Need new chip burned if EGR not used?

[AirBuick]

I've got GN1 heads with no EGR and someone posted recently that you should get your chip re-burned to accomodate this. Apparently, you'll get a lot of part throttle knock (as I've been struggling with) if the chip is not changed. Can anyone explain why this should be done and do I have a good chance of getting rid of the part throttle knock if I do it? I've got a trans w/ extender and not afraid to have a new chip done. Thanks.

 

[Scott231]

Yes, you need to hav the chip altered for the following 2 reasons:

1) The stock chip parameters are to use a particular table to interject exhaust gasses at certain Load vs. RPM points. With the GN1 heads, none of those gasses will get past the cylinder head. BUT!

2) The The stock chip parameters also add timing during exhaust gas recirculation (which actually cools the temperature within the combustion chamber). If there is no additional cooling from the EGR, then the timing will be too high.

Now note that there is a relatively low RPM point where the EGR function is not active anyway (~2,200?). Accordingly, you may not give a damn. You only have to change one byte on the chip (and the corresponding change tot he check sum). Myself and many other chip buringing individuals can do this for you.

 

[bruce]

Originally posted by AirBuick
I've got GN1 heads with no EGR and someone posted recently that you should get your chip re-burned to accomodate this. Apparently, you'll get a lot of part throttle knock (as I've been struggling with) if the chip is not changed. Can anyone explain why this should be done and do I have a good chance of getting rid of the part throttle knock if I do it? I've got a trans w/ extender and not afraid to have a new chip done. Thanks.

In your sig you list an extender chip.
It's already turned off in there.

 

[AirBuick]

Thanks Scott!

 

[AirBuick]

Sorry Bruce, didn't know that was a feature of the extender chip. I guess my kr is coming from somewhere else. Thanks.