Hello all!

Have a 99 GT with about 75k miles and the followings mods (right now plugs and wires are stock)

DHP PCM
SLP 180 T-Stat
SLP Loudmouth Exhaust
Motorsports CAI (more of a open air intake)

Within 2-3 weeks I plan to add the following

MSD Coils
SLP Headers
SLP Hi-flow Cat
U-bend

With all this, I'm going to replace the plugs and the wires since they probably need replacing anyway. With the mods I've mentioned above, what plugs and wires would you recommend?

Any help is grearly appriciated!!
Thanks!

Mike

i was reading on a site i think it was www.zzperformance.com and they have a whole list of parts that should not be replaced and parts they recomend to buy. they say on their GTPs they build all use the stock wires. they said the stock wires can really habdle some heat and power. now mind you, not every car is the same depending on how the car is driven, miles, and other things may have an affect on the kind of wires you may wanna use. otherwise i use to have a 95 grand am. i put Bosch platinum 2 spar plugs and they seemed to give better spark and i felt a little take off boost. but that was a 4cyl too the 3800 may be different then the 2300 hope i helped.

vince

Even with your mods you'll be fine with the regular GM Packard 7mm ignition wires. On spark plugs, the AC Delco 41-101 Iridium.

If you want to go with 8mm and up wires, MSD and Taylor work well too. IMO the Taylors probably have the best price.





http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

I have never had good luck with Bosch plugs. Stick with the AC delco iridium 41-101 like Bnaylor said. One thing to always remember on gimmicky multi-electrode plugs. Electricity seeks the path of least resistance, so it doesn't matter how many electrodes a plug has, it will only jump spark between the shortest path.

I have never had good luck with Bosch plugs.

I agree. Stay away from Bosch Platinums or Double Ps. I've got 6 old ones that I use for paper weights. P030X error codes galore and not good for the CAT convertor.








http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

I have a 2000 GT and the taylor cable 8mm spiro pro wires (http://www.pfyc.com/store/merchant.mv?Screen=PROD&Store_Code=PFYC&Product_Code=WB3008&Product_Count=22&Category_Code=GPUNDER) work awsome. and like the others i have, and would deffinatly go with the AC Delco Iridium spark plugs (autozone).

Hope this helps

I'll go with the Delco's...any idea as to what to gap them to?

Thanks!!
Mike

I'll go with the Delco's...any idea as to what to gap them to?

Thanks!!
Mike

The stock .060 for a normally aspirated Series II 3800. I gapped the AC Delco Iridium for .058 when I used to have them in my GTP.







http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

Be careful re-gapping Delco iridium and platinum plugs, as you can mis-align or knock off the platinum/iridium discs that give them their longevity.

Be careful re-gapping Delco iridium and platinum plugs, as you can mis-align or knock off the platinum/iridium discs that give them their longevity.

Hey Rich, while we're on the subject of AC Delco spark plugs, how many of the Rapidfire Platinums (14) have ever been returned back to your store? I believe that there is a 2 year warranty on them.

I had my first ever failure on a Rapidfire Platinum #14 on my wife's Regal LS or any AC Delco for that matter. These are the same OEM plugs in a Grand Prix GT. I replaced them in a set of 6 about 3K miles ago. She was going up a hill and the SES light flashed (indicates misfire) and then came on steady. She got home OK. I test drove it and saw a stumble at around 3500 - 4000 rpms. Then I hooked up the Actron scanner I have and picked up a generic P0303 which is misfire detected on cylinder 3. I removed the plug and it appeared OK. But on the ceramic part I noticed a hair line crack with a carbon track on it. It's about a half inch long and lines up with the A in AC Delco imprinted on the ceramic. I never drop my plugs so I know for a fact that I did not cause it. The crack is a perfect straight line not jagged which looks like it was done in the manufacturing process. I saved it for future reference and just went to Autozone and bought one new one. Put it in and everythings fine.

I was thinking about getting it replaced for free under the warranty but this one AC Delco plug is now like a collector's item to me....lol. What say you?






http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

I've never personally used the rapidfires, but we rarely get any back. They seem to work good in hi-performance motors, as they have the tapered electrode that is more self cleaning than the broad/flat center electrode on a copper core/sintered iron tipped plug (due to the smaller surface area at the tip). I think that you may have just gotten one of the few bad ones that get through, and you should be able to get a new one for free (unless you're attached to that little rascal)

I used the Iridium plugs in my car....Like most plugs they claim to be pre-gapped from the factory....problem is, like Rich said you cant re-check the gap, it could damage the tip...i didnt notice any difference in performance or milage...the only plus i see is that they are supposed to last forever...Iridium is thought to be the most dense conductive metal in the world