AC Delco 9mm wires & AC Delco Iridium plugs

**NitrOmm** · 07-12-2009, 07:03 AM

I read the sticky above ... but could not find any mention of the 9mm wires from Ac Delco. I was wondering if anyone has had experience with them as well as the Iridium plugs.
I am asking because I already had them on order before I researched and will gladly cancel and change to what would be a better combo.

Any help ?

**Hi-Po** · 07-12-2009, 07:26 AM

Never ran those wires. Just MSD.

Im currently running those plugs, coming from NGK. They are expensive and made to last longer then NGK TR's. I got them cheap, and have no plans of running them any longer then my NGK's. They are good plugs though.

**rbob93** · 07-12-2009, 02:23 PM

Gap for the iridiums should be set @ 1.01mm or .040

**NitrOmm** · 07-12-2009, 04:23 PM

thanks, thought they came pre gapped .. I will be sure on that.

**Hi-Po** · 07-13-2009, 04:24 PM

Originally Posted by NitrOmm

thanks, thought they came pre gapped .. I will be sure on that.

They do, kinda. But its so simple to check and set. Compared to changing plugs, checking for the correct gap is easy.

**NitrOmm** · 07-14-2009, 01:20 PM

are we sure about .040, the plugs at TSP are pre gapped at .55 ?

NGK TR55-IX Iridium Spark Plugs
NGK TR55-IX Iridium Spark Plugs for Stock Heat Range, Gapped at .055"

??

**Hi-Po** · 07-14-2009, 01:34 PM

I think hes referring to the ACD. Here, read this recent thread. http://www.ls1.com/forums/showthread.php?t=117637

**rbob93** · 07-14-2009, 01:54 PM

Originally Posted by NitrOmm

are we sure about .040, the plugs at TSP are pre gapped at .55 ?

NGK TR55-IX Iridium Spark Plugs
NGK TR55-IX Iridium Spark Plugs for Stock Heat Range, Gapped at .055"

??

You asked about AC Delco plugs & that's the info I responded for, but glad you want to be sure.

Here's the TSB on it.
http://www.acdelcotechconnect.com/pd..._03D-J-171.pdf

They were using the large gap (.060) for the platinum plugs which were OEM.

NGK TR55 is a copper plug. Guys have gapped them anywhere from .060 to .035 from what I've been reading here.
NGK TR55IX is an iridium plug. I have them gapped in my car @ .045

Sorry if I confused you.

**NitrOmm** · 07-15-2009, 04:11 AM

The confusion is on my part, sorry.
At this point I am considering returning the Ac Delco Iridiums & wires. Replace with MSD wires & NGK plugs.
My reasoning is, I can't get any feedback re: resistance on the AC Delco 9mm wires so I may as well go with what we know re: MSD. As far as the plugs go what is your opinion on the AC Delco Iridiums compared to NGK.

**rbob93** · 07-15-2009, 08:04 AM

I went with the iridiums for the long service they provide. Some of these cars now have to be dismantled to change plugs.
This is what they made them for.....cars so inaccessable that they could run a plug reliably 100K miles.
Copper plugs have a short service life & I rather not change plugs every 12K to 15K.
I'm pleased with the iridiums. No noticible performance gain, just run for a longer interval.
50K on them is coming up soon & I'll change them out to see what condition they are in.
I'm running the NGKTR55IX BTW.
Also, there's nothing wrong with the OEM ignition cables. They do just fine for our cars.