Adding Fuel - 2006 Charger SRT8

[robinkorea]

I have a 2006 Charger SRT8 and I've only added a CAI, Magnaflow Hi-Flow Cats and Magnaflow Catback. The gas octane rating over here is a bit different as it says 98 but is really 93 or 94. Should I add fuel with these mods seeing as I don't have longtubes? Thanks for the help.

[smoke74]

you could add some fuel around 4%

[robinkorea]

Thanks. I guess I'll try it and see what happens.

[robinkorea]

I added 3% fuel and it pulled harder. I haven't done any datalogging yet so I may bump up the percentage if everything is ok.

[smoke74]

Good.
just check if you don't have any st knk retard, some knock when the car shifts is normal.
you car should be fine now.

[robinkorea]

Well I did have some st knk retard during WOT. Was getting up to about 3.5 in lower rpms and up to around 6 above 5000rpm, so I added 5% across all ranges. It's now down to 1 or 1.5 in the lower rpms but still up to 5 in the higher ranges. I will bump up the fuel in the high rpm range to 8% and see what happens. I don't have any lt knk retard so that's good.

[smoke74]

try 8% i'm sure that will help get the retard down.

[robinkorea]

I thought I had the retard down but today I ran a 0-82mph run and had st knk the whole way through. It ranged from 1.5-4.5 and I also have lt knk above 78mph, it gets up to 2. I noticed this two days ago on a 0-80mph run. Both runs were made with the car at 200 degrees. Right now I have added 5% fuel to the low and mid rpms and 11% at high rpms.

I should also mention that I've never had great gas mileage, 9 mpg when the car was stock. I now get about 7-7.5 mpg. I guess it's all the stop and go traffic in Seoul.

Anyway, my question is, if the octane level is really 94 and I am running the 93CAI tune, should I keep adding more fuel until the knk completely goes away? Should I change any other settings?

Thanks for the help.

[Quick]

You can expect knock retard around shift points. It should recover quickly and it shouldn't go much above 3*. You shouldn't be seeing constant/steady knock retard at WOT. Keep adding some more fuel. If you get to around a total of +15% or so then I'd start pulling timing.

Giive the corresponding 91oct tune with the same gas a try and see what that does. It's basically less timing.

[robinkorea]

Thanks, I'll give it a try tomorrow and post the results when I am done.

[robinkorea]

Well it rained yesterday so I couldn't log anything but today I did. I was at 6% low, 7% mid and 12% high. Still had knock throughout the run but it was lower. I added 1% more to mid and high however, the place where I was making my runs started to get crowded with traffic so I couldn't log anymore. I'll try again later tonight or early tomorrow.

[MagnumSRT8]

So far, im at about 6% low 15% mid and 16% high, that got rid of almost all my knock and I ended up running a 12.72@110mph at the track with minimal mods.

[BlueBee6.1]

I have just purchased the predator and have a K&N CAI, no exhaust mods yet..next year christmas.
I will load a tune in this weekend and try it out
I am very concerned about the knock retard I will get as I do not want to do any damage to my engine.
What tune would you guys recommend I try first to get performance and no knock retard. fuel is 93 Oct

Would putting a bottle of octane booster in the tank help maybe??

What is the advice that the Diablo guys can provide to reduce knock with one of the canned tunes for the SRT8's