Procharger Pullley Size
06-01-2012, 10:14 AM
#1
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Procharger Pullley Size
Can anyone tell me the correct procharger pulley size, I am trying to make 15 to 18 lbs of boost on a 402 stroker motor with a F1A, I also have a cam with 238 intake lobe.My present set up is a F1A with a 8 rib 4.50 pulley,the most boost I can get out of it is 10 psi,any help will be great,and if you have a 8 rib procharger pulley for sale, that will make 15 to 18 lbs of boost I will buy it.
06-01-2012, 12:52 PM
#2
Safety Car
Can anyone tell me the correct procharger pulley size, I am trying to make 15 to 18 lbs of boost on a 402 stroker motor with a F1A, I also have a cam with 238 intake lobe.My present set up is a F1A with a 8 rib 4.50 pulley,the most boost I can get out of it is 10 psi,any help will be great,and if you have a 8 rib procharger pulley for sale, that will make 15 to 18 lbs of boost I will buy it.
06-03-2012, 09:16 AM
#3
Can anyone tell me the correct procharger pulley size, I am trying to make 15 to 18 lbs of boost on a 402 stroker motor with a F1A, I also have a cam with 238 intake lobe.My present set up is a F1A with a 8 rib 4.50 pulley,the most boost I can get out of it is 10 psi,any help will be great,and if you have a 8 rib procharger pulley for sale, that will make 15 to 18 lbs of boost I will buy it.
Assuming you are using a near stock 7.5" diameter balancer. The F1A is 74000 max RPM. It uses a 5.4:1 internal step up.
Your 4.5" pulley is turning the SC about 59000 rpms (at 6500 engine rpm). That is about 79% of the capability of the SC max rated RPM (roughly 20% underdriven).
You could try a 4" pulley that would increase the SC rpm to 66k (~89% of max rpm), or a 3.6" pulley making SC RPM 73.5k (~99%).
So if you want to try to get 10% more out of your system, try a 4" and see where that puts you. If you want to run your head unit at full capability (max recommended anyways), shoot for a 3.6" pulley. Of course a 3.8" will work too if you wanted to stay a touch more conservative.
Last edited by jimmyb496; 06-03-2012 at 09:24 AM.
06-03-2012, 05:03 PM
#4
Safety Car
Boost PSI is effected by so many variables including cam and engine restriction. So its not necessarily an exact science estimating boost. A big stroker motor w/ free flowing heads, exhaust, etc isn't going to make the same boost as a 346ci w/ a smaller header, cyl head port config, etc. I wouldn't get too hung up on the boost number. Rather I would try to just make sure I'm making the most of the head unit you are using. Let the boost numbers fall where they may.
Assuming you are using a near stock 7.5" diameter balancer. The F1A is 74000 max RPM. It uses a 5.4:1 internal step up.
Your 4.5" pulley is turning the SC about 59000 rpms (at 6500 engine rpm). That is about 79% of the capability of the SC max rated RPM (roughly 20% underdriven).
You could try a 4" pulley that would increase the SC rpm to 66k (~89% of max rpm), or a 3.6" pulley making SC RPM 73.5k (~99%).
So if you want to try to get 10% more out of your system, try a 4" and see where that puts you. If you want to run your head unit at full capability (max recommended anyways), shoot for a 3.6" pulley. Of course a 3.8" will work too if you wanted to stay a touch more conservative.
Assuming you are using a near stock 7.5" diameter balancer. The F1A is 74000 max RPM. It uses a 5.4:1 internal step up.
Your 4.5" pulley is turning the SC about 59000 rpms (at 6500 engine rpm). That is about 79% of the capability of the SC max rated RPM (roughly 20% underdriven).
You could try a 4" pulley that would increase the SC rpm to 66k (~89% of max rpm), or a 3.6" pulley making SC RPM 73.5k (~99%).
So if you want to try to get 10% more out of your system, try a 4" and see where that puts you. If you want to run your head unit at full capability (max recommended anyways), shoot for a 3.6" pulley. Of course a 3.8" will work too if you wanted to stay a touch more conservative.
