Cobb AccessPort for 370Z!

Denny McLain

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.

theDreamer

No offense, but your car should not be running that badly, the person who did your tune is to blame not Cobb (unless you went directly to Cobb to have your car tuned).

__________________
theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN
theDreamer's Silvia // URAS // GREDDY
Houston Zs // Facebook // Twitter // Instagram

Denny McLain

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.

theDreamer

I know how dyno tuning works, but they are not just suppose to tune top end power only. They should be doing different pulls, tuning all sides of the car, performance, cruising, etc. You mentioned you made your own edits, was this before or after you were having bad MPG?

__________________
theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN
theDreamer's Silvia // URAS // GREDDY
Houston Zs // Facebook // Twitter // Instagram

Denny McLain

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?