Just tuned my car this weekend with Brenspeed 93 tune (later tried 91 as well). I have a C&L Street CAI. All went well with tune, no error codes, seems to run/idle just fine. However, under load (for example when pulling hard in 2nd or 3rd gear) between 4000 and 5300 RPM i get a strange metallic sound that i hope isn't the engine pinging.

Anyone have any advice? What could it be? Is there something i can do with the SCT XCal3 to fix it myself? Is this something i should get in touch with Brenspeed about?

On an unrelated note, the three tunes i got were 87, 91, and 93, but in my area 91 isn't available, only 87, 89, and 93. Is this something Brenspeed would redo for me for free or would I have to pay extra? (I don't really need the 91 tune for anything)

Thank you!

 

Try the 87 tune with 93 in the car. If the sound goes away it's probably detonation. They should adjust it for no cost if necessary.

 

I am running their 93 tune with no issues. It is always touchy on the first tank of 93 and a new tune. If I were you I would just keep my foot out of the throttle (WOT) and just take it easy thru a tank of gas. If you still have the issue with the 2nd tank of gas I would call Brent. And PS...don't try to fix it yourself with the tuner. And Brent will not charge you to adjust your tune if that is what is required!!
Scott

 

That is scary, I'm about to pull the trigger on that tune too

 

you could always just pull a degree of timing out of the tune in the 4k rpm band

 

Is there any reason to believe that the 93 in my area (or summer blend with 10% ethanol) is just weak, i.e. 93 will never truly be 93? Should i just run the 91 tune but put in the 93 gas to ensure that the octane/gas is good enough?

 

Check with your tuner first and make sure your getting the octane you're paying for.

 

In my part of Ohio, there are only a few stations that sell 100% 93 octane. Most of the others have 10% ethanol.

 

Could be the tune, could also be the fuel. I would also recommend what Anthony said, which is try the 87 tune with the "93" octane that's in the car now.

 

I've been having the same issue. Mine is definitely pinging in the upper rpm range like yours. I'm seriously considering having my tune modified to a 91 octane tune. Mine was dyno tuned for 93, and though there weren't any issues then, I'm thinking it could just be the gas that I'm getting

 

Ethanol has an octane rating of 113. Hence, 93 octane E10 fuel(90% gas/10% ethanol) has an octane rating of approx. 95, which reduces the engine's tendency to ping.
In addition to trying different brands of gas, pulling timing, etc., as suggested by others to eliminate the pinging, you may also be able to stop it by dumping a can of Seafoam into the tank. Doing that solved a pinging problem with my 05 S197 GT.

 

SKI is correct about ethanol accually raising the octane rating of the gas that is blended. It does not have near the BTU's of energy as pure gasoline but I don't think your problem is the octane rating you are running. You should call Brent and see what he suggests.
Scott

 

Also try different gas.. I have a 93 tune from tillmanspeed.

ExxonMobile = constant reproducable pinging
Shell/BP = very occasional pinging on hard shifting or WOT around 4k-6k
Chevron = practically no pinging, except on hard shifting.

Also, during the winter, even Chevron gas resulted in mild pinging and I retarded the timing 1-2 degrees in whatever RPM ranges I noticed it (I don't remember, I think it was 0-2k and 4k-8k)