I know a lot of people have already purchased piggybacks then been frustrated at wildly oscillating fuel trims and random check engine lights.

I don't want to sound like a broken record here but the electronics of the MAF circuit are not compatible with a piggyback because it's impossible for the piggyback to predict when the ECU switches load sites. Injector drivers like the FIC could be made to work except the factory ECU stays in closed loop at all but WOT. Larger injectors can almost work except for the closed loop issue but good luck getting them to start in the cold. EICs sort of work except for the fuel / cylinder distribution problem, the fuel trim / open loop issue and the DBW failsafe codes. There are a host of other problems too numerous to list.

What about if I just made a reflash available to people that raised the rev limiter, changed the open loop behaviour and rescaled the injectors to whatever the user wanted so you can use your existing piggyback for turbo with big injectors. Although you really can't solve the MAF translation problem it would make the car a LOT more piggyback friendly.

Is this something people would be interested in?

I'm still open to suggestions and trying to figure out what people would want as I'm getting closer and closer to turning this thing into a product.

-Michael

 

nice work..! RPM 7,4k rpm, 2step 3.5k rpms, scaled injectors, pulled timming, and adjustable boost cut. That would be my order...

 

You say you can scale big injectors as with the stockers for example can you scale 620cc injectors close to the stock 340cc so they can behave close on idle and wont go crazy on loop.
I would love to try and tune my car with your software but the problem is that with a mail in it may take a while to set parameters right as we wont be able to see the triming behavior live and a/f parameters. If you lived closer to PR I would have gone there to tune my ecu anyways its a good offer and business you have there, you can set up max timming for customers, rev limits, 2step launch and even offer preprogramed flashes with specific basic boltons giving a bit more timming, higher rev limit and a bit leaner mixture.
You will un-corked the hidden potential of the 4g69.

Thanks..

 

The 4G69 is a decent engine. The test car is putting down really good numbers for a moderate amount of boost (6psi). It sure doesn't like a lot of timing in the hot weather! Based on the math in the ECU the stockers appear to be about 320cc. I can adjust the injector scalar as well as the latency values - that's no problem. I can also extend the tables so it can deal with boost properly too. The test mule has been running 440cc RC injectors and it starts first crank and idles smoothly at stoich every time. Adjustable settings are not easy at this point in time but I'm working on a few things like that. Perhaps with a daughterboard installed in the ECU.

-Michael

 

This I would REALLY like. This is actually what I'm looking for a reflash. One good thing about having piggybacks is that you can do some fine tunning easly; the problem is that the 4g69 ecu doesn't like them very much.
That reflash would really work for me!
An aditional idea would be to have a configurable injector (very difficult for al possibilities) but may be a switch form a ecu terminal to used the requested injector or going back to stock ones.

 

Hmm. That's actually a really interesting idea. There are a number of unused ADC channels that I could hook into and give you a knob or a couple of resistors to select your injector size. That could at least get you close... There are 3 settings related...

Latency table. Different battery voltages means different injectors take more or less time to open. Base latency base amount of time it takes the injector to open and injector size which is a multiplyer after the duty cycle is calculated but before the latency is added.

-Michael