Transmission shifting mods for '09 sedan
 

I've had my G37 for about 6 months now and i love it except for one thing. The transmission. There's nothing wrong with it mechanically (as far as i can tell), but the way it shifts is quite annoying. I'm nearly certain it is a programming issue and I'd love to figure out a way to change it.

Here's an example: I love to hammer it on the on-ramps of the freeway that i take every day. I hammer it until i reach my cruising speed and then abruptly let off the gas. For some reason, it thinks i should stay in the lower gear for several seconds after i let off. The result is that the car falls a bit on its face. It does this whenever i'm accelerating and then quickly let off the gas. It seems to do this in DS and D.

Another example: When i move it into the manual mode, i like to use the downshifting to slow down sometimes instead of braking. It seems to think that i want to downshift to speed up so it blips the throttle way up to match the RPM for that gear. That takes away the whole reason to downshift.

I did some looking around and it seems to be a relatively unexplored topic.

Does anyone know how i can go about making some programming changes?

Thanks!

It's "unexplored" because it is a bonus feature called "rev matching". It's generally considered a bad practice to use your transmission to slow/stop your car, that is why you have brakes. Would you rather replace your brake components, or your transmission components? Yes, when you accelerate aggressively it will hold the lower gear for you in case you decide to accelerate further and you won't have to wait for it to downshift again.

Here is some info about rev matching:

http://www.drivingfast.net/car-control/rev-matching.htm

Note: Only review the concepts of rev matching and ignore the parts that explain how to accomplish this with a manual transmission since the computer does all of the hard work for you.

Fair enough. It's a once in a while thing i like to do. Having rebuilt several transmissions and engines personally, i get the reason you shouldn't use the transmission as a brake, but sometimes it's fun. Life is too short to not have some fun.

A previous car was a BMW 540i that i much preferred the transmission in, but that car was such a drama queen on repairs. I'll take the rev matching any day over that "what have you done for me lately" from the BMW.

Thanks!

Heel & toe shifting | drivingfast.net
^^ This looks more interesting. Either my feet are too big, wrong shoes, or am just not coordinated enough to do this.

Its probably not so much your feet or shoes as it is the placement of the accelerator and the brake. Most car builders do not build their cars with heel/toe in mind.