I notice that you guys stock are getting 10psi?

man, I just put on a 4lb pulley, and The most i got on the dyno is 11.4psi...

I was expecting at least 12....

I am wondering if I should add a 2.75" upper? or would that stress out the s/c too much? or should I have my s/c serviced and or ported and polished? or should i just go out and get the 6lb lower? would that be safe on a stock block, and will my s/c be able to handle a 6lber?


is it possible that as the s/c gets older, it gets more ineficient? I have 48K miles on my truck..

Thanks

 

That sounds about right to me for a 4lbder. Do you have stock exhaust? How's the condition of the sc belt, maybe a little belt slip? Are you reading that boost on an aftermarket gauge? What was the air temp?

Lots of people run 6lbder's on stock block but you should run a good tune and probably modify the MAF to be safe in cold weather.

 

the S/C will handle any combination of pulleys as long as the rotor pack rpm does not exceede 20,000. some have pushed the eaton well beyond, but at 20,000 the design of the S/C becomes inefficient and you will lose power due to the excessive heat produced, if not damage an engine. If I were you I would get a ported (stigemeier) supercharger and run a 6lb with a good tune.

 

What dave said , you can't beat the port job for the $$$ IMO .

SC

 

2.75 wont stress the eaton. Even with a 4lb lower. A buddy of mine has this exact combo and is runnin strong

 

I put a 6lber on the bottom, and the most boost I see is 12.85 PSI...


i was hoping for more... but eh...