hockeyhead019

Hey guys,

Just looking to see what people recommended to put in for new plugs and wires. I'm slowly refreshing everything on the 92 and these are next up on the list since they're original with 72k on them.

9T3VETTE

While the factory plugs were platinum, i'm always an advocate of swapping to an iridium plug. Many will bash the iridium plug saying it wasn't put in from the factory but overll its a much better plug. Ignitability is improved with an iridium plug (smaller center electrode) and they will last much longer than a platinum plug. I'm biased but DENSO Irdium TT's are a high technology plug at a great value.

For wires many upgrade to a larger 8mm wire from Taylor or others, but they can be difficult to get through the small pass-through on the drivers side. I'd stick with OEM sized wires personally.

THE 383 admiral

NGK race plugs. Magnecore wires. great quality. I say worth the money.

Mike 92LX

Factory plugs and GMS wires

aklim

I have put a lot of stuff on my car that wasn't factory but as far as iridium goes, what is your comment if better ignitability based on? What test was done and under what circumstances if I might ask?

9T3VETTE

It's well documented that ignitability is improved with iridium plugs mainly because the diameter of the center electrode is reduced, compared to a platinum plug. A finer electrode does two things;
1. Lower the required voltage from the ignition system. The smaller diameter electrode creates a higher potential concentration rate at the tip, creating a stronger electrical field, ultimately reducing demanded voltage from the ignition system.
2. Ignitability is improved as the smaller diameter electrode has reduced heat loss, and provides more room around the electrode tip for the initial flame kernel to form.

aklim

I think people have tried higher voltage ignition systems so instead of requiring less voltage, they increased the voltage. Didn't do anything significant to the car although in theory, it sho9uld

I read the theory just fine. What I didn't find is how much better it is for a street vehicle. For an all out race vehicle, all bets are off. However, what can I expect to see if I put them into my car? I did that before and there wasn't really any better mpg and it didn't show at the track either.

cardo0

Usually the stock AC Delco platinum plugs are good for 100K mi.. For completely stock car i would replace with the cheaper AC Delco platinum plugs which are only like $2-$3 each. The AC Delco double platinums are more than twice that price and gain nothing but longer life on your LT1. More likely u will never need to replace the plugs again so why spend more?

For plug wires i like my Accel wires with ceramic boots. They work great with headers and would work just as good on stock manifolds. Sorry i dont know the part # for '92 LT1's.

Good luck.

aklim

I don't think I like the long life plugs. Had a Ford Ranger with maybe 60 K on the clock. All we did was changed plugs to gain mpg. Gap was way too much and have not been changed since factory build. This is measured against the OE plug. Besides I don't like to have a plug stay too long in case it seizes up. I like to check no more than 2 years apart.

9T3VETTE

High voltage ignition systems are reserved for those combustion systems that demand it (aka high cylinder pressure). There's a reason all new downsized t/c engines use a high voltage COP and an iridium plug.

On an NA street car like our C4's your not going to get much benefit out of an iridium plug, except incredibly long life and a small fuel economy improvement. I'd estimate idle stability would improve a bit as well. However, unless you have direct cylinder pressure measurements in the cylinder it's going to be hard to prove that point.

aklim

Kinda my thought that there is no real benefit for our cars except for the long life or so they say. I really don't like leaving plugs in the head for a long time

vader86

I will splurge on wires for MSD superconductors, but as far as plugs I will never buy a plug that says it can be left in the head for years. 2 years tops before I start pulling to check, and my engine runs just as good on Autolites and Delcos as it does the expensive stuff.

ddahlgren

Once you light the fuel the job is done. A typical stock Corvette has cylinder pressures so low as to be comical compared to engines that need high end ignition systems. Low dollar Moroso 8 mm wires spiral core 700 to 800 ohms per foot is a very good bang for the buck the rest is snake oil. Champion plugs every other year and never missed a beat. Low cost cad plated for corrosion won't seize in the head and a dap of lubri-plate never a bad call on the threads.

aklim

OP has a 92 which is an LT1. Don't those have trouble with wiring being larger than stock size to get around the opti or something?

hockeyhead019

I've read to stay away from the 8mm because of this exactly, they're just harder to route back to the opti

Sounds like I'll just snag some iridium plugs (I use them on all my other cars so more out of habit than anything else) and stock wires. Wasn't sure if the cars were picky for any reason. Glad to hear they're not

ddahlgren

I have an L98 so new dividers and job done for 3 bucks.

tlong

I have returned to factory AC Delco Platinum and Gm wires and found the performance is great. Did splurge on LT4 reds but the car loves factory parts.I think it runs smoother with the GM stuff.

aklim

Factory parts as in what? The cheapest stuff they can get away with that will get them out of warranty period? The stuff designed to comply with the EPA and the bean counters? Somewhere is the customer. Not sure where. Sorry, I don't buy that GM is always the best. If it was, Rick Wagoner might not have been fired by Obama and Frederick Henderson replaced him with an "I'm Barrack Obama and I approve this appointment".

http://www.washingtonpost.com/wp-dyn...032900708.html

ddahlgren

I have a 14 year old Pontiac with everything as delivered short of tires(second set) battery (second one) O2 sensor (second one) filters and oil. Gets 28 to 29 mpg on highway and used to get 31 before the ethanol added. By this time next year it will have 100k on it and will do plugs and wires then. Maybe dump trans fluid and a new filter LOL. How long do you guess anyone's aftermarket parts will last? Ever seen a 15 year old exhaust system that was aftermarket?

aklim

Depends. Are you going after the cheap aftermarket or premium stuff?

Borla?