I was just looking at the frontside of my motor and started to think it looks like a PITA to change the spark plugs. And even more difficult with my coil on plug bracket. I've never owned a boosted motor, so I'm not too sure.
They are easy to change, much, MUCH easier than the 2.8l. You should only need to changed them every 100,000 miles if you use OEM plugs. 20,000 miles if you use the cheaper copper ones.
True. 100,000 miles IF you use platinum tip plugs. 30,000 miles if you use copper core plugs. The platinum tip plugs are usually about 3 times the price of copper core, but you don't need to change them as often. Make sure your ignition system is capable of using platinum plugs. They demand more from the coil(s). The 3800 (series 2 and 3) are capable of running platinum. The 2.5 and 2.8...not so capable.
They are easy to change, much, MUCH easier than the 2.8l. You should only need to changed them every 100,000 miles if you use OEM plugs. 20,000 miles if you use the cheaper copper ones.
What he said...I changed my 104s to 103s after about 12K when I dropped pullies....The 104s still looked good after 12K of semi hard miles.....
Just a note: Platinum plugs are not recommended for 3800SC's that have been modified with a larger pulley and or higher boost than stock. Standard Autolite 103's or 104's should do . They should last 20K miles. If you insist on using platinum plugs, they will increase KR's and may prove harmful.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Just a note: Platinum plugs are not recommended for 3800SC's that have been modified with a larger pulley [......] If you insist on using platinum plugs, they will increase KR's and may prove harmful.
Who mods to a larger pulley anyway? I used to go about 15k on my 104s. I change the 103s once I went turbo every 10k. They're cheap and I run it rich. For the 'typical' 3800sc swap, 3.4 pulley, etc, I'd run about 15-20k on a set of 104s. (or just change them once every spring)
LOL, sorry misread your post...miseed the word "often" .............
They dont need changed often if you use good plugs, avoid platinum though. My AC's have been great, I do clean them every other oil change and check gaps, just cuz they arre so easy to get at !
Cheap Autolite copper plugs didn't last 6000 miles in my Turbo 3800 before I started getting misfires. I switched to Denso Iridium IT-22's about 5 years ago and have not had one problem since, so I haven't changed them.
The stock Delco 41-101 Iridium plugs that come in the 3800 Series 2 and 3 engines are pretty hot (heat range); usually too hot of a heat range if you plan on installing/doing any mods. Autolite just started making their own line of Iridium plugs not too long ago that are about 1/2 the price of the Denso's I'm using now, and you can get them in colder heat ranges than stock.
Who mods to a larger pulley anyway? I used to go about 15k on my 104s. I change the 103s once I went turbo every 10k. They're cheap and I run it rich. For the 'typical' 3800sc swap, 3.4 pulley, etc, I'd run about 15-20k on a set of 104s. (or just change them once every spring)
I could get easily 60k out of 104s on a simple setup with a good non 10:1 tune that most run.
Paying 3 times the price to change plugs less often sounds worth it to me.
Using some Denso Iridium IT-22's sounds like it would be the best choice for me. But I will be running a smaller pulley than stock, the N* tb, and pacesetters on the sc3. Those will work fine, correct? I would like to avoid changing my plugs often with this Coil On Plug setup I'm building. Removing the bracket and boot will be a tad difficult on the front side when the motor is in the car.
Cheap Autolite copper plugs didn't last 6000 miles in my Turbo 3800 before I started getting misfires. I switched to Denso Iridium IT-22's about 5 years ago and have not had one problem since, so I haven't changed them.
The stock Delco 41-101 Iridium plugs that come in the 3800 Series 2 and 3 engines are pretty hot (heat range); usually too hot of a heat range if you plan on installing/doing any mods. Autolite just started making their own line of Iridium plugs not too long ago that are about 1/2 the price of the Denso's I'm using now, and you can get them in colder heat ranges than stock.
-ryan
I'm going to be running a stock series 1 supercharged engine in a couple Lemons races. That means two 7-hour days on a given weekend. I've looked at your chart at gmtuners, which plug should work best with long,sustained high RPM use? Thanks.
On my other 3800 car I have been changing copper plugs every year which turns out to be about 15k-20k miles, at that point the gap is about .004~ larger than where it was originally, so I wouldn't take it any further.. On my 3800 Fiero I plan to change it yearly as well, even though that might only be 2-4k miles.
------------------ 86 Fiero GT 4spd - L67 swap: VS cam, GenV. Needs exhaust (ETA 9/13) Build Progress 98 GTP - Some mods