NX Spark Plug Question??

[egokilr]

I ordered my new NX Dual Nozzle setup for the car and will be installing it. My question is what type of spark plugs have u guys used with similar setups and what gap do you reccomend. It is for my 98 GTS. Other mods will include cat-back exhaust with cat-deletes and smooth tubes/kn filters. Looking foward to putting down some good numbers on the dyno, just want to make sure I cover all my bases.

Thanks,

Andrew

[Schulmann]

I am not expert in Nos but I spent my saturday morning to look for a new set of plugs for a supercharged car. Search for "NGK plug" under the forums. You will find plenty of use full information for NOS. NOS requires special care regarding plugs. My friend uses NGK BKR8EIX to run 150 NOS. Here are the plugs that you should NOT USE:

Bosch FR8DC #7527 : Comes with Roe SC, a little to hot for my set up.

NGK FR4 : Same heat as Bosch FR8DC

NGK FR5 : I will use this one with the Supercharger

NGK FR5-1: Same as stock stock Champion plug with extended electrode

With NOS you should go in much colder plugs and should avoid using Platinium plugs due to chimical reaction. Personnaly I prefer the NGK FR serie because the cup on the top of the plug is fix.

Have a look on the web site www.roeracing.com they have great supercharger kits (600-700hp) for Vipers like yours. Sean Roe, the owner, provides an outstanding customer service. NOS is cheaper but hard on the mechanic.

[Jack B]

Schulman:

A minor correction, the FR5-1 is the same heat range, but, it is not extended reach (ignore the description) and there is no hp diff on the dyno. If you compare the Champion and the FR5-1 side-by-side you will see the difference. The electrode on the FR5-1 also has far more mass than the oem plug. It is a nice all-around plug for both NA and nitrous.

With nitrous there are two issues, the heat range and the possibility of the electrode turning into a glow plug. You can have a cold plug with an extended reach and still melt the tip. The extended tip in general is not a good plug for nitrous.

For some reason, our combustion chamber design tolerates the oem plug on nitrous if everything is right and you are running 10.5 to 11:1. The colder plug is just additional insurance. With nitrous and the viper I don't see any reason to go more than one range colder. It is just too easy to maintain the correct a/f with nitrous, if you tune carefully.