Got an 04 4.8l with a whipple 2.3 kit, with intercooler. 221/225 .609/.612 112+4 cam. how much boost can i run safely on 91 pump gas. No meth. Tuner said im currently at about 7.5 lbs max. 16* timing. 462 hp, 430 tq at tires, Running the stock 4 inch pulley on the whipple. Considering going down to a 3.625. Which according to whipple's website would add about 3 psi using the rule for each .125 pulley change is a 1psi change. THis would put me at 10.5 lbs roughly. should add around 35 to 45 hp maybe. Would this be safe enough with proper tuning to make it worth it? Motor has alot of miles but the timing set is new. Valve job on the heads, all new valve train. New higher pressure oil pump. thank you for your thoughts.

 

I'd run the smaller pulley but thats just me. I used to run 12-14 psi on pump 91 all day on my turbo set up.

 

I know i dont want to go any smaller that the 3.625. I really dont want to worry about meth yet because its a daily driver. But i want it to last me at least another 2 years. I dont race or go to the track. Just like to feel the power every now and then. And pass slow pokes real fast. I generally keep my rpms under 6k best i can. Power leveled off at 6k and stayed steady to 6500. But i dont like revin it that high. Other than that i could run the 3.75 pulley and get around 9.5lbs. Only warranting bout 20-30 hp. But im really lookin for more mid range torque. as opposed to top end hp, because this is where i spend most of my time, between 2500 and 5000 rpms... This is my target area, but i want to be safe when i hit 6k+

 

damn thats pretty stout as it sits I would leave it alone and spend money on other ****.

 

you can turn it up... i been running 12 psi for like 4 years on my daily driver

 

no meth? whats your timing at?

 

Yea you will be fine at 10psi. You will want to think about meth for anything much beyond that though.

 

not sure about timing tuned by nelson