bigjacksauto

I have been building modifying and drag racing cars for years and I have yet to see a spark plug Chang help any where near what is claimed below but I thought it was very interesting. Hope the link works scan down to what mike from socalhhr wrote

http://*****************************...opic.php?t=173
Well having trouble with link but herevis what was written
BTW: Here is the data we came up with on performance with the two different plugs:

AC Delco Plugs (stock) 0-60 = 9.60sec 1/4-mile = 17.22

Autolite APP 5263 Plugs 0-60 = 8.80sec 1/4-mile = 16.69

*(Keep in mind these runs were done with my "heavy" wheels on; they weigh 6lbs per wheel more than the stock alloys. This is why the times are "slow.")

Still, a noticeable difference. The car even launches harder; it pulled .44 g's stock, and .46 g's with the Autolites. The 2.4L engine runs noticeably smoother with these plugs too. I use the remote start feature everyday and I can hear the engine sounding much smoother. In addition, it has not "failed" once using the remote start since changing the plugs.

My "old" stock plugs had only 9k miles on them, and before someone says "hey, it's just the new plugs" - know that we tested the Bosch Platinum 4 plugs also and the car ran slower than the stock AC Delco plugs. These Autolite's are definitely a worthwhile upgrade for the HHR owner wanting max performance from their ride.

Hope it helps,

Posted: Sat Sep 23, 2006 6:18 pm

Message

hhrfreek

I think the only difference is the Autolites are 1 step colder. The 5263 are the same plugs I am running in my SC setup. If I recall correctly though: I replaced the original plugs when I got my '06 HHR in '09. At that point the stock AC Delco plug was no longer available and it was replaced with another AC Delco plug with a different part number. Maybe there was an issue with the spark plugs on earlier models, but still, getting performance numbers like that seems like a far cry with just plugs.

bigjacksauto

I agree I just do not see how they where picking even a tenth of a second
I do run the autolites on my race car and a trick I picked up from a NASCAR engine builder was to use a anti seize type product called copaslip it is the only product they have tested that transfers the heat of the plug properly and therefore keeps the plug from being insulated and running at the wrong heat range.
Great stuff .
I think you may be right about the old plugs maybe not being correct.

Snoopy

Old news. If you do a search you may be able to locate the original thread. But it was "slammed" ( by a number of very knowledgeable people) and continues to this day. You CANNOT pick up 8/10ths of a second with just a plug change, as you have said....especially on a stock car. Maybe .1 or .2, but that is all. Don't you think the manufacturer of the vehicle would have used those plugs or duplicated them in their own brand, to attain that efficiency? Like you, I had done many plug changes in my younger days of competitive racing and NEVER discovered the "magic" plug.

The variance he discovered was more due to change of engine temperature, intake temperature, etc. I believe. And by the way, his testing was done with a electronic "add-on", not at a drag strip and not under any professional circumstances.

The person who authored that, while a really nice guy, made many claims about different add-ons, that later was discovered to be questionable. He even sold magic pellets that increased gas mileage by 3-5 miles per gallon.

SS fan

Where do I get me some of them, www.majicpellets.org. could use me some better mileage.

bigjacksauto

Snoopy thanks for the info on that.I knew it was to good to be true and was hoping to see someone here shed some light on this story thanks
I cannot believe someone would post those claims without a true test. I thought at least he was using
A vericom or gtech computer for testing
Magic pellets for gas mileage?
Maybe they where tums or some form of antacid to help the hhrs out back then with the BS going around ?

Snoopy

By the way....A veryto you. A little early, yeah. But better early than never

bigjacksauto

Thanks Snoopy I appreciate it.

Hib Halverson

I've been testing performance parts (including plugs) for many years and in a controlled test environment, I've never seen a spark plug change cause a significant decrease in e.t. unless the plug change either solved a misfire problem or solved a problem with too hot a heat range which was causing detonation or preignition.

It's likely the decrease noted by the OP was due to some other issue that occurred at the same time.

Possibilities:
lane choice and/or changes in track condition between passes
driving inconsistencies
ECT or IAT run-to run differences in ECT or IAT
run-to-run differences in KR
comparing old plugs to new plugs

I'll add that anyone who's drag racing their truck needs to run one heat range colder plugs. The stock spark plug recommendation for an Ecotech is quite hot in the interests of preventing fouling during pre-delivery or with engines with see a lot of short trips.

My favorite plug for HHRs in "performance street" duty cycles is the Denso ITV-20.