Germansheperd

Got a pic of the pulley set?

LT5

Germansheperd

Your harmonic balancer will piggyback your BBK under drive pulley like the pictures above.

LT5

I don't have 2 things on mine, mine is just one, kit says it just replaces it.....it looks like this pic right now ill send real pics tomorrow if i do the job.

Germansheperd

I made that mistake that Injuneer and Shoebox pointed out. Your BBK pulley will go over the hub (3 hole triangle illustration 45 in your pic) then you will line up the small circle on your BBK pulley with the triangle on the stock harmonic balancer (see my 2nd pic).

LT5

Yeah so its a simple replace, the part i have is about 3 lbs less then stock or more i think....ill weigh them both and see how much exactly.....honestly im just trying to squeez ever bit of cheap power i can out of her for now. I do have bad 02s i believe to so ill be replacing those soon to.

Germansheperd

Actually your adding weight. Your adding an extra part (crank under drive pulley).

Injuneer

The factory setup is shown in Shoebox's photo you posted. There is no second “thing” on the stock setup. You DO NOT remove the stock pulley, throw it away, and simply replace it with the shiny new pulley you picture. You remove the stock pulley. Slip the shiny new pulley onto the hub. Then you put the stock pulley up against the shiny new pulley, insert the bolts to sandwich the shiny pulley against the hub.

Now you too have “2 things”..... and have gained virtually no power at all, because you HAVE ADDED THE WEIGHT OF THE SHINY NEW PULLEY to your rotating assembly.

The shiny new pulley IS NOT A DAMPER. If that is all you run on the nose of the crankshaft, harmonic vibrations in the crankshaft, caused by the oscillating twist induced by the firing of each cylinder, will start to fatigue the crankshaft and damage it.

And.... if you use those longer bolts that came with the shiny new pulley, and don’t also add the stock damper back on, the bolts will probably be so long they will stick out the back of the hub, and hit the Opti, DESTROYING IT.

Read the next-to-last paragraph in my post #13. The underdrive pulley is a useless gimmick that hurts more than it helps. You seem to reject any advice that tells you the things you are using on your engine are not good things to do - the Hypertech “tune”, the airfoil, the U/D pulley. And I see you are ditching the Hypertech, but are going with pcmforless, which as I recall, we tried to discourage.

LT5

I called bbk and they said thats what i should do, I did it the same on my last engine and had 0 problems...i wanted to go with the fludampner or the other one from ati or w/e but there about 400 dollars or so....maybe i should have saved. And i agree the pcm for less tune was an add in power but he said he was going to shut off vats and it still comes on at random times. Least the cardone optispark i got brand new for less then 100 dollars is solid lol.

Injuneer

OK.... I'll butt out and stop giving you all this bad info.

Germansheperd

Lol I’m going to remember that line.

LT5

You have never given me "bad" info i was just simply telling you what i was told is all.

Never be fast

I should probably replace mine also. The rubber on mine is starting to look bad. Was hoping to put a ATI on mine at some point but is out of my price range. Someone correct me if i am wrong but isnt the stock harmonic balancer only good for like 6000 rpm???

LT5

Im sure an ati or w/e from what ive read is a huge upgrade and will keep the motor running longer for sure.

ACE1252

In my opinion, stick with a stock replacement damper or an ATI damper. Stay away from the underdrive pulleys.