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Spark plug suggestions?

P

projectGTP

New member
i have a 97 gtp and i have the 3.4 pulley, 180 thermo, colder plugs(im guessing), resonator delete, and soon to have the u bend and high flow cat. i just blew out my trans and am currently rebuilding it. since i pulled the motor i started to disassemble everthing to paint it. everything was clean but there was alot of sludge build up. anyways, the car ran like **** when i had it out in the summer. when i removed the plugs they were very dark and my dad said it was running too rich. the plugs were bosch platinum i believe. is there any plugs that anybody recommends i should run?
 


projectGTP said:
i have a 97 gtp and i have the 3.4 pulley, 180 thermo, colder plugs(im guessing), resonator delete, and soon to have the u bend and high flow cat. i just blew out my trans and am currently rebuilding it. since i pulled the motor i started to disassemble everthing to paint it. everything was clean but there was alot of sludge build up. anyways, the car ran like **** when i had it out in the summer. when i removed the plugs they were very dark and my dad said it was running too rich. the plugs were bosch platinum i believe. is there any plugs that anybody recommends i should run?
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Your best bet is probably 104's (regular copper). Our cars don't like platinum very much. The copper's will have to be replaced often but, $1 a plug im not complaining :D
 
99prixgt said:
Your best bet is probably 104's (regular copper). Our cars don't like platinum very much. The copper's will have to be replaced often but, $1 a plug im not complaining :D
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I'll have to agree.
 
projectGTP said:
i have a 97 gtp and i have the 3.4 pulley, 180 thermo, colder plugs(im guessing), resonator delete, and soon to have the u bend and high flow cat. i just blew out my trans and am currently rebuilding it. since i pulled the motor i started to disassemble everthing to paint it. everything was clean but there was alot of sludge build up. anyways, the car ran like **** when i had it out in the summer. when i removed the plugs they were very dark and my dad said it was running too rich. the plugs were bosch platinum i believe. is there any plugs that anybody recommends i should run?
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al 104's! the car was prob running like crap because you have a 3.4 on with stock manifolds & stock down pipe.
 
bluegtp91 said:
X2...you could probably HEAR it knock:th_tongue2:
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the car ran weird. somedays it would run perfectly fine, but then if i let it sit for awhile and then drive it again and get on it, it would run so horrible i dont even know how to describe it. the rpms would knock back like 2k rpm every half a second at wot. not good
 


104's .035 gap..either get a stoock pulley or after market headers or plog and rework rear mani, and d/p
 
badbrad said:
104's .035 gap..either get a stoock pulley or after market headers or plog and rework rear mani, and d/p
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I would not go smaller than a .045 . There is no need to go that low. On my 2.8 I/c'ed setup I had a 0.45 gap.
 


guy that tuned it sat. was adamant about the gap...hhhheeeeeeee said on cobras and lsx cars thats what he recommeds.....still i was very hesitant on that little a$$ gap. could it affect the tune going back to .050 ??? didn't mean to high jack this thread.
 
badbrad said:
guy that tuned it sat. was adamant about the gap...hhhheeeeeeee said on cobras and lsx cars thats what he recommeds.....still i was very hesitant on that little a$$ gap. could it affect the tune going back to .050 ??? didn't mean to high jack this thread.
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Nope it won't affect the tune. But it will more than likley improve idle and throttle response.
 


Bigger gap is better as long as you have the ignition system to put enough voltage behind it. If you coils are in good shape and you have low resistance wires, you'll see the same power with greater efficiency (MPG) with the stock size gap than going to a smaller gap.
 
104's .035 gap
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That seems a little small. For a 3.4" setup, I don't see why you're running anything less than a 0.050 gap.
Try something like 0.052 or 0.055, and if you don't see spark blowout then consider increasing the gap up to as far as 0.060.
Like people have said, you'll see better efficiency with a bigger gap as you will get a bigger, longer spark and therefore more complete combustion.
Just keep an eye on misfires at WOT if you increase the gap size over 0.055.

Also-
x2 on the plog/3" dp idea. Don't blow up your motor by running a pulley that's too small for your mod list.
-Riggs.
 
BiggRiggs said:
Like people have said, you'll see better efficiency with a bigger gap as you will get a bigger, longer spark and therefore more complete combustion.
Just keep an eye on misfires at WOT if you increase the gap size over 0.055
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I have a feeling that after I finish the top swap and start tweaking it, I'll see some benefit to having the huge PRJ wires on what size gap I can run.
 
BiggRiggs said:
Also-
x2 on the plog/3" dp idea. Don't blow up your motor by running a pulley that's too small for your mod list.
-Riggs.
Click to expand...

well what if my car is running perfectly fine wit the pulley? i heard that every grand prix is different and some have KR when others with the same mods dont. and i dont think the dp is all that restrictive. just the cat
 
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