I changed my spark plugs yesterday. I gapped the new ones to .048". Just for kicks I measured the gap of the old ones and the were in the range of .03 or close to there. Stock gap is .05", right? Anyway, my questions is what does the spark plug gap really do?


-Avenger
99 Eclipse RS out of the shop!! :)

I think stock gap is like .038"

Bigger gaps are good *IF* your ignition can handle it. A bigger gap creates a bigger spark and supposedly a better ignition of the air/fuel mixture. I think a gap of .05" is too big for our stock ignition. Granted we have a pretty good ignition stock, but I'm not sure our ignition produces enough spark energy to really cross this gap efficiently. When I do the ignition amp I will run a gap of somthing like .048".

"To strive to seek to find... and not to yield."
Michael J. Kulaga e-mail: Michael_97RS@2gntDSM.zzn.com
aol IM: MJKulga Website: http://highlander.dsmpower.com/

Injen CAI w/ K&N Breather Filters, AFX UDP, 55mm TB, GS-T Muffler, FU/RU/RL STBs, Front NRG Susp. Motor Mount Ins., Red Silicone Hose Kit, 8.5mm Magnecor Wires, Bosch Rapidfire Plugs, TSW Blade 17x7.5, Bridgestone Potenza RE730 215/45ZR-17.

And in my Room: Rear disc brake conversion kit, SS Brake Lines, Intake manifold 4 porting, Rear Motor Mount Ins. Silver Cadmium Plated KVR Cross Drilled Rotors and KVR Carbon Fiber Kevlar Pads.

Waiting for from RRE: Front Lower Tie Bar, SS Clutch Line.

You're kidding, right? I'm gonna have to look it up when I get home. They are set to .048 right now. I think it's actually making a difference. Seems a little more responsive.


-Avenger
99 Eclipse RS out of the shop!! :)

I think that is what they recommend, but if the ignition can cover the gap then you probably are doing better

"To strive to seek to find... and not to yield."
Michael J. Kulaga e-mail: Michael_97RS@2gntDSM.zzn.com
aol IM: MJKulga Website: http://highlander.dsmpower.com/

Injen CAI w/ K&N Breather Filters, AFX UDP, 55mm TB, GS-T Muffler, FU/RU/RL STBs, Front NRG Susp. Motor Mount Ins., Red Silicone Hose Kit, 8.5mm Magnecor Wires, Bosch Rapidfire Plugs, TSW Blade 17x7.5, Bridgestone Potenza RE730 215/45ZR-17.

And in my Room: Rear disc brake conversion kit, SS Brake Lines, Intake manifold 4 porting, Rear Motor Mount Ins. Silver Cadmium Plated KVR Cross Drilled Rotors and KVR Carbon Fiber Kevlar Pads.

Waiting for from RRE: Front Lower Tie Bar, SS Clutch Line.

LAST EDITED ON 08-Jun-01 AT 12:39 PM (PST)

The range is supposed to between 0.048 and 0.052, 0.050 essentially being what it's supposed to be.

The old timers 0.035 rule doesn't apply to us, our cars can handle 0.050

Todd Scungio
98 RS
15.803 @ 86.48 MPH

I think .045 to .05" is correct for stock too with champions and other plugs but NGK V-power recommeds a smaller gap (maybe due to the V that has to be at least .02" although the spark doesn't have to jump that far).


Stan2gnt
Stan2va@aol.com
95 Talon 420A-Turbo
Former and future nitrous user

The gap for the 420A is .048 to .053". I'm running the NGKs gaped at .052 with Magnecor wires. I was able to notice a little extra response and better startup.

Just remember that the tip of the electrode burns away gradually. So, overtime, your .050 gap will eventually turn into a .060 gap. Naturally, if you change your plugs every 5K-8K miles, you won't have that problem. : ) The higher a plug gap, the more voltage is required to jump it, thus reducing performance.

Soniclipse
1997 Black Mitsubishi Eclipse RS A-4
Mobil 1, Valvoline Synpower PS fluid, Bosch Plat. plugs, clear bumpers, Ractive Fusion headlights, more to come.

I have mine set to .050 and it is fine. However, whn I got my car, I changed plugs and wires within a few months. Set to .050. I recently crossed 30k miles. My car developed a sputter and backfired at stop lights. I changed the plugs and the car is better than ever now. I went with the .050 gap again. I think whoever said it was right, the gap may expand overtime, but if u change the plugs pretty often, u have no worries. I can't really remember, I think I checked the plugs when I took them out, and the gap did't change, but I can't remember. I think they were just pretty old. They were NGKR platinums.

I set my gap to .048 2 weeks ago and yes the response time is MUCH better it really did make a difference anyway i had to change my valve seals and main gasket seal so changed the plugs while i was at it car is running good now!!