Thread: what spark plug should i get.

Didnt know they made a 140º thermostat.

Swap that for a 195 when you buy plugs.

I would get rid of the MSD coils aswell, they are known to cause problems down the line.


As for plugs just get some stock repalcement AC delco 41-101 Iridiums, I don't see a need for you to run anything differen at this point in time.

I think he doesnt know much about cars, there isnt a 140 option, I bet its a 160 or a 180, which there is no need to run them. If the 160 is in there its far too cold for the car, mpgs suffer and car never reaches proper temps on the inside.

Measure the pulley with a ruler or a digital or non digital caliper. I bet its a 3.5 or 3.4, but either way it should come off unless you plan on running more exhaust mods very soon.

The stock manifolds cant handle the extra air being brought in by the smaller pulley and causes alot more stress on the engine, pistons etc etc and can make a piston chip and your out a motor. I would swap it back to a stock pulley.

Copper to avoid knock. AL 106 or 105s stock.

there aren't 106 105's they are 606 or 605. the stock plug would be a 606. I have heard to run copper or iridium. with boost it is said they do not like the platinum plugs. and i know that even NA they don't like double platinum. from personal experience in warm climate I deff recommend a 180* stat for any vehicle. up north yeah you might be better off with a 195* regarding the MSD coils. there are two diff types of MSD coils for these cars. ones look just like stock and others have a more square shape to them. the ones that resemble the stock plug are the ones that had the issues. I have been running a set of the square ones for 7 years now and they were used. I got them off a GTP that i parted out. Now I will say that they do not increase performance at all and I would not ever buy them myself. you might be able to sell them and get some money

Oops yeah 606 or 605, long week. Personally I got the AL606's just because I couldn't find a lower heat range plug where I live. If you do go copper replace them every 15k these cars use waste spark system, eats these plugs up.

Originally Posted by Z34Phoenix

with boost it is said they do not like the platinum plugs. and i know that even NA they don't like double platinum.

Like 94GrandPrixSE said, it's about the waste-spark engine, not whether or not there's boost. Platinum gets brittle and breaks because it can't handle the abuse. Copper's soft enough not to break off in the engine, but doesn't last very long. Iridium does a great job.

Originally Posted by jakeb157

I was wondering what the best plug I should get and your opinions. its a 97 gtp, cold air intake, 140 degree t-stat (was in it when i bought it) slp cat back, msd coil packs and wires.

stock. and go back to the stock coilpack. I also am assuming your joking on the 140* thermostat. Your car would act retarded.

At that low a temp, it would probably be like running without a thermostat - possibly water in oil because it doesn't boil off, decreased efficiency, etc.

I agree with Blackflag, AC delco Coilpack > MSD. As for thermostat 195 if your stock, the knock sensor doesnt even come on until 160.