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View Full Version : Help please. KNOCK


tylorjefcoat
October 20th, 2008, 05:08 AM
Ok, ill start from the beginning.
Ok, first time in a while to a full 1/4 track, im very dissapointed.....
mods include.
243 heads untouched
tr224 cam
PS longtube headers
3200stall
dyno tune
nitto 555r's
ported TB
hardcore intake

my best time that night was a 13.1

60ft--1.8666
330ft--5.3797
1/8th--8.34
1/8mph--82.40
1000et--10.92
1/4et--13.10
1/4mph--103.90



60ft--1.84
330ft--5.49
1/8th--8.47
1/8mph--82.16
1000et--11.06
1/4et--13.24
1/4mph--104.46


the car feels great coming off the line, but i dont know what the hell is happening at the topend... i ran a 13.2 stock only with PS longtubes....

temps were nice, and i know how to drive lol


I ran some logs the other day and was getting some knock in third gear and only third.

Here is a print screen.

http://i28.photobucket.com/albums/c215/tylorjefcoat/Log.jpg

The tuner that i used is not used to EFIlive and also tunes on supras and turbo cars. So basically we are tuning it lol.

I have attached 2 logs and the current tune.

HELP please.:help2::help2:
SSpdDmon
October 20th, 2008, 05:32 AM
Are you actually seeing the AFR's you're commanding on a WBO2? That cam should be able to make good power with a flat 27* of timing @WOT from 2800 RPM up with a 12.7:1 AFR. What kind of gas are you running? Do you have any vibrations (triggering false knock)?
tylorjefcoat
October 20th, 2008, 05:45 AM
Are you actually seeing the AFR's you're commanding on a WBO2? That cam should be able to make good power with a flat 27* of timing @WOT from 2800 RPM up with a 12.7:1 AFR. What kind of gas are you running? Do you have any vibrations (triggering false knock)?


No, we didnt have the WB02 that time. I always use premium and i dont belevie that i have any vibrations, i did find it funny it only occured in third gear...

im at a loss..
SSpdDmon
October 20th, 2008, 06:50 AM
No, we didnt have the WB02 that time. I always use premium and i dont belevie that i have any vibrations, i did find it funny it only occured in third gear...

im at a loss..
No point in tuning on the car if you can't measure the changes. Get a WBO2! :) If the NBO2's are any indicator (not a reliable source), I'd say you were lean. Usually, LT cars show mid-to-low 900's on the NBO2 mV's. You driver's side bank is about 100mV shy, which would lead me to believe you're short on fuel.
joecar
October 20th, 2008, 06:56 AM
tylorjefcoat, welcome to the forum... :cheers:


SSpdDmon is right, you need a wideband otherwise you won't know your actual AFR... NBO2 is not designed to give the AFR away from stoichiometric.

I agree, the HO2Sx1 voltages indicate your WOT is lean... can't tell by how much.
nonnieselman
October 20th, 2008, 10:46 AM
I dont like the way he copied the high octane and low octane spark tables.. ??


Get a wideband on it and log your IDCs....
GMPX
October 20th, 2008, 10:50 AM
I dont like the way he copied the high octane and low octane spark tables.. ??
That is an old school way of thinking on the LS1 PCM and I agree with your statement. There is no harm in having the low octane table even 10 degrees below the high octane table, if the engine isn't knocking then it will make no difference to the final timing values from the high octane table, but of course if it does knock then it gives you a nice safety net.

Cheers,
Ross
nonnieselman
October 20th, 2008, 10:55 AM
That is an old school way of thinking on the LS1 PCM and I agree with your statement. There is no harm in having the low octane table even 10 degrees below the high octane table, if the engine isn't knocking then it will make no difference to the final timing values from the high octane table, but of course if it does knock then it gives you a nice safety net.

Cheers,
Ross

Thats what i was always told..
I been lookin at his logs, and the timing is all over the place.. Kinda strange?