For all you Fluid Physics guys

[nate_v8]

I have a supercharger kit in the works and a klze. The high compression and fi are a dangerouse combo if not well tuned and monitered. Now I understand that using a smaller diameter pipe from the output side of the s/c or turbo means you hold pressure differently than a larger diameter pipe. My question is if I use a larger pipe would this work in reducing some pressure so that the setup would be better for the higher compression or is the difference in size not substantial? I'm talking about a 2.5" to 3" difference. If this isn't clear enough let me know.

[Radar]

how much boost are you talking about? I'm no enganeeer but i have some experience with boost.

DO NOT use the size of a pipe to help prevent detonation issues. That is the WRONG way to look at it. Frankly, it won't help either. What you need to do is determine how much power you are looking to make and let that determine your pipe diameter. 2.5ID will be more than sufficent for 95% of boosted KLs.

[nate_v8]

I didn't figure it would really help prevent detonation. I am hoping to achieve 250hp with the ze engine supercharged, and when I get the other engine built hoping for 300+ but that is with forged pistons and millenia s rods. I know that my buddies 1g eclipse has 2.5" tubing post turbo. But I know that it takes longer to build pressure in a larger space, so I wasn't sure what kind of effect I would get using a larger diameter pipe. But like I said hoping for 250hp with the stock ze block and 300+hp with the built engine, focusing more on the ze for the time being. The kit is set up for 8psi with the pully it comes with, but I would like to find a pully that gets me 4psi untill I get more adequated with the megasquirt system and tunning this set up all together.

[KING6]

How are you able to use 3.0 pipe?

[DrBrown]

The differences in a 2.5" to 3" charge pipe would hardly make any differences, especially if its less than 3 feet in total length. You are talking about 1 second of extra lag at the most. Like Jordan said, you dont use the charge piping to adjust the level of boost or flow of the system. Thats like trying to make something less efficient just because you want lower goals.

Shouldnt be too tough to find a larger pulley on the Net. I would stick with 2.5" piping for your setup. The biggest factor in changing the boost level is the actual combustion cycle efficiency. If you were to fully port your heads and intake you could lose 0.5-1.0psi boost total because the engine scavenges the blowers forced air easier and uses more of it so in turn you'd actually make more power from less boost with everything else being equal. I would worry about the pulley first!

[nate_v8]

I didn't figure it would be effective, or I would have heard about it elsewere. The guy that made the kit says he run 8psi on his ze successfuly, but I'm just a little worried about it and would be much more comfortable with 4psi. I believe the supplied piping is 2.5 king. I will just find a diff pulley and keep an eye on the a/f.