Knock under light throttle

99SSragtop · Post by **99SSragtop** » Mon Jul 28, 2008 6:08 pm

2000 RPM and up and under light throttle.
Should I increase PE or decrease timing.
Ltrims are bang on.
I guess I could run 94 octane but I want to run the car on 91 octane.
Thanks

neonhomer · Post by **neonhomer** » Mon Jul 28, 2008 8:34 pm

Could be bad gas...

Post by **06MonteSS** » Mon Jul 28, 2008 9:16 pm

what tune do you have installed??

and on the predator, what tune choices do you have?? a diablo tune and 91 octane tune??

CANUCKPREDATOR · Post by **CANUCKPREDATOR** » Mon Jul 28, 2008 11:25 pm

if you are experiencing this under "light" throttle, adjusting PE won't help. PE is for WOT only.

Post by **06MonteSS** » Mon Jul 28, 2008 11:35 pm

nice catch, Canuck!!

99SSragtop · Post by **99SSragtop** » Tue Jul 29, 2008 8:30 am

06MonteSS wrote:what tune do you have installed??

and on the predator, what tune choices do you have?? a diablo tune and 91 octane tune??

I have one of the older predators.
Tune that is in there is just the performance tune from predator.
So I guess I should try and pull timing, how much % relates to degrees of timing ?

Post by **mikel** » Tue Jul 29, 2008 11:03 am

Well, you cant make part throttle spark changes.
How much KR are we talking about here?

First thing I'd do is try different fuel...

99SSragtop · Post by **99SSragtop** » Tue Jul 29, 2008 10:12 pm

I can make 0-1800 rpm and 1800-4000 rpm and up.
15% degrees on the predator what is that in timing degrees ?
I had an update done.

Post by **06MonteSS** » Wed Jul 30, 2008 8:57 am

4% is roughly equal to 1* of timing

99SSragtop · Post by **99SSragtop** » Wed Jul 30, 2008 10:31 am

I'm wondering if the EGR is causing some KR

eber66 · Post by **eber66** » Wed Jul 30, 2008 11:06 am

That is funny because last night I noticed the same thing with my truck. My LTFS are dead on and I notices a slight KR when I got out of the gas. I am using the same fuel as always and have never had a problem with it. Ive got the old U7193 ( By the way is there an upgrade for that yet???) and I was doing some checking and I believe at most my KR was at 10* but I have never seen it before. Any ideas on this would be appreciated.

CANUCKPREDATOR · Post by **CANUCKPREDATOR** » Wed Jul 30, 2008 11:12 am

If you are letting off the gas and getting KR, don't worry about it. The stuff to really watch is when your at WOT. That's the stuff that will hurt you. You will see some in every motor at some time. Most likely times is when you go to WOT, that initial pedal push. Also just as the vehicle is shifting and when you are lower RPM, part throttle (and increasing) with a load. Those are normal times to see KR. Now if you are seeing excessive amounts for long periods of time (not just one or two seconds worth), that's something to watch and address.

eber66 · Post by **eber66** » Wed Jul 30, 2008 11:14 am

Thanks Canuck that helps. I am just surprised I never noticed before. I guess I am getting used to the Predator and now Im just starting to let off the throttle. Ha.

99SSragtop · Post by **99SSragtop** » Wed Jul 30, 2008 11:16 am

I don't get KR at WOT. Which of course is a good thing. Its just entering the freeway under light acceleration. I think Ill leave it, at that speed and engine rpm who cares the PCM is doing what it suppose to do and Im really not looking for hp at that range anyways.

Knock under light throttle

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