I have a sr20det red top in my s14. I have tracked it about 4-5 times with the sr20 in it. When I do track it I am usually on the track for about a half hour at a time. So I do beat on it a bit. I am running the altima fans, mishimoto rad, and a FMIC for cooling. For power, I’m running 10psi boost with a 3" exhaust from turbo back. stock turbo and internals. I have a walbro fuel pump with sparkplugs one heat range colder.
I was at the track last week (Mosport DDT) did about 2 laps and lost a cylinder(#4). I thought it was a bad coil because it was hot and they are original. So I swapped coils around and it was still the #4 cylinder. checked the plugs and it was bent to shit, gap was closed.
This had happened to me before, but the gouge marks on the sparkplug looked liked something had bounced around in the cylinder. So I thought i got lucky and it spit it out. The Compression was still good,and so was the boost from the turbo. So I changed plugs and kept driving it.
So now I know it is knock/detonation. I thought with my setup I should not be leaning out. I am putting on a wide band now and changing the knock sensor.
Was my set up leaning out?
^ Wouldn’t leaks in the intercooler piping create a rich condition (assuming you’re running MAF still) since some of the air the MAF sensor has measured is escaping, but it still dumps the same amount of fuel in?
I would do as crx said if you have the resources, and put a scope in the spark plug hole and look for any debris. That damage is very likely to be from detonation. It also looks very likely as though there’s something in the cylinder that was hitting the plug, 'cause detonation alone wouldn’t cause the dents/pitting on the plug.
Also, check to see if cylinder #4’s injector is pulsing properly, as well as fuel pressure. If those are ok, try swapping out ECU’s with one that’s known to be working well. If all that stuff fails, check your wiring, there might be a frayed/broken wire somewhere in the harness for that injector/coil pack.
That’s all I can think of for now. Should keep you busy for a while lol.
“That damage is very likely to be from detonation. It also looks very likely as though there’s something in the cylinder that was hitting the plug, 'cause detonation alone wouldn’t cause the dents/pitting on the plug.”
That is what I originally thought, because the pit marks where on the plug and on top of the piston, when it first happened to me on cylinder #3. I had done a compression test and it was Ok. So I went to Mosport for a day and it was fine (big track all day, had fun) . The next track day is when it happened again, cylinder #4.
So now I am using it as an excuse to finally swap the turbo, along with injectors, MAF and a tune. I will do a compression test and if it is ok, will continue with the turbo swap.
I took the turbo off and it was not damaged so it is just detonation.
The swap will take a while though, pre-occupied with other stuff.
