Just upgraded to a sdce setup on my 99 formula. I was running a 6" crank and a 3" pulley

Sd concepts told me that to run 6ish lbs of boost I need to get a 4.25" pulley. My car has just a ls6 intake an Mac mid headers.

Now doing the math. I'm now spinning the procharger slower.

6 rib setup is 49200 at 6000


8 rib setup is 41964 at 6000.


Now was I getting so much belt slip that this new setup will net me 6 lbs? Or did sd screw up? Bc now I need a new pulley and a new belt.

I don't have a boost gauge installed. Dumb I know. I've had it sitting on a shelf for two years. Just didn't want an. A pilar pod so I didn't know where to put it.


Anyone have any ideas

And also can I change a pulley with the procharger still on the car.

And if I change pulleys I'm going to a 3.4 will my belt be good?

 

So what crank pulley are you running? If it's the ATI 8-rib hub, it's 7.65", so take that into account for your calculations.

Also, which blower? Is it a P1 or D1?

I'm not sure about the SDCE bracket, but I know with my Aster bracket, I need to unbolt the blower and part of the bracket to remove the belt. If you go from a 4.xx to a 3.4" pulley, chances are you need a smaller belt.

 

mount the boost gauge in one of the 3 a/c vents. no need for 3 anyways. I am going to use all mine.

 

Or if you have a scan tool, just measure the map sensor and do the calculation yourself.

210kpa = ~14.7psi of boost. So 150 kpa would be (150/210)*14.7 = ~10.5 psi of boost.