I am in the process of doing my first tune, I have the blms close and have locked them to 128. I am tuning off the INT and I am getting close.

My question is when I am in WOT at 3500-4500 I am getting about 1-2 deg of knock retard. I have 21.4 lb injectors at 44psi I have the afpr set at 48 psi. I have the injector constant set at 21.39lb.

I have been increasing the 90-100 VE amounts in this area and some but not all of the knock is gone.

My question is am I out of injector? How do I figure it out. I am linking my scan and my bin. I would really appreciate learning how to figure this out.

I have as yet not done any MSA. However, I have pulled a bit of timing from the PE spark advance. I will pull more if I am out of injector.
my scan

my bin




Thanks in advance.

Tom

 

For someone with a 15" screen to read thur that log is really challenging, can you edit it down to the areas of concern and repeat the header once in a while?.

When you exceed 90% of the possible time available for the injector to be firing your out of injector.

At 6,000 RPM you have 10 msec between injector firings. So if your at over 9 msec pulse your out of injector. At 4K RPM you have 15 msec., so at 12 msec you'd be out of injector.

RPM divided by 60, and take the inverse of that gives you the time possible.

 

Grumpy

does that meen that at 6000rmp you can never see a pw over 9ms? will the computer stop the pw from going into 100%dudy cycle?

 

This is what I wanted to know. I guess I am not out of Injector BasePulseWidth ms, at say 4100 I am only at 9.69 so I still have more left.

I am in the mid 90's ve at such an rpm so I will try to add a touch more fuel.

Should I pull spark from the MSA or from the PE spark advance to help out with the knock?

Also, is 1-2 deg of spark retard on an WOT full out run anything to be concerned with?

In addition how come some times no knock count is regestered but knock retard is still shown?

PS. I modded my scan file so it is small now.

 

The ecm will continue to calculate whatever lenght pulse width, it's commanded to. You can see Duty Cycles of 120%, but that just means the injector is static.

When things are correct, you shouldn't see a PW of over 9 msec at 6K RPM.

 

The PE spark table is just to give the car the FEEL of going fast. I never use it.

If you see 2d of timing retard, the engine is only knocking by about 1d, so your just wasting advance. For a street car, you'll do fine to run 1-2-3d less and add just a little fuel.

Excessive timing always makes a car feel fast, but it's not always the case, that it is faster.