[G8-4-Speed]

Originally Posted by PQ

So, recently I discovered kinda what I suspected for a while........

My 2.8" pulley on the front of my Maggie ideally should be creating around 11-12 pounds of boost and not 8.

I have had my TVS2300 Magnacharger on my car for a long time now. LOVE it. But it never sat well with me that I am running such a small pulley to only get an 8-8.5 psi average through a dyno pull.

Now to be accurate, I am running a 3.2 inch pulley on it with my daily driving. Keeps me safe as far as boost goes and the 2.8 is not needed for the street anyway imo. I can throw the 2.8 on in 5 minutes if I want to go to the strip or have some fun.

But the 2.8" pulley produced an average of 8 pounds on the dyno and the 3.2 produced an average of 6 pounds. (see bottom two dyno graphs) Before my cam I had dynoed the car with a 3.6" pulley to a 7-8 pound average. I know I lose some adding a cam and I still have to get my cam specs but it's a mild cam and I can't see losing THAT much boost.

So now I'm going to be buying an OD cog drive for the back and getting a boost gauge so I can see what size pulley will net me an 8 pound average.

Now my ultimate question that drove me to create this thread is what the hell is the point of 6 rib 3.2 down to 2.8 pulleys if they can't pull solid and they slip so badly?

I mean that's some seriously shitty belt slippage to lose so much boost. I just don't feel comfortable with my car tuned for a level based on a slipping belt.

What if the belt decides one sticky day that it wants to grab for a minute? BOOM............... right?

Or is that not possible?

I may need a fuel rail or cut my existing fuel rail but I am going to get a rear OD Cog drive so I can take care of this but WTF? Why the hell are they selling these pulleys if they don't work?

I was thinking, instead of chasing belt slip, your problem could be much simpler...CHECK YOUR BY-PASS!

If your bypass blade set-screw is adjusted wrong, your bypass blade could be set open too far and bleeding off several pounds of boost. It is supposed to be just "cracked" open so it doesn't go into boost too soon under light throttle, keep cruising IAT's down, and keeps it from getting stuck closed. If you are curious, just back out the set screw 1 to 1 1/2 turns. If you boost climbs and drivability is still good, BAMB! fixed. Best news, cost nothing.....