Anybody heard anything about this carb style EFI?

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I work on/with Skyline GTRs, I know of a lot of the high powered GTR will covert their mass air systems in favore of speed density. More power, easier to tune, better drivablity. But, of course that is a different set up, but it can be done. I was just wanting to see if these guys have their stuff together, like Apexi does for the GTRs.

I know Hot Rod mag will do an article on the system, but they advertise the system, so how fair could that be?
 
how is a speed density setu self-learning? how would it know I want 15:1 on the highway and 12.5:1 at WOT?

Not sure I'm getting your question right. But programming normally allows only a certain amount of adjustment based on the o2 sensors input. I'm thinking that this system may allow more fuel adjustment based on the wideband o2 sensors readings than what we would normally see with systems using regular o2 sensors.

It should know the diference between WOT and highway cruising from RPM and throttle position readings. It would shoot for whatever air/fuel ratio the system thinks is best for the current condition.

I'm only speculating on how this sytem might work for the sake of discussion. Maybe someone will find out more about it and bring some hard tech.
 
This new Boss system uses wideband o2 sensors. And is using a completely new ECM. What we know about tuning/modding the old Speed Density (MAP) systems from the may not apply. I'm hoping that that using wideband sensors will make this a true self learning system and manual tuning would not be needed in most cases.

New ECM in terms of what? I've never seen the old one....

Self tuning speed density ECM's aren't something new. My megasquirt ECM for example has an "auto-tune" function.

The wideband O2 sensor definately makes tuning easier. Especially for an initial tune. But I still prefered the manual tuning method for the finer tuning.
 
how is a speed density setu self-learning? how would it know I want 15:1 on the highway and 12.5:1 at WOT?

It's quite simple actually. I'll describe how it works for my megasquirt ECU, this BossEFI system probably uses the same method.

With a speed density ECU you tune the engine by using a table of engine RPM vs manifold vacum. This table accounts for all driving conditions (high vacum = cruise, low vacum = WOT). This table is called the VE table.

With my megasquirt ECU, I also have a table called "Target AFR" that matches up with the VE table. So I can basically tell it that at WOT I want 12.5:1 and at cruise I want 16:1. The ECU uses this table to decide how much to modify the fuel to get the correct AFR.

When I turn on the self tuning mode the ECU keeps track of how much more/less fuel it had to inject in order to achieve the target AFR. Then it adjusts the VE table so that it doesn't have to add any more/less fuel to achieve the target.

Basically, you tell it what the AFR's should be and the ECU self tunes in order to achieve those AFR's.
 
New ECM in terms of what? I've never seen the old one....

Self tuning speed density ECM's aren't something new. My megasquirt ECM for example has an "auto-tune" function.

The wideband O2 sensor definately makes tuning easier. Especially for an initial tune. But I still prefered the manual tuning method for the finer tuning.

By "new ECM", I mean one that we don't already know about. Personally, when I think Speed Density or MAF I always think OEM GM and Ford stuff and what I know about them, mainly late 80's-early 90's. And you already know about megasquirt. But this is "new". The computer itself and it's self tuning features may be better than the ones we already know about. Just pointing out that, any preconceived notions we have may not apply. Maybe, I don't know. :shrug:

Didn't you have your megaquirt write-up in your sig? You should put it back.
 
By "new ECM", I mean one that we don't already know about. Personally, when I think Speed Density or MAF I always think OEM GM and Ford stuff and what I know about them, mainly late 80's-early 90's. And you already know about megasquirt. But this is "new". The computer itself and it's self tuning features may be better than the ones we already know about. Just pointing out that, any preconceived notions we have may not apply. Maybe, I don't know. :shrug:

Didn't you have your megaquirt write-up in your sig? You should put it back.

Ahh.. gotcha.

When I think ECM I think aftermarket... especially when swapping into another vehicle.

I don't like relying on the ECM's self learning feature. There's too much that could go wrong.. an exhaust leak, ignition problem, or fuel injector problem could all cause the wideband O2 sensor to have a funny reading. In these cases the ECM would try to compensate, and would actually make the tune worse to the point where the vehicle would be un-driveable.

It's great as an initial tuning aid, but you want to be able to turn this feature off and eventually set the wideband O2 controller authority. In most cases, you only want to allow a 5 - 10% compensation based on O2 sensor reading. If you need more than that, the initial tune is too far out or there are other problems that won't be resolved by just dumping more/less fuel into the engine.
 
I thought maybe there was something new here that might make the "learning" better than what we've known. But I just did a quick read through of the installation docs (didn't notice the link before). Nothing new here as far as the ECM or tuning is concerned. Still looks like a nice system though.
 
I've been checking out the stack injection system from Dynatek. They make the exact claim about a "self-tuning" ECU.

It would arguably be the coolest-looking thing ever, but it's $6k. :(

http://www.dynatekracing.com/fuelinjection.htm

fuelinjection02.jpg
 
I did call Retrotek the other day.
I had a good conversation with them, I do like the fact that, anywhere in the world as long as you can get your laptop connected to the internet, they can check your engine ECU.

Before you buy the ECU, you tell them the exact specs of your engine and they will load up the ECU with a base map.
After that (all wiring done), he said to me: start the engine and drive.
It's a true self learning system
 
I've been checking out the stack injection system from Dynatek. They make the exact claim about a "self-tuning" ECU.

It would arguably be the coolest-looking thing ever, but it's $6k. :(

http://www.dynatekracing.com/fuelinjection.htm

Very, VERY nice setup and very, VERY pricey! The Weber style throttle bodies are available separately as they are used on many different EFI conversions from outboards over snowmobiles to classic race cars. Megasquirt + DIY? Check these Brits out:
http://www.dtafast.co.uk/Throttle bodies/Throttle_bodies.htm#twin bore