Engine Knock

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Mar 6, 2006 | 01:42 AM

#11

ktmrider

TECH Fanatic

Joined: Apr 2003

Posts: 1,107

Likes: 2

From: Albuquerque, NM

Thanks for the info Erik!
I would DEFINITELY think there are some funny things going on inside the Dodge PCM. We were seeing lots of drivetrain power loss on the dynos. Just taking away the torque management on the 1-2 full power shift netted no HP but reduced 1/4 mile times by 0.3 seconds. Plus the fact that Dodge is still holding on to their coding harder than Fort Knox guards its gold makes you wonder.....

Mar 6, 2006 | 09:46 AM

#12

kbracing96

TECH Senior Member

iTrader: (26)

Joined: Jul 2004

Posts: 9,485

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From: Oakland, OR

Quote:

Originally Posted by TurboBerserker

The "boost knock" refered to above is "burst knock" and is somethign the PCM does when it expects knock to occur but hasn't seen it yet.

Kbracing -- your issue may be tip in KR -- a result of throttle transients and can be tuned out via SD VE tuning. If you are getting a big downshift say 4-2, it might also be from the TCC settings (these trucks are notorious for it) -- start by adding 5-7mph to all your TCC apply settings if that's the case. It can be tuned out (everyone I've talked to has had the same issue).

I am running a full MAFless, SD tune Via EFILive CO3 and the VE is pretty much spot on. Mine isn't burst knock, as it does show up in the scanner as regular KR, only I can't hear it. It happen in OD as I slowly roll in to the throttle going up a hill on the highway and it crosses over from vacuum into boost. (Remember, it's only a little 4.8, it need help to go up the hills

) KR wants to bring timing clear down to about 10-12* at 2300 rpm and 2-3 lbs of boost. Seems a little low to me. I'm commanding about 13.6 A/F for fuel at this point too. This happens with both 89 and 91 octane in the tank.