epitrochoider

yeah, the turbos were 4 ports. I don't think the ports were in "stages" if they were, then there is something in the intake manifold that turns on/off some of the runners inside. I have helped put together a stock twin turbo for a FD, and it was a regular 4 port 13b. No difference in the engine. Maybe in the intake, however i doubt it. Also, this pport idea would allow much higher rpms than the side port design probably. I just think that the side ports are inherently less efficient than peripheral porting. Wouldn't you agree? Its like the difference between a header and a stock exhaust manifold.

j200pruf

iTrader: (4)

PPort Idea. Couldn't you have one two barrel throat for each port that are fairly small, and have a secondary throttle plate in one throat that would remain closed so the engine would only breath through one port and get intake velocity up. And when the engine gets to a certain RPM open the secondary plate in other throat so the engine can breath through both ports?

epitrochoider

kinda like Eson's idea?, without a picture it sounds similar to Eson's idea. Yeah, i think thats a good way

j200pruf

iTrader: (4)

Kinda, but what I was talking about is a IDF/IDA type throttle body that has 2 throttle plates in it one would be in the regular position, and one below it. The lower one would just be controlled by a servo or something, it would either be fully closed or fully open.

epitrochoider

What do we do if a fish stick gets caught in the throttle body, it could mess things up a bit.... ok

j200pruf

iTrader: (4)

Here is a pic of what I was talking about.



This is a SDTV (Suzuki Dual Throttle Valve) TB, I want to put a set of these TB's on a full BPed 6 port so that the aux scondary ports won't be open untill 4000RPM or so.

Eson

Hm, i need more info on how and why you get more torque on low RPMs. Must the engine "work" more for the air in order to increase the torque?
(By decreasin the intake as we do here, it will be harder to get the same amount of air as from a bigger intake)

rotarygod

iTrader: (1)

The idea behind the original post in the thread sounds like it was inspired by the new BMW engine in their new 3 series. It does not use a throttlebody but rather has continuously variable lift valves that only open as far as they need to. The ecu controls their movement to control rpm. It also keeps intake velocity high at all times. Interesting concept.

Eson

I found this article: http://www.autozine.org/technical_sc...h_engine_2.htm .
Where it says: "The longer one is for low-speed use. The shorter one is for high rev."

So my design wouldnt make any diffrence, dunno about the SDTV. And look at the variable manifolds on the 26B engine, there it is.

Dom_C

there is such thing as a semi p-port engine. there is actually already a manifold for it. Although it is not variable. I have also though about this, i think stock side ports with butterfly controlled p-ports would work pretty well. It would be a relativly small p-port though.

epitrochoider

The reason that more torque is created at lower rpms, is that more air has a chance to enter the chamber at 4000rpms instead of 8000. Remember, don't think of torque as power, think of it as the amount of pressure applied to the crankshaft. Torque is a diesel engine, lots of pressure, to pull much harder, but slower because of lower power ratings. Power, hp, is effected by time, torque is not. Maximum torque is achieved when the most air per cycle is digested, not the most air because of higher rpms. Since hp is a function of torque, time, and distance, this is why hp graphs fade as rpm become higher. If the same amount of air had the chance to enter the housing at 8000 rpms per cycle as it did, 4000, then hp graphs would be linear

epitrochoider

wasnt inspired by that particular car, just the concept, but that car isssssss sweeet.