Sounds crazy, I know.. But here's the deal.
A little background: Had the car for about a two years now so I know her pretty well. She's an 06 coupe AT with an exhaust, spacer, k&n, and a tune. Car always felt pretty strong, especially after the tune. Managed to cut a 14 flat last summer on street tires and full weight (sound system, 20" wheels, etc.).. I'm happy with it, but occasionally I'd notice a little lag from a dead stop, even after the tune.

Anyway, for the same last year my oem battery has been on its way out. It would die real easy if I left the radio on or used my bluetooth. And then recently, it basically just died altogether. So about week ago I replaced it. Popped in a Duralast Gold,. Started right up. Ahhh much better than that weak start. After that, didn't think much else of it other than now I don't have to worry about my car not starting. The next day, I randomly decided to get on it. The car pulled harder than ever! Literally. No lag, no soft spots, nothing, just a strong steady pull... But wait, this can't be right, it's just a battery.. I know some people are thinking that, because I would and was too, but it's been this way since last week.. I find myself testing it just to see if it will go away, lol.
I'm thinking maybe the oem due to age was interrupting the grounding capability of the chassis or something. Who knows? I really don't. I just the know the difference is there. And It's fun.

Moral of the story (and this is important!) - mod first, tune next, and then, and only then, you set it all off with the battery upgrade, Oh yes. Easily the best bang for buck. .

 

tcu's in automatic transmission tend to be sensitive to voltages. Since your battery was on its way out, more then likely the tcu was slightly being under powered but not enough to trigger a cel.

you swapping out the battery allowed the tcu to receive full voltage, thats why the car seems more responsive.

Same reason why some people with automatics feel a performance difference when they add a grounding kit.

Basically you didn't get more performance but the performance your car should've been performing the whole time.

If your car was manual, you wouldn't have noticed a difference between batteries.

 

Wow! cool story though, but this guy^ is right.

 

reset ecu = more power

 

6spd = more power

 

^ lol

 

^ not if the driver thinks he can drive a stick, in reality he can't . Automatic will beat it Everytime.

 

You'd have to be pretty damn bad or a complete noob. Anyone with more than 2 weeks worth of experience and not a complete tard should have enough skill to pull it off effectively enough.

 

Uh oh, this is turnin' into a MT vs AT topic... You'll never convince everyone that one is better than the other, so why bother. Just choose your preference and be done. I enjoy the flexibility of an nice auto.

Just a little food for thought Jhambor and cakestar, Every car I've owned/modded has been AT and I have yet to get beat by the same car w/MT..

But yeah Temjin, that's kinda what I was thinking. I drove it again today and the power is still there. The TCU and the ECU must also talk to each other in some way cause it seems like there might have been some timing adjustments too now that the TCU is getting its full signal. Cars a beast right now. Can't wait till track season.

 

This was all in your head. The battery is used ONLY to start the car. After that, the alternator runs the entire car. Replacing the battery simply gave more cold cranking amps to the starter to kick it over. Then the alternator distributes voltage back to the battery to replace the energy that was used to start the motor as well as keep the ECU fed.

It won't make it perform any better. Only start better.

 

i have AT and didn't feel anything different after replacing mine :\

 

Broh, I hope your not a doctor or a psychiatrist. Reminds me of an article i read...

Maybe it is all in my head. But as long as I'm mentally making my car go physically faster, I'm happy.
Anyway, read what we've discussed above. I think that's what's going on.

 

Yeah, not sayin' everyone will notice this. But I think this is probably a good example of how having your car in the right order can make a big difference. Just cause something works, doesn't mean it's working to its full potential. Maintenance baby, maintenance.
Or like dude said above, maybe I have mental powers I didn't know about lol.

 

if thats true then i wished i had these powers too

 

Why was the resetting of the ECU not mentioned in this thread yet? OP, its common for the car to feel like that when the battery has been disconnected for a little while.