My 2.7 build with a 304 cam is sputtering/knocking above 5k rpm, and I'm thinking its the plugs.
I have pretty high compression, around 11.2/1, and I've been having problems revving the engine smoothly all the way to redline (6900rpm). I first put in standard plugs (Bosch W8LCR), and the engine wouldn't rev beyond 3.5k no matter what I did. I switched to W8LPRs (plats) because platinum is a 'cooler' alloy than copper, and that kinda fixed the problem.
Now the engine runs all the way to redline, but it sputters up top. I tried playing around with both fueling and ignition advance (SMT7) with no real luck. I'm thinking I need plugs that are 1 step colder than stock (not half a step like LPRs). What plugs would those be?
Any other suggestions as to what might be up if it's not the plugs?
I have a pretty strong spark at idle, and my injectors are 19lbers, in good condition. I have an m30 afm, and that's working just fine, no voltage drop anywhere across the track.
Help?
I have pretty high compression, around 11.2/1, and I've been having problems revving the engine smoothly all the way to redline (6900rpm). I first put in standard plugs (Bosch W8LCR), and the engine wouldn't rev beyond 3.5k no matter what I did. I switched to W8LPRs (plats) because platinum is a 'cooler' alloy than copper, and that kinda fixed the problem.
Now the engine runs all the way to redline, but it sputters up top. I tried playing around with both fueling and ignition advance (SMT7) with no real luck. I'm thinking I need plugs that are 1 step colder than stock (not half a step like LPRs). What plugs would those be?
Any other suggestions as to what might be up if it's not the plugs?
I have a pretty strong spark at idle, and my injectors are 19lbers, in good condition. I have an m30 afm, and that's working just fine, no voltage drop anywhere across the track.
Help?
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