I've just installed a 125hp nitrous on my '79 Elky and I am deciding on the sparkplus to use. The advice from NOS is to go two heat ranges colder but when I asked them for a specific plug (brand and number) they did not answer my Email. I have been advised to use a copper core plug and stay away from fancy multiple ground electrodes and rare metal center electrodes (no platinum, iridium or unobtanium). Does anyone have any experience?

I don't have any advice on plug selection. But I sure hope you built the bottom end to handle a 125 shot 8O

The bottom end is basically stock. According to NOS it can handle up to about a 140hp shot. I guess I'll find out.

We have a blown 350 (GM 6 75 Blower) with NOS on our buggy and we use regular stock plugs. We're running around 9.5:1 before the blower compression 1.6 Roller Rockers cast Iron World Products heads. We're running 350Hp charge with Dual 650 Holleys.

Pistons are Federal Mog, noting fancy 2 bolt mains. Turns around 500 Hp before we add the blower or Nos. using also a MSD Magneto accel wires.

The little buggy runs the 1/8th in the low 4s. Turbo 400 and a Christler 12" rear with 5.88:1 spool.

I remember reading that you should run regular plugs a step or two colder when running Nos.

I'd run a set of autolite #24's, same plug that I run in the El Camino and Mustang. its 2 heat ranges colder then stock and havent had any problems on either car while spraying. I also set my base timing @ 8 degrees BTDC on the 400.

Thanks for the info.

No Problem. Just tryin to make sure no one does what I did on my first motor with Nitrous. Ever see a Pontiac 455 piston and rod completely leave the block @ 60 mph? Scared the hell outta me!

I have never had a nitrous accident but in my younger and unwiser days I had a similar motorcyle experience that scared the hell out of me. I had just bought a new Honda 450 and was accelerating hard down a freeway on-ramp when I missed the 3rd-4th shift. I saw the tach needle sweep past 12,000 rpm and then "ka-boom". I was going about 60 mph and the engine was on fire right under my gas tank! After a very quick stop I beat the fire out with my jacket. A connecting rod had broken and pieces of it had blown a big hole in the engine case. The bike was less than a week old so I loaded it on my friend's pickup and took it to the dealer. The service manager came out to the bike and took out the oil dipstick and then told me he couldn't warranty it because it had no oil! I looked at him increduously and told him "of course there's no oil because the hole in the engine case is big enough to stick your stupid head thru". Honda of America did warranty a new engine/trans even though the destruction was of my own doing.
On my El Camino I installed a Jacob's Mastermind and I am being very cautious about detonation and monitoring the sparkplugs. This is my first nitrous experience and I am surprised how it woke up a mild 350. On nitrous the little kitty turns into a big cat. You can get addicted real easily, I am already on a first name basis with the NOS fill station.

I hear ya on the addicting part. In my Mustang Ive probably been through atleast 50+ bottles if not more. It got to the point where i bought a refill kit and a 100 lb tank just to save money. I personally believe if nitrous is tuned correctly it's actually easier on the motor components. My chassis in my pony let go WAY before the motor even had a hint of blow by. The bottom end of the 5.0 had over 220k miles on it and the last 60k I was puttin a fairly big shot into it (250-300 hp) and she loved it. All i did was monitor my a/f mixture with 4 EGT gauges and adjusted the DFI system accordingly. As long as u have plenty of fuel you should never really have a problem.