fstr n u

Regarding an HP Tuners file:

The car is a 98 Camaro with a stock ECU/PCM. A 2 bar MAP sensor was installed and tuning was setup to allow for this upgrade.

The question i have is how can a tuner determine how much timing/spark advance to write into a tune:

1. pre-boost (to allow the engine not to "bog" so much)
2. in boost (to maximize the rpm table while the turbo is spooling up to max boost).

What factors have to be considered?

What levels of timing are normally considered dangerous?

The engine is an 8.5-1 compression forged motor with rear mount turbo pushing 10#'s boost with a manual transmission and FMIC.

Any help/suggestions would be appreciated.

danieloneil01

Knock is one of the main things you watch for. You slowly add timing until it stops making power, then you back it off a bit. Most tuners who've been tuning awhile know what a lot of engines like based on setup. They start there and make pulls. Your noobie (like me) start very conservative on the timing table taking small steps so the engine doesn't blow up. All the while taking 20x as long and looking over your shoulder for cops.

soundengineer

iTrader: (16)

You look at the plugs....
Plugs dont lie...
Watch the heat marking on the strap..when it gets to the bend, you have enough timing.
watch the fuel ring, start a little rich and watch for it to clean up
If you do it at the track...when your MPH stops seeing any increase, then you have enough timing.

If you watch for knock, and back it off...you will damage your engine...
Knock sensors on the stock pcm respond too slow and by then its usually too late to save the motor anyways.

Sarg

iTrader: (6)

Agreed. By the time it knocks on a high hp car, you have a good chance of breaking something. I will usually tune until I see deminishex returns. If I add a degree and don't see over 10-15 hp I will not take it any further and will back it off. Where to start and where you end up will vary greatly from set up go set up and is dependant on fuel being used as well.