Vortec350ss

iTrader: (20)

With those cubes you won't need 18# of boost to put your *** in the seat... why not start with a larger pulley, say a 3.5 or so which will net you about 12# based on atomic's math. That you could get away with a 6 rib rip cut I would think.

That being said... 650 sounds too low to me. Based on that calculation using a my TVS1900, and the boost I know I make, my engine flows 650 as a cam only LQ9. That being said the only number in that formula I'm not sure how you got was the 12^3. So if thats not the same for my blower then it would explain a lot hahaha

1.9L is 116ci, and blower pulley is 2.7"

So blower CFM at 6000rpm is (116/12^3)*6000*(7.55/2.7)= 1126.3
Engine CFM at 6000rpm is around 650cfm

1126.3/650= 1.73
1.73*14.7-14.7=10.7psi of boost

ou812sm

iTrader: (16)

Well I ordered a 2.75 pulley and I have a power bond 10% overdrive being installed with the short block I figured with this setup I would have between 14-16 so hearing 18.5 got me a little worried but if that number is correct then that would only be at peak and I usually don't spin up that high I will run it and see what happens and then correct whatever I have to

MikeGyver

iTrader: (5)

The bigger crank pulley should give you a couple psi. Top or side mount Whipple? I know, I am living in the past by even bringing up side mounts. If it is, though, a 2-3/4 inch driven pulley will only give about 5 psi with your setup.

BlackGMC

iTrader: (31)

Always breaking out the math...

Atomic

iTrader: (42)

The 12^3 is to convert units between cubic inches and cubic feet. Its a very rough estimate like I said. Math is what makes the world go round

I have a spreadsheet I got from somewhere and its pretty good about estimating blower boost, and it says a 2.75" pulley will give you about 14.5psi. Truck crank normal diameter is 7.527" btw.

A 3.5" pulley would be around 8psi.

BigKID

iTrader: (5)

I calculate 15.13psi with the given information. However, in my own experience, this calculation is about 2# high. The formula really doesn't account for the higher efficiency of aftermarket heads/cam. My previous setup calculated #17.1 but I only saw #15 in actuality. So my guess is in the #11-12 arena if you have a good set of heads on that 416 with a 2.3L.

Vortec350ss

iTrader: (20)

Pretty sure he is sticking with the stock L92's. They flow great though as we all know.

I know I've said this to you before, but I would think about a mild port job on the exhaust side. For the square port head design that cam doesn't have much of an exhaust bias. I would think there is a lot of power sitting in those exhaust ports... You certainly aren't sparing any other expense.

Mike @ New Era

iTrader: (10)

We did a 416 truck with ls3 heads, NEP custom cam, ARH 1 7/8 headers without cats, NW 102mm throttle body, using a whipple 2.3 with 10% overdrive crank pulley and 3.0 supercharger pulley and it made 12 psi, I would assume your combination will produce about 14-14.5psi.

Also FYI, with this pulley combination you will be exceeding maximum recommended blower speed by the manufacturer at 6100 engine rpms, if you rev the engine past this by a good bit and do it often don't be surprised if your supercharger fails. And I would recommend a hefty dose of methanol injection to help keep the temps down. Just trying to give you some advice.

Mike @ New Era

iTrader: (10)

Also, I forgot to mention, the D/A will play a roll in how much boost it produces as well, lower D/A will increase boost.

Vortec350ss

iTrader: (20)

Being in the Boston area mid winter we regularly see DA as low as -2500, and sometimes -3000. You'd know a thing or 2 about that being in NY. Right, Mike?