spark plug recommendations

fixing to replace the plugs on my 2001 gt 3.8. anybody recommend some good plugs?- i have heard good things about the ngk's and bad about the bosch's. also, i was thinkin bout doin the coil packs with msd ignition packs- good or bad???? and the wires- how much better are the 8.5's??? thanks

I'd stay with oe plats or iridiums.

There is nothing wrong with the NGKs. Just make sure they are the proper heat range for your car and properly gapped. A lot of GT and GTP owners use them. For example the AC Delco 41-101 Iridiums are made by NGK.

Whether you go with MSD ignition packs is dependent on your mods, if any. If you go with the MSD coils go with the MSD 8 or 8.5mm wires.








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 second what Bnaylor said, stick with OE unless you're modded, the Delco's are made by NGK, so they are fine.

what mods would i need for the msd coil packs

what mods would i need for the msd coil packs


What mods do you currently have?

The MSD Blaster coils work well if you have a re-programmed PCM like the ones from DHP or Intense. It's applicable to both the GT and GTP. The aftermarket coils improve midrange to high rpms even if your car is stock. Most re-progammed PCMs enrich the fuel mixture. Also shift points are raised from 5800 to 6000 rpms. Plus timing advances sooner. So the aftermarket MSD coils are a logical choice in this respect.

A CAI, FWI, or even K&N Aircharger would be goods mods. On exhaust a u-bend delete and hi-flow CAT to start.

IMO it will not just be one specific mod that will make your GT faster. It will be based on the totality of the mods. And modding is relative to how much you are willing to spend for the end result.







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.

Aftermarket coil packs

The stock ignition on a Grand Prix is very good. So good that we run stock coil packs on all of our cars at ZZP. Failure rate of stock coil packs is almost zero and the spark output is extremely high. We have A/B dyno tested aftermarket coil packs and seen no difference in HP. We have seen many aftermarket units fail and when customers have a problem it's very hard to diagnose with 'extra' mods on the car.

Aftermarket Plug wires

Unless you have a problem with your stock wires, don't buy aftermarket ones. In our experience of working on GPs the failure rate of aftermarket wires is over 10 times that of stock wires. GM puts everything they have into making cars get the best mileage they can with the least amount of problems. A poor ignition system would increase emissions, which GM couldn't afford. This means plug wires from the factory are designed for high spark, low radio noise and excellent performance. All of the ZZP cars run stock wires.

Aftermarket coil packs

The stock ignition on a Grand Prix is very good. So good that we run stock coil packs on all of our cars at ZZP. Failure rate of stock coil packs is almost zero and the spark output is extremely high. We have A/B dyno tested aftermarket coil packs and seen no difference in HP. We have seen many aftermarket units fail and when customers have a problem it's very hard to diagnose with 'extra' mods on the car.

Aftermarket Plug wires

Unless you have a problem with your stock wires, don't buy aftermarket ones. In our experience of working on GPs the failure rate of aftermarket wires is over 10 times that of stock wires. GM puts everything they have into making cars get the best mileage they can with the least amount of problems. A poor ignition system would increase emissions, which GM couldn't afford. This means plug wires from the factory are designed for high spark, low radio noise and excellent performance. All of the ZZP cars run stock wires.

I agree with part 1 from ZZP. On part 2, I disagree. The ZZP Grand Prix I saw had Taylor Spiro Pros. They've back tracked on the use of the OEM 7mm wires. BTW - Info on their web site is rather outdated. Just my 2 cents. :2cents:

See link below to the ZZP/Stattama Grand Prix project. Scroll down and behold Taylor Spiro Pro Race wires.


http://www.stattama.com/index.cfm?fuseaction=browse&id=28534&pageid=53

I have the iridium plugs...i believe the brand is Bosch...i dont believe they give better performance...they do promise that they last for the life of the car...ive heard mixed things on rechecking the gap on these plugs...if you scratch the surface with a feeler gauge you may cause damage...but then again ive heard that iridium is the densest metal on earth and may be hard to scratch

twin turbo race car vs. mild/heavy modded GTP/GT
apples to oranges

and how can u agree w/ the stock coils and then come up with

"The MSD Blaster coils work well if you have a re-programmed PCM like the ones from DHP or Intense. It's applicable to both the GT and GTP. The aftermarket coils improve midrange to high rpms even if your car is stock. Most re-progammed PCMs enrich the fuel mixture. Also shift points are raised from 5800 to 6000 rpms. Plus timing advances sooner. So the aftermarket MSD coils are a logical choice in this respect.."

Is this just personal experience, I just cant believe that you actually noticed a diffence from going to the msd setup. Unless the stock setup was bad/old to begin with. Just my .02

twin turbo race car vs. mild/heavy modded GTP/GT
apples to oranges

and how can u agree w/ the stock coils and then come up with

"The MSD Blaster coils work well if you have a re-programmed PCM like the ones from DHP or Intense. It's applicable to both the GT and GTP. The aftermarket coils improve midrange to high rpms even if your car is stock. Most re-progammed PCMs enrich the fuel mixture. Also shift points are raised from 5800 to 6000 rpms. Plus timing advances sooner. So the aftermarket MSD coils are a logical choice in this respect.."

Is this just personal experience, I just cant believe that you actually noticed a diffence from going to the msd setup. Unless the stock setup was bad/old to begin with. Just my .02

What have you got against MSD products? It's the racers choice. How people spend their money on mods and what mods is their business. Try em you might like em. We've debated issues such as this in the past. It's the totality of the mods that count not just one specific one.

BTW - When you pop the hood it sure looks nice too. If I thought the MSD coils would help a stock vehicle I would have installed them in my box stock Regal GS a long time ago. :biggrin:









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 heard nothin but good things about NGK

I replaced the plugs in my '97 at 126,000 miles with the stock AC Rapidfires. Still smooth and 25 mpg at 300,000. May be time to change again.

and the wires- how much better are the 8.5's??? thanks


MSD 8.5mm wires have a much lower resistance than the stock 7mm wires or aftermarket 8mm wires. A 1 foot length has 40 - 50 ohms. The OEM GM Packard 7mm wires have approximately 500 - 600 ohms per 12 inches. Also, they will withstand heat better and survive repetitive pulloffs of the plug boot whereby the stock wires will eventually come apart and need replacement. But I would not recommend them unless you are modded with headers which generate a lot of heat or you seriously race. An alternative brand would be the Taylor 8mm Spiro Pro custom fit. They are a lot cheaper than the OEM GM wires and come in different colors. You be the judge.

http://www.msdignition.com/wire_1.htm








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.

At about 6000 miles one of my plug wires went bad and about 6 months later, two more went bad so they replaced all eight. When my mechanic replaced the plugs at 126k, he was supposed to replace the wires again. Not sure he did but haven't had anymore trouble out of them. If I replace the plugs, I'm sure that I will probably break one or two. Would you recommend the MSDs as replacements at that time?

At about 6000 miles one of my plug wires went bad and about 6 months later, two more went bad so they replaced all eight. When my mechanic replaced the plugs at 126k, he was supposed to replace the wires again. Not sure he did but haven't had anymore trouble out of them. If I replace the plugs, I'm sure that I will probably break one or two. Would you recommend the MSDs as replacements at that time?

If you are stock go with the OEM AC Delco Packard 7mm wires.

However, as an alternative you might consider the Taylor 8mm Spiro Pro custom fit wires. They come in 3 different colors if you want to dress the engine up and cost around $49.99. I was quoted $55.00 for the OEM 7mm wires at an AC Delco authorized parts store.

In my situation my GTP is moderately modded and drag raced so I go with MSD, unequivocally. IMO - plug wires and spark plugs are a matter of personal preference and your circumstances.







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.