Common plenum or individual runners???, for gas milage and drivability |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Common plenum or individual runners???, for gas milage and drivability |
Mueller |
Dec 16 2004, 10:04 PM
Post
#101
|
914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
for my 2316 it seems that the stock plenum might be reaching it's limits as far as volume goes.....so, I either fabricate a larger common plenum, or go with individual throttle bodies such as TWM or Jenvey*
single plenum would be easiest, but the individual throttle bodies look better (IMG:style_emoticons/default/smile.gif) has anyone switched from one to the other on the same motor with everything else being the same??? *Jake Raby is the U.S. distributor of these.... |
Brett W |
Dec 19 2004, 12:38 AM
Post
#102
|
Advanced Member Group: Members Posts: 2,856 Joined: 17-September 03 From: huntsville, al Member No.: 1,169 Region Association: None |
The early 90s Honda Prelude which was a 2.0 engine used a 62mm throttle body. It should more than be able to supply the air for a 2270 or 2316. Especially if the plenum is sized correctly. They can be had for less than 50 dollars all day long. The TPS is adjustable and can work with most any injection system.
Barrel throttles do an awful job of delivering a smooth mixture to each cylinder. They vector the mixture much more than do slide throttles or standard butterflies. The benefits to either are at WOT anyways. The real ticket would be to take a set of Motorcycle TBs and adapt them to work with your injection system. You could run two sets of injectors. Have low mounts for part throttle driving and a set of high mounts for WOT and High rpm work. It would make great HP. I had thought in the past of building some sort of common plenum kinda like the Ford Taurus SHO unit. A unit with long and short runners so you could get good torque and high rpm power. The Porsche Vario Ram unit works very well. You could use two throttle bodies and stagger the openings for a similar effect. There is no formula for designing a manifold. You can run a bunch of numbers but you still need to do lots of testing. Most engines can get away with intake plenum volumns of .8-2 times that of engine displacement. Lots of that will depend on the application. The Subaru runs a very small plenum, while some of your F1 cars, GT cars etc, use a pretty large air box on top of an IR manifold. Look at the Carrera GT manifold. dual individual plenums. The Ferrari I believe uses a common throttle body though. |