SCT 93 Octane Stock GT Tune - Engine Knock

[FalconGuy016]

I just flashed my stock 2004 GT last night to test it out with a 93 octane tune

It seemed to be performing well, but I picked up some sort of sneaky suspicion that there was some engine knocking. When I pull it with low RPM in 5th, my fear was confirmed with some clear, loud engine knocking.

Now here's what I hope is happening. The octane in the tank is around 91.5, since there was about a quarter tank of 87 left when I put 93 in. Does anybody know that this will happen if the octane isnt exactly up to par? I sure hope so, and that there isnt some detonation or pre ignition problem.

Now this was all overshadowed with a loud creak in my steering, but thats going to be solved today and now im onto this one. Im going to wait until my octane is almost pure 93 before I try to do anything about it, but I was wondering if this was a normal situation.

Thanks

 

[propellerhead]

How many tunes did you get with the Xcalibrator? Did you get one for 87 octane? Try that, or flash the original factory tune back in. See if it knocks.

If it helps, my 04 GT pinged under heavy load with 87 octane. With the DiabloSport Predator tune and 93, no ping.

 

[FalconGuy016]

No I didnt

I'm going to wait till I get my octane up to 93 (or 99%), because technically its 25% too low

 

[instangator]

I had/still have a problem with some light detonation w/ my SCT 93 octane tune, and my car runs fine w/ 87 and no tune. I'm assuming you have a mail order tune? If so, the tune may be a little too aggressive for your car. All cars react differently to mods and tuning. Call your tuner and let them know. I'm sure they will help you in any way they can.

 

[propellerhead]

Where did you get the Xcalibrator? The vendor I was talking to was willing to throw in 3 tunes. I was gonna have one set for 87 octane.

However, I went the a Predator instead. I'm slowly bumping up my timing to see how far I can go without it pinging. It only takes me a few buttons hits and about a minute to flash the EEC.

 

[FalconGuy016]

Yeah the two other tunes are a long story, but they have nothing to do with performance.

I think I may have too agressive a tune, but again im not going to do anything until I get a good 93 octane tank of gas. Thanks though, good to know it might have been shipped that way too agressive