11SAPG37

It's definitely a quick shifting automatic if you redline it into the next gear. Not denying that. Like you said though if you decelerate then press the pedal 70% it will stay in 4th but rev til redline. I hate that. If I slow down to about 35-40 mph taking a turn I don't want to rev the car to the moon just to get some speed. Maybe some people like the lazy glide like first to second shifts during normal driving but It really bugs me. Maybe it's just my car but during every shift I get an annoying push-forward like jolt. If my car is going to behave in that manner I'd rather have a neck snapping instantaneous shift. I think if our cars were to shift sooner and a lot more firm/crisp and quick it would dramatically improve the feel of the car.

But yes, I can chirp the tires from 1-2 and sometimes 2-3. I'd like it if the trans were to shift that fast all the time, not just during hard acceleration like the ZF built 8 speed.

Please someone, tell me how this can be done...

esesnipey94

Yea I get you, in those moments tha tranny annoys me too. But in tha end you just have to remember that this car, or at least the software, is made to please a wide spectrum of consumers. From enthusiests to granny's.

If I drive in manual mode or even DS mode I can downshift into tha corner & if I don't watch out with the throttle the car will spin out. All I'm saying is out tranny's are pretty good & I can accelerate like hell in 2nd gear aha anyways getting off topic.

If anybody knows ways to improve out tranny you can "chirp" in anytime aha

crazjayz

Actually, chirping the tires when shifting is a sign of a SLOW transmission. Essentially if the transmission was really fast there wouldn't be a break in power, and thus, a weight shift causing the chirp.

But to answer your question, yes, I can do a 1-2 chirp under hard acceleration. With the stock RS-As, I used to do a 2-3 as well, but with my Michelin AS2+ I can't 2-3 chirp anymore. I'm bone stock as well.

From what I've heard (though it's a mixed bag), people have claimed that grounding wires have helped decrease the shift lag/time, especially when using the stick instead of the paddles.

11SAPG37

Never thought of it like that but it makes sense. Except a lot of high powered RWD SCT & DCT cars chirp from 1-2 and 2-3 I.E., the BMW M5. The DCT shifts in 8 ms.. I believe that is the fastest transmission available in a production car today. This Lexus IS-F has a very impressive "Direct Shift" 8 speed auto. I believe it up-shifts in 10 ms. That's faster than a lot of DCT's.

When I had my Michelin PS2 with 275/40/19 rears I couldn't get the tires to squeal at all, even with traction control off. Best tires I've experienced on a car.

I saw a G35 on of niccoclub with tons of blue ground wires all over the engine bay. I don't understand how that can have any effect on the shift speed of the transmission. Anyone care to enlighten me?

jorwick

iTrader: (7)

I had the VB upgrade done at GTM and it was $2100. Yes the core itself is only $900 but then there is another $600 for the flash file if you do not already have it. GTM sells their flash kit and then if you go FI with them or other work they will give the new flash for free. I did that thinking I was going to go TT with them but decided to move on to another platform.

The additional costs come from the labor, trans fluid, a new pan gasket, etc.

Does it make a dramatic difference in the speed of the shifts and at higher rpm's... absolutely, night and day in my opinion. Like I said I did it in preparation to go FI and whether you are or aren't and want to spend that money is up to you. To me it was the same cost of my diffuser and it positively affected how the car drove day to day so I was happy with it and whoever buys my car now will benefit.

crazjayz

The BMW M-DCT is the same Getrag unit as the Ferrari F430, which means it does have a ~8ms "ideal" shift time, which is in league with many other dual-clutch systems. I don't know about your quoted time regarding the IS-F since (I believe) it's still a single clutch system. But yeah, a hypothetical fastest shift is ~8ms. With this in mind, I've never heard any high powered RWD dual-clutch system chirp any gears with TC on. I know that without TC, you would just light up the wheels due to the amount of power. The chirp is actually caused by the tires losing grip for a split-second with TC is on. With TC on, the car can manage how much power to send to the wheels without spinning the tires. (this is pretty much the basis of using "launch control").

Pretty much you can think about it like this. Take a F10 M5 which has 560hp or so and a DCT. The tires are 295mm. From a standstill without TC, the M5 will smoke it's wheels all day, going from 1-2-3. That's because a 295 section isn't wide enough for 560hp (or rather the 550ft/lb of torque). Regardless of shift time, the car has too much power for the wheels, and thus you have to be quite ginger with the throttle without TC. The opposite is true for the G (as you mention below). With really good tires, you can put all the power to ground with no chirp (even though the transmission's shift speed isn't helping). Ideally, with the best tires, you can have zero wheelspin/chirp. Look at F1 cars when they launch, they plow from 1-3 in about 1 second and yet they don't chirp or wheelspin. Roughly a 350mm rear section and slicks tend to have really good grip, hehehe

Yeah, these tires were a beast. You should check out the Michelin PSS if you want something even better than the PS2 for the road.

Essentially, a very simplistic version is that it "cleans" the circuitry of the car. With a stronger ground the result is a more consistent voltage. For example, try opening your sunroof, putting down your window, and then turning on your radio at the same time. What you'll notice is that the window will "lag" for a second when the radio comes on. This also work if your putting up/down multiple windows at once. This is due to a surge in electrical dispersion (more things using more power), and thus causing a slight voltage drop across the system. Supposedly, grounding wires alleviate this. Many people note that there is a "lag" when using the gearstick to shift (which I agree; for me it's about 0.3 to 0.5 of a second), and after installing grounding wires, this "lag" is decreased dramatically.

That's as far as I know about the subject. I don't have them myself, so I can't comment on a first-hand basis. Hope this helps.

gsm026

I had no issue with the shifts on my '09. It would often chirp the tires shifting to 2nd ... at 5,000 feet. Shifting was nice and crisp. What I didn't like was the slow and inconsistent response to the gas pedal and slow response to the steering wheel paddles.

RavensMinded00

iTrader: (1)

Have you added a grounding kit to your car yet? I followed the DIY after having some of the same issues and it actually helped out quite a bit with the responsiveness of the shifting. Give it a shot. At the very worst you helped your cars electronics run better at a whopping $15 and two hours of your time.

11SAPG37

I'll give it a try. Like you said, only loss is $15 and at least the systems voltage will be more consistent during multiple draws.

Off subject but now that I am thinking about it, sometimes when I turn the A/C compressor on the idle drops about 500 RPM for a sec. I always thought it was because the clutch was engaging (which it can) but it could also contribute to a the electrical system because it draws from the same place the alternator does, the motor. IDK, I feel like an all around stronger circuit coul .

My eyes are still on this thread. Any other thoughts, suggestions?

gugarci

Ever since I went directly from the stock programing to the current .027D on my 09 the gearbox has become a lot more responsive in D. In fact since the reflash I've been driving in D only. Before the reflash I mainly used M in the HWY.

Also turn off the traction control unless the weather is bad. I've been doing this since I got my car in 09. The accelerator and gearbox from the seat of my pants feel more responsive with the traction control off. Not to mention off is tons of fun.

forrmark

Do you guys think you're formula 1 drivers? The G is not a race car. I have no problem with the 7 speed as it is on my 2011 G37. When I step on the gas, it takes off like a rocket. I don't take it to a track. It's fine as it is for street and highway driving.

Di3s3l_power

D is more for fuel economy than spirited driving. remember the car addresses the mass population, is not a special model for enthusiast like amg, s, rs and m cars.

If I want to drive more aggressively I switch to DS or M mode

We have to give credit to G37 for what it is, and the car is trying to satisfy the crowd.

11SAPG37

Thanks for your input guys!

There are others that actually do track their cars and have actually transformed their G's into some killer machines. I started this thread to address the available upgrades for the 7AT, not to read how satisfied one may be with it. We are all aware the G is built and tuned for the 95% that buy these cars. However, there is that other 5% that seeks better performance and realizes the potential the G has. I am glad to hear that you have no problem with your 7AT, that's great. I obviously do, and there's nothing wrong with that.

Silver37

Did you ever try the grounding wires to see if they'd help with the shifts?

Travivelli

I know this thread is old. But guys, all you need to do is let off of the throttle around the same time you shift then get back on. You will feel the gears engaging. It’s like burning the clutch on a 6mt. All you’re doing is power shifting when holding on the throttle.