I am thinking of making an intake manifold for my k20a2 just to see what kind of power that I can make until I get an IPS manifold or ITB's or something but anyway.
What affects the where in the powerband the intake manifold will make power? I am looking to build a stock more and stroke race motor and looking to rev to 9500rpm. I am looking to make the manifold flow up to that point. What does the runner length and plentum size affect? Do longer runners make it flow higher up top, or is it shorter larger runners with a large plentum make more power up top? I hope I am getting this across correctly. If anyone can tech me some things I would appreciate it. I know that skunk2 lengthened the twm itb's for their race car. I also know that on the k series the center mount throttle body seems to beat out a traditional side entry throttle body position. What about velocity stacks in the manifold and their length? What do you guys think?

 

Bump, professor from k20a.org

 

anybody????

 

wow, this is remarkable.

 

bump

 

If you are gouing to "make" "manufacture" an item you should atleast know some of the engineering, or design behind it, and why it works. Try SAE engineering books and design papers, instead of H-T.

 

well I figured that at least someone could tell me that longer runners and larger plentum make more power "here" and opposed to this making power "there".

Don I think vteckidd and I are coming to see you soon.

 

Generally, longer, smaller runners are for low end torque, larger shorter runners are for top end power. Those are sweeping generalizations, though. And the ratios of runner size to runner length and plenum size are also a big part of the picture.

At the OEM level, they are considering flow, velocity and intake pulse balance ALL as variables which work together and affect each other. Pretty tricky ****. There's a LOT of computer modeling that goes into it.

That's all you get from me. I have a pretty realistic understanding about how much I DON'T know on the subject....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by josh green &raquo;</TD></TR><TR><TD CLASS="quote">well I figured that at least someone could tell me that longer runners and larger plentum make more power "here" and opposed to this making power "there".

Don I think vteckidd and I are coming to see you soon.</TD></TR></TABLE>
"here" is related to IN. cam closing and duration, and head, IN. runner flow, plenum volume. "there" is related to Ex. cam opening, duration, primary header size, and lenght. Tons of SAE engineering papers on it.

 

Well I know that longer larger primaries on a header make for more top end power, but I am only talking about the intake manifold. I kind of figured that shorter runners and a larger plentum were for more power up top. But I think I kind of have the gist.

 

Longer, larger headers do not make more top end power. Ever seen a TOP fuel or F1 car?