NAN777

Hi all,

recently i've just ported my motor during my rebuild. reason i rebuild is my dead water seal and iron housing chips.

basically, my motors are pretty stock with some mild mods.

my question will be.... the tuning difference between the street port and a stock port motor.

1) INJ - does ported motor needs to be richen up or lean up ?

2) IGL - does ported motor allow more +ve angle or less angle ?

3) IGL-IGT Split - does ported motor needs to be tuned at higher +ve splits or lower -ve splits?

i don't want to blow my motor the 1st movement i do to adjust the timing or fuel map.

SPICcnmGT

I'll answer 1 and 2. I'm not sure for 3 but I would think about the same as stock.
1) It will need richening because or more airflow in/out of the engine with less boost due to larger ports. Since the MAP reads manifold/boost pressure and not air flow like a MAF.

2) it will need retarding some. It depends on your port how much, but I think -(3-4) will be safe to start with if it is just a street port.

NAN777

-ve 3 to 4 for IGL ? on boost ? that's something new to me... haven't seen my map having any negatives at the moment other than my IGT...

any more ideas ? wanna her some more feedbacks before i put my fingers on it to start changing the values...
before and after is just ported and 2 piece seal.

SPICcnmGT

I might not have been very clear but just remove 3-4 degrees from the stock/tuned map you had before. Example: If you had 15 degrees of timing under full boost for the IGL at say 6400 rpms, you would retard that to 11 degrees of timing under full boost for IGL at 6400rpms.

NAN777

okay... understand that...

anyone who can shed some lights on the split ?

NAN777

anyone know about the splits on ported motors ?

fd3s7007

hehehe. rent a dyno with hold capabilities.