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Standard Nissan modules are free with all Nissans and you should be able to use them as other ECUs do.

I agree.

But suppose a guy was building an RB30DET for his VL Commodore, and had no ignition for it. He COULD use a set of standard Skyline modules, or he could do something quite different.

Six Bosch modules plus six XF Falcon ignition coils ($10 ea), about $1,000

An Autronic CDI and three, or six, ignition coils, again maybe $1,000

Six (brand new ?) Nissan ignition modules, $ ????

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Do the Autronics run closed loop for idle, and cruise?

How well can they be tuned for good economy?

The SMC & SMC2 does not provide closed loop for idle but the SM4 does provide closed loop for idle.

Closed loop is provided in both SMC 1.92 (some of them) and all 1.94,SMC2 & SM4. Tune has to be within 2% of set A/F and their is also a lean hwy funtion where you can run leaner A/F when on the HWY.

There is also adaption rate and range in SMC4, function is there in SMC 1.94 & SMC2 but these do not work.

does it have more then 4 drivers? hahaha

It has 4 drivers so for a 6 cylinder car you need to run wasted spark or get a SMC4 & multiplexer, this will give you 6 ignition drivers to run full sequential ignition.

Does The autronic map fuel with seperate maps for each given RPM vs manifold vac, like the microtech matrix mode?

what are the RPM increments in, say 2500, 2750, 3000, etc. ?

It maps via TPS and Manifold pressure for turbo cars. There is no seperate maps. The RPM increments are what you want them to be, that being said Autronics have very good mathematical calculations to run the right A/F between RPM & Load ponits.

They don't have closed loop idle, simply because 14.5:1 is usually far too lean for a stable idle, and that is all you are going to get with a narrow band oxygen sensor.

But there is automatic closed loop idle speed control available, and separate fuel and ignition maps for idle that allow for water and air temperature correction, as well as battery voltage correction. (faster idle with flat battery). There are also time functions that can be set for idle enrichment. The whole idle thing can be set up to work wonderfully well without closed loop.

Closed loop operation (for highway) is available if you wish on a basic SMC. It requires fitting a narrow band oxygen sensor and just enabling the closed loop function. You can have it run either closed loop, or open loop, at any location anywhere in the fuel map. So you can set it up any way you want. In closed loop you only get 145:1 which is where the oxygen sensor switches from rich/lean.

But if you choose to run it open loop you can select any air fuel ratio you want. It will run at 17:1 without any problems if that is what it is set to. I run my SMC open loop set to 14.7, and that is exactly what it runs at. No real need for closed loop, but it is there if I ever wanted to try it.

Agreed!

You can also set the base A/F to 14.7:1 for city driving & in the Target A/F place leaner mixtures, leanest possible & enable open loop lean hwy funtion. This will mean that light loads (city driving) closed loop will operate and be set to 14.7:1 and when the ECU see's your on the HWY it will run leaner ratio's.

This all equals great economy.

Saying all this, its not the only way to get good economy, just like Warspeed has said, select the A/F you want to run at the load & rpm site and she'll run that A/F.

Does the Autronic CDI still have only two Capacitors or has it been upgraded?I had trouble with this setup on a Porsche and had to use 2 CDI units so each cap only had to fire 2 coils.Does anyone make a CDI unit with 6 caps?M+W said awhile ago they were going to have one.

Does the Autronic CDI still have only two Capacitors or has it been upgraded?I had trouble with this setup on a Porsche and had to use 2 CDI units so each cap only had to fire 2 coils.Does anyone make a CDI unit with 6 caps?M+W said awhile ago they were going to have one.

It still only has 2 dump capacitors. I don't think M&W have yet to design a 6 dump capacitor model. I do know that Autronics is still rated as a high power CDI and 1 of only 2 CDI's out there that can run low resistance coils like Mercury Outboard coils without blowing up.

so wasted spark setup as i plan on using is gonna have trouble with my rather large cams (272/11.35mm lift)? also im signing onto the autronics forum asap now i have the serial number and place of purchase sorted :P good info guys, plenty of people are interested in the finer details of the ecu's options/functions, so dont hold back telling everyone info :)

cheers

Brad

I have personally run 280 cams in my car while running wasted spark - no problem at all. Alot of people who run an Autronics ECU also have larger cams, let alone all the V8 boys who run even bigger cams.

Wasted spark will only cause the CDI to work harder and the coils have to be able to recharge fast enough for the next strike. Even the stock Skyline coils have fast enough recharge rate, can't say anything about other cars. Don't know how this came about about wasted spark not being compatible for larger then stock cams. If this were true my car would not even start let alone rev and produce power.

I have personally run 280 cams in my car while running wasted spark - no problem at all. A lot of people who run an Autronics ECU also have larger cams, let alone all the V8 boys who run even bigger cams.

Wasted spark will only cause the CDI to work harder and the coils have to be able to recharge fast enough for the next strike. Even the stock Skyline coils have fast enough recharge rate, can't say anything about other cars. Don't know how this came about about wasted spark not being compatible for larger then stock cams. If this were true my car would not even start let alone rev and produce power.

Sure it runs o/k with wasted spark. But how do you know it will not run a lot better with a properly timed ignition system ? Firing the plug during the beginning of the induction stroke is NOT a good idea. Firing it during the end of the exhaust stroke will work fine. What is actually happening in the combustion space during plug firing depends very much on valve timing, ignition timing, injector timing, and relative boost/exhaust pressures.

Think about it. Talk to experienced engine builders and engine tuners, read some serious books. Wasted spark runs perfectly well on some combinations, but simply will not work at all with other engine combinations.

You don't have to believe me. But if you think it all through very carefully, you may begin to see some potential problems that you may not have been previously aware of.

A turbo engine with very high total exhaust back pressure will be much more tolerant of waste spark, than a highly supercharged engine with open exhaust.

Sure it runs o/k with wasted spark. But how do you know it will not run a lot better with a properly timed ignition system ? Firing the plug during the beginning of the induction stroke is NOT a good idea. Firing it during the end of the exhaust stroke will work fine. What is actually happening in the combustion space during plug firing depends very much on valve timing, ignition timing, injector timing, and relative boost/exhaust pressures.

Think about it. Talk to experienced engine builders and engine tuners, read some serious books. Wasted spark runs perfectly well on some combinations, but simply will not work at all with other engine combinations.

You don't have to believe me. But if you think it all through very carefully, you may begin to see some potential problems that you may not have been previously aware of.

A turbo engine with very high total exhaust back pressure will be much more tolerant of waste spark, than a highly supercharged engine with open exhaust.

post-2711-1142253641.gif

Just out of interest then, would I be able to run an SMC on my N/A RB30DE with big cams?

I was hoping to run a wasted spark set up using either the standard Nissan coils or a Falcon coil pack.

Well, you could always try it and see. Many people do run waste spark successfully without any problems as stated above.

But why bother ? The SMC has six independent ignition outputs already there. So why not just use six standard Nissan modules ? That is the ideal setup and it is so very easy to do.

smc is a great ecu. easy to tune. the only downside is that it needs a special trigger disk for the crank angle sensor. like 50 bucks or somthing.

you need to look at the serial number on the side of the unit . if it ends in a 4 its high current injector drivers/if its a 2 its low current. but is a 200buck upgrade if it doesnt.

only has 1 variable auxilary output. (un used injector drivers can be used as on/off)

autotune feature is great(with a temp cominsated wide band lamder sensor

im using the 500rcdiwith mine with 3 series 4 13b doulbe coils.. its great. no static like a msd and just doesnt get hot!! at all

mines making only 315kwatw through a sock 26 with a t04z and mild tuning. very smoth drivability. can be tuned in may ways as a load input. for a 26 id sugest throttle position/map.

all the adjustabe fetures are all usfull not just marketing ploys.

like changing the ttriggers to +trigger to - trigger etc.

basicly its just really user friendly with excelent resolution.

can be set up for closed loop and lean highway cruise modes for economy.

the fuel injector control is very good. 3 decimal place acuracy. comes with preprogramed injector responce times in the current software. the way wich it is tunes is really simple. none of this direct m/s adjustment or carby style shit.

just a really logical ecu.

id highly recomend using it.

www.autronic.com

Well, you could always try it and see. Many people do run waste spark successfully without any problems as stated above.

But why bother ? The SMC has six independent ignition outputs already there. So why not just use six standard Nissan modules ? That is the ideal setup and it is so very easy to do.

All of the SMC's have only 4 ignition outputs.

Only the SMC4 with a multiplexor will allow addition ignition outputs.

Also agree with all T04GTR has said

Edited by WetGTR
First, the SMC has eight individual ignition outputs, (none of which provide any dwell). They are simply on/off outputs, where the on/off transition is the ignition firing point. The software allows many different ways to set all this up, but basically for a six cylinder engine there are three alternatives.

All Autronics have only 4 ingition outputs - even the SM4. You might be thinking of the injector drivers which are fully sequential. The SM4 needs a multiplexer which used other outputs to be converted to ignition outputs.

1/ Use one ignition output to drive a single ignition coil via an external Bosch igniter module that provides the necessary dwell angle. This one ignition output could also trigger an external CDI unit. Obviously a distributor cap and rotor button will be required to fire six plugs.

2/ Use three ignition outputs to drive three external Bosch igniters, and use three double ended waste spark ignition coils. The Autronic CDI can also be used with this system as it can drive up to four coils.

3/ Use six ignition outputs to drive the six standard Nissan coil on plug igniters. That would be my preferred option with a Skyline.

Use of the waste spark system is perfectly o/k if you ARE RUNNING THE ORIGINAL CAMS. All modern emissions cams have zero (or almost zero) valve overlap. The ignition system fires two plugs at once, and the inlet valve of the other cylinder MUST be shut when you simultaneously fire both plugs.

SMC with a dwell board or SM4 still uses wasted spark with the ignitor module & standard coil packs. As for original cams, well not many people run origianal cams when they use a Autronics ECU.

Now suppose your ignition fires 15 degrees BTDC in cylinder 1. Cylinder 6 also fires, but the inlet valve will be shut, and that cylinder will be at the end of the exhaust stroke with only exhaust gas in cylinder six.

But suppose you have a set of 262 cams where the inlet valve opens at 22 degrees BTDC ? Cylinder six will have its inlet valve open, and the combustion chamber will be open to the intake runner and full boost pressure. The injector will also be spraying. What do you suppose might happen if the plug fires !!!!!!

I run 260in &ex cams & I've also run 280in &ex cams - not a propblem all over 400awkw. Wasted spark work by firing 1&6, 2&5, 3&4. Say when 1 need to fire at TDC, no.6 also fires where it is wasted. I'm sure some here can go into more detail about this.

Waste spark is great for stock emission engines with standard cams. Even boosted engines. The Commodore supercharged 3.8L V6 uses waste spark. But if you fitted some decent cams to it, expect trouble.

The other issue is that CDI ignitions give vastly higher output energy, but the spark duration is very short. Straight coil/igniter ignitions can also give fairly high energy outputs, but the spark burns for much longer, rather like a welder.

Most CDI's have multispark up to 3500rpm and for 30 degree duration to combat this, works very well. Above this and it gos into single spark mode.

For competition it probably doesn't matter much. But for a road car, if you plan on running fairly weak mixtures (for economy) a longer plug burn time is likely to give less mis firing at very light throttle.

CDI units can sometimes be more susceptible to cross firing unless great care is taken with plug lead layout. But if done properly, it should work fine.

This can be the case but as anything correct installation is nessasary as you have said.

My choice would be coils and igniters for a road car, either one, three, or six. It all depends on the application.

The Autronic CDI is around $1000

The Bosch igniters (with dwell) are $175 each. So six would cost about the same as a CDI.

Lots of alternative ways to do the ignition with an Autronic ECU.

I agree with this

Sorry for the comments, I'm not here to give anyone a hard time.

is there an autronic plug and play ecu? by any chance

There is a plug and play type but its only for:

Mitsubishi EVO 4,5,6,7 and 8. Subaru WRX 1995-96, 1997-98, 1999-00 and 2001-2005. Honda Civc/Integra 1992-95 (OBD1) and also 1996-00 OBD2 cars when used with the supplied adapter harness.

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