2012 g37 sedan owner here, RWD, still gets acceleration lag to this day, was looking to getting a ecutek tune eventually, anyone have experience with this / fixes that ISNT the sprintbooster. Thanks!

 

I experience it every now and then... I've learned to deal with it by giving it more throttle, like a lot more... 6mt btw.

 

If you mean the car is hesitant to accelerate or downshift then yes. I read it is partly the driver's fault if they are driving like a grandma. Apparently drive by wire adapts to your driving style. I notice my car will shift gears up quickly, or won't downshift when I want to accelerate quickly. I was able to reduce this issue by turning traction control and driving in D or DS, or simply putting the car into manual mode and rowing the gears by myself. I am not sure about any ECU updates. You can also try resetting the ECU by unplugging your battery or by inputting a manual code via acceleration. You can find the full instructions on YouTube.

 

I had it all but eliminated with 90 degree spacers but it would still show up sometimes. A tune was the only thing that made my car run like it should. Just guessing here but you use spacers to turn off the CEL's but it causes a delayed reading at low RPM to the rear 02's which is sometimes used for fueling. Also make sure you don't have any leaks around any of the o2's.

 

I had my own thread going on this but has died out. My "lag" that I was experiencing was a major loss of power under 3k rpm. I've since then come to realize that it gets much worse after doing hard accelerations shortly after the engine has gotten up to temp. I think it has something to do with too much of a difference in temperatures in different parts of the engine. It seems to get much better after half an hour or so of driving which is unfortunate because that's about the max driving I do at a time. But in a scenario like going to the store where the car sits, temps even out and you start driving again in a short amount of time, the problem is mostly gone. At least for me.
From what I've seen there's many different things that could potentially cause this, so it just depends. Also, I'd suggest getting one of those bluetooth/wifi OBDII readers. They help a lot in diagnosing what's going on.

 

so while driving i notice i still have alot of lag downshifting from 6th to 5th or from 5th to 4th or sometimes 6th to 4th if im trying to pass someone on the freeway.

my car was tuned, but im still experiencing this issue.

any ideas?

 

Try a throttle body relearn. Make sure mafs are clean. No leaks around o2's. Use some ultra copper on the cat gaskets. OBD2 reader is a good idea. Watch your o2 and fueling readings they should be very close together for both banks.

 

I find this topic very interesting and confusing...
Is the "throttle lag" due to the automatic transmission not going down a gear quick enough -OR- a delay between the accelerator pedal and throttle body due to the ECU?

It is important to keep in mind the VQ37 doesn't make very much power at low RPM. Any engine that makes peak HP at 7,000 RPM won't be very strong a low RPM.
For example on a stock engine, it makes about 130 WHP at 3,000 RPM and about 220 WHP at 5,000 RPM.

If you want to figure out if it is the transmission or ECU, use a good OBD app (OBDFusion or Torque Pro) and data log the accelerator pedal, the absolute position of the throttle body, and engine RPM. If you look at the data, you will be able to see if there is a delay between the APP and TB position.

For what ever reason, my 2011 G37 Sport Sedan (6MT) has never had any throttle delay.
This is why I find it confusing... why do some 6MT have throttle lag and some don't?

 

OP has a 7AT. I can't relate to it either.

Bread, you had two "lag issues" threads, so I merged them.

 

figured, thank you

 

heres a real example of a situation i have alot,

50 mph, in drive, 6th gear, need to accelerate to pass someone, have to almost like half throttle for it to shift into 4th gear, sometimes stuck in 2000rpm(6th gear) and takes alot of umph* to get it to go

 

To me, that sounds like normal automatic trans programming that priorities fuel economy.
Also, I don't see it as throttle lag, it is the auto trans not shifting down as quick as you would like.

If I read between the lines, is this what you would like:
• to have the trans to drop down a gear when the accelerator pedal is push about 1/4"

 

yes, kinda. just want it to be more responsive sometimes, cause sometimes it DOES work as i want it to, other times it likes to be a real pain
remember i am tuned, and using the performance map

 

WHP wouldn't matter at low RPM that is what Torque is for!
its the 7at its garbage only way to get it fixed is to spend the money and get it rebuilt with new clutches and upgrade the valve body..

 

Your tuner can further increase the "Estimated Toque Delivered" table (UpRev) / "Torque Demand" table (EcuTek).
This tells the transmission the current engine torque.
If the values are increase the line pressure in the auto trans is increased, the shifting is quicker and the kick down should also happen sooner.