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Knock Retard settings
Posted: Wed Oct 17, 2007 9:55 pm
by rainmaker
Hey guys,
Can you explain the difference between the long term and short term knock settings? Is this sort of like long/short term fuel trims?
What effects does disabling one and not the other have?
What do you recommend for street use?
Just wondering.
Thanks
Posted: Thu Oct 18, 2007 12:30 pm
by rainmaker
Bump for a reply.
and
New questions:
Am I wrong in saying that the Canned tunes can not be altered unless you use QA's or the CMR software?
When will the CMR software be distributed publicly?
Thanks
Posted: Thu Oct 18, 2007 12:43 pm
by mikel
Canned tunes can be altered through the adjustable parameter settings in the tool.
I'm looking into the Knock question.
Posted: Thu Oct 18, 2007 3:16 pm
by rainmaker
mikel wrote:Canned tunes can be altered through the adjustable parameter settings in the tool.
I'm looking into the Knock question.
Thanks for looking into the knock question.
I must be doing something wrong modifying the canned tunes, because it seems that when I try to make changes to it, the car goes back to stock...
How do I modify the canned tune Mike?
Oh one more question (last one today promise) how often do you guys update the actual calibration (fuel maps, timing, etc...) of the canned tunes? There are a bunch of guys complaining about the canned 93 tune for the Jeep SRT-8. I've felt what they're talking about too. Low end and mid range seem to bog a bit, but WOT is good. SOTP is no good indicator of power, so I'll be testing at the track soon. I'm planning on doing my wideband this weekend as well. I'll let you know what i see.
That's all. Thanks for the help/info.
Posted: Thu Oct 18, 2007 3:21 pm
by mikel
We only make changes to the tunes if/when necessary.
I have heard the issues from the Jeep guys, and it turns out that the Jeeps just do not respond to tuning like the other SRT8s do.
They are also very prone to KR.
As for modifying the canned tune, select the tune you want to modify, then select modify tune, and make your changes.
Install the tune and you are all set.
Thanks
Posted: Thu Oct 18, 2007 3:44 pm
by rainmaker
mikel wrote:We only make changes to the tunes if/when necessary.
I have heard the issues from the Jeep guys, and it turns out that the Jeeps just do not respond to tuning like the other SRT8s do.
They are also very prone to KR.
As for modifying the canned tune, select the tune you want to modify, then select modify tune, and make your changes.
Install the tune and you are all set.
Thanks
Doh. I was doing the modify after installing the tune...wrong order.

Thanks.
Thanks for the info on the tunes. The other reason I ask is because it seems the Jeeps are missing out on a lot of "goodies":
Raise shift points by a predefined setting, 5.7L's (1-2 5800rpm, 2-3 6000rpm, 3-4 6000rpm), 6.1L's (1-2 6400rpm, 2-3 6400rpm, 3-4 6400rpm).(N/A on Jeep)
Autostick auto upshift
Enable/Disable automatic upshift when in manual autostick mode, ie. raise your rev limits and you can shift manually at any rpm without the vehicle automatically upshifting (as it would do stock).(N/A on Jeep)
I'm sure you can't comment on future stuff, but do you know if they're looking into that?
Thanks again,
J-
Posted: Thu Oct 18, 2007 4:06 pm
by mikel
Yes, we are absolutely looking into any and all issues involving the Jeep SRT8s.
Thanks
Posted: Fri Oct 19, 2007 10:43 am
by rainmaker
mikel wrote:Yes, we are absolutely looking into any and all issues involving the Jeep SRT8s.
Thanks
Thanks Mike. Looking forward to hearing about those KR settings.
Posted: Fri Oct 19, 2007 11:49 am
by MikeWDiabloSport
Short term is your instantaneous knock retard.
If the PCM sees short term knock for a given amount of time, it increments the long term knock values.
It's just like you suspected.. similar to short/long term fuel trims.
Posted: Fri Oct 19, 2007 5:22 pm
by Boggus
So.... when you disable both long/short knock sensors, what exactly are you accomplishing? Does the disable mean that you lose the KR since the sensors are off? What exactly does the disable do?
Posted: Mon Oct 22, 2007 1:43 am
by MuscleMan305
Boggus wrote:So.... when you disable both long/short knock sensors, what exactly are you accomplishing? Does the disable mean that you lose the KR since the sensors are off? What exactly does the disable do?
Does anyone know the answer to this?? Diablo u out there?
Posted: Mon Oct 22, 2007 1:48 pm
by mikel
Boggus wrote:So.... when you disable both long/short knock sensors, what exactly are you accomplishing? Does the disable mean that you lose the KR since the sensors are off? What exactly does the disable do?
Yes, you would lose the ability to monitor and prevent knock if disabled.
Not a good idea for a street car....
Thanks
Posted: Mon Oct 22, 2007 9:47 pm
by bacafrog
Turning off your KR sensors is liking getting rid of your car insurance. The only time I would ever turn them off is if they are getting false knock and you know it for sure, and if that was the case I would try to fix that problem instead of turning them off. These vehicles are suspect to Knock from all sorts of things. Bad gas, high engine temps, high intake temps, bad plugs, the list can go on and on. Leave them on for your sake.
Posted: Tue Nov 06, 2007 9:04 pm
by echo412
mikel wrote:We only make changes to the tunes if/when necessary.
I have heard the issues from the Jeep guys, and it turns out that the Jeeps just do not respond to tuning like the other SRT8s do.
They are also very prone to KR.
As for modifying the canned tune, select the tune you want to modify, then select modify tune, and make your changes.
Install the tune and you are all set.
Thanks
Any update on this one guys?
Posted: Mon Feb 04, 2008 10:11 am
by philp69
Any updates on this? I just picked up a predator and installed both the 93 and 91 r20 tunes on my GC and I'm getting 8-9 deg of KR on the 93 and about 7 with the 91. I run Hess 93 most of the time...