General 1G Fuel cut & Knock Sensor Question

[Smedleybutler]

I am working on building my car, it's as described as my build indicates plus my exhaust is installed finally.
My question is given my cars knock sensor and fuel cut, what is the danger of simply continuing to turn up my boost, which is now 15, until I hit said fuel cut, then back it off slightly?
I understand a wideband is preferred and will be included in my next major steps for fuel tuning, but until then given the stock safety failsafes is my plan feasible?

 

[steve]

How are you going to know how much knock or if you've run out of fuel injector before you hit fuel cut from airflow? What are you going to log with?

 

[Justin DuBois]

I am working on building my car, it's as described as my build indicates plus my exhaust is installed finally.
My question is given my cars knock sensor and fuel cut, what is the danger of simply continuing to turn up my boost, which is now 15, until I hit said fuel cut, then back it off slightly?
I understand a wideband is preferred and will be included in my next major steps for fuel tuning, but until then given the stock safety failsafes is my plan feasible?

Fu*k arround and find out?
Steve asked the right question. If you are not logging, and you are using your butt dyno - it's all a crap shoot.

Data logging tells you where you are at.
Assembling parts and blindly testing by twiddling knobs and "trying it out" is maybe not the best approach.

If you are concerned about fuel cut, that tells me you are running MAF, and stock injectors, and probably a stock fuel pump, stock regulator etc etc..

If you don't have logging tools, and Wideband, then stick with a stock configuration, at stock boost levels. 15psi is plenty to get running.

 

[1990TSIAWDTALON]

You will know when to back it off after you melt the side of a piston or worse.
Spend the time and money and install a wideband gauge, preferably one that will work well with tuning options.
Here was a brand new motor, just broke in and "someone" fiddled with the timing on the tune and added 4 extra degrees. Melted a piston down to the rings and left slag all over the cylinder wall. I winched it onto the trailer and we went home.....

 

[Smedleybutler]

How are you going to know how much knock or if you've run out of fuel injector before you hit fuel cut from airflow? What are you going to log with

I wasn't planning on knowing how much knock I had, rather if any occurred.
But it sounds more like I just don't have a proper understanding of the amount of protection provided by the fuel cut.
How would I get into that situation you mentioned, running out of injector before hitting fuel cut?
I thought a fuel cut was there to prevent an overly lean condition.

OK guys keep in mind this was just a question. I've got my wideband right here, just wanted to get a take ya know

You must be logged in to view this image or video.

 

[Justin DuBois]

I wasn't planning on knowing how much knock I had, rather if any occurred.
But it sounds more like I just don't have a proper understanding of the amount of protection provided by the fuel cut.
How would I get into that situation you mentioned, running out of injector before hitting fuel cut?
I thought a fuel cut was there to prevent an overly lean condition.

OK guys keep in mind this was just a question. I've got my wideband right here, just wanted to get a take ya know

You must be logged in to view this image or video.

Fuel cut is a condition where the airflow is asking for more injector duty cycle than is available, which would definitely result in a lean condition. This protection makes no accommodation for a lean condition when the injectors still have more to give. The wideband will tell you your actual AFR condition under any circumstances, not just during a lack of injector duty cycle.

 

[steve]

Fuel cut is a condition where the airflow is asking for more injector duty cycle than is available, which would definitely result in a lean condition.

It's not even that sophisticated. If it was nobody would ever get IDC's over 100% and that happens all the time when people turn the boost up and don't upgrade the injectors.

Fuel Cut is the ECU seeing the airflow exceeding a limit in the code and in turn turns off the injectors. As far as I can tell it's there to protect from the hose to the wastegate failing and letting the turbo run away. It would be nice to have a Mitsubishi engineer to ask but the best we can do in infer from reading the ECU code.

It does a pretty good job of letting people know when they have boost leaks.