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ViCiouS · 11-24-2014, 10:36 PM

^ that was gains from headers and manifold. Still no real knowledge on manifolds alone. :/

Well anyways I got my manifolds off yesterday, started doing some measurements and such on breaks from installing headers (a pain in the *** to do alone btw, passenger done, drivers side getting done sometime this week). Got to thinking about what options for manifolds can be made and what will be most efficient.

Equal length manifolds
Pros - easiest to design, equal air to all cylinders
Cons - more bends in piping, reducing efficiency

Shortest runners direct from TB
Note - a smaller plenum with short runners is also an option to help with harmonics of opening and closing valves
Pros - least bends, probably most efficient
Cons - very difficult to design, lots of math, will need to look into pressure changes from opening and closing valves, piping diameter will be different for each cylinder, longer piping slightly narrower to start. This will increase airflow velocity and overall volume to that cylinder vs equal size, this will ensure all cylinders receive equal air.

Large Plenum, equal runners
Pros - better application for turbo/boost, the plenum acts as a surge tank for when the valves open and close (pressure not released by the bov) These will have the shortest runners possible
Cons - my goal is more for a NA vehicle, but this is something to consider.

11-24-2014, 10:36 PM	#37 (permalink)
ViCiouS Base Member Join Date: Nov 2013 Location: Tampa Posts: 207 Drives: '14 981 Cayman S Rep Power: 11	^ that was gains from headers and manifold. Still no real knowledge on manifolds alone. :/ Well anyways I got my manifolds off yesterday, started doing some measurements and such on breaks from installing headers (a pain in the * to do alone btw, passenger done, drivers side getting done sometime this week). Got to thinking about what options for manifolds can be made and what will be most efficient. Equal length manifolds Pros - easiest to design, equal air to all cylinders Cons - more bends in piping, reducing efficiency Shortest runners direct from TB Note - a smaller plenum with short runners is also an option to help with harmonics of opening and closing valves Pros - least bends, probably most efficient Cons - very difficult to design, lots of math, will need to look into pressure changes from opening and closing valves, piping diameter will be different for each cylinder, longer piping slightly narrower to start. This will increase airflow velocity and overall volume to that cylinder vs equal size, this will ensure all cylinders receive equal air. Large Plenum, equal runners Pros - better application for turbo/boost, the plenum acts as a surge tank for when the valves open and close (pressure not released by the bov) These will have the shortest runners possible Cons - my goal is more for a NA vehicle, but this is something to consider. __________________ 2014 Cayman S - Daily and Track - PDK \| PSE \| SC \| PCM \| H&R \| HRE 2009 Ducati 848 - Weekend and Track - HMF \| Ohlins \| Microtec \| Woodcraft \| ASV 2010 370z Sport - SOLD -** KWv3 \| SPC \| Stance Wheels \| Z1 \| Stillen \| FI \| Takeda \| Uprev Last edited by ViCiouS; 11-24-2014 at 10:50 PM.