Brenspeed Tune and Other Strange Events

[pagerart]

I have had my Brenspeed tune since November and am very happy with it. I retune the car back to stock when I take it to the dealer, even though some of you say it is a waste of effort. I do notice a change when I tune it back, but either way it seems pretty peppy, at least until yesterday. I was sitting in the car waiting for my wife and decided to plug in the programmer. Nothing happened and I was hoping it was only a fuse. I didn't want to have to explain to the dealer what the problem was. When I left the parking lot, I noticed my air conditioning wasn't cold and that my instrumentation was off. Since the programmer port and the instrument cluster are on the same fuse, I immediately stopped at a parts store to buy fuses. After replacing the fuse, the car was fine, but the engine light was on. I pulled over and programmed the car to stock tune. After that it ran fine, but just didn't seem to have the responsiveness it usually has when I tune back to stock. It just ran like a Mustang. Later I set it back to the 91.5 octane tune and it ran better than ever. I don't recall such a big difference between stock and 91.5 tunes. The car was running great. Does the tune really go back to regular stock (the Shelby version it loaded the first time I used it) when you go back? It seems the resetting of the system due to the fuse issue made a much bigger difference between the two tunes.

 

Here is another interesting related event. Ever since I got the car, the air coming out of the air vents always seemed to be warmer than the outside air. Even when it was a little cool outside (that is about 68 degrees in California) I would still have to cycle the A/C to keep the car comfortable. I took it back to the dealer and they said everything was fine. They said they checked the switching in the ducting and the heat wasn't leaking into the vents when set to cold. Well after changing out the fuse, the vent problem was fixed. I no longer need to run the A/C at night. Somehow the repowering of the system had some effect on the hot/cold ducting.

 

My car was better than ever. So today I finally got my Steeda underdrive pulleys installed. Now the car is really hot, and I don't mean the interior temperature. I love this car!

[07SHELBY GT]

These new fangled contraptions never cease to amaze me!Glad it all works better for you regardless of what took place.

[SGT1171]

I'm very close to doing a Brenspeed tune, but not being very up to date on these matters, I don't want to have performance issues or dealer issues.

 

Is it really necesary to tune back to Shelby SGT tune when taking in for service.

 

And does the car hold the Brenspeed tune when battery is disconnected while in winter storage.

 

Would appreciate everyones experience and advice. The car runs pretty good without running into hassles.

 

Thanks.

[Reino]

I'm very close to doing a Brenspeed tune, but not being very up to date on these matters, I don't want to have performance issues or dealer issues.

 

Is it really necesary to tune back to Shelby SGT tune when taking in for service.

 

And does the car hold the Brenspeed tune when battery is disconnected while in winter storage.

 

Would appreciate everyones experience and advice. The car runs pretty good without running into hassles.

 

Thanks.

 

I cant answer your questions about storing it but would assume it would retain the tune much like it would retain the SAI tune. Dont believe you have to put the SAI tune back in the car when taking it in for service though I plan on doing it and would recommend it.

I just installed my tune 2 days ago and am very happy with it. I noticed a difference the moment I turned on the car after the install. Much more responsive and I dont have that lag anymore when taking my foot off the accelerator. The car actually slows down without hitting the brake now.

[CudaFly]

It seems the resetting of the system due to the fuse issue made a much bigger difference between the two tunes.

I'm definitely not an expert but disconnecting the right fuse or the battery won’t erase the tune but will reset some of the parameters associated with your tune. Then, when you first start the car the adaptive strategy logic will kick in and start making adjustments to your fuel trim (and other) elements based on information from the O2 (and other) sensors. You may notice improved performance at first that will ‘degrade’ from peak over time (a day or two?) this is normal and the adaptive strategy is there to keep your motor running within acceptable ‘safe’ ranges, and probably reduced emissions.

 

If you want to get more consistent peak performance you may want to consider getting a more aggressive custom tune with verified performance on a dyno.