Okay so I pulled out my plugs on my 87tii....basically stock, emissions removed, s5 turbo and running 6psi. This I believe is one of the trailing plugs, the others don't have the back spot(oil deposits??) but are cracking..to hot?????...This one is pretty white, the others are not really white but show signs of wear and cracking. So I'm pretty sure it's running way to hot. My question is what could cause this? I believe these are a bur7ex and bur9ex combo....should I be running a bur6ex/bur8ex...any suggestions?

 

I would look at the fuel system if you are mostly stock. Personally, I would change the fuel filter, check the fuel pump voltage and cooling system.

 

Run higher octane till you figure out whats going on.
Check AFR and EGT. A low EGT can signal impending pre-ignition (engine goes boom).

 

post pics of these other cracked plugs. i see nothing wrong with the plug in question, it's a light tan color. sure it's not fully even in terms of color but rotary engines have weird burn characteristics anyway

i've seen my share of messed up plugs and judging by that one pic you posted there's nothing that you should be worried about. If you're REALLY worried about something going wrong, run four BUR9EQ plugs. FD's run BUR7EQ/BUR9EQ from the factory and they boost 10psi, making 220+ to the wheels.

 

Thanks for the replies so far, that's proabably the worst plug, the others are tan colored but seem to be breaking down and I assume their getting to hot. I honestly don't think this car is running lean..it used to have a weird idle sometimes like it was going to die from over fueling but I recently looked at my 02 sensor wire and it was attached (two pieces) by the guy twisting the wires together and farther down with a butt connector which I touched and it pratically separted in my hands. I fixed that and the idle is great. The car runs fine, a little backfire every now and then but nothing major.I don't know when the last time these plugs were changed so they proabably need changing.

Note: Going to defintely check into proper fuel pressure, voltage to the fuel pump and will probably change the fuel filter for the heck of it.