First off the big one. At what CR should I start worrying about my spark getting blown out on a stock ignition and causing a miss. I've got a miss I cant find. Usually its spark plug wires burned and arcing. But I cant find an arc anywhere. I'm pretty sure its not detonation because there is no spark retard on datamaster. I want to say my CR is in the 11.5-12:1 ballpark.

Secondly, I've had a speedometer problem for about 6 months now. The speedo is all over the place. I was going to replace the sending unit today and was messing around with it. I unplugged the connector to the sending unit and started the car and it was reading 55-100 while idling in the drive way. Could this be something in my cluster causing this. I checked both grounds; the one at the coil and ICM and the one on the other side on the block and they are both fine.
Also my oil pressure guage is maxed out. I unplugged the sending unit on that one too and no change. I looked for a pinched wire but found nothing. It just maxed out Friday while driving and wont come back down.
Thanks for any help

 

The second question would appear to be easy. If you unplug something and it DOES NOT change, it would indicate the the signal was missing to begin with. As in the wire may have been cut or the connection bad or corroded. Best to "buzz" out the wiring with an ohm meter. Be careful not to fall into the bad connector trap. Some will buzz from end to end without buzzing through the connector. The wire appears to be fine, but the connection was poor in the connector itself.

An easy test for the oil pressure gage is unplug the sensor and jump the connector to ground. If it goes down, the sensor could be defective. If it does not, the cluster could be bad. And make sure the 10 amp gages fuse and the PCM Bat fuses at the IP fuse panel are clean and intact.

The first question is little more involved. I would think if your CR were the problem, an inductive timing light would not give an indication of a miss. The pulse would travel through the wire, through the plug and just get squelched when it tries to fire. This would "fire" the timing light just as it should. You would however, still experience a miss. HOWEVER, I don't believe your compression ratio is too high to create that sort of problem. I think if your problem were from the ignition, a timing light would show an erradic spark on some plug wires. If however, the problem does not show up at idle, it would be impossible to find the problem with this method. In that case, putting the car's ignition on a scope, might find it.

You should still use a more powerful ignition. Together with higher octane and a step cooler plug and the custom tuning you planned on, you should be fine.

 

I run the highest octane available and I also put some Stabil in the tank to get rid of any water that maybe in there because it set for a couple of months. But I've also ran about 2 tanks of gas through it too. Im running TR6 plugs and I'm pretty sure they are a colder plug because they are used for N2O. Guess I should start shopping for a ignition box.