Thread: Hiport Or Lowport

i seriously doubt low ports flow 240+ unmodded, ie no porting or anything, i have never seen these figures thats for sure

I've heard mixed information about Highport vs Lowport. Snickers did a head flow test and lowport was much better. But then there was this article. This is from How to Modify Nissan Subcompacts...

Better pictures posted here.

LOL! V, you need to take a better picture, or learn how to scan documents

I can't read shiit!

EDIT: After adjusting my eyes and screen, I was able to read that. The higport head makes 5~10 more HP than the lowport because of emissions requirements, and because of the cam. You should know that!

I'll trust the man with a flow bench.

Snickers says 240 cfm for stock lowport head

He said it first in another thread I could dig up if I had time.

Ah, the misinformed. Well, I'l go with snickers on this one. You can tell by looking at the lowport that it would flow a bit more. My RR motor here has a pretty decent shot in the cylinder, which looks about the same as my KA motor does. The KA flows pretty decent from what I understand.

I want to see some back-to-back pics but I don't have a highport here to look at.

the lowport manifold does look slightly better for airflow as it goes into the head i thought.

i'll have to try and take some pics see how they compare

although there isnt much point as i want gti-r throttle bodies

unless the fwd de's are very different in flow to rwd det's. Cause there is no way a rwd det low port is flowing 240cfm

Also from what i have seen, the high ports will flow a bit better without intake manifold, but with the intake manifold on high port will easily win. This is on rwd engines anyway

Here's the other thread:

http://www.sr20-forum.com/all-motor/15394-gtir-54c-head-flow-data.html

Not my picture, I just got my copy of the book, here is a better version.


Some more information from the book though.




Source for Text is "How To Build Performance Nissan Sport Compacts" by Sarah Forst.

It really just sounds like everyone made a best guess for years with the information they had and no one ever put a lowport on a flow bench to confirm.