Autolite Vs Bosch plugs

[98gpking]

currently i have Bosch plugs in my car. I've always heard nothing but good things about Bosch until i bought a GP now everyone tells me Bosch is garbage

i do currently have Bosch plugs in my car but i bought Autolite 104 Platinums last night since everyone seems to swear by the colder plug for the supercharged engine.


does everyone else agree on this???

[BNaylor]

I don't think that statement is true and I don't agree. Unless you have a smaller SC pulley other than the stock 3.8" for higher boost you typically run the stock heat range spark plugs and brand of your choice based on your experiences since everyone gets different results. The only way to know for sure if you have any knock retard (KR) is to run a scan with a scan gauge capable of reading out KR or a program like Autotap running on laptop computer. It is true many of us with SC mods run Autolite spark plugs but the colder copper core race type plugs and not the regular Autolite AP (Platinum) or APP (Double Platinum). Other reasons are cost and easy to remember numbering system.

No comment on Bosch spark plugs.

[98gpking]

Originally Posted by BNaylor

I don't think that statement is true and I don't agree. Unless you have a smaller SC pulley other than the stock 3.8" for higher boost you typically run the stock heat range spark plugs and brand of your choice based on your experiences since everyone gets different results. The only way to know for sure if you have any knock retard (KR) is to run a scan with a scan gauge capable of reading out KR or a program like Autotap running on laptop computer. It is true many of us with SC mods run Autolite spark plugs but the colder copper core race type plugs and not the regular Autolite AP (Platinum) or APP (Double Platinum). Other reasons are cost and easy to remember numbering system.

No comment on Bosch spark plugs.

but otherwise its ok to use the platinum 104's. someone just told me the platinums suck....sheesh i go and get the 104's and they still complain...i shoulda just kept my WS-6

[BNaylor]

I think you missed the point of my reply. Why are you using colder than normal plugs instead of equivalent to stock? The Autolite AP/APP104 are two ranges colder than necessary unless you have a smaller SC pulley or have confirmed you in fact have unacceptable knock retard (KR).

See the Tips & Maintenance forum that has a thread explaining Autolite spark plug heat ranges. The AP and APP fall in the same category.

Click here

[98gpking]

Originally Posted by BNaylor

I think you missed the point of my reply. Why are you using colder than normal plugs instead of equivalent to stock? The Autolite AP/APP104 are two ranges colder than necessary unless you have a smaller SC pulley or have confirmed you in fact have unacceptable knock retard (KR).

See the Tips & Maintenance forum that has a thread explaining Autolite spark plug heat ranges. The AP and APP fall in the same category.

Click here

im sorry i forgot to mention im putting a 3.4 pulley on this friday

[BNaylor]

Thanks for sharing that critical bit of info. Now back to your issue or question. The Autolite AP104 (Platinum) or APP 104 (Double Platinum) should work fine with a 3.4" SC pulley. As I mentioned earlier they are two ranges colder than stock. Stock equivalent in Autolite is 606. 605 is one range colder. The only other thing I can recommend is getting it scanned for any KR after the mod is performed.

[richtazz]

Bosch Plugs?!?! And that's all I have to say!