2007chevy5.3l

iTrader: (21)

Can I throw in a circle d 278mm 3k stall in and run it without a tune for awhile? Im just curious since its such a mild converter if I can get away with it.

hotrodhorton

iTrader: (2)

i dont know if this helps but i am running a trail blazer converter and its not tuned for it with no problems.

B-r-y-a-n-t

Wondering this myself.

Static54

iTrader: (1)

X3. I ordered a Yank TT3000 and plan on getting a tune right away but was just curious how long you can go without it and what affects will it have on it.

greenz71

I ran mine for about a week without my tune, but it is so much better with it. Only issue was low idle everything else was ok.

2007chevy5.3l

iTrader: (21)

What happened at low idle??

Rhino79

iTrader: (7)

The reduced weight of the aftermarket converters affect the idle and decel airflow because of the difference in what it was calibrated for originally. The weight difference also can make the pcm think it is misfiring (in relation to the idle issues). That can cause lockup-unlock issues, or a no lockup issue. With a looser converter you can usually squeeze some more timing out of it and the shift points really need to be modified. Reason is, the converter is looser, there will be some slip even in the upper rpms and you will be hitting that shift rpm sooner at a lower mph. So if your shifts are setup to have to meet rpm and mph requirements, it may cause an overrev if it sees the rpm requirement but has to rev say 200 rpm higher to hit the mph requirements.

With a 278mm, these side effects will be minimal BUT you could experience any of them.

Circle-D

iTrader: (21)

Very well said sir, good info.

Chris

14psisupra

iTrader: (1)

been running my circle-d 2800 with no tune or issuses..I was told anything under a 3k and a tune is not needed

2007chevy5.3l

iTrader: (21)

Thanks for the info guys. Guess I will toss one in and see what happens