I use copper 7's, the part number is 6282. For 8's I use iridiums.

 

The NGK 7173's are non resister plugs. Not recommended. I had poor results when experimenting with them, mostly my radar detector would go haywire, some intermittent interference issues. If you want a 8, go with the iridium's as mentioned.

 

Yeah, you need to use a resistor plug with the S. I tried non resistor NGK copper 7's and 8's and both caused missfire and idle issues on mine. I went to the NGK iridium 8's gapped to .018" and they have been great all the way to ~775 whp on e85 and stock low mileage AP1 coils.

 

Guys im still having issues with my S2000 I get miss fires on ALL cylinders and I am out of ideas other then replacing coils and the battery. I have adjusted the valves and no change. I have tired running 8's and 9's gapped to .020" on race fuel and I get the same thing. I have tried 8's gapped to .020" on 8lbs and 93 octane and I get the same thing. My car on has 12K miles on it and would hate to have to buy new coils. Anyways which ones are the best? Should I try a new battery first? If so which one? I even added a ground to the back of the valve cover and no luck.

 

I hate to say it, but it sounds like you could have bigger issues then ignition blow out. What do your plugs look like? If you have a coil that is going out your plug will typically look wet from unburnt fuel. But spark blow out is different, and if you cant cure it with plugs then you have to look deeper into the engine. Some excess oil getting into the combustion chamber under high load could take that cylinder over the edge as far as making clean combustion. Or best case scenario you need some sort of ignition boost. I'd just be surprised with race fuel at only 500+ you would need it. Is it possible you got a bad batch of fuel? have you considered running water/meth injection instead? it is more versatile, being you can play with different % to help trouble shoot things like this. A higher % of meth obviously burn better then water. Might just have to get tuned on pump and see what happens, that should tell you if its engine related or spark capacity.

On a side note, I'm an SC guy and I don't often get the chance to say, but I'm rather envious of your blower and power range, its what I'm working towards when funds allow. Just not your issues

 

sadly it happens with 93 octane also. Plugs are dry and now oil at all on them. I have a appointment on monday at a local shop. I my actually buy a certain persons 680WHP meth setup...but he blew his on the dyno. I have ran meth before on my JRSC'ed CRX.

 

sadly it happens with 93 octane also. Plugs are dry and now oil at all on them. I have a appointment on monday at a local shop. I my actually buy a certain persons 680WHP meth setup...but he blew his on the dyno. I have ran meth before on my JRSC'ed CRX.
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Yeah, obviously the even distribution with the multi port system is the most reliable at this power level.

Too bad he never got to see the benefits of his nice set up.

 

I agree but E85 is looking to be the best right now. no need to drain fuel as with Race Fuel. 900 bucks and a tune and your done. I already have everything else needed other then the injectors. I dont drive the car enough to worry about the fell ups.

 

 

well I had the battery tested and it came back with 340 CCA and its rated for 410 with a 12.97 Voltage reading. To me that sounds fine but all three different places said the battery is a little less then half of its state and they feel it should be replaced. Does this sound right? Should I just replace it due to my misfires?