Spark plugs for ECOTEC

[RyanD]

The manual says to change the spark plugs every few thousand miles, so I bought a set of NGK BKR7E plug.  They are copper plugs recommended by tuners.  The Brammo manual says to use a platinum plug gapped at 0.045.  I pulled out the original spark plugs, which were iridium plugs gapped at 0.035.  I split the difference and gapped the copper plugs at 0.040.

The car runs fine, but I wonder if I would be better off with the iridium plugs.  They last for ever, and the plugs are a bit of a hassle to change.  What do you guys think?

[silver]

Ryan, I don't have your answer, but rather a question....how do you change the spark plugs, can you give a little detail about what you do with those little black boxes, and how they come out and stuff......thanks...I think as part of my mods It's probably a good idea to move to a cooler heat range but I'm unsure.

[bolus]

once you get the coil cover off, each coil (black box) has 1 bolt.  Then they pop off and you can see the spark plugs.  Very easy once you get the intake and coolant tank off.

[silver]

ok I guess it's just one of those things...when you haven't done it before it's intimidating....like changing the fuel injectors...then after it's done, you're like..........easy as pie

[Alec]

I don't know much about the Ecotec engine but I would have thought that the Iridium plugs would be better than the standard plugs if they're the correct grade.

I've had a set of Iridium plugs in my bike for 35,000 miles and in all that time they've never had to be cleaned let alone re-gapped.

[positron]

True for you streeties.. but I want a big ole fat copper cold plug set close not to blow out at high boost at WFO..


yeah yeah I know.. Eaton's a oven..

[quote="MadMaxedAtom"]
What kind of pie...
[/quote]..

Chicken pie... Mr. Tweedy...

[bolus]

spark plug temp info
http://en.wikipedia.org/wiki/Spark_plug#Heat_range

any other good resources for heat indexes?

[Terry Kennedy]

[quote="RyanD"]
What do you guys think?
[/quote]

There's an interesting article here. In part, it says:

The stock spark plugs for the LSJ motor are NGK PFR6T-10G platinum plugs. Platinum and iridium plugs are much harder and more expensive metals that can last up to 100,000 miles however they are not the best metal for heat dissipation. In our experience copper based plugs are far superior in supercharged applications and while they may not last as long as platinum or iridium plugs they will offer better performance. In addition to being copper based these plugs are also one heat range cooler than stock which helps reduce the possibily of detonation and the resulting knock retard.

New spark plugs should always be gapped prior to installation. The stock LSJ spark plug gap setting is .045", and that works fine for the lower boost settings. As the boost increase, smaller plug gaps are required to prevent spark blow-out. Following are our dyno-proven LSJ spark plug gap recommendations:

Stage 1 - 3.30" to 3.20" supercharger pulley - .045" gap
Stage 2 - 3.10" to 3.00" supercharger pulley - .045" gap
Stage 3 - 2.90" to 2.80" supercharger pulley - .040" gap
Stage 4 - 2.70" to 2.60" supercharger pulley - .035" gap
Stage 5 - 2.50" supercharger pulley - .035" gap

[RyanD]

[quote="Terry Kennedy"]
[quote="RyanD"]
What do you guys think?
[/quote]

There's an interesting article here. In part, it says:

The stock spark plugs for the LSJ motor are NGK PFR6T-10G platinum plugs. Platinum and iridium plugs are much harder and more expensive metals that can last up to 100,000 miles however they are not the best metal for heat dissipation. In our experience copper based plugs are far superior in supercharged applications and while they may not last as long as platinum or iridium plugs they will offer better performance. In addition to being copper based these plugs are also one heat range cooler than stock which helps reduce the possibily of detonation and the resulting knock retard.

New spark plugs should always be gapped prior to installation. The stock LSJ spark plug gap setting is .045", and that works fine for the lower boost settings. As the boost increase, smaller plug gaps are required to prevent spark blow-out. Following are our dyno-proven LSJ spark plug gap recommendations:

Stage 1 - 3.30" to 3.20" supercharger pulley - .045" gap
Stage 2 - 3.10" to 3.00" supercharger pulley - .045" gap
Stage 3 - 2.90" to 2.80" supercharger pulley - .040" gap
Stage 4 - 2.70" to 2.60" supercharger pulley - .035" gap
Stage 5 - 2.50" supercharger pulley - .035" gap

[/quote]

Yeah, I posted that link a while back.  My question is why the plugs that came in the car from Brammo are different plugs with different gaps than recommended in Brammo's manual.

[silver]

why ask why....haha, we're all asking why about a LOT of things Brammo did...not many of us are finding answers as to why, it's a hard question to answer....at least you have received good feedback so far.

[positron]

There were probably the plugs that came in the motor in the crate.. Do we know who upfit these motors or did GM prep and drop?

And was there ever a final A2 GM count for posterity?

[RyanD]

http://www.sparkplugs.com/sparkplug411. ... lts&mfid=0
Here are dyno results for several different spark plugs.  The results favor the iridium plugs.

It sounds like the advantage for copper plugs is better heat transfer due to the larger electrode.

[RyanD]

There is a typo in the Brammo manual for the spark plug model numbers.  It should be "LTR5IX-11  NGK" instead of "LTR51X-11  NGK".  This is the NGK IX iridium plug.  They are around $8 per plug.

[Bottoz]

Ryan, those plugs listed in your first post are the same I used. I swapepd to those plugs when I Dyno'd and Pulley Swapped. I gapped them at .040. You may need to close it up a little more at sea level as comparied to my 6000 feet.

[dial911]

I spoke with Richard at Brammo several weeks ago about this and he basically said don't worry about the plugs "should last 100k miles". I figure I'll replace them every 2-3 years.