Is cracker really necessary other than...

[efizjb]

just on decel and while transitioning to idle? Please excuse the ignorance here, but I can't see where it is really needed anywhere else or beneficial given the follower? It seems your foot and throttle blade are plenty in all other areas of the table?

[WeathermanShawn]

It helps control how quickly Rpm's drop on decel, but is also used in normal cruise functions (along with Desired Airflow).

Too much in the Throttle Cracker..it will feel like permanent cruise control..not enough and it feels like your car is slamming the brakes on every time you barely lift off the throttle.

I think I ended up with no greater than 1-1.5 g/s in my TC Table (M6). I do not like the feeling of having none..but some do zero it out in the 400-1600 Rpm range..

..WeathermanShawn..

[5.7ute]

One thing I did notice with mine with TC disabled, (zeroed out as well as the enablers raised,) was TC decay still played a role in returning to idle.
Logging showed no TC addition to airflow, but having the decay rate set too slow still caused the idle to hang.
I run just enough TC to give a nice decelleration with some engine braking, too much as WeathermanShawn said will give a cruise control effect, and can cause bucking & surging.

[efizjb]

Thanks guys. I have no intent of disbabling it completely. I guess my main thought was any other area of the table other than the previously mentioned decel etc, will cause a cruise control at any other speeds which makes no sense. If you have your foot on the throttle at a light cruise, I didn't know why any add in from the cracker made sense like the factory tables on steady cruise areas, however the feeling of slamming the brakes when lifting the throttle does make sense.

I guess peoples tunes would have to be really spot on to eliminate it in the 400-1600 cells and not almost stall coming to a stop(particularly for me being auto, M6 probably easier to deal with in this respect)

Thanks to you both, you both made great points to put this in perspective!!!!!

I think understang cracker and follower have been the most difficult thing to grasp and fully understand. I'm coming from a FAST standalone, and the factory ECM's have more features and tables, not to mention adders and modifiers that are creating a learning curve for me.

[WeathermanShawn]

I agree, it is one of the toughest concepts to get ( I have not mastered it either..just managing it).

It could be that there is some auxiliary function to keeping the throttle blade open via the IAC function during cruise that serves some other function. I know in a previous thread I was discussing a rich decel problem I was encountering. It was more evident when I 'zeroed' out the TC. If I add a lot of air to the TC..let off throttle, the rich decel was not as noticeable. In effect it was as if you were still having your foot on the throttle..so it addressed one problem, but too much TC air drove me crazy. Nothing like going 80 mph and taking a mile to stop.

I agree. Still seems like 'voodoo'. Being an auto must be challenging. M6 wise I have been running a 2002 Z06 TC Table instead of the stock one. Works out pretty good.

Good luck.

..WeathermanShawn..

[hymey]

I think it can all be controlled from idle air being correct for start and not having the idle trim tables overactive and then even using timing to control how fast rpms dip. I can see how people overuse one table to compensate for another table being overactive. There is nothing wrong with this as long as the car runs fine. I personally don't use it and control it by other means and works extremely well. The throttle or air bypass still trims during the cracker operation it just adds desired air to the point you desire.

[efizjb]

I think it can all be controlled from idle air being correct for start and not having the idle trim tables overactive and then even using timing to control how fast rpms dip. I can see how people overuse one table to compensate for another table being overactive. There is nothing wrong with this as long as the car runs fine. I personally don't use it and control it by other means and works extremely well. The throttle or air bypass still trims during the cracker operation it just adds desired air to the point you desire.

Yeah I think you can achieve good results in a number of different ways. Are you running an auto or M6?