HELP understanding how to tune for boost!

[nonnieselman]

Hey guys,
I need a tutorial or some help from you guys about tuning and fine tuning for boost..
I am in the process of installing a STS (6psi) on my truck in sig.

Im still kindof lost in the tuning.....
I kindof understand what needs to take place, but not sure what tables and cells to change to make it right.


Thanks for any help!!!!!

[hquick]

The AutoVE tutorial is a good place to start. That helped me alot.
Are you running a COS (custom operating system...ie COS3 or COS5)?

[nonnieselman]

Now running COS3 with a 2 bar MAP

[zapp168]

I commanded the boosted AFR to 11.7 Then logged BEN for 2bar and followed the auto VE tutorial to set up the boost VE table. I am running 14* advance in the boost area on the main spark table and using the boost spark table to retard 3* I am still tweeking it.

[Dewglass]

Reviving this thread:

Is there a tutorial for tuning for boosted/COS?

The questions I have are:

Do you set your maximum desired boost and work up to that (fueling), -or do you do small increments up to the boost desired? ( eg 2 psi, then 4 psi etc up to what your limit is.)

I plan on using a manual boost controller set to around 15 PSI.

Or do you set your max boost and just (initially) go up to 2000 RPM, make adjustments and then do 3000 RPM etc up to your maximum RPM.

What is the best approach? :doh2:

[zapp168]

I attempted to go max boost and set everything what I felt was rich enough to cover the power. The car launched...took off and fell right on it's face! :shock: I then dis covered that my fuel system was not adequate, so your safe bet is to start low on the boost and work up making sure that you are not leaning out, check the A/F and the Injector duty cycle, I believe I read not to go over 90% duty cycle on the injectors. I have actually not done much tuning to my car in years, but will try to remember if you have questions. I set the boost VE table super rich and backed it down, always better to be too rich than lean!

[Dewglass]

Okay thanks that helps. I know the truck ran with 15 psi from the factory , so that will be my set point -and it has a fresh walbro 255.

Just wasn't sure of the best way, since I am on the learning curve.