Popping exhaust
- Thread starter m_dogg
- Start date
Exhaust is too big, and it's loud too...so you can hear how poor the scavenging is. Your getting raw fuel past the exhaust valve, and too much heat in the exhaust when it should be in the cylinder also. Higher compression requires a leaner mix, with less timing. I would start trying to hit something like a 12-12.5 AFR with a max of 15-17 degrees advance.
and Gf is complainig about exhaust being to loud
His exhaust is not too loud, it's barely loud enough to pick up inside the car,and it's an SLP, not too big either 
Second, his problem has nothing to do with WOT, therefore the AFR is moot. On top of that, GL getting a non-i/c'd m90 car with an l26 bottom end to run anywhere near 12:1 AFR without KR on pump gas. Not happening.
MDogg, send me a vid with your phone of this happening, definitely very odd...
Second, his problem has nothing to do with WOT, therefore the AFR is moot. On top of that, GL getting a non-i/c'd m90 car with an l26 bottom end to run anywhere near 12:1 AFR without KR on pump gas. Not happening. MDogg, send me a vid with your phone of this happening, definitely very odd...
In all seriousness, the occasional Exhaust pop usually means a rich condition (this is why it happens on Decel) and are not usually something to worry about as there is not much damage that can be caused... The backfires that go into your intake side due to a lean condition on the other hand, are very bad, and should be fixed immediately, but normally those are on Acel, not Decel
So weird, i've never heard either of your cars do this
My car actually pops at idle too.... It's hard not to hear
Some sort of sealing issue, Burnd valve, messed up valve seat, head gasket bridge blown out... Many options, not tearing into it until maybe the end of April, or beginning of May. shit has been broke for 2 years, whats another few weeks... on the up side, I did run a 14 on 4 - 5.5 cylinders
My cell phone vids = FAIL. Gotta stop by one of these days and you'll see for yourself. Few things I've been looking at, AFR 10.8, o2s in 1025mv range, LTFT -10 - all going WOT that is.
Got an original GM o2 sensor, will put that on this week along with other minor things...new belt and some pulleys and other shit.
I've had it happen on other cars I've rodded, but it's easier to 'splain in 3800 language.
Back when I was playing with DP sizing, I got really bad popping with the 3" DP, and 3" exhaust. I was tuning with an AFC, and reading the plugs to check AFR. Couldn't make the car happy with the big pipes. I installed a cone taper inside the DP that reduced the diameter to 2.5. Car picked up a bunch, and the popping went away. I was able to bring the tune in much better also. Headers will react differently than ported mannies, but you get the idea. Generally, higher CR will require leaner AFR. If that means dropping the timing a bunch, then so be it. IMHO, anyone considering a build with a SC, and the L36/26 block should be intercooled, or expect to have headaches with KR.
Back when I was playing with DP sizing, I got really bad popping with the 3" DP, and 3" exhaust. I was tuning with an AFC, and reading the plugs to check AFR. Couldn't make the car happy with the big pipes. I installed a cone taper inside the DP that reduced the diameter to 2.5. Car picked up a bunch, and the popping went away. I was able to bring the tune in much better also. Headers will react differently than ported mannies, but you get the idea. Generally, higher CR will require leaner AFR. If that means dropping the timing a bunch, then so be it. IMHO, anyone considering a build with a SC, and the L36/26 block should be intercooled, or expect to have headaches with KR.
Poping at idle is an issue, poping at decel is not an issue, just sayin
I wish someone had told me that 4 years ago. but it is the truth, with headers, and a CAI, i couldn't even run 15* w/o KR
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