6bangr

Just recieved my whipple HO kit for my 09' GT. The kit came with the M-12405-3VO (05-08) 16mm spark plugs which won't work with the 09's and up. Can I use the stock plugs or should I be getting the 12mm FRPP spark plugs (M-12405-3V12mm)?

Would anyone recommend any other brands? I've heard mixed reviews about the brisk plugs and the ngk Iridiums. Not sure which route to go and I'm having a hard time finding someone with the FRPP ones in stock locally.

Thanks again,

hammeron

you do not want to use the stock plugs with the HO kit, so yes
go with the FRPP M-12405-3V12mm

moosestang

Why didn't it come with the correct plugs? You need plugs that are 1 heat range colder than stock.

Diabolical!

Autolite. As Moose said, 1 heat range colder than stock.

Simon1

Yeah, Autolite HTOs.

6bangr

An oversight on my behalf - all the whipple vendors indicate that the M-12405-3VO 16mm plugs are included with the kit. I never followed up on the disclaimer "Spark Plugs M-12405-3V12MM recommended for cars equiped with 12mm spark plugs, sold separately." I'm glad I have the 12mm spark plugs but it would have been nice if frpp/whipple had a spark plug option when ordering as opposed to sending out the 16mm plugs with every 08/09 kit.
Oh well, the right plugs are on the way. I've already installed the fuel pump and would like to get going on the blower while waiting for the new spark plugs to arrive. If I loosen the stock plugs before starting on the manifold how difficult is it to change the spark plugs with the compressor already mounted? It looks like the throttle body mounting flange may get in the way.

Diabolical!

It's a pain to get at the rear driver side plugs with the blower in place, but it is possible.

S197GT07

Didnt think the autolite's came in the 12mm thread...

6bangr

I can confirm that you cannot get Autolites in the 12mm thread. The only ones I've seen that would fit the build are made by NGK, Brisk, and FRPP (aka NGK from what I've heard). I think I'll leave the compressor off until the plugs are in - it does look like it would be a PIA

moosestang

It's easier to remove the #8 spark plug, than it is to remove the little screw for the coil on plug, but both can be removed and installed without even taking off the intake tube. I just disconnect the vacuum lines just behind the throttle body and use a long wobble extension. A long piece of fuel line makes removing and installing plugs a snap.