The 3.5" Pulley. - Pontiac Bonneville Forum - Official home of the Pontiac Bonneville Club.

Bwayney · 07-03-2009, 10:03 PM

Currently i have a 02 SSEI with only 2 current mods: 180* T-stat and a Off the shelf tune from ZZP.

Could i safely run a 3.5" pulley with these current mods without risking KR?

If not, what other mods do i need to get?

**Black Pearl** · 07-03-2009, 10:23 PM

I believe you need spark plugs that are one heat range colder. I have NGK V-Power TR-55's in mine, with a 3.4" pulley, 180 Stat and factory tune. All is well for me

**Danthurs** · 07-03-2009, 10:47 PM

Every car is different. I can not say nor can anyone else if your safe with a 3.5" pulley. Only scanning will say for sure. 3.5" is the smallest I would recommend for a mostly stock engine. Chances are you should be fine. Ive seen two cars side by side, both with a 3.4" pulley, both with the same ZZP tune and basic support mods. One car with a PLOG, and 1.9:1 rockers had zero KR, like you would expect. The other car had headers and a XP hot cam. With that set up you should be able to run a 3.3, or even a 3.2 pulley, but he had 3* of KR with a 3.4. Like I said, every car is different.

Bwayney · 07-03-2009, 11:34 PM

how do i scan for knock retard?? Where is a good place to buy colder spark plugs?

**Danthurs** · 07-04-2009, 12:04 AM

You will need something like a aeroforce scan gauge. I get my autolites at Menards.

**Purplehazeir** · 07-04-2009, 12:14 AM

If you're going to drop pulley sizes, definitely get an Aeroforce Scan Gauge - it's cheap insurance and if you have too much KR then you can go for a custom tune. I dropped to a 3.5 pulley and had no problems. I'm also running a 180T and 605 plugs. So far, no KR noted on my set up, but every car is different.

Bwayney · 07-04-2009, 12:24 AM

I actually work at menards hah. the spark plugs there dont say 104 on them, they have iridium, iridum copper, heavy duty, etc. Which ones do i get?

**Purplehazeir** · 07-04-2009, 12:28 AM

Use Autolite's. 605's (one heat range colder), 104's (two heat ranges colder) or 103's (three heat ranges colder). Because you dropped you T-Stat t0 180, run the 605's like I am.

Bwayney · 07-04-2009, 12:34 AM

i dont know where to find them however. they sell autolites at my work, but they dont say 104 or 105 on them, they just say autolite copper or iridum on them. Installing spark plugs are a bitch, well the ones in the back are.

**Purplehazeir** · 07-04-2009, 01:07 AM

I get my plugs at Autozone or RockAuto. The ones in the back can be a bit challenging, but far from a bitch. A bitch would be replacing the plugs on a 1992 Chevy Astro van.