Diablosport Forums

Hey Mike...

I noticed yesterday while it was in the low 70's here, that I had more KR showing up, and more often. I'm currently running the Diablo (93) No DOD tune and using Shell 93 Octane V-Power gas (always have).

My fuel trims and settings still look good... but I notice in the Predator that there is no parameter for removing spark/timing from closed-loop / normal driving - only from the WOT ranges.... so...

to remove some spark/timing from closed-loop normal driving to try and reduce the KR I'm getting - while still using the 93 octane gas - can I install the 91 Octane No DOD tune instead (with my same inj. slope and PE settings)?? does that 91 tune have less spark/timing advance in closed-loop/normal driving than the 93 tune??

thanks man!
-Lew

Yes the 91 has less timing overall. One thing i would try first is to try a different brand of fuel. More than once have i had vehicles with Shell fuel have KR on the stock tune, once i get Mobil in there, the KR is no more. I have seen good results (no KR on stock tune) using Mobil, Sunoco and Amoco/BP.
Last example i had was a bone stock C6 corvette, saw 5 deg of KR pulled from stock tune, drained tank, put Mobil in and no KR plus the dyno run was 20hp higher.
I would try that first.

ok cool! thanks Johan!!

My area do not have Mobil, but Exxon. Same brand, right?

And Amoco/BP gas is sold at AM/PM convenience store!

I know the Sunoco's here in my area have a higher 94 octane, so maybe that will help as well, right? ...instead of just trying to find a Mobil or using the Shell 93...

Should be just as good yui.

Lewis, I'd look at possible causes of false knock as I had an issue with part throttle KR in my car for a while. It was definitely not a spark issue as it would only happen under light load/part throttle operation.
It disappeared after changing the MAP sensor, as to why, well.......

Let us know how it goes with different fuel and/or the 91 tune.

Thanks

hi Mike...

yeah, was watching it log while driving home last night, and noticed that I was getting KR like you said - under light load/part throttle... but then I also got KR during both WOT blasts too... like I mentioned, I always had some, but when it was warmer out yesterday, there was more, and more often. I can email you some logs later on tonight if you want... maybe I need something "special" setup.. LOL

I can also notice the difference in the engine/intake sound when it's warmer - like it's running richer / sucking in warmer air - has a deeper tone to it compared to the nice crisp, cool mornings.

Hmmm, interesting... dunno what else could be causing the false knock - I don't hear any rattles or clanks or anything else while driving... unless it's caused by these wonderful pot-holed, cracked, bumps every 30 feet roads we have here...

I just cleaned my MAF and intake hose 2 weekends ago (CRC MAF Cleaner), and it wasn't even really contaminated at all to begin with - so it shouldn't be that... the MAP sensor, hmmm.... does mine even have one, since I have the MAF?? Where the hell would I find that under the hood?? LOL

...bump...

MAP is usually in the back of the intake manifold.

thanks mike... I'll try the different fuel thing first (Sunoco 94 octane) and see what that does for me.

I had filled up the other day with the shell 93 before we started talking about this, and still have half a tank of that left - so I'll report back next week on my findings...

well, come to find out, Sunoco doesn't have the 94 octane anymore around here, only 93... but anyway, I've been through 2 tanks of Sunoco 93 and half a tank of Mobil, and am still getting all kinds of KR...

I guess the next thing to try is to drop down to the 91 Octance No DOD tune - and still run the 93 octane gas.... let's see what that does I suppose...

also, when logging this stuff, should we be driving around in D (overdrive) or 3 ?? seems like these are geared too high, and perhaps that's why I'm getting knock at light throttle/no load on the town roads and even on the highway...

so I'm wondering if we're supposed to be driving/logging in 3 to get our numbers/readings...

I am running into this as well with my 06 Monte Carlo SS. I was not having any problems with KR showing up until recently. I even went so far as to change the plugs out, and still getting KR under wot in 1st and 2nd gear. For some reason once it gets up into 3rd at wot, I am not getting knock retard showing up. I can't seem to figure it out. I always use Sunoco 94 Octane. How did you overcome this?

had them create a custom tune for me so that my car goes into PE mode sooner, so I get more fuel at WOT sooner/quicker... plus pulled out a little timing/spark advance

monte are your wires arching??? check it out at night with no light