knock at 6000-7000 rpm, 92 oct, need tuning advice...
Apr 8, 2008, 12:19 PM
#1
knock at 6000-7000 rpm, 92 oct, need tuning advice...
Now that I have my LC-1 installed, I'm working on optimizing the tune. I started off by leaning out the 4000-6000 rpm range to 11.0:1, and that worked well. I picked up about 5-10 WHP. Now working on 6000-7000 rpm range which has traditionally been knock prone. At 10.5:1, 11-12 deg, and 20 psi, its pretty well knock free. However when I leaned it out to 11.0:1, I instantly started getting 5-7 knock counts.
Trying to decide on the best course now. Should I just go back to 10.5:1? Pull back a degree of timing? Should I try lowering the boost to 19 psi and reoptimizing there? Any value to messing with the MIVEC? Mods are listed in my sig below.
10.5:1 at 6000-7000 rpm
10.5:1 at 6000-7000 rpm, HP and TQ
11:1 at 6000-7000 rpm
11:1 at 6000-7000 rpm, HP and TQ
Trying to decide on the best course now. Should I just go back to 10.5:1? Pull back a degree of timing? Should I try lowering the boost to 19 psi and reoptimizing there? Any value to messing with the MIVEC? Mods are listed in my sig below.
10.5:1 at 6000-7000 rpm
10.5:1 at 6000-7000 rpm, HP and TQ
11:1 at 6000-7000 rpm
11:1 at 6000-7000 rpm, HP and TQ
Apr 8, 2008, 01:25 PM
#5
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I would keep the 11:1 afr and take a degree of timing out right before the knock starts. I have seen 1 degree removed take away 5 counts of knock on my car before so that could be all it needs.
I prefer building my timing map around my afr rather than vise versa.
I prefer building my timing map around my afr rather than vise versa.
Apr 8, 2008, 01:50 PM
#6
yea, bring down teh timing if youre having a problem. Ive noticed that it averages teh timing across the 5 cells, so if you ahve any steep slopes you might not get consistant timing across the board.
I ended up with a map that looked very similar to the timing map Naji posted in his thread. I ended up just using his timing map (cause it was more well tuned in the 100-140 load areas), and you'll find its pretty knock proof. I then went back and tuned out the lift off knock parts (i.e. the load areas of 80-120 from 3250-7500)
I posted logs of my 93ish mixed octane logs in here. It was built off a mix between Naji's timing and the stock timing map.
p.s. i run 11.8:1 on 91oct all day long. No difference in EGT's between that and 10:1. But, I did notice that taking out the cat lowers EGT's by 100°F
I ended up with a map that looked very similar to the timing map Naji posted in his thread. I ended up just using his timing map (cause it was more well tuned in the 100-140 load areas), and you'll find its pretty knock proof. I then went back and tuned out the lift off knock parts (i.e. the load areas of 80-120 from 3250-7500)
I posted logs of my 93ish mixed octane logs in here. It was built off a mix between Naji's timing and the stock timing map.
p.s. i run 11.8:1 on 91oct all day long. No difference in EGT's between that and 10:1. But, I did notice that taking out the cat lowers EGT's by 100°F
Last edited by SoCalRedLine; Apr 8, 2008 at 01:53 PM.
Apr 8, 2008, 01:55 PM
#7
yea, bring down teh timing if youre having a problem. Ive noticed that it averages teh timing across the 5 cells, so if you ahve any steep slopes you might not get consistant timing across the board.
I ended up with a map that looked very similar to the timing map Naji posted in his thread. I ended up just using his timing map (cause it was more well tuned in the 100-140 load areas), and you'll find its pretty knock proof. I then went back and tuned out the lift off knock parts (i.e. the load areas of 80-120 from 3250-7500)
I posted logs of my 93ish mixed octane logs in here. It was built off a mix between Naji's timing and the stock timing map.
p.s. i run 11.8:1 on 91oct all day long. No difference in EGT's between that and 10:1. But, I did notice that taking out the cat lowers EGT's by 100°F
I ended up with a map that looked very similar to the timing map Naji posted in his thread. I ended up just using his timing map (cause it was more well tuned in the 100-140 load areas), and you'll find its pretty knock proof. I then went back and tuned out the lift off knock parts (i.e. the load areas of 80-120 from 3250-7500)
I posted logs of my 93ish mixed octane logs in here. It was built off a mix between Naji's timing and the stock timing map.
p.s. i run 11.8:1 on 91oct all day long. No difference in EGT's between that and 10:1. But, I did notice that taking out the cat lowers EGT's by 100°F
Yeah, I don't think the leaner mixtures affects EGT as much as it affects burn rate.
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Apr 8, 2008, 01:56 PM
#8
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i ran in the same situation, I decreased my MIVEC a little. I would keep your timing and a/f ratios the same and just decrease MIVEC. If that dont work, keep a/f ratios at 11.1-11.5 and decrease timing a little.
Apr 8, 2008, 01:58 PM
#10
Reduce your mivec advance after 6.5K to 0 for the top end knock if it's not already like that. I think some smoothing of your fuel map could get rid of that 1 count of knock in the midrange. In your logs it looks like it goes just a tad lean right before the onset of that 1 knock.. see if you can flatten that out. But overall I agree 1 less degree of timing will make it much more knock resistant.
Last edited by Mr. Evo IX; Apr 8, 2008 at 02:00 PM.
Apr 8, 2008, 02:20 PM
#11
this is the base map i tuned off of. ITs tuned for 91oct. Its a great starting place, especially if you are runing his Mivec map.
I never had to tune out my Mivec to rid myself of the knock. It was all in the timing/fuel.
here is my log thread:
https://www.evolutionm.net/forums/sh...d.php?t=329699
Originally Posted by travman
I run 11.8 - 12.0 as well....loves it (but im on 93)
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