Detonating at 12 psi help please
Unless you are logging the car, how do you know it's detonation?
You don't hear detonation out of the exhaust. That's one of the weirdest things I've heard anyone say.
You hear detonation directly from the motor.
The factory has some significant knock retard capability and I'd doubt youd get the car to the point where you were pinging loud enough for you to hear it out of your exhaust.
How about a datalog and a modification of your map?
You don't hear detonation out of the exhaust. That's one of the weirdest things I've heard anyone say.
You hear detonation directly from the motor.
The factory has some significant knock retard capability and I'd doubt youd get the car to the point where you were pinging loud enough for you to hear it out of your exhaust.
How about a datalog and a modification of your map?
Ok, that's totally different.
The popping may be unburnt fuel in the exhaust igniting and "popping"
Typically backfire sounds like a gunshot so I wouldn't say that you are backfiring either.
If you changed the hotside, that will certainly affect your AFR and you should check that first. With the 10.5 hotside you're gonna spool later and if you are dumping in fuel earlier you may be dumping it in too soon.
You should pick and choose the advice you listen to.
I don't know why people are suggesting the things they are.
Your only symptoms are a popping in your exhaust? Or what else?
But again, a datalog or an AFR reading will tell you what's up.
Ok, that's totally different.
The popping may be unburnt fuel in the exhaust igniting and "popping"
Typically backfire sounds like a gunshot so I wouldn't say that you are backfiring either.
If you changed the hotside, that will certainly affect your AFR and you should check that first. With the 10.5 hotside you're gonna spool later and if you are dumping in fuel earlier you may be dumping it in too soon.
The popping may be unburnt fuel in the exhaust igniting and "popping"
Typically backfire sounds like a gunshot so I wouldn't say that you are backfiring either.
If you changed the hotside, that will certainly affect your AFR and you should check that first. With the 10.5 hotside you're gonna spool later and if you are dumping in fuel earlier you may be dumping it in too soon.
It sounds like like it could be a pre-turbo exhaust leak. Either the gasket seal between the head and exhaust manifold, the gasket seal between the manifold and turbine housing, or thirdly, your new Megan Racing header has a hairline crack in a weld.
Any pre-turbo exhaust leak is serious stuff and plays havoc with the MAF-ECU-O2 sensor loop by causing lean O2 sensor readings which triggers the ECU to add fuel which makes the car run rich and the ECU pulls fuel which makes the car run lean and detonate which causes the ECU to pull timing and etc.
To check for a header crack which are sometimes very minute,but almost always occur along the weld beads, apply the light of one of those million watt lamps to the header and eventually you´ll find it. Good luck.
Any pre-turbo exhaust leak is serious stuff and plays havoc with the MAF-ECU-O2 sensor loop by causing lean O2 sensor readings which triggers the ECU to add fuel which makes the car run rich and the ECU pulls fuel which makes the car run lean and detonate which causes the ECU to pull timing and etc.
To check for a header crack which are sometimes very minute,but almost always occur along the weld beads, apply the light of one of those million watt lamps to the header and eventually you´ll find it. Good luck.
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Joined: Apr 2007
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From: OH
At this point, I think you need to get the car logged. The only way afterfire can occur is if there's fuel in the exhaust. Sounds to me like you're going very rich. I could make some guesses, like maybe a stuck injector, but I think going to a tuning shop and having them datalog your car on a dyno is the next thing you should do.
It sounds like like it could be a pre-turbo exhaust leak. Either the gasket seal between the head and exhaust manifold, the gasket seal between the manifold and turbine housing, or thirdly, your new Megan Racing header has a hairline crack in a weld.
Any pre-turbo exhaust leak is serious stuff and plays havoc with the MAF-ECU-O2 sensor loop by causing lean O2 sensor readings which triggers the ECU to add fuel which makes the car run rich and the ECU pulls fuel which makes the car run lean and detonate which causes the ECU to pull timing and etc.
To check for a header crack which are sometimes very minute,but almost always occur along the weld beads, apply the light of one of those million watt lamps to the header and eventually you´ll find it. Good luck.
Any pre-turbo exhaust leak is serious stuff and plays havoc with the MAF-ECU-O2 sensor loop by causing lean O2 sensor readings which triggers the ECU to add fuel which makes the car run rich and the ECU pulls fuel which makes the car run lean and detonate which causes the ECU to pull timing and etc.
To check for a header crack which are sometimes very minute,but almost always occur along the weld beads, apply the light of one of those million watt lamps to the header and eventually you´ll find it. Good luck.
I also had similar symptoms when I had a leak at the 02 to downpipe junction. If you log it you will see you are getting some high knock counts as a result of the popping as well so that is probably what you are feeling, the ecu thinks you are knocking and is pulling timing.
Could also be over rich or need to change the plugs, but is sound more like an exhaust leak near or before the 02 sensor.
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lots of good advice in here and kudos to everyone trying to help... I'm going to echo what some of the others are saying.
it sounds like spark blowout to me but a pressure test and some logs are in order.
it sounds like spark blowout to me but a pressure test and some logs are in order.
I think you're getting a lot of bad advice.
1. Describe your problem in more detail. That'll help point advice in the right direction.
2. You can definately hear exhaust leaks, regardless of how small they are. If you don't hear one, you don't have one.
3. Exhaust "popping" can be caused by the exhaust itself, if pressure builds up in some resonator or chamber and then a change in engine exhaust pressure or velocity causes it to "pop"
4. It is easier to get more information if you log your driving with a tactrix cable.
1. Describe your problem in more detail. That'll help point advice in the right direction.
2. You can definately hear exhaust leaks, regardless of how small they are. If you don't hear one, you don't have one.
3. Exhaust "popping" can be caused by the exhaust itself, if pressure builds up in some resonator or chamber and then a change in engine exhaust pressure or velocity causes it to "pop"
4. It is easier to get more information if you log your driving with a tactrix cable.
I suspect you have a boost leak and are running into sub 9's AFR until the fuel just cannot be burnt any more. Check for leaks, then when you're done with that, go check for leaks.