knock knock

white_lightning · Post by **white_lightning** » Thu Nov 19, 2009 3:17 pm

09Laramie wrote:I added 5% fuel across the board this morning and took another log- looks like it got rid of at least most of the knock. Now, if anything, it's just a blip here or there.

did you look at what rpm the KR was happening? you may not need +5% fuel across the board if KR is happening in just one spot.

you can also control KR by pulling WOT spark. I think the options for adding/subtracting spark are the same as fuel: 1k-3.8k, 4k-4.8k & 5k-7k.

Kahler · Post by **Kahler** » Thu Nov 19, 2009 8:14 pm

Butch 1581 I see your at 205 deg temp. Try lowering to 180 deg. I have read in the threads that this may help. Also gives much desired horse power, by lowering.

white_lightning · Post by **white_lightning** » Fri Nov 20, 2009 6:43 pm

Kahler wrote:Butch 1581 I see your at 205 deg temp. Try lowering to 180 deg. I have read in the threads that this may help. Also gives much desired horse power, by lowering.

I like my Jet 180* thermostat.

tried a Milodon 160*, but it was too cold, lot of P0128 codes. probably could run a 160* with no CEl with a custom tune though.

Kahler · Post by **Kahler** » Sat Nov 21, 2009 12:15 am

I am using the 170deg stat and setting fans to keep temp at 180 to 185 deg not getting no codes this way. Other threads say it helps keep knock away and more ponies with the cooler temps. Just a thought

hemihead · Post by **hemihead** » Sat Nov 21, 2009 5:27 pm

Quick and 09Laramie, Great exchange. Filled in many blanks I had on running the mapping features. Thanks, interesting learning experiance. Good info for those of us who want to tinker correctly with positive results. I need to get on the ball with my Ram and Challenger. Map them both. See what's what.
Thanks JP

09Laramie · Post by **09Laramie** » Sat Nov 21, 2009 7:34 pm

white_lightning wrote:
09Laramie wrote:I added 5% fuel across the board this morning and took another log- looks like it got rid of at least most of the knock. Now, if anything, it's just a blip here or there.
did you look at what rpm the KR was happening? you may not need +5% fuel across the board if KR is happening in just one spot.

you can also control KR by pulling WOT spark. I think the options for adding/subtracting spark are the same as fuel: 1k-3.8k, 4k-4.8k & 5k-7k.

yeah, I looked at it a little bit, but the knock seemed to be happening across the board. After adding the 5% fuel to all rpm ranges, the knock went down a lot and the little that was left seemed to be more limited to the higher rpm ranges and after shifting.

I just tried the 93 tune today and saw some higher than desirable knock, so I'll be basically starting from scratch with the dialing in again.

Any ideas or opinions on when to increase fuel vs retarting timing to reduce knock? I'd imagine you'd see the best performance with a balance of both.

Also, does anybody know what the differences are between the 93 tune and the 87 tune as far as timing and fuel are concerned?

white_lightning · Post by **white_lightning** » Sun Nov 22, 2009 6:32 pm

09Laramie wrote: Any ideas or opinions on when to increase fuel vs retarting timing to reduce knock? I'd imagine you'd see the best performance with a balance of both.

well, I tinkered with WOT fuel a couple days ago while waiting for a tune revision. got WOT a/f in the 4-4.8k rpm range to 12.5-12.6:1 and got 2 degrees KR @ 4,300-4,600 rpm. added 1% fuel back in, hope to check results later today.

12.2:1 to 12.5:1 seems to be a good WOT a/f for the Hemi, so if I richen up a/f to 12.2:1 & still have KR, pulling 1-2 deg spark seems like the next logical step.

the right amount of spark + the right amount of fuel = the most power.

09Laramie wrote: Also, does anybody know what the differences are between the 93 tune and the 87 tune as far as timing and fuel are concerned?

no, but you could find out by loading each tune & doing a datalog of part-throttle & WOT driving on each tune.

I'm guessing fuel is similar, 93 has more spark.

Quick · Post by **Quick** » Sun Nov 22, 2009 10:40 pm

white_lightning wrote:12.2:1 to 12.5:1 seems to be a good WOT a/f for the Hemi, so if I richen up a/f to 12.2:1 & still have KR, pulling 1-2 deg spark seems like the next logical step.

Which hemi? I think, with the 6.1L, I'd go to 11.8 -11.9 before pulling timing? don't know about the 5.7L

white_lightning · Post by **white_lightning** » Sat Nov 28, 2009 4:15 pm

Quick wrote:
white_lightning wrote:12.2:1 to 12.5:1 seems to be a good WOT a/f for the Hemi, so if I richen up a/f to 12.2:1 & still have KR, pulling 1-2 deg spark seems like the next logical step.
Which hemi? I think, with the 6.1L, I'd go to 11.8 -11.9 before pulling timing? don't know about the 5.7L

my Hemi is a 5.7, but I don't think it matters. dline has a 6.1 based 418 cid stroker in a truck and targeted a 12.2:1 WOT a/f ratio, CRAZY powerful truck!!

some have gone as lean as 12.6-12.8:1 WOT a/f, don't know what spark advance.

my 2 cents, set it where the most hp & tq is without KR.