Diablosport Forums

U7135
9r12
07,Dodge Charger SRT8
Put the 93 tune on my car.Went and got gas but got 92 octane.Went to work getting 25.6 MPG..Put the 91 octane with CAI...Drove home getting 22.5-23 MPG...Is it better to leave 93 tune on car? Will it be ok?

Its gotta be knocking on 92 octane with the 93 tune. Most SRTs knock on the 93 tune with 93 gas. Log it.

I don't hear any knock at all..feels pretty good..How do I log it?

Log it with the Predator.

You will never HEAR knock on a late model car. If you do, you already destroyed the motor. The knock sensors will pull timing way before its audible to a human.

i do logs with my dog. he barks when he hears knock

Thanks for the info.....as for the last one.....Wow!

The engine knock and subsequent failure of your motor is related for sure... I had to rebuild my 5.7 recently (due to a broken valve spring), and only have 92 octane where I live. I did the 93 octane programming, then adjusted the timing advance too far, it was pinging like crazy. There has not been any problems with the engine at all from pre-ignition. If you hear knocking, keep your foot out of it and adjust the timing as soon as possible. Catastrophic failure can happen, but unless you ignore the knocking, you should be ok..

To clarify, don't ignore the knocking if you hear it, it most definately will cause engine failure if you let it go. But I disagree that if you hear it, it's already too late... It wasn't with me, and I have plenty of internal engine mods on my truck. It's just fine. I have to say, the programmer really made this truck HAUL BUTT, that is, once I got the timing correct and fuel/air leaned out. I just wish I could change the idle rpm, shift points, and tranny pressures with the programmer. I guess you can't unless you get a custom tune for the 2003 Hemi pickup. Bummer.

If you can hear the knock, that means you exceeded the maximum knock the sensors can compensate for. Its very likely at that point that you've damaged the pistons. I've burnt and blown my share of pistons, and its not pretty.

I wasn't going to blow the engine by romping on it after I heard the pinging...I stayed out of the throttle and changed the timing right away.

I already rebuilt it once, I don't want to do it again.

DanielNix wrote:I guess you can't unless you get a custom tune for the 2003 Hemi pickup. Bummer.

how are you running your cam without a custom tune?

I'm not done with it yet, supposed to get a tune for it sent to me today... I am headed out to put in some racing spark plugs right now.

Also, the only person in my area that will do a custom tune wants to charge $800 and keep it for a week. I am not gonna throw $800 (that I don't have, I am broke as a joke) for someone to time it, adjust fuel/air ratio, and raise the idle rpm, and leave me without wheels for a week.

I have a new program I just got today to even this thing out, we'll see if it works.

Make sure you use NGK cooper core plugs! Not 100% certain on the early Hemis, but the late ones will turn themselves off if you don't use copper core plugs. Been there, done that. Auto shutdown relay doesn't like platinum cores and doesn't let the motor stay running with them (which sucks, cause the motor loves them).

Yes, I have heard horror stories with the platinum plugs, even on the early hemis. I have copper core plugs, just got them in a couple hours ago, and they are really good so far.... However, I asked my tuner guy to raise the idle rpm, but my truck is still idling at 600rpm, and it is STILL quitting when I stop or slow down quickly. I am gonna attach the file, if any of you can help, I would appreciate it.. it needs to idle at 800rpm while its in gear... the cam is much more aggressive than I anticipated it would be. If you look at this file, are you able to tell what he did? I'm curious if he did all that I asked. I wanted to get a 30 degree advanced timing at WOT, and 13.0 to 1 F/A ratio at WOT. I figure the small block chevys really like 32 degrees, and 13.0 to 13.5 F/A ratio, the BB's like 34 degrees, so I would start at 30 and work forward or backward to get it dialed in, and then mess with the fuel air ratio.