RapidFire Spark Plugs

[silversport]

Anyone know the RapidFire spark plug number for the 5.3 Litre???  Anyone have any experience with the new platinum RapidFires from A/C???  I had used the old splined center RapidFires on my old Bonneville and liked 'em...any help would be appreciated.

Thanks, in advance!  :thumb:  

[Tucson_02Silverado]

On the Vette forums they list the #3 RapidFire for the LS1 5.7L.  I too have used the original spline type in my past TransAm's and wagon.  They definitely crispin' up the throttle response.  I currently have the "old" spline and new platinum RapidFires.  I plan on putting in the spline type in by next weekend when the truck rolls past 6K miles along with a set of MSD 8.5 wireset.  I think the spline types are no more, only the platinum's

[silversport]

Thanks...I had read somewhere it was the #12's (Hib Halverson, I believe on one of the 'Vette forums) I got 2 sets at a close out at Walmart...not such a great deal if these won't work...I hoped 1 sset for the Avalanche and 1 for the 'Vette...  ???  

[Tucson_02Silverado]

I think the #12 is for major engine mods.  The #3 is listed along with the NGK TR5, TR55, TR55vx in the stock group.

 

http://www.ls1.com/index_faq.html#601

 

On ACDelco.com, cross reference NGK TR55vx comes up with #3

 

Yet if you look at LS1Tech.com most of them are saying that the #12 is the TR55 equivilent, and some say #8.  And if you look at their sigs, most of them run Nitrous which require plugs around 2 levels colder.....uh....

 

And another part is some are describing types by box color red and blue and they are not relating it to copper spline or new platinum type.  That hasn't even covered the gap yet.

[Tucson_02Silverado]

Ok, I went and researched this again.  The official AC Delco replacement plug is 41-974.  That plug is direct replacement for the 2002 Vette engine codes G and S, 2002 Firebird/Camaro engine code G, 2002 GMT800 V/T/N/U/Z

G=5.7 LS1

S=5.7 LS6

V=4.8

T=5.3

N=6.0

U=6.0HO

Z=5.3 Flex

 

There is a Rapidfire plug listed for just one variant of the list.  Firebird/Camaro engine code G.  Rapidfire 12.

 

As for NGK, the official part number that GM uses is PZTR5A15 or 7862.  It's an OEM part number.  It does not match directly to NGK TR5 or TR55 nor TR55VX.  If you match the description of TR5 type platinum, you conclude TR55VX which crosses to RapidFire 3.

 

The only other concensus I can find is to gap at .050 not .060 for most of the non 41-974 plugs.

 

Sooooo, it looks like RapidFire 12 at .050

[tfchip1in]

I bought a set of Platinum Rapidfires from Auto Zone.

The application guide called for #12's. I gapped them at .060 and they were no better than the plugs w/ 60,000 on them.

I pulled them out a re-gapped @.050 and could immediately tell the diffrence at idle. Hope this helps.