy 
#1 · (Edited)
The first eight of these posts were made by several people regarding this subject. However they were located in Engine Conversions under the title of "Twin Spark head on 2L Nord Block".
 
#2 ·
One important detail most people overlook when 'carbing' the std TS engine, is the intake timing variator (ITV for short) which most of the time is -unfortunately- removed. The std TS intake cam has 12mm lift and a duration of 300*-definitely not what you'd call 'road spec'.. By moving it around ~30* we can have both good low speed tractability and high end power. If the device is removed, we are left with a pig of an engine! It will either work well low down or high up, depending on where you have timed it, but not both! The VIT device operates by taking load and rpm info from the ecu. Load info is lost with carbs. A simple throttle switch won't do. One practical way to restore this operation is to employ both a throttle pot and an rpm signal. These two inputs are fed into a comparator cct and they dictate when cam shift will occur. The cct will have two trimpots which will allow you to adjust the point at which the cam solenoid is powered, ie throttle angle and rpm. I have done just that in a similar mod and it transformed the car. If however you choose to install Godzilla cams, the VIT can't operate as you'll have definite (and fatal) v/p contact. Cam sellers are careful to point out that VIT must be disabled.
Jim K.
 
#3 ·
Quote:
Originally Posted by Jim K.
The std TS intake cam has 12mm lift and a duration of 300*-definitely not what you'd call 'road spec'.. By moving it around ~30* we can have both good low speed tractability and high end power.
I assume that is 30 crankshaft degrees = 15 camshaft degrees.

Quote:
.....The VIT device operates by taking load and rpm info from the ecu. Load info is lost with carbs. A simple throttle switch won't do. One practical way to restore this operation is to employ both a throttle pot and an rpm signal. These two inputs are fed into a comparator cct and they dictate when cam shift will occur.
What's a "comparator cct"?

Can you outline what the algorithm is to compute when to energize the ITV as a function of rpm and % throttle position? I know the precise formula would depend on the engine's state of tune, but in general, how are the two inputs combined to produce a step function in ITV solenoid voltage?
__________________
Jay Mackro
San Juan Capistrano, CA

'63 Guilia spider
'65 Guilia Sprint GT
'67 Duetto
'91 164L
 
#4 ·
Can someone verify what the increase on the compression ratio - assuming the head hasn't been milled - would be by using nord rods? I (thought I) read where it would then be 11:00 to 1. I'm going to have Spruell modify a set of their TS pistons to come up with 10:3 to 1.

Jim K. yes, I too have both of your 4-cylinder Alfa books. When I read in a Bosh manual what the mid 80's Motronic does to meet numerous driving/running scenarios - whereas frequently the fuel and both the ignition and cam timing are affected, I'm thinking that not even a good aftermarket EFI system would be nearly this 'efficient'. And using carbs, oh why would one do that?

Is the stock inlet cam timing set-up the ideal setting? I'm referring to the initial setting of the inlet cam during a rebuild.

Sorry to do a bit of hijacking here.
 
#5 ·
Std TS timing: open between 29-22* BTDC, close between 90-97* ABDC (hi rpm).
Open between 61-54* BTDC, close 58-65* ABDC (low rpm).
No fancy stuff like algorithms etc for setting rpm and throttle angle switch points, just trial and error by searching where the best all-around performance is obtained by driving the car in all kinds of traffic conditions. The owner/driver is the final judge of where the cam will switch!
Rather than explain the comparator lets consider it as something easier, a black little box with 2 changing inputs and one output. The output is enabled when the two inputs reach the preset points (chosen throttle angle and rpm) which can be set with two trimpots on the pc board.
For such carb conversions, when no VIT is present, it would probably be advantageous to regring the intake cam to some other spec with less duration to improve low speed tractability.
There is no ideal cam setting, you can't have the best of both worlds with this profile.
As for Bosch ecu's vs aftermarket, I don't think anyone is naive enough to believe any private company has enough resources to refine their product in a better way -for road use. The same is true for competition; what I mean, is if Bosch decides to specially map a high-end racer, it will most probably have better all-around performance than anything offered by other specialty ecu makers. If you argue 'it ain't so', it will take names like Zytek to compete -and at what cost?
Jim K.
 
#6 ·
Jim:

Thanks for the explanation.

I think what you are saying is that a home-brewed algorithm could be as simple as "turn on the IVT when both of these conditions have been met: throttle position exceeds X% and engine speed exceeds Y rpm".

But that Bosch might be using something more complicated, perhaps using engine temp. or the product of throttle position and RPM as a parameter.
__________________
Jay Mackro
San Juan Capistrano, CA

'63 Guilia spider
'65 Guilia Sprint GT
'67 Duetto
'91 164L
 
#7 ·
Not wanting to hijack the original idea of this thread, so will move it to a separate thread if this 'area' continues.

That said, I'm glad to hear that I'm correct regarding the sophistication of even mid 80's Bosch EFI technology.

The 75 TS shop manual treats the installation of the cams the same as if they're nord cams. Yes, being a bit lazy but has anyone made lists of what happens - or more precisely, what benefits are there - if the inlet cam is slightly retarded or advanced? I'm assuming the exhaust cam remains in the stock position, though that might not be the case.

Also...assuming I go to 10.3 to 1 pistons is there any likelihood of cam/piston interference when trying retard and advance positions for the inlet cam?
 
#8 ·
Starting with the last question, I don't recall what v/p clearance there is in the TS engine on overlap.
Altering intake cam timing is a bit involved in the TS, as its not like the exhaust cam (which follows normal Alfa tradition). You need a couple of huge wrenches to loosen the big-a$$ mechanism and then you can play with 60 little teeth, which connect the front part to the rear. Therefore you have 60 teeth of leeway. Well, thats 6* /tooth -cam degrees. If you also count the number of chain gear teeth, you can vary timing in smaller increments. Blaaaah! Performance cams usually have the same gear sprocket as the exhaust so life becomes easier (however, no VIT). I personally haven't played with timing these cams back and forth, nor have any of my cronies here. I guess that on efi engines, people tend to change eprom chips rather than playing with cams. One possible reason is the fact that they're afraid it'll require costly mapping every time, for perfect results.
I built an engine recently with 12.5:1 pistons from P.Spruell, 47mm valves and Godzilla cams from Alfaholics. V/p clearance is a huge 4.5-5mm so I suppose there's plenty room to play (don't ask, the engine is not in the car yet).
Jim K.
 
#9 ·
Quote:
Originally Posted by Biba69
That said, I'm glad to hear that I'm correct regarding the sophistication of even mid 80's Bosch EFI technology.
I've just fitted a modified 25 year old Delco (GM) ECU to a nord engine, and it's certainly very sophistocated compared to the aftermarket ECUs that I've looked at.
There's over 500 tuneable parameters in the firmware, not counting map cells
This ECU would have no problem driving the IVT, there's a couple of PWM outputs that can be mapped to things like engine load.

One area that this ECU shows it's age though is lack of sequential injection, and that's a hardware limitation so can't be overcome with a firmware change.
 
#10 ·
Jim, if you've made the transition... What kind of gas/petrol/benzina do they have in Greece that you can use 12.5:1 pistons? I'm aware that some automotive manufacturers are upping the compression ratio fairly high - I assume it is more efficient - but you can't even use a knock sensor on a TS or nord. Although I'm sure the fuel in Greece (or anywhere outside the US) isn't spiked with corn gas.

I should know their names but there are 75 TS Motronic chip guys in both the UK and the Netherlands. I've exchanged emails with the fellow in the Netherlands and he implied that his Motronic chip would have no problem handling higher compression and 'larger' injectors - though suggested I bring my Alfetta GT by his place and put it on his dyno so he could make a custom chip. That's a long drive from SoCal.

I've been following the "Programmable Ignition" thread in Engine Management and the consensus seemed to be that dual MirelliPlex or MSD units would work fine on a TS. Any opinions on this?

I'll throw this into the mix but I've found only one thread regarding NGK's Iridium spark plugs. I've been using their BPR6EIX plugs for a couple of months and am very impressed with them. Interestingly the part # for the 75 TS is BKR6EIX.
 
#11 · (Edited)
Why do you say you can't you use a knock sensor on a nord? Because of the cam chain noise?


--------------------------------------------------------------------
fast forward a few weeks and a couple hundred posts:
We've made significant progress with understanding the
ML4.1 ECU - both what it does, and how to modify/tune the system.

For newcomers to this thread who want to jump straight to the
details rather than read the whole thread, there's an index to some
of the more interesting technical information here.
---------------------------------------------------------------------
 
#13 ·
I'm (slowly) working on making a digital knock filter for my nord, using DSP and RPM derived gain to separate knocks from the noise floor.
Running the knock sensor on the back of the engine gives a better signal than the front, and although the valvetrain still produces a fair bit of noise, the knocks occur in a very specific frequency range (around 6.8KHz from memory for a 2L nord) so a bandpass filter on the input stage *should* clean most of the background noise up.
Windowing would really help a lot too, but I haven't worked out an easy way to get the necessary signal to trigger that from my ancient ECU yet...

I'll let you know if it works when it's finished ;)
 
#14 ·
In all our $hitty predicament here in Greeceland, we at least have good pump fuel, the well-known (in Europe) BP-Ultimate, Shell V-power Racing and many other brands, all claiming around 98-99ron and the cost is ~1.70€/liter. There is definite performance difference between these and the 'normal' 95ron, going for ~1.58€/liter.
The particular TS, has 12.5:1 cr, and 300* intake, so I don't anticipate any problems. As another indication, consider that my 'road' 1.8T has 8:1 (up from 7.5:1) and I run 1.3bar (19psi) with a 10548... intake cam. So, fuel is good!
The 1.8T has a knock sensor as std so I wouldn't worry about the feasibility of putting it on the TS or any other Nord. It is fixed on a stud between cyls 2-3 on the lower side of the intake manifold. Here's how it works: when it detects knock, it retards advance (all cyls) by 2* at a time until knocking disappears. If the max of 8* retard is exceeded, it signals the famous Pierburg solenoid valve which opens the wastegate! Very effective -remember now, this is a 1985 design! As a matter of fact, if you try to increase static advance to greatly improve low speed tractability (from 8* to ~15* BTDC) the engine won't boost at all -ask me how I know :D
I've also talked with Stephan Lenior (Squadra Chips, Holland) and he usually insists on people taking their cars to him if its anything other than a std engine. He is right as only on the dyno he can tailor-make a proper map. Fortunately, we have several people here who can do the same -mapping of a std ecu runs ~400€.
Few years ago, I made a knock sensor cct for a friend who maps cars. The display is a series of LED's; he says its a great help in properly mapping an engine on the road. Now, if I could only design an ignition to fire a plug just before the verge of detonation....Maybe in the next lifetime...
Jim K.
 
#15 · (Edited)
This is an excellent idea for a thread topic.
I'll add a couple of thing here that based on research but aren't necessarily Bosch specific.

Some/most older engine management systems stop listening to the knock sensor after a set engine speed. This is because the noise filtration circuits couldn't cope with the sheer amount of racket and that racket could cause false knock signal causing the computer to do what it does to deal with knock. Whether that's what Bosch were doing back in the day, I don't know.
Higher processing speed computers and better (digital) noise filtering systems would help a lot here.

Narrow band exhaust gas oxygen sensors can only supply a very limited amount of information. They obviously help during low load (cruising down the road at anything upto highway speeds), normal operating temperature condition to keep the engine around stoichiometric air/fuel ratios. The ratio where catalytic converters work the best. This is not best for fuel economy.
The other advantage the EGO sensor give to digital engine management systems is to allow the computer to help deal with wear in the fuel system that accumulates over time. What tends to be called long term fuel trim(s). As pumps get older, their pressure may drop a small amount. Injector flow characteristics can change and the fuel pressure regulator may also start to get old and not hold correct pressure over all of the pressure range it needs to work. The feedback from the EGO sensor allows the computer to calculate an overall correction to injector pulse width and apply it to just about all operating condition.
What needs to be understood is that there is a real limitation to this. It can only be learned during close loop conditions (the computer won't know if your engine is running stupid rich or lean at high loads) and is probably an overall percentage of change applied to injector open time. I don't know how much capacity for this the older systems had, but the earlier systems were built with simple processors (compared with wht's used now) and small memory, so I would be reluctant to try and expect them to deal with injectors flow changes (up or down) past 15% (experiments would need to be done to get real answers about any self learning of the ECU).
Engine management systems using narrow band EGO sensors don't look at the signal from the EGO at high load. It doesn't have enough meaningful information in it do be useful.

Imagine this:
You've modified the engine to make significantly more power. More than what the factory computer can tolerate in terms of fuel delivery, anyway. So you figure (measured and calculated) that the engine needs 20% more fuel flow at full power. So you manage to get this by cranking in extra fuel pressure via an adjustable rate fuel pressure regulator. Now as you cruise down the road, the engine doesn't need to make more power to do that job, and is getting 20% more fuel than it needs at anything other than full load. At full load, it's running sweet (good AFR on a wide band meter).
Lets say that the ECU can deal with 20% extra fuel in a cruise condition and starts to 'learn' what correction it needs to apply to get injector open times back to a point where the computer can again go into proper close loop during cruise. After a while (hours/days), the long term fuel trim applies an overall correction of 20%. It's only doing what the engineers designed it to do but it doesn't know that the extra 20% of fuel you added was needed at full power. And that correction is applied EVERYWHERE because that learning is used to allow for wear and tear and small production variations.
After the ECU learns that correction, you may well stick your boot into it and have your engine run dangerously lean. 20% lean or there abouts........
 
#16 ·
Duk, thanks for this information, although I'm now somewhat concerned about how much latitude the Motronic will be able to handle even with a remapped ECU.

What can I expect from a remapped ECU? I certainly don't want to lose all of the good stuff (technical term) but I want the Motronic to be able to recognize 'slightly' oversized injectors. I would think that even if I don't have Spruell modify his 10.5:1 TS pistons to 10.3:1 would that be a big deal with a remapped ECU?

Jim, again thanks for your comments. It sure seems to me that if one stayed with the dual distributors, there should be some sort of solution to have planned (?) pre-detonation. Okay, I have to admit I have no idea how these distributors work. The shop manual only tells how to align them once removed. That said, the rotor in the distributor drawing in the shop manual appears to be an analog rotor. Whereas mine appear to have an electronic pick-up rather than a brass 'contact'.

If I'm correct regarding an electronic pick-up on the rotor, couldn't it be staggered a few degrees clockwise on say the forward distributor? As I think about it, probably not.

I am very interested in having a knock sensor, but is there any way one could be tied into the Motronic's ECU so that it would then retard the ignition timing when sensing knock?
 
#17 ·
Duk, thanks for this information, although I'm now somewhat concerned about how much latitude the Motronic will be able to handle even with a remapped ECU.

What can I expect from a remapped ECU? I certainly don't want to lose all of the good stuff (technical term) but I want the Motronic to be able to recognize 'slightly' oversized injectors. I would think that even if I don't have Spruell modify his 10.5:1 TS pistons to 10.3:1 would that be a big deal with a remapped ECU?
Ahhh! Proper remaps are the ONLY way to go (within the capacity of the ECU) if you plan to retain the factory computer. There are other ways, but we'll keep that for a different day.
What people need to understand is that there are fuel and ignition maps inside the factory ECU in the same way there are fuel and ignition maps inside an after market ECU. There is, however, a rather different approach in their 'internal lingo' in the way they tend to intemperate certain stuff, particularly engine load.
When a car manufacture/ECU supplier (like Bosch) tune a/their computer, they calibrate the processors interpretation of various sensor's data and change the fuel and ignition maps. What they ABSOLUTELY DO NOT DO is fiddle externally with sensor values or fuel pressures to get their desired results. And it doesn't matter who's marketing says what (No one here on the AlfaBB, but there are a few aftermarket controller makers that make such claims) about that.
Car manufacturers get right inside the coding in their ECU's.
This can also be done by those who truly know what they are doing. Fortunately there are people in the world who have figured out what is going on inside the ECU. Actually, they have been able to look at the raw Hex code in the ECU 'chip (stupid word)' and figure out what parts of the code do what. That is, what lines of the code represent the fuel maps and the ignition maps (amongst a whole bunch of other stuff!).
Real tuners who want to change fuel and ignition timing at given rev and load points do so by changing the appropriate information inside the Hex code.
That way, 1 breed/brand/model of computer could be used to run an engine from the lowliest shopping trolly to a very decent performance car all because of what is programmed into the 'chip (still a stupid word)'.

*** The 'chip' in older computers (car ECU's haven't had them for 10+ YEARS) is called an EPROM. 2 translations of that are: Erasable/Programmable Read Only Memory or Electronically Programmable Read Only Memory.
On the 'chip' is all of the data that tells the processing unit how to interpret the data from the various variable voltage or variable resistance sensors, how to calculate engine speed and position via the crank/cam angle/engine position sensor(s) and what to do in all of the myriad of combinations of engine speed, load, engine temperature, air temperature, knock sensor feedback, EGO sensor feedback and others. It will also contain the data for the 'self learn' corrections that are applied.***

If you want to have a good look at how Nissan ECU work, have a look at ECU Tuning. You can learn how involved factory ECU's are.
For some offline (not real time) tuning software for Nissan ECU's, go to z31.com | Nissan PROM tuning and download Live Edit.
Now obviously this is not applicable to Alfa Romeo's and Bosch ECU's, but it can help people learn what is going on inside their ECU. If you can get your hands on the software for an EPROM read/programmer like the Darkwire stuff, then you can actually look at the Hex code in the Nissan ECU files that come with the Live Edit software.
Live edit won't let you change certain things in the Nissan coding. In particular, it won't let you change the 'airflow meter limits'. What lots of people call the 'over boost fuel cut'. It's not a fuel cut and it's not based on boost pressure. What it is, is a 'potentially faulty condition' that causes the ECU to dump extra fuel into the engine and retard ignition timing if the airflow meter shows 'to much air flow' (to high an AFM voltage at a given rev point. That will happen when the boost is wound up in turbo cars). These changes can be made in the raw Hex code IF you know where to look!
Why any mention of Nissan stuff? Well I do believe that the very early digital Nissan ECU were based on early Bosch digital systems. Probably not applicable directly to Bosch stuff, but given the sheer lack of REAL info out there (at least in English), and a very good aftermarket support for a the popular Nissan's, you've gotta get your info and education from where you can ;).
 
#18 ·
I always wondered why nobody (?) in NA has set up a shop/dyno with the capacity to remap all kinds of factory ecu's. There are several serious companies in Europe who will sell or rent this know-how and equipment to any such aspiring business. These people -as Duk said- get inside the factory codes and have translated the ..alien hex to appropriate x-y tables with load/rpm/fuel/advance/temp/xxxx. When inside, you can access all engine parameters and optimize all on a brake dyno. Its funny, but you can always get more power from the std ecu by doing this! Why? Because the oem guys have allowed for 'worst case condition operation' meaning low octane fuel, high altitude, high temperature an high load...On the average, if all these are eliminated and your only condition is trackday use with great fuel, you can sure get more power out of the std ecu with no other changes. This however, has been minimized with the passing of time, as ecu's have knock sensors, trionic spark systems, sophisticated lamda control and 'learning' features. I am digressing here though..
Ok, back to mapping std ecu's; have a look here: Engine tuning parts - Dimsport Technology
and here: Electronic Chip Tuning
Costs are very reasonable for anyone deciding to add this twist to their business, especially if they already have a dyno. Tech support is great and they will even help you over the phone for hours on end if you have a problem. These people analyze new cars as they appear and they sell/rent the 'ready-to-play' maps to their customers. Just browse the two above sites and see how many cars they deal with. Selling modified chips is only one aspect of what they do.
Back to the TS, distributor positioning has nothing to do with advance. You just have to make sure they line up to supply the spark. That's the reason the rotor has a wide brass tip: the spark will occur sooner or later but the rotor will not 'advance' as in older distributors with springs/weights.
A few words about 'fooling' std management. The std 1.8T has .65bar (9.6psi) boost and 155hp. Since this Alfa engine has proved to be one of the most robust units around, I decided to go for ~18psi boost in my road car, with as few changes as possible, after the initial CR increase to 8:1 -up from 7.5:1 by milling 1mm off the head. There are a few prerequisites before embarking on similar projects and in this case a timing light, wbO2 and a %CO meter. Having the car in proper std form, I drove around with the wbO2 jotting down all different readings and conditions. Light cruising gave 16:1 afr and max power 11:1. Idle CO was adjusted to a factory 1% and fuel pressure a std 2.8bar (41psi). Ok, time for change! Out goes the infamous Pierburg valve (wastegate controller in the std 1.8T) and in goes a manual valve (~40€) set at ~1.3bar (19psi). Figuring I would definitely need higher fuel pressure (not changing the injectors) I replaced the regulator with an Aeromotive unit and the pump with a Bosch performance unit, 0580254044 (total ~280€). To make a long story short, I ended up having to crank up fuel pressure to 54psi, reduce idle advance to 4* BTDC (from 8*) and tighten the afm clockspring to obtain the same general afr's as before. The car has 210hp and ~32kgm (231ftlbs). Granted, with the ancient Garrett T3 its still a pig low down, but in a little while it'll be replaced with a GT2854R, from which I expect great things! Anyway, I outlined all this to show that sometimes we can change factory systems to our benefit if we really know how. In my case, I even have a set of higher flow matched Weber -044 injectors, which would allow me to reduce fuel pressure to std, loosen the clockspring and increase boost to maybe 1.6bar (over 23psi). In this case, the std ignition ecu becomes very questionable and it would be best replaced with a programmable MSD ignition for excellent tuneability. We're then looking at ~260-270hp from the std fuel ecu and afm....Not bad I'd say. All this, for a total cost of a manual boost valve+Aeromotive regulator+Bosch performance pump+4 injectors+MSD+new snail+exhaust pipe= 1800€ = $2300. Sorry for the long post guys....
Jim K.
 
#19 ·
Jim, there is a seller on Ebay selling Motronic tuning software.
Aspiring tuners would still need an EPROM emulator, a chip reader/writer and blank chips of the size, type and access speed that the Bosch uses. These old digital system EPROM are getting pretty rare these days. It doesn't matter if access speed is faster but slower isn't a good idea.
Electronically rewritable chips (still need a chip programmer but they can just be overwritten rather than erased 1st) can be had but they need to be the right physical size.

Note that it probably can't do realtime tuning like a programmable system can.
This isn't a big deal but having data logging equipment that logs AFR's, engine speed and engine load would be a must, that way you can see what happened in what conditions. Obviously keeping an eye on AFR and ear for knock is essential to make sure nothing dangerous happens when doing data log runs.
The biggest problem is converting the AFM signal to the actual load points used inside the chip. Certainly with the Nissan ECU you can't just look at AFM voltage and interpret that as the ECU's load point, it is MUCH more complicated than that.
That is, the AFM is a 0-5volt device. The maps are 16 rev x 16 load points but you can't just divvy 5 volts up into 16 equal pieces to determine which voltage equal what load point.
I would guess that the Bosch would be similar.
 
#20 ·
What these guys do (I've sat with them in a couple of sessions with my 3liter) is real time stuff on the dyno. They set the load/speed on the rollers and vary fuel/advance checking torque and afr. All the equipment necessary to do this is offered by the links I posted. When finished with the dyno run throughout the speed/load range, the new info is loaded on a new chip (or an erased old one) and that's it.
One thing, its getting rare to find the old 256/512 DIL-28 eprom chips... Very few places still have them for sale!...Not that our cars are state of the art...
About 5 years ago, a mapping joint closed here in Athens and were offering everything for sale (no dyno) for ~3,000€ ...Unfortunately, I took too long to decide I wanted the stuff and someone else bought it. Them guys are now a few financial light years ahead of me...
Jim K.
 
#21 ·
What these guys do (I've sat with them in a couple of sessions with my 3liter) is real time stuff on the dyno. They set the load/speed on the rollers and vary fuel/advance checking torque and afr. All the equipment necessary to do this is offered by the links I posted. When finished with the dyno run throughout the speed/load range, the new info is loaded on a new chip (or an erased old one) and that's it.
Was their equipment able to tell them where the Bosch was looking at any given rev/load point? Cost of the equipment they used?

It's all redundant for me, I've got an Adaptronic E420c for my 75 ;)
 
#23 ·
The x-y maps on the laptop screen gave numerical values (ms) for injector operation and he went to the 'box' in use at any particular time and altered the value looking at afr. I don't know the current cost of everything required (emulators, burners, programmers, universal adaptors etc) but you should be able to get an answer from the two sites mentioned.
I also have a new and still unused E420C I got, but for the 24v I chose to use the std 164Q4 management which will soon be remapped. It has a hot-film afm so no flaps or restriction, sequential injection, two knock sensors, two lamda sensors (one per bank) cam sensor, coil-on-plug...That's std Bosch stuff for this engine and ...1992 vintage, 20 years old now! I just find hard to believe the E420c would do any better!
Jim K.
 
#28 ·
I also have a new and still unused E420C I got, but for the 24v I chose to use the std 164Q4 management which will soon be remapped. It has a hot-film afm so no flaps or restriction, sequential injection, two knock sensors, two lamda sensors (one per bank) cam sensor, coil-on-plug...That's std Bosch stuff for this engine and ...1992 vintage, 20 years old now! I just find hard to believe the E420c would do any better!
Jim K.
Nissan were also providing that sort of technology back then too (a little earlier). So was Toyota, but they preferred MAP sensors.
Definitely, for a decent road car, a properly sorted and capable factory system with Zillions of dollars/euros/pounds of development will achieve much. Here in Oz, the madest of the Ford Falcon XR6 turbo's use retuned factory ECU. 1 company who were very strong Motec supporters/users dumped Motec systems on their earlier engine once the equipment for properly tuning the OEM ECU became available.
Obviously they have their limitations tho. Packaging is one that I found a problem when adding forced induction to some cars. The AFM can seriously get in the way and cause all kinds of challenges.
Then there are auxiliary control features. Not the the Alfa has it, but the Adaptronic will control continuously variable (not just a single step) valve timing but the E420c can only do 2 camshafts, not 4.
Mad camshafts and AFM's aren't a great combination, but could possibly be made to work.
Reversion back through turbos (big turbo equipped Nissan GTR are pretty notorious for this) can cause the AFM signal to measure air in the opposite direction when the engine doesn't need it and cause fun things to happen. Similar story to externally venting blow off valves.
 
#24 ·
The cost of the hardware to do this is quite low - you could get set up for just a couple of hundred dollars. The tricky part is knowing where the maps and parameters are that you want to change ;)

I had a very quick look at a rom dump from a 75 last night, and there appears to be a bunch of tables starting at 0x4000H. I also found a few of the functions that reference some of the maps - but without a schematic of the ECU and a *lot* of time and effort, I have no way of knowing what any of these maps are, or how the values are calculated.

If a table was identified, it would be a simple job to write a definition file to get a generic tuning program to interpret the data, then you could edit the table and 'upload' the new bin to an eprom emulator in the ECU - or burn to a flash chip to plug in to the ECU.
 
#25 ·
While way over my head, I find this discussion very interesting and keep it going as long as you care to.

However, if any or all of you can give me a reasonable guesstimate as to what an 'enhanced' chip* for a 'stock' engine would offer that the original one doesn't. I'm guessing it allows for an increased rev limit along with more fuel at higher rpm's. I would assume that there also might be changes in the ignition timing at 'some point'.

Perhaps I should start from the beginning. The TS will go into my '75 Alfetta GT daily driver. This means I want a minimum of downtime, so I'm trying to cover all bases beforehand.

It's very doubtful there will be any track-days, but I want to be able to leave it in gear should I be on some twisty roads which might mean high revs. I don't do heel and toe for diddle. Of course all rotating parts will be balanced.

One of the most important features I want is for the engine to maintain a good idle, Especially when the A/C is on.

I'll add should there be any situations where an enhanced chip might cause a problem, the Alfetta does not take well to idling or going slow when the temp is much over 85 F.

This isn't very orderly, but there will be no catalytic converter though I have a bung installed for an oxygen/lambda sensor before the resonator.

I'd be happy with 148 HP at the rear wheels, though a few more would be welcome, providing it doesn't impinge on drivability.

*Sorry Duk, even the fellow who wrote my Bosch (1989) book uses the word chip.

Boy does this look like a magnetic pick-up to me.
 

Attachments

#26 ·
This is the top distributor and like the bottom one, it has no pickups, nothing. Both TS engine distributors are 'dumb'; all they do is distribute HV. The sparks are generated by the ecu based on a number of inputs: crank toothed wheel inductive pickup (which supplies rpm+crank angle) afm (load+air temp) coolant temp sensor and throttle switch. As Bosch says, one of the throttle switch functions is to enable proper idle speed which is mostly set in Motronic systems by varying the spark advance as this is considered faster acting than the idle stepper motor. You can verify this by hooking up a timing light on idle and turning various loads on/off (lights/aircon/heater etc).
A 'chip' for the TS will maybe give you 6-8hp more than your engine has, it will move up the rpm limiter and will most probably hurt economy -as some friends observed here. As to your 148hp idea... I know some dynos measure std TS cars at 125-135hp on the engine....so don't be too optimistic about what to expect on the wheels!
One word about your pic: note how wide the brass rotor tip is and remember what I said about this a few posts back.

Festy: As I said, these companies sell/rent what you need to map cars and you are seeing proper x-y maps with real values, just like with the aftermarket ecu's. Buying outright costs a few thousand $$ but you can see and address all important tables (idle, warmup, fuel/rpm, advance/rpm etc).
Jim K.
 
#27 ·
Festy: As I said, these companies sell/rent what you need to map cars and you are seeing proper x-y maps with real values, just like with the aftermarket ecu's.
Here's a screenshot of how my tables are displayed for editing. I was playing with some rev limiter settings this morning, hence the rev bounce at 3600rpm in the logs (if you can even read those numbers).
This one is an old GM ECU, not a motronic - but it's the same vintage, and it's running a nord now at least :D

What I was getting at was that if the tables in the motronic were deciphered, they would be displayed just like this - and anyone with an eeprom emulator and a laptop could have a go at tuning themselves.

I found a basic map definition file for the 155 Q4 on the net last night, so 'home tuning' of those is already possible by the looks of it.

The (free) software I'm using is ECU agnostic, it just needs to be told where in the eprom image to find the tables and how to interpret the values.
 

Attachments

#29 ·
My most 'sophisticated' application so far is the 24v engine and as long as it has one throttle plate I believe the stock 164Q4 management (Bosch 3.7) to be entirely adequate for any upgrades. If my proposed 3.2 with ITB's ever gets off the ground, maybe it'll be time for the e420c.
On the other hand, the 1.8T engine is clearly ...Bedrock vintage and therefore perfectly happy with the remapped Marelli management from the almost equally ancient Sierra Cosworth 2wd (~1985, L6 ecu) or the very similar -but more advanced- Lancia Integrale management (L8 ecu). Correctly mapped on the dyno (and possibly road-trimmed) these systems are capable of exploiting 100% what these engines can do and I for one, am happy to leave it at that.
I still mess a bit with some electronics wizardry -when I have to- but I think I'll leave the serious delving to more eager and inquisitive minds, as according to the now famous phrase ...I'm too old for this $hit!;)
Jim K.
 
#30 ·
I've disassembled a 75 TS rom image and started work on creating a tunerpro definition file for it this morning.
I have a couple of 3d tables mapped out already - I think I might possibly have a spark advance and/or a VE table from the look of the graphs, but will need to work my way through a lot more code before I can really tell what I'm looking at.
I haven't got as far as determing the calculations to show any 'real world' numbers in those tables yet, but at least it's a start ;)

When I get a bit further with this (assuming I actually do), I'll have to get myself of one of these ECUs so I can play around a bit.
 
#31 ·
festy, I'll be curious as to what you come up with.

I'm getting crappy gas mileage out of my nord with DCOE's, 10:1 pistons, and (I think) the factory 10548032 cam.

Do people get poor gas mileage out of the remapped chip/chips simply because of how the chip has been remapped...or because owners then put their foot into it more and more often?

Oh yes, does one remove and then send their TS chip to be remapped, or does one receive the remapped chip and then send the original one in as a 'core'?
 
#33 ·
Oh yes, does one remove and then send their TS chip to be remapped, or does one receive the remapped chip and then send the original one in as a 'core'?
It's hypothetical at the moment, but the cost of posting the 'core' back would be more than the chip is worth. Either a new flash chip and adapter board would be used in it's place, or for under $100 you could set yourself up with the hardware and software to do your own tuning.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top