991.1 Guy

I would like to hear some feedback from M. It looks like boost is being limited until about 4600 rpm to keep the AFR in check.

M Engineering

Great questions everyone! Nice to see the community using logging from M-Tuner for further data analysis. This is something we are always happy to review. MegaLogViewer is a great tool for datalog review that you can download for free or purchase an upgraded version. The boost chart that Tupper has shown has the PSI on the left and AFR on the right. Boost is the red curve.

We intentionally limit load and boost on the hit to keep the torque down. It has nothing to do with keeping AFR in check. The lambdas operate on a closed loop system and have setpoints to target based on various conditions.

Keeping torque down is very important for the transmission until PDK tuning can assist with clutch clamping forces. Too hard of a hit and too high of torque on an initial pull can cause clutch slippage. When this occurs, RPMs dip and the cars do wonky things and shut down and can cause errors.
For this purpose, boost is kept lighter on the initial ramp-up (you can see this where it holds at a plateau) and then continues again as the RPM range continues upward.

-Charles@M

Tupper

That's what I and a few other forumers figured, Charles. Thanks for answering (I emailed your team the same question, so you can ignore that).

Tupper

By the way guys, I hit over 25 psi boost on one run, and between 24-25 psi on another. Keeping in mind that with stock calibration peak psi is 16, if I'm correct. That's a major uptick in power

M Engineering

I know Charles responded but I wanted to pop in here and give some more feedback.

We do this with boost on purpose. We don't want torque to be really high in this range as this is the range that has the highest chance of bending rods. Our OTS maps are made to be faster, but also safer. We have raised torque enough, but want to keep stock clutch and components in good shape.

We are very clear with data, and we enjoy the feedback and working with the community on feedback and looking at what has been changed.

You can get software from here to view the .csv's if you want to see it. Happy to chat more about it and go over it with the community.

http://www.tunerstudio.com/index.php...egalogviewerhd

Cheers!

Mitch McKee

LifesAnesthesia

Anyone with a Base C2 have the M tune? I'm curious to know how much harder the car pulls and if the power and feels similar to stock?

Skarz

interested as weep, as I have a stock base C2 and am thinking about a tune.

mattchow

im sure I could search as well, but best way to data log is 3rd gear starting at 60mph?

mattchow

I just tuned my base C2 on Friday, I'm still trying to get used to everything. The car behaves like stock, but you can definitely tell its waiting to be opened up and get violent.

Ah10

I would do 3rd gear at 3k rpm all the way to redline

M Engineering

WOT 3rd gear pulls to redline are generally the safest to do on the street. 2nd gear is also ok if 3rd is not possible. We do 4th gear pulls on the dyno when we are tuning, but those tops speeds are a bit too high for the street.

-Charles@M

Homecast

Hi Charles,

sent Scott today two logs from 3rd to 5th gear redline (German Autobahn), so lets see what he can find :-)

Christian

Snapperkid

I have a base. It pulls very hard. I haven’t found anything I don’t like yet.

Tupper

So I have done a few WOT’s without problem.

Today I did a WOT and I suddenly got a message on the dash:

“Transmission failure: Park vehicle carefully”

That message flashed for a couple of seconds and then disappeared.

I drove around and it never came back.

But now I’m really concerned that that happened. Does this tune generate too much torque? I’m really wondering what I should do here. Has anyone else gotten this message?

Snapperkid

Did you go back in a read the faults? I’d read them take a pic, send to M then clear the faults.