Nissan 370Z Forum - Cobb AccessPort for 370Z!

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- - Cobb AccessPort for 370Z! (http://www.the370z.com/tuning/6522-cobb-accessport-370z.html)

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Originally Posted by Zsteve (Post 426860)

I agree that they should have waited till they had maps before putting it on sale. Thats why I dont always buy aftermarket things when they first come out, I wait till others have it too and the price wars begin.

:iagree:

While I am glad someone is working on VVEL, in the meantime I think they should have released maps without any VVEL work to help keep people happy until then. Plus I am sure they could have charged an "upgrade" fee for the new map with VVEL unlocked.

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Travis

How about a refund? Bought mine almost a year ago and in disguest, unloaded my $$ dyno tuning programming converting the ECU back to stock.

Finally figured out why the car got such poor gas mileage...... It's the AccessPort. Not really one that into gas millage, but on a trip noticed the car was getting less than 19 mpg on the hwy doing 85-90. OK, me driving fast. By happenstance, the AccessPort was in the car and used it for something it actually kinda does do (even though it's not accurate)...... read the 02 settings. They were pig rich. Pulled over, downloaded the stock tune and the car jumped 4-4.5 mpg better still driving the same speed with normal looking 02 readings.

Kept the stock tune in the car for a while and tried downloading a newer version hoping the bug was fixed. Reprogrammed the ECU and this time doing a road trip to a seminar down in Houston. Same story..... The Accessport negatively effects gas mileage causing the car to run pig rich. How much additional wear does this put on the cylinder walls and rings Travis? Guessing a fair amount as it's washing the lubrication away.

The bottom line is between poor quality from Stillen, things that don't work like the Accessport and grossly over rated items like the Stillen headers, I'm selling the car.

What kind of fun is this when expensive items that are suppose to work...don't.

Refund?? I'll gladly take one and forget about all the dyno time money I spent.

I am dismayed to hear about your experience with the AccessPORT and I hope we can resolve this for you. I was able to pull up your dyno graph from Plano and do not see anything that would lead me to believe that your car was running overly rich when it left the Plano facility.

http://surgeline.cobbtuning.com/dyno...rgb2=204000000

The data displayed by the AccessPORT is the actual reading from the stock O2 sensors and is not any more or less accurate than the sensor itself.

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.

According to your post, the stock map ran leaner on cruise than the tuned map and your MPG jumped 4-4.5 mpg, were you able to log this and tell what was going on with the car? 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?

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Cobb in Plano Tx did the original tune and I tweaked it on three dyno tuning occasions after finding the car was pulling out timing and tried to correct the Cobb tune.

No offense back, but you need to learn how tuning software should work. Changing the fuel/air ratio to optimal during acceleration has no effect on driving fuel tables with other software I've used like LT1.edit and HP Tuner. Your tweaking apples and oranges. The computer is suppose to be looking for certain air/fuel ratios and correcting itself to them. Obviously this is not working correctly with the AccessPort.

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?

Were you altering the calibration that Plano created for your car or did you start with the stock calibration? 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. Again, graphs and logs would be beneficial to help understand where the issue was.

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To be absolutely honest, did not purchase the car for gas mileage and really never check it. It was basically an accident that I discovered it on an impromptu unplanned urgent family business trip. So when did it start?? Damned if I know, but I downloaded updated software and checked it again to verify what was going on.

Not a professional tuner, but I used to hang around a bunch who were to the point where I'm pretty confident doing basic tuning by all means. When the car was tuned at Cobb I spoke extensively with Calvin whom does their tuning on what tables they use and what parameters they look for. Everything he said was consistent with what I've seen in the past and basic tuning 101.

Calvin recommended for open loop conditions (WOT) the primary fuel table be adjusted and for finer tuning where the primary fuel table is not adequate, tweaking the MAF tables. In my experience the MAF tables can be very tricky plus the primary fuel tables seemed to give the desired effect so the MAF tables that can effect drivability and fuel economy, were not touched.

This comes directly out of the Cobb AcessTUNER tuning manual:

"Primary Fuel"

This table is referenced by RPM and Theoretical Pulsewidth (Engine Load) The tables values represent the A/F ratio you wish to run during open loop conditions. Doing so will normally not result in an appreciable decrease in fuel economy since these conditions are only met only when driving the car aggressively.

During idle and cruising, the ECU uses a Closed Loop strategy designed to optimize fuel economy, not power."

The only other tables that were touched were primary ignition A and B which I found from logging did not like adjustments more than 1 or 2 degrees. This also has no effect on fuel economy.

In my experience basic bolt on moded cars do not need drivability tuning. When you get into more radical cams and high compressions, playing with timing segments and driving A/F tables can smooth out driveability plus help pass emissions tests. Basic bolt on cars.....no fricky way do you need to.

So.....you tell me what magic does Cobb have that you think I don't I have? How would you tune the car?

The calibration you recieved was for performance driving it would appear. If you are in need of an "economy map" we can certainly address that for you so that you have a map for performance drivng and one for highway driving, that is one of the advantages of the AccessPORT.

We have found that adding modifications, especially to the intake system of any modern, MAF-based car, can drastically alter the way the car behaves. While in the past you could make drastic changes to a vehicle without negatively impacting driveability and performance, we have found that this is no longer the case, even with basic bolt-ons. Even the simple addition of an intake can drastically alter the way a modern car, such as the 370Z, runs.

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

That is what you call service and why I'm getting a Cobb AP this week.

Hell yea.... Thats what i am saying... This is a great company and even though there product still has some bugs to be worked out, they are more than willing to lend a helping hand.

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Originally Posted by bluestyle55 (Post 428117)

Hell yea.... Thats what i am saying... This is a great company and even though there product still has some bugs to be worked out, they are more than willing to lend a helping hand.

Then buy mine...... $50.00 less than anyones best price or offer to sell. I'm moving on to other things.

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