HELP 1jz custom manifold design questions?

[onlydrinkkoolaid 240Love]

Ok I just brought this Tig welder with the hopes of fabricating a custom 1jz manifold for cheaper then the labor inflated 1000+ manifolds no knock on them just cutting cost with the trade skills I have picked up along the way. I have all the desires to do a high horsepower design but have no idea on what size piping, flange thickness, and metal for best durability.....

Please any suggestions would help and maybe a quick measurement around the pipe on a top of the line design no knock on anyone who doesnt have one but your suggestions are welcomed too...

[ravera]

Do it in Sch40 Stainless and it will never break. What size tubing you pick, since you can pick whatever you want, should now be dependant on hp you'd like to have, turbo you're running, and how important spool is, or if you just want a graph that looks like ____/ (you're running a JZ, so it's a legit question).

[onlydrinkkoolaid 240Love]

well to be honest my target numbers are 500hpand I didnt know what size should be used whentrying to target those kind of numbers

[ravera]

Best answer: I don't know for sure with a JZ.

Second best answer: Get your flange, measure ID of flange. Use tubing with that as the OD.

[2_Liter_Turbo]

Intake manifold design is very in depth. There are two ways to go about it.

1. The better of the two ways is to actually do engineering, and design the manifold using CFD, CAD, and other computer aided engineering packages. A knowledge in fluid dynamics, thermodynamics, machine design, and high end calculus is a must. I know these things (graduating with a BSME in just under two months) and it would still take me quite some time to design a manifold correctly.

2. How most manifolds are designed is trial and error. The intake manifold is one of the most important designs on the engine next to the head design itself. The IM will change the characteristics of you motor drastically with just a few minor changes. A good method is to start with the dimensions of the stock manifold and modify it according to what power band you are looking for. If you want more top end: larger plenum and shorter runners. If you want lower end power, then the opposite is true. The main design change that will change the characteristics of how the motor will run is the runner length and diameter. This is because of how the "pulses" of incoming air collide between the valve and the plenums "virtual" wall of air. The characteristics will change with different cam setups as the timing of when the valve is closed changes.

Sorry, I'm rambling, ha ha.