My car is an '89 IROC-Z 350 TPI. The factory plugs are set at .035". Should I go with the AC Rapidfire plugs (.045") or just go with AC Platinum plugs at the stock .035"? Is it safe to go from .035" to .045"? I'm not all that crazy about spending $4 for a spark plug (rapidfire) but if that's what I need to go with my new ignition (new cap/rotor/coil and maybe box) then so be it. Oh and is there a difference between AC Platinum (.035") and regular AC plugs (.035")?--- I know one is platinum and the other isn't but if there is a large price difference should I just go with regular AC's? Tell me what you guys think. -89IRO

 

the platinum's supposedely last longer due to the fact that the platinum metal is more resistant to corrossion and such. Just stick with regular old Delco plugs and set them to the factor .035". enlarging the distance to .045" would make for some adverse effects i believe because you might not get full spark or something like that but i'm not sure. save your money and go for regular AC's they'll do the job just fine

 

I use Bosch Platinums (just the regular ones). The AC platinums are $10/plug. Not worth it, IMHO. It is a double platinum, from what I understand, but..who cares.

 

AC platinums are not $10/plug. Maybe you saw $10 where they really meant for a set of them, making them about $1.25 each. -89IRO

 

I just got the AC Rapidfire ones, its nothin but good for my Grand Prix, so i bought them for my GTA as well. Havent droven the car yet, but did turn it on, and everything runs fine.

 

350 TPI, just regular AC delcos, and stay at 35 unless you got an aftermarket coil. See ya!

- Tom

 

I will try to clear up the myths. The more applied voltage(spark) the cleaner the plugs will stay. Modern electronic ignition(yes, TG's included)will keep even a copper plug well within specs for in excess of 30k miles. With a platinum plug even with a larger gap the increased conductivity because of the material will keep the plug basically self-cleaning. That is why they can realistically go 100k before replacement. These days plugs are really insignificant because of electronic ignition. Unless there is an issue with the engine any plug you choose will give fine performance. I often joke that if you could seal the cyl you could just lay the wire in the the plug hole and it would run. If you are the type who routinely changes the plugs then run the stock plugs. I think R-43TS for that year. The thing is I have a MAJOR babe across the street, when she washes her car in a bikini I change 4 sets of plugs every couple of weeks. It's gotta be those substandard delco parts. RIGHT GUY's!

 

Drek- is this true? On my next tune-up I was planning on an MSD blaster coil, so do I need to go with a .045" gap (AC Rapidfires)? Some people say that it is dangerous do go away from stock (.035") I thought the new coil would just give me a little hotter spark, what does the gap distance have anything to do with it? -89IRO

 

The hotter the spark the larger the gap you can use. It is all relative. With a large output coil you can go to .060 if you want. With a stock plug, safely use .045 as a gap. Honestly it is totally irrevolent.

 

The hotter the spark the larger the gap you can use. It is all relative. With a large output coil you can go to .060 if you want. With a stock plug, safely use .045 as a gap. Honestly it is totally irrevolent.

 

The hotter the spark the larger the gap you can use. It is all relative. With a large output coil you can go to .060 if you want. With a stock plug, safely use .045 as a gap. Honestly it is totally irrevolent.

 

very true, check yo make ure they are all gapped the same and screw them in.

 

I'm going to put in an MSD cap/rotor/coil/wires next tune-up. But I am going to stick with .035" gap on good ol' ACs. -89IRO

 

I am going to install MSD cap/rotor/coil/wires next tune-up. But I am going to stick with .035" gap ACs. -89IRO

 

so why under my hood the factory sticker for the car says gap at .45 its a 85 305 tpi and i always gap it there ? so is it wrong ?

 

how do any of u actually get the spark plugs out with the TPI cars? i cant reach some!

 

I am using the rapid fires and lemme tell you this...they kick ***...i used to have teh bosches in there and the rapid fires are alot nice it think...

 

I opened the gap up to .45 on mine and have had no adverse side effects what so ever.