jeremy341a

iTrader: (2)

I am intersted in bracket racing a 2000 Z28. I would like to have the PCM programed for consistency and not best performance. What is the best way to go about this. I want to bracket race and not have the car spitting numbers everywhere because of it running on a million different fuel and spark maps. Give me all the options and please take it easy on me, I'm new.

Thanks in advance.

SSpdDmon

iTrader: (10)

Tuning for consistency...

1) Install 4L60E (if not equiped).
2) Install drag radial tire (if not equiped).
3) Install competent driver w/ good reaction time (if not equiped).

Enjoy.





On a serious note, the only thing you can really do is to copy the high octane spark map to the low octane spark map and turn off COT. Make sure the spark advance isn't too high because the knock sensors will still pull timing if they detect knock (unless you want to turn them off - not recommended). Other than that, just make sure your MAF stays clean and the O2's are working right.

MeentSS02

iTrader: (11)

Consistency? It really doesn't have much to do with the tune except for what was listed above. You need to make the car consistent in the conditions it sees. In addition to the list above, I'd probably install an electric water pump to keep the coolant temps down in the staging lanes. That'd be about as consistent as you could hope for.

jeremy341a

iTrader: (2)

I would think that the computer picking a different fuel and/or spark map would affect consistency a great deal. I am fairly sure that is what was happening with my old car when it through me a crazy number. This car will be mostly stock so traction issues won't be a great concern. Is there anywhere that does pcm programing for something like this. keep the ideas coming.

MeentSS02

iTrader: (11)

The PCM's we use only have a couple of interrelated fuel maps, and those can be skewed by higher IATs or ECTs, and are adjusted as a function of a multilpier. Getting rid of the multilpiers, and making sure that your spark values are consistent (getting rid of adders and subtractors, and even setting your high octane table the same as your low octane table) is about as good as you can do.

Keep the IATs consistent, and the ECTs consistent (EWP), and that's all you can do.

I'll keep my thoughts to myself as to who could do it...but I'd lean more towards a private tuner that really knows their software instead of a large shop that is simply looking for as many customers as they can get.

SSpdDmon

iTrader: (10)

No different fueling MAPs - there's only one MAF sensor, which is used almost entirely for WOT runs. Natural motor performance and spark is the area where inconsistencies will occur (due to intake temp variances). If you start off the day in 110* heat running 13.80's and stick around for an all-night event, plan on running faster. As intake temps drop, the motor will naturally perform better since the charge density of the incoming air is changing for the better. The spark adders (or subtractors in this case) will also begin to fall off. A good example of this is the spark vs IAT table. Once the intake temps are over ~100*F, up to 3* of timing can be subtracted from the commanded values.

The point is, the variables that cause most of the inconsistencies in a nearly-stock car's performance are the ones we don't have any control over (ie weather, track temps, head winds, etc.). That's why die-hard drag racing teams measure everything. That way, when they encounter similar conditions...they know roughly where they're going to run before they even make a pass.

Slowhawk

iTrader: (12)

You just need someone to tune it to lock down fuel/timing.Only weather conditions will change the times.