View Full Version : JRSC Choosing the right spark plug?

02-19-2012, 01:46 PM
After researching, I am still not able to find a definitive answer. Currently I have the stock ep3 engine with intake and headers, but I just bought a JRSC race kit and a k20a2 engine. I don't plan on swapping right away, but I do plan on putting the s/c on. When I do swap, I will also be swapping the supercharger onto the a2 as well. What is the best spark plug to use on either or both engines? I know I need colder plugs, but which ones? Sorry if this has already been answered. Thanks

02-19-2012, 01:54 PM
What size pulley?

A general guideline will be using k20a2 OEM NGK plugs in a JRSC'd k20a3.

After you swap in the k20a2 engine, you may need to go one heat range colder... but that depends on how much boost you run.

02-19-2012, 03:05 PM
It is the 4" pulley, and I am going to run only as much boost that doesn't compromise engine reliability. I have AEM v2, kidd racing 4221 headers, and kpro, probably going to go with apexi ws2 or tanabe exhaust, and I'm probably going to leave the internals stock for now. Any suggestions?

02-19-2012, 03:15 PM
Headers? K series only has one header...

I used a v2 on mine and it worked fine. Might not be the best as far as performance goes... but it will serve its purpose. Snag the exhaust of your choice... but if you do intend on swapping in a k20a2, i would buy the exhaust closest to 2.5" and larger.

Youll find yourself doing little things to improve the overall throttle response and power delivery of the JRSC (ported TB and SC inlet, ETC), but remember the JRSC and k20a3 has its limits. If you are looking for more than 300whp with a JRSC'd k20a3... you really need to consider the swap first... and then turbo instead.

02-19-2012, 06:19 PM
Header* Yes, I wasn't extremely impressed with the V2. Once the engine bay heats up, power is significantly reduced. I understand SRI is safer than CAI as far as hydrolock is concerned, but they engineered the V2 way too close to the exhaust manifold, they possibly could've tucked it in a little closer to that wheel well.Thank you very much for the info!

02-23-2012, 06:26 AM
You two best choices are going to be the Stock RSX-S NGK plugs (IFR7G-11KS), which are iridium plugs, or you can save money and use the NGK BKR-7E copper plugs, which are the same temperature as the RSX-S plugs. The BKR-7E will have to be gapped though. I ran these for a long time in my EP and had them gapped at .036. Once the car is tuned, do not change the gap. The iridiums are pre-gapped and also will last longer, but are more expensive.