Pulley Swap Info

[AlphaJaguar5]

Stock = 3.35"

12 psi
bypass mod pointless
you need to upgrade
Blower speed 14,000 rpms at 7,500+rpms


3" Pulley

14+ psi
10 hp and 15 ft/lb gains**
Stock belt/idler pulley OK
no engine management required
bypass mod OK - good for additional 10 hp
Blower speed 14,000 rpms at 6,700 rpms


2.8" Pulley

16+ psi
15 hp and 25 ft/lbs gains**
belt or idler pulley modification required
engine management recomended
bypass mod OK with engine management, good for additional 10 hp
Blower speed 14,000 rpms at 6,250 rpms


2.6" Pulley

18+ psi
gains depend on tune**
belt or idler pulley modification required
engine management required
fuel injectors required

[D Rock Z75]

What is a bypass mod, i know what a bypass is, but what mods can you do for it when you do a 3" pulley. The 3" is in my plans for the future. just want to know some thing i will need to do:jester:

[Doc]

Something I learned today...if you want a 76mm idler pulley, don't go to one of the various forum vendors....they are charging way too much.
The maker is Gates Corporation and the part number is 38009. Just search pulley 38009 on google and you'll see it cost $12 from rockauto.com
Its a 76mm drivealign® groove pulley part number 38009

[D Rock Z75]

Something I learned today...if you want a 76mm idler pulley, don't go to one of the various forum vendors....they are charging way too much.
The maker is Gates Corporation and the part number is 38009. Just search pulley 38009 on google and you'll see it cost $12 from rockauto.com
Its a 76mm drivealign® groove pulley part number 38009

so 76mm equates to 3" pulley? i kinda like the idea of having an intense pulley. with the numbers and sig engraved. or maybe just get the gm stage 2 kit variant. does anyone know the size of the stage 2 kit pulley?

[Doc]

Dude...I was talking about the idler pulley that gets changed when going to a 2.7" or smaller pulley on the supercharger (plus the stage 2 belt). The various vendors are charging $20+ for this when its a $12 part.
The stage 2 pulley is a 77.9mm which is a 3.06" or 3.1"
The stage 3 pulley is a 76mm which is a 2.99" or 3.0"
Remember these are the stage kits I am referring to are from GM.

[D Rock Z75]

Dude...I was talking about the idler pulley that gets changed when going to a 2.7" or smaller pulley on the supercharger (plus the stage 2 belt). The various vendors are charging $20+ for this when its a $12 part.
The stage 2 pulley is a 77.9mm which is a 3.06" or 3.1"
The stage 3 pulley is a 76mm which is a 2.99" or 3.0"
Remember these are the stage kits I am referring to are from GM.

Yeah thats what i mean:p
i want a 3" pulley damn it:satan:

[Doc]

FYI - the oversized idler pulley (76mm) has a GM number. It is 88909590 and its made by ACDelco.

[06blackg85ss]

good shit... Keep that info flowing

[Blackss05]

ok my question if i run a 2.6 and just change the idler pulley with a stg2 belt will i be ok?

[bc3tech]

2.6... doesn't that require some snout machining? aside from that... why change the idler when u can change the belt? :shrug:

[Doc]

With some 2.7's (and smaller) machining the snout is necessary. Oddly enough a ZZP/INTENSE 2.7 hub & pulley came in and I had to machine the guys snout, it sucked big time. A smaller belt will help with a 2.7, with a 2.6 or smaller, I'd suggest getting a bigger tensioner and the stage 2 belt.
The ZZP tensioner relief tool will eat the bigger tensioner pulley btw, I broke 2.

[06blackg85ss]

I never liked using the over sized tensioner pulley myself. always had belt issues. I got the adjustable tensioner and called it a day. when the belt stretched, just bump it up a notch.

[Doc]

Thats an alternative. I need to look into that. The ZZP relief tool loves to eat the bigger pullies.

[Blackss05]

i already have the stage 2 belt so i wont need to change it. and as for machining on intense it says 2.6 does not require machining of snout so i was asking if anyone has experience with that?

[Doc]

I've done four 2.6's that needed machining.....a major PITA.

[spaz]

I'd recomend the larger idler, it helps the push the belt over closer to the sc pulley for a slightly better wrap for the smaller pulley's.

[victory_red_SS]

I'd recomend the larger idler, it helps the push the belt over closer to the sc pulley for a slightly better wrap for the smaller pulley's.

"Thread Hijacking"
Hi Chris. Glad you could join us.:orangehat:
"End of Hijacking"

[hoosierdaddy]

Something I learned today...if you want a 76mm idler pulley, don't go to one of the various forum vendors....they are charging way too much.
The maker is Gates Corporation and the part number is 38009. Just search pulley 38009 on google and you'll see it cost $12 from rockauto.com
Its a 76mm drivealign® groove pulley part number 38009

thats very nice to know DOC