today i changed my tune to 87, didnt adjust anything except to turn of mds. i am running 91 fuel in it

i went for a drive and at one point got a knk st retard of 5, i was decelerating to around 30 and then punched it to 60 or so. other than that the highest i got was 2.5, 0-60 or so(fastest i could get around here). seemed to occur around 5k rpms. do you guys think i need to worry about this?

i tried attaching the logs but it says invalid file

thanks for any help

 

why would you run 87 tune with 91 octane?, id say thats your problem

 

UHH, no, running 91 octane fuel on a 87 tune will definitely not cause knock.

You might Check out the Diablosport sticky thread at the top of the forum.

 

Or better yet, try going over the Diablos site and go through their forums. But running 87 on a 91 tune is definitely a No-No.

 

so the computer expecting 91 and getting 87 won't cause knock, i beg to differ all the timing will be off and THAT is what causes knock

but differently check out that sticky.

 

He is running the 87 tune with 91 gas, that should be "extra safe" defenitly should not have any knock. I would log it and post on the diablo forum

 

regardless of octane level if an engine is expecting one octane and getting another its not going to react well. especially if its a computer controlled fuel system
i just don't know why you would load 87 and run 91 thats just asking for trouble, i bet if he fills up with 87 everything will be fine

 

Loading a 91 tune changes the timing of the engine and when coupled with lower than 91 octane will produce knock as well as less power (kinda related to one another).

However, doing the opposite such as loading a 91 tune and using 93 octane will produce less knock obviously.