Re: False knock at 2000 rpm?
Posted: Sat Nov 10, 2012 11:55 pm
I've been reading through this and have a bit of input.
You can not tune around mechanical issues. You have to find and repair the mechanical before the tune. Otherwise your just "spinning your wheels" and wasting time.
Irregular and inacurate information from the owner doesn't help in resolve. Its like going to the doctor and leaving out what you think is unimportant, but to the doctor it is key information.
There are plenty of references on this thread that recommended checking the mechanical funtion of the engine. And yes, a knock sensor on a Subaru is sensitive to noise. It will even pick up heat shield vibration.
The fifth gear @ 65Kph was an indication also of a mechanical issue when the fuel and ignition was altered. The car was "lugging". Too much load.
I don't believe the wastegate was the total issue. Either the true cause is being withheld or it hasn't been located. A wastegate flutter would cause irregularities in boost which would show up in logs. If the AVCS was not operating properly, why? Lack of oil? Incorrect weight? Electrical issue? Mechanical within the actuator? The flutter may have been causing a knock retard but the cause of the flutter has not been rationalized properly. Was there a vacuum leak to the wastegate?
Five Minutes is a stretch. Within this post, Kido makes suggestions towards mechanical outside the relm of wategate flutter long before the 5 minute fix which leads me to believe that Sheik was fishing for answers trying not to spend any money and trying to guess at what the problem is. (Which I believe will rear its ugly head again if it was not truly located.)
Any modifications to a vehicle need to be complete before a tune. Modifications after a tune necessitates a retune, no matter how small you think it effects the performance. When mechanical, electronic control or actuator issues arise, these need attention and repair before proceeding. When I ran into mechanical issues on the OE 3.0, I informed Ed that we need to stop until I have it resolved and begin again. In my case, it was quicker and easier to replace the engine entirely, not to mention the cost factor. Replacement with a JDM was 1/3 the cost of a rebuild.
Yes, building a modified car is costly. I have $14k USD in my build. I planned, figured cost, researched, calculated and calculated again what I intended to do long before I started the actual build. Sometimes you can get by with staged builds to stretch out the outflow of cash, but regardless, you will put out until its correct.
Ed did a great job with my build. He assisted in accomplishing something no one has been able to do before now and worked long hours on this to help me complete the car. All on a stock ECM. I am not running any EMS. I only expected Ed to handle the programming while I covered all the mechanical. When an issue arose that was mechanical, it was time to stop the tune, take care of the mechanics then resume to the next step. This is just common sense.
I can understand the frustration in trying to get the car corrected. I also understand that the whole issue was handled in a poor fashion by the owner. If you can't budget for proper operations to achieve your goal, put it on hold until you can. And I don't know anyone that can diagnose a vehicle properly without putting their hands on it. I get close most of the time, but I have also been building and repairing vehicles for almost 26 years. No car has ever beat me. And I am never wrong in my diagnostics.
You can not tune around mechanical issues. You have to find and repair the mechanical before the tune. Otherwise your just "spinning your wheels" and wasting time.
Irregular and inacurate information from the owner doesn't help in resolve. Its like going to the doctor and leaving out what you think is unimportant, but to the doctor it is key information.
There are plenty of references on this thread that recommended checking the mechanical funtion of the engine. And yes, a knock sensor on a Subaru is sensitive to noise. It will even pick up heat shield vibration.
The fifth gear @ 65Kph was an indication also of a mechanical issue when the fuel and ignition was altered. The car was "lugging". Too much load.
I don't believe the wastegate was the total issue. Either the true cause is being withheld or it hasn't been located. A wastegate flutter would cause irregularities in boost which would show up in logs. If the AVCS was not operating properly, why? Lack of oil? Incorrect weight? Electrical issue? Mechanical within the actuator? The flutter may have been causing a knock retard but the cause of the flutter has not been rationalized properly. Was there a vacuum leak to the wastegate?
Five Minutes is a stretch. Within this post, Kido makes suggestions towards mechanical outside the relm of wategate flutter long before the 5 minute fix which leads me to believe that Sheik was fishing for answers trying not to spend any money and trying to guess at what the problem is. (Which I believe will rear its ugly head again if it was not truly located.)
Any modifications to a vehicle need to be complete before a tune. Modifications after a tune necessitates a retune, no matter how small you think it effects the performance. When mechanical, electronic control or actuator issues arise, these need attention and repair before proceeding. When I ran into mechanical issues on the OE 3.0, I informed Ed that we need to stop until I have it resolved and begin again. In my case, it was quicker and easier to replace the engine entirely, not to mention the cost factor. Replacement with a JDM was 1/3 the cost of a rebuild.
Yes, building a modified car is costly. I have $14k USD in my build. I planned, figured cost, researched, calculated and calculated again what I intended to do long before I started the actual build. Sometimes you can get by with staged builds to stretch out the outflow of cash, but regardless, you will put out until its correct.
Ed did a great job with my build. He assisted in accomplishing something no one has been able to do before now and worked long hours on this to help me complete the car. All on a stock ECM. I am not running any EMS. I only expected Ed to handle the programming while I covered all the mechanical. When an issue arose that was mechanical, it was time to stop the tune, take care of the mechanics then resume to the next step. This is just common sense.
I can understand the frustration in trying to get the car corrected. I also understand that the whole issue was handled in a poor fashion by the owner. If you can't budget for proper operations to achieve your goal, put it on hold until you can. And I don't know anyone that can diagnose a vehicle properly without putting their hands on it. I get close most of the time, but I have also been building and repairing vehicles for almost 26 years. No car has ever beat me. And I am never wrong in my diagnostics.