BOOST LEAK/ PULLEY SIZE ati
I would see a good 9 psi with a 3.7.
I have a P1SC and a 3.55" pulley, I get 9 psi at 6000 rpm. I am told it's a 11 psi pulley but that's at 7000 rpm which I'm not going to see (or want to) with a totally stock LS1.
I would see a good 9 psi with a 3.7.
The lesson is that the stock ATI tension setup is only good for 50000-52000RPM impeller speed and after that you will start getting belt slippage. If you compare the pulley combo for getting 11psi with the ATI 8 rib setup and 11psi with the SDCE setup u will notice that ATI is running at 55000RPM to get 11psi while SDCE setup is running at only 51800RPM and sometimes even see 1 more psi. That is 3000 RPM less from the SDCE to achieve the same amount of boost if not more. So you can imagine at 62000RPM which is the max for D-1SC the difference would be huge between the two setups. Im thinking 11-12psi with stock ATI setup due to belt slippage Vs. 15-16psi in SDCE setup. Although i hate SDCE customer service and it took us forever to get my stuff and one blank crank pulley that we had to take to a mechine shop to make the holes so we can use it... i must admit that their product does work.
Good luck
The lesson is that the stock ATI tension setup is only good for 50000-52000RPM impeller speed and after that you will start getting belt slippage. If you compare the pulley combo for getting 11psi with the ATI 8 rib setup and 11psi with the SDCE setup u will notice that ATI is running at 55000RPM to get 11psi while SDCE setup is running at only 51800RPM and sometimes even see 1 more psi. That is 3000 RPM less from the SDCE to achieve the same amount of boost if not more. So you can imagine at 62000RPM which is the max for D-1SC the difference would be huge between the two setups. Im thinking 11-12psi with stock ATI setup due to belt slippage Vs. 15-16psi in SDCE setup. Although i hate SDCE customer service and it took us forever to get my stuff and one blank crank pulley that we had to take to a mechine shop to make the holes so we can use it... i must admit that their product does work.
Good luck
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My setup, SDCE 7.25 crank pulley, 4 in SC pulley = 11 - 12 lbs.
Stock motor, LS6 intake, Stock MAF, Ported TB, headers, 1.85 rockers.


