I'm running 12 lbs of boost and I would like to increase to 15, maybe even 18lbs. I have enough fuel pressure. Do I need to have the car retuned when I add more boost?

 

Yea, you have to get the car retuned for that much boost being added. You dont need more fuel pressure...just more fuel. They will have to richen up the a/f ratio when you up the boost because with that much more air, you are gonna be running lean as a ****.

 

You defiantly need to retune and stay out the boost until then.

 

It depends on your air/fuel. If you have a wideband and can keep an eye on it, then test it out and see where it goes. one or two lbs of boost doesn't automatically mean a necessity for a re-tune anything more then that, absolutely you'll need a re-tune.

 

He has 12 and wants to go to 15 maybe even up to 18. You also have timing to consider when adding boost, because of the increased intake temps.

 

I guess I didn't much consider the other variables like temp, altitude and Timing. I've known plenty of mustangs with a conservative tune on 10lbs going up to 12 lbs without much problems. If he's I/C'd that would help but you're totally right, if he's going from 12-18lbs then absolutely he needs a tune.

 

I plan on adding a wide band F/A meter before I add boost. I had the car tuned by a mustang shop here in south florida on a dynojet. I don't have a problem taking it back to have it retuned, but I'd like to know what I can do without spending $150.00 an hour for tuning. Can I add a Diablosport or other type hand held tuner to adjust the timing?

 

$150 an hour is worth it to have a well running engine that you dont have to worry about. Rebuilds are expensive.