Nissan 370Z Forum - Cobb AccessPort for 370Z!

Quote:

Originally Posted by COBB Tuning (Post 427487)

I am dismayed to hear about your experience with the AccessPORT and I hope we can resolve this for you. QUOTE]

COBB Tuning

Travis

I appreciate your response.

Frankly liked everyone at the Cobb Plano facility and all seemed to be stand-up regular people. A third party within the industry with a vested interest in Cobb doing well hooked me up with you guys thinking it may be a good marriage. (At one time I worked directly with the engineers at Haltech to developed an engine management system for LTx F-bodies. Currently have money invested in developing some other new 370Z products.)

On at least two occasions prior I e-mailed back dyno findings with attached logs on issues found with the program directly to you and copied both Neil and Calvin. No one seemed to give a fat rat on feedback and never heard boo back. So much for the marriage as I couldn't even get a hello kiss.

Quote:

Originally Posted by COBB Tuning (Post 427487)

Keep in mind that the O2 sensor in your car is a narrowband sensor and not a wideband so it does not read AFR accurately. The data displayed by the AccessPORT is the actual reading from the stock sensor and is not any more or less accurate than the sensor itself. COBB Tuning

FYI.......The 370Z front 02 sensors are wideband according to a number of sources.. As mentioned, literally threw away all my logs but from memory the AccessPort 02 readouts were all over the place below 4000 rpm and showed about a half a point rich over 4000 as compared to RPM's dyno wideband.

Quote:

Originally Posted by COBB Tuning (Post 427487)

That said, what AFR was the tuned map reading? What do you consider pig rich? Your graph shows an AFR of around 12.5:1 tapering to 12.2:1 which is just about perfect for an NA car. Cylinder wash shouldn't be a concern till about 9:1, which is beyond the range of the stock sensor to read and if this were the case, I would start leaning towards a mechanical issue of some kind. COBB Tuning

Pig rich is a 20% reduction in fuel economy for no real reason showing A/F readings in the 12's during hwy cruising. Under perfect conditions, it takes about 14.6 lbs of air to completely burn 1 lb of fuel (an air/fuel ratio of 14.6:1) Most factory driving fuel maps are below but very close to that magic number under normal operating temperatures and loads. Although 14.6 A/F is the perfect ratio chemically, not every oxygen molecule in the air will "find" a fuel molecule to react (burn) with.

During my last trip to see if the software was working better, the car was getting 23 mpg at a steady 70mph. Pulled into a gas station, removed the tuning putting the stock program back in and it jumped immediately to a steady 27 mph.

How can that be mechanical?? Nice try, no cigar!

Your correct on full throttle A/R readings, however as a general rule WOT A/F can vary greatly depending upon the individual car. I've seen optimum N/A performance in the mid 12's and also seen mid 13's work the best for certain cars. fyi.....Pro Stock tunes for low 14's. Forced induction in the high 11's to low/mid 12's. Agreed, these cars seem to like mid to mid high 12's. The WOT reading are fine. No issues. Driving A/F's are always higher.

Quote:

Originally Posted by COBB Tuning (Post 427487)

You state that you then downloaded a new version of the AccessTUNER software or Firmware hoping that we had fixed a bug to deal with your poor fuel economy. The firmware and software do not impact the calibrations in any way; what map did you reinstall on your car? Was this the original calibration from Plano or the stock calibration? Were you able to datalog the car during this time to see what changes had been made and how the car was behaving?

The AccessPORT unit itself does not actively alter the calibration while the vehicle is in operation, it can only read or write data so if a stock calibration was installed, you should not have seen any change in performance. If you were using the calibration from Plano, this too would remain unaltered by the software or firmware update. Can you tell me what new software you downloaded? COBB Tuning

Cobb website and download your latest software and made sure my firmware was current. So as to prevent prior issues, I transferred the primary fuel A/F and other settings such as rev limit manually making it a complete fresh reflash. The MAF tables were not touched by either myself or Calvin at Plano. Nada, Zippo. Stock to stock to stock MAF.

It did the exact same thing with the latest of latest everything from a fresh start.

Quote:

Originally Posted by COBB Tuning (Post 427487)

Do you have graphs and datalogs from when you tweaked the map? In what way and how was the car pulling timing? Were you seeing knock correction under high-load or in normal cruising and low-load conditions? COBB Tuning

As mentioned prior, these were e-mailed directly to you hoping to not only resolve issues for myself, but anyone else using it. I paid for the dyno time out of my pocket and offered everything free.

Quote:

Originally Posted by COBB Tuning (Post 427487)

Were you altering the calibration that Plano created for your car or did you start with the stock calibration? COBB Tuning

Again, found in the past altering MAF calibrations can be a real pain and a lot of driving/dyno time to get everything correct. If I were to play with the MAF settings, it would be because issues are obvious or trying to find that extra 1-2 hp. Generally not worth the effort if it ain't broken.

Quote:

Originally Posted by COBB Tuning (Post 427487)

These cars are very sensitive to changes to the MAF sensor housing/intake and MAF calibrations. If you were using a stock map and not altering the MAF calibration correctly, this could be the reason your car was not running properly.. COBB Tuning

At one time thinking bigger was always better, used to always either purchase a larger or have the existing MAF bodies ported only to find out I was taking a step backwards. The advent of wideband 02's and data logging changed that.

Yes, air input can adversely affect tuning and A/F. However, I've not experienced anything drastic enough to warrant the type of issues I'm seeing from simple air intakes. Again, nice try, no cigar.

COBB Tuning[/QUOTE]
We are more than happy to take another look at your car and we would like to get you back on the road with the car behaving to your satisfaction. You are always welcome to bring your car by our Plano facility if you are having issues with your tune. Barring that, if you can supply us with datalogs or graphs from your other tuning sessions, we can be of more service to making your car perform up to your standards.

Travis
COBB Tuning[/QUOTE]

Thanks for the offer but I'm washing my hands entirely. Really would rather have that refund...Please!