Does anybody know what a 4" blower pulley on a D1 is rated at boost wise. I tried to call ATI but the tech didnt know I think the crank pulley is 7.6" if that matters. Thanks

 

Anyone?

 

Ok...if anyone else on here has a D1 please post your pulley size and how much boost your seeing. Im trying to figure out about what size pulley to get before I put this thing on. I want to see about 15-17#s at 5800-6000rpms. Thanks

 

i have a 3.75" on a well breathing 383 with intercooler and it makes 15psi. figure a 3.5" pulley is about max rpm on the blower around 6600-6800 engine rpm and the blower is rated for 1400cfm so a 4" pulley probably is flowing like 1200cfm. that would be 15psi on a non intercooled decent breathing motor, IMO.

mike

 

On my old engine (built 383), I was seeing 12 psi intercooled and 19 psi non-intercooled (corvette intercooler) w/ 7.6" crank and 3.4" blower (D1SC).

 

wow, a 35% drop in boost with the intercooler. sounds a bit much. what intercooler was that. was it rated for your set up?

be careful when comparing boost on the D1. the D1SC has a smaller step up ratio and would require a smaller pulley to spin the same speed as the D1 standard.

 

Yes, there was a considerable drop in boost w/the intercooler. I have a C4 Vette and the way those things are configured they just can't flow much more than 450 rwhp (the piping gets squeazed to go over top of the radiator and then makes a very hard 90 degree left turn then through a small core and squeazed again to go back over the radiator). I'm working with a shop here to see if we can fit a set of twin high-flow intercoolers in the wheel wells (under headlights) and get my pressure drop in the 2-3 psi range.

 

cool. makes sense. those vette compartments are tight as hell. ever consider water/alcohol injection instead?