sources for detination @ 13psi and up???
#1
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Thread Starter
sources for detination @ 13psi and up???
hi,
i have an '87 t2 that i have built from the ground up myself. mods list:
E6K w/3bar
fuel pres gauge
egt (approx 800 deg C under full load)
j&s knock (stupid thing keep lighting up)
FMIC
full exh.
T78
550 pri
1600 sec
walbro 255
fp reg (44psi static)
street port w/ Hurley 3mm
wideband tuning (cruise=14.4, <5psi=12.5-13.5, >10psi 10.0AFR)
i am writing this b/c i am completely frustrated about the fact that i can still see detonation @ 13psi and up!!! this cost me 1 engine already @ 6000miles!
i think that 93 octane on this set up should be able to support 16-18psi. am i right?? please look at the following and tell me any suggestions that you have:
fuel AFR's= cruise=14.4, <5psi=12.5-13.5, >10psi 10.0AFR
timing= from 3k rpm to 8k rpm- 30deg adv @ 0psi, linerized to 12deg adv @15psi
trail split (>2k rpm)= 10deg @0psi, 2deg @ 5psi, 10deg @15psi (linerized between points listed)
corrections:
timing vs. intake air temp= starting @ 100deg 1deg ret per4-6deg temp rise
fuel vs. intake temp= i have it taking away very little to nothing above 100deg inorder to further richen the mixture
the thing is this engine is NOT leaning out. the detonation is coming from something else. i am baffled. i feel those timing values are already too conservative. can an engine detonate from being too rich? is it possible that small imperfections in the rotor housings/side plates could allow blow-by igniting the next charge?
please forward any input that you have. thanks for your time.
justin
513 518 1994
i have an '87 t2 that i have built from the ground up myself. mods list:
E6K w/3bar
fuel pres gauge
egt (approx 800 deg C under full load)
j&s knock (stupid thing keep lighting up)
FMIC
full exh.
T78
550 pri
1600 sec
walbro 255
fp reg (44psi static)
street port w/ Hurley 3mm
wideband tuning (cruise=14.4, <5psi=12.5-13.5, >10psi 10.0AFR)
i am writing this b/c i am completely frustrated about the fact that i can still see detonation @ 13psi and up!!! this cost me 1 engine already @ 6000miles!
i think that 93 octane on this set up should be able to support 16-18psi. am i right?? please look at the following and tell me any suggestions that you have:
fuel AFR's= cruise=14.4, <5psi=12.5-13.5, >10psi 10.0AFR
timing= from 3k rpm to 8k rpm- 30deg adv @ 0psi, linerized to 12deg adv @15psi
trail split (>2k rpm)= 10deg @0psi, 2deg @ 5psi, 10deg @15psi (linerized between points listed)
corrections:
timing vs. intake air temp= starting @ 100deg 1deg ret per4-6deg temp rise
fuel vs. intake temp= i have it taking away very little to nothing above 100deg inorder to further richen the mixture
the thing is this engine is NOT leaning out. the detonation is coming from something else. i am baffled. i feel those timing values are already too conservative. can an engine detonate from being too rich? is it possible that small imperfections in the rotor housings/side plates could allow blow-by igniting the next charge?
please forward any input that you have. thanks for your time.
justin
513 518 1994
#3
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how hot are your intake air temps?
mike
mike
#4
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The J&S can easily retard over 10 degrees and with 10 degress split, you end up firing the trailing plugs first.
So a little noise, too little split , too much J&S sensitvivity, and the engine gets blown by detonation that the J&S caused.
That is why I got rid of my J&S when I started running under 15 degrees split. It was causing pinging and detonation.
So a little noise, too little split , too much J&S sensitvivity, and the engine gets blown by detonation that the J&S caused.
That is why I got rid of my J&S when I started running under 15 degrees split. It was causing pinging and detonation.
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i'm thinking about hooking up for the display, but not actually putting it into the ignition system
mike
mike
#7
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Try going wider with the split , when my engine was stock with the E6K running things at settings similar to yours , I would get knock no matter what iI did , I even retarded the ignition to zero and it still rattled , when I checked the split it was at 12 deg , I openrd it up to 15 deg , and there was no sign of knock after that .
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#8
Learned alot | Alot to go
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Originally posted by j9fd3s
i'm thinking about hooking up for the display, but not actually putting it into the ignition system
mike
i'm thinking about hooking up for the display, but not actually putting it into the ignition system
mike
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Originally posted by cewrx7r1
The J&S can easily retard over 10 degrees and with 10 degress split, you end up firing the trailing plugs first.
So a little noise, too little split , too much J&S sensitvivity, and the engine gets blown by detonation that the J&S caused.
That is why I got rid of my J&S when I started running under 15 degrees split. It was causing pinging and detonation.
The J&S can easily retard over 10 degrees and with 10 degress split, you end up firing the trailing plugs first.
So a little noise, too little split , too much J&S sensitvivity, and the engine gets blown by detonation that the J&S caused.
That is why I got rid of my J&S when I started running under 15 degrees split. It was causing pinging and detonation.
J&S w/low split == bad
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