Ford Mustang Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
272 Posts
Discussion Starter #1
I currently have a vortech v2 s trim with a 6.87 crank pulley and 3.33 headunit pulley on my stock block 331 combo, I was seeing 9lbs of boost and making 450+hp at the rear tires on a very conservative tune due to being a stock factory block.

I have now dumped my same combo into a dart block and would like to turn up the boost and would like to know what kind off boost level should i expect to see with a 8" crank pulley and 3.15 headunit pulley swap
 

·
Registered
Joined
·
332 Posts
I run the Renegade crank and upper pulley you mentioned on an Si-Trim and I'm seeing about 16-16.5psi. It's on a 366ci motor.
 

·
Registered
Joined
·
3,425 Posts
Really depends on your combo...but, on my old boss block 347, with a custom cam, AFR 185's and Edelbrock RPM II, I saw 19 psi @ 7,000 rpm with the pulley combo you are asking about. This was through a T-trim with renegade brackets and a Gates green stripe belt.

I never dynoed it with that much boost, but at 15 psi it made 650rwhp with way less timing then what I had in it.

At 19 psi I was running 19 degrees (running E85 for fuel) and it was pretty damn fast.
 

·
Registered
Joined
·
272 Posts
Discussion Starter #4
Thanks for the reply's guys, I was expecting to see 13-15lbs of boost from the s-trim with that pulley combo on my 331. Just waiting on my aeromotive stealth twin 340 pump setup to get here and install it, and then it's off to the dyno. Gonna be running e85 now too. My future plans are to do the si upgrade to my s trim, should net me a Lil more psi and be more efficient.
 
1 - 4 of 4 Posts
Top