87 Octane Tune: Mission Accomplished!
02-24-2011, 07:19 AM
#62
Registered User
Join Date: Feb 2011
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
I would not use 87 octane They're supposed to be okay to run on 87 or 89, but they knock a lot, resulting in near-constant KR. Most likely, you won't hear the knock, but you'll definitely see it if you hook a scan gauge up to it.
Personally, I think any KR is bad, because it means some knock is still occurring. Fortunately, the LS motors don't normally blow head gaskets, so that isn't s major problem. However, knock is still hard on pistons, rods, and cranks, and I would do anything I can to prevent it.
That's the other criteria for this tune: Little or no KR.
Personally, I think any KR is bad, because it means some knock is still occurring. Fortunately, the LS motors don't normally blow head gaskets, so that isn't s major problem. However, knock is still hard on pistons, rods, and cranks, and I would do anything I can to prevent it.
That's the other criteria for this tune: Little or no KR.
I had a 2002 z28 and I had used 87 octane from 32000 miles to 120000 when the engine blew because of head gaskets. This was more likely the cause of using 87 octane all the time.
02-24-2011, 08:04 AM
#63
TECH Addict
Thread Starter
iTrader: (15)
Join Date: Aug 2002
Location: 78°14′46″N 15°27′56″E
Posts: 2,419
Likes: 0
Received 5 Likes
on
5 Posts
Not surprised to hear that blew after 90,000 miles on 87 with presumably the stock tune.
07-11-2011, 11:02 PM
#64
How much knock is considered ok? I have a 2007 4.8L LR4 controlled by a LS2 E40 computer.
LS2 intake
88mm throttle body, cold air intake (sometimes hot air)
Long tube headers
My stock tune was from a 6.0 SSR I changed the injector tables, and engine displacement. I then tuned the VE and MAF tables wiht HP tunners. I am still running the 6.0L spark tables though, and see 4-6 degrees of KR under light loads and moderate loads between 1200-1600 RPM, and also under heavy acceleration in the upper RPMs .
I always run 92 octane in it. I have tired a lower octane table, and also subtracting 10 degrees in the trouble areas still get knock. Is this normal under light to moderate loads?
LS2 intake
88mm throttle body, cold air intake (sometimes hot air)
Long tube headers
My stock tune was from a 6.0 SSR I changed the injector tables, and engine displacement. I then tuned the VE and MAF tables wiht HP tunners. I am still running the 6.0L spark tables though, and see 4-6 degrees of KR under light loads and moderate loads between 1200-1600 RPM, and also under heavy acceleration in the upper RPMs .
I always run 92 octane in it. I have tired a lower octane table, and also subtracting 10 degrees in the trouble areas still get knock. Is this normal under light to moderate loads?
07-11-2011, 11:39 PM
#65
TECH Addict
Thread Starter
iTrader: (15)
Join Date: Aug 2002
Location: 78°14′46″N 15°27′56″E
Posts: 2,419
Likes: 0
Received 5 Likes
on
5 Posts
IMHO, no knock is tolerable. If you've pulled that much timing and are still seeing KR in normal driving, then I would look at fuel trims and O2 numbers to see if you're not running too lean. I would also make sure you don't have anything loose that's causing false knock.
Do you have any way to log data?
Do you have any way to log data?
07-12-2011, 12:09 AM
#66
IMHO, no knock is tolerable. If you've pulled that much timing and are still seeing KR in normal driving, then I would look at fuel trims and O2 numbers to see if you're not running too lean. I would also make sure you don't have anything loose that's causing false knock.
Do you have any way to log data?
Do you have any way to log data?
YES I have HP tuners, and I can log with my lap top, I have setup a custom PID to log cylender grams verses rpm main knock retard in degrees.
The problem is that I have tried subtracting those numbers form my main spark table and I still get spark knock.
I posted the logs, config , histo, and scanner settings.cfg They all have to have there file extensions renamed except the log file.
07-12-2011, 12:54 AM
#67
LS1Tech Sponsor
anything 2.xxx degrees of knock retard or less at WOT is acceptable...
make sure you're using GOOD gas!!!! exxon, mobil, sunoco, amoco, bp, chevron...
make sure you're using GOOD gas!!!! exxon, mobil, sunoco, amoco, bp, chevron...
__________________
06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS - LS3, 6-speed manual, short-throw performance shifter, NPP dual-mode performance exhaust, 1LE front splitter, ZL1 rockers, Z28 Rear Spoiler, all paint-matched Red Rock Metallic, BMR strut tower brace, Cold Air Inductions cold air intake, Apex Motorsports, Inc. catch-can, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS - LS3, 6-speed manual, short-throw performance shifter, NPP dual-mode performance exhaust, 1LE front splitter, ZL1 rockers, Z28 Rear Spoiler, all paint-matched Red Rock Metallic, BMR strut tower brace, Cold Air Inductions cold air intake, Apex Motorsports, Inc. catch-can, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
07-12-2011, 02:49 AM
#68
I am getting very frustrated I just pulled so much timing that while cruising it will maintain speed, while letting off the gas?? And I am still seeing 1-2 degrees of knock retard, under the above mention situations.
I should mention that it is manual transmission, so you can be in maybe one gear lower then I really should be, and that's when the knock retard goes crazy??
I also wonder if it has to do with running a cast iron block with knock sensors that are setup for an aluminum block.
Is there some kind of program that I can use to generate a new spark table based on displacement and cam specs? I am running a lot smaller cam than what this tune was meant for. But hell I have taken more then 15 degrees of timming out in spots.
Do I just set the entire table to 15 degrees and see if I get any knock then?
