I have a built 359w with edelbrock 205 heads, f303 cam, and turbonetics 7868. I am using a fast xfi system and 60lbs injectors. Anyways I am trying to get it tuned by a buddy, and it doesn't want to idle with a high afr then 13.3. He says that turbo combos don't like to idle with anything higher. Is this true? This is my second engine, the first one washed the cylinders out due to excessive fuel.

 

Some will idle at 14-15:1, and many others won't. I've never had, or heard of a problem with a moderately rich idle. I personally wouldn't be worried with an afr in the 13's.

 

One thing I've noticed about tuning idle is tune it to what ever af it likes. What fuel? Stoich for 10% ethanol is 14.3 and 14.64 without ethanol.

 

93 octane

 

That's what he's doing

 

Make the engine happy at idle and don't worry too much about the AFR unless its like 10.5:1 or something ridiculous. You can change the timing at idle and get some differences in AFR but again, it's all about making the idle as smooth as possible. The other thing is your 02 Sensor is more likely to see the effects of the exhaust pulses, reversion, etc. so it may or may not be totally accurate at that point.

 

our last set up idled at 13-13.5:1 at idle in park then in gear would be close to 14,, our combo was carbed,, cold idle was closer to 14 maybe a little more but when warmed up it would come down a little

 

cam has a lot to do with it.

Reversion can throw off 02 readings at idle. So as was said , give it what it wants.