: Going with MSD Wires and NGK Iridium Plugs...



GM-4-LIFE
02-08-09, 02:18 PM
In all my Corvettes, I always ran the MSD wires and NGK Iridium spark plugs (as long as they have been out on the market) and they always tended to smooth out idle and overall driving, offer better throttle response while providing better performance and fuel economy, not to mention much better longevity over the stock AC Delco platinum plugs and the thinner GM wires.

I located both part numbers from both MSD and NGK Corporate in case you guys were wondering what they are.

MSD part number 32819 for the red color and 32813 for the black color and they both fit the C5 and C6 Corvettes as well.

NGK 3689 which NGK cross referenced for me from the stock AC Delco platinum part number and they are the proper heat range for our supercharged engines.

I will be ordering them ASAP and getting them installed soon, most likely when I swap engine, tranny and rear end fluids. Do it all in one shot.

SG

NormV
02-08-09, 03:57 PM
What's the stock plug gap? Just curious. :)


Norm

GM-4-LIFE
02-08-09, 04:35 PM
What's the stock plug gap? Just curious. :)


Norm

Norm,

According to GM, the factory gap in our engines is .040, however Iridium plugs come pre-gapped in the box, so you don't have to gap them. I think if you try and gap an iridium plug, you can break them as the electrode and tip are so fine.

The Iridium plugs are a install em and forget em type of plug.

SG

CSX
02-08-09, 04:49 PM
Norm,

According to GM, the factory gap in our engines is .040, however Iridium plugs come pre-gapped in the box, so you don't have to gap them. I think if you try and gap an iridium plug, you can break them as the electrode and tip are so fine.

The Iridium plugs are a install em and forget em type of plug.

SG

Having run iridium plugs in both my Trans Am and GSXR for years, I can say I've never once had a problem gapping them. Sure, they're supposed to come pre-gapped, but ask me how much I trust that.

As for the wires...due to the very short length of the wires, I don't know if I'd expect anything at all from swapping them. Even on the original LS1s, there was practically zero appreciable gain from "upgrading" the spark plug wires, and I don't think GM has made them any worse over the years.

GM-4-LIFE
02-08-09, 04:58 PM
EDIT: I just ordered Denso Iridium Power part number 5326, model IT20 along with the MSD 8.5mm Superconductor spark plug wires.

I ordered both from Amazon.com which offered FREE SHIPPING and the lowest price on both items.

Total shipped to my door for plugs and wires: $127.49 which is a steal compared to others that are offering the same parts.

Just wanted to edit my initial post. From my research and data I have seen in the last few years, I have always seen better dyno results with the Denso Iridium spark plugs.

SG

GM-4-LIFE
02-08-09, 05:03 PM
Having run iridium plugs in both my Trans Am and GSXR for years, I can say I've never once had a problem gapping them. Sure, they're supposed to come pre-gapped, but ask me how much I trust that.

As for the wires...due to the very short length of the wires, I don't know if I'd expect anything at all from swapping them. Even on the original LS1s, there was practically zero appreciable gain from "upgrading" the spark plug wires, and I don't think GM has made them any worse over the years.

I haven't had a need to gap any of the Iridium NGKs I have used and I have checked each one out of the box and they have all been on the money. I always do check them though and I will check the Denso plugs when I get them.

As far as the wires, GM goes with the lowest bidder and I don't trust the lowest bidder's quality. Besides, for $50.00 for a set of MSD wires? That is cheap insurance for me and peace of mind. I have always had good luck with MSD wires over the last 10 years or so.

SG

wait4me
02-09-09, 12:11 PM
Without tuning, lesser ohm plug wires are a waste and create more heat on the coil itself and cause less spark strength at higher rpms due to starving from no reserve from the previous spark event.....

Dwell time is the amount of time (in ms) that the coils are charged before firing.
If the dwell is set too low a weak spark can occur, if the dwell is too high there is a risk of overheating the coils.

You can fix this by modifying the dwell tables.. http://www.megamanual.com/seq/coils.htm explains alot, but you have to notice, they are saying to run 5-6ms of dwell to handle those msd plug wires. Where as the stock ecm and programming on our cars is about 3.4 to 1.8 at 13.5 volts.. So what does this mean? You "Might" see a gain down low, but then the higher rpms you climb, the more the coils are now starving and wont have as strong as a spark as you would with the stock wires..

Im not saying that aftermarket wires arent good. They just arent good unless you modify your programming to compensate for the lower resistance.

wait4me
02-09-09, 12:33 PM
LS2_Yukon_ign_coil_test.wmv this vid is pretty good.

GM-4-LIFE
02-09-09, 02:52 PM
wait4me,

I will be getting my V custom dyno tuned soon. I ordered the plugs and wires, but I just don't know when I will install them. I will most likely install them right before I get the car tuned.

Will that be ok?

SG

wait4me
02-09-09, 03:26 PM
It should be just fine. :) However, are you sure that your motor didn't come with denso iridium plugs already???

GM-4-LIFE
02-09-09, 03:35 PM
It should be just fine. :) However, are you sure that your motor didn't come with denso iridium plugs already???

According to the owner's manual, AC Delco Platinum tipped spark plugs which don't last at all! I have had them in so many of the GM vehicles I have had since 1994 and they don't last at all. After a few thousand miles in normal driving conditions, they are GONE! I am not going to wait until my car runs like crap losing power and wasting fuel. The parts I want to change out are what I feel are the weakest links GM has installed.

SG

wait4me
02-09-09, 04:58 PM
12571165 Denso spark plugs are what is in our block. They are iridium.


Platnum on a supercharged car is not a good choice Due to the higher heat they run. So i doubt gm ever thought of dumping them on this engine. :)

A better choice if looking for more power would be to ditch the iridiums and go with a cheap ngk copper core plug with a 6 heat range.

GM-4-LIFE
02-09-09, 05:47 PM
12571165 Denso spark plugs are what is in our block. They are iridium.


Platnum on a supercharged car is not a good choice Due to the higher heat they run. So i doubt gm ever thought of dumping them on this engine. :)

A better choice if looking for more power would be to ditch the iridiums and go with a cheap ngk copper core plug with a 6 heat range.

The AC Delco plugs in the LSA are the 41-104 plugs. I don't know why GM put the platinum plugs in the LSA if it's not the best heat range plug to use.

If I go to a cheap NGK copper like the TR6, wouldn't I have to swap them out often since they don't last long like the Iridiums?

SG

NormV
02-09-09, 08:08 PM
Norm,

According to GM, the factory gap in our engines is .040, however Iridium plugs come pre-gapped in the box, so you don't have to gap them. I think if you try and gap an iridium plug, you can break them as the electrode and tip are so fine.

The Iridium plugs are a install em and forget em type of plug.

SG

Just put a set of TR-6's in my 05 and they were all around .026! :)

Norm

BeagleBrains
02-10-09, 04:03 PM
Nice information. I have tried another alternative Spark Plug.
http://www.pulstar.com/
I had problems with arcing from the plug wires on all of my cars. Have been unable to find an upgrade wire because of the cars being recent years. My C6 Vette should like the MSD wires. MSD sounds like just the ticket.

GM-4-LIFE
02-10-09, 06:03 PM
Nice information. I have tried another alternative Spark Plug.
http://www.pulstar.com/
I had problems with arcing from the plug wires on all of my cars. Have been unable to find an upgrade wire because of the cars being recent years. My C6 Vette should like the MSD wires. MSD sounds like just the ticket.

I ran MSD wires on all my C5s and my C6 and they worked great! I was looking at the pulstar plugs, but they don't have them for the 2009 CTS-V and at $24.95 per plug looked to be a bit much compared the NGK and Denso Iridiums.

SG