Timing Retard with FI

[Lextreme II]

Hey Gang,

Right now I am retarding about 1 degree with every psi. The car still needs more tuning for it to run perfect. Just wondering if my setting is too much or too little as far as timing is concern. This is both RPM and PSI dependent.

 

[Peewee]

I reckon its a bit much personally, but I haven't played with any high psi applications.

I reckon at most it should be retarded 10 degrees MAX.

Anything more than that, are you would be better off lowering the boost and dialing in more timing.

But its something you will have to play with on the dyno.

 

[Lextreme II]

PeeWee,

Is the 10 degrees boost dependent or independent?

 

[Peewee]

Probably independant.

As you retard the timing, you loose power, regardless of how much boost you have.

For instance (this is just figures I'm guessing, I have no proof, its just a hunch)

running 20psi with 10 degree advance, will probably net less power than 15psi with 20 degrees advance.

Its sometihng you will have to play with on the dyno.
Are your stock knock sensors working?
Can you get someone to listen to them as you play with the boost levels and the timing?
You will have to set to boost to a limit, go through the rest, and dial in as much timing as you can before it knock.
Then up the boost, and repeat the process.
You will then know how much boost you can run before retarding the timing too much causes a dip in power.
It all depends on intake temps too.
I hope the intercooler is nicely sized.

 

[Lextreme II]

thanks.. i will try 10 degrees retardation with 15 psi.

 

[MaxPower]

Just as a reference a friends car (Built low-compression 1UZ in a JZA80) runs a total of 15* advance at WOT with 15psi (has a GT35/40 strapped to the side). Iam running about 28* with a stock NA engine.

I have no idea what total timing u could run with the stock engine before it knocks but id thought id let ya know anyway as it may give u an idea where to start.