critique my square exhaust ports
 

This is a practice housing. I decided to go a different route than I had planned when I bought the pineapple template after doing a bit of research. but the jig was still helpful, so not a complete waste.

Instead of making a curve at the bottom of the port as the template shows, 1/2 the template distance on the down cut I scribed a line straight out the width of the port. The idea in my mind -since I didn't port down as far as the pineapple template- is the gasses won't be released as soon during expansion, therefor torque won't suffer as much as the pineapple template (not that it is an extraordinary amount anyway) Additionally the exhaust will all be let out instantly instead of gradually helping to spool the turbo up sooner. Looks like if you add up the area that I did not port downward, then add the area that I did cut away to make the corners, it comes out to be about the same, therefor the port is roughly the same size but a different shape, so they should flow about the same, but in different ways.

Note: I did not port up at all and of-course not widen the port.

I'm only looking to make around 400 horse on this s5 block, knowing this.. what would you do differently? do you like the idea? hate it? think it's unnecessary? have good/bad experience with it? I'd like to hear your input before I port my good housings.

http://i1009.photobucket.com/albums/...g/102_0071.jpg

http://i1009.photobucket.com/albums/...g/102_0077.jpg

http://i1009.photobucket.com/albums/...g/102_0076.jpg

http://i1009.photobucket.com/albums/...g/102_0079.jpg

http://i1009.photobucket.com/albums/...102_0071-1.jpg

Only way to tell is to run it. I know one thing, it's gonna be loud as hell with the very long straight bottom. :eek:

lol yep probably

anyone ran an exhaust port like this on the street?

hope you dont plan to run 3mm seals

no i don't, im running some fresh mazda 2 piece 2mm, whys that? wear?

well i read your post again and you didnt go up or side to side..if you did the heat would be too much for 3mm seals, they would warp

I find that interesting. Cool, didn't know that.

and the reasoning 2mm wont warp?

z

3mm with a very very very large peripheral exhaust port will warp because 3mm has more mass, its harder to dissipate the heat compared to a 2mm, not to turn the thread into a "which seal is better" but 3mm vs 2mm, 2mm wins all the way around for sealing, weight, etc...a good tune will make seals not break..so just get a proper tune and you are good to go!

anyone have a video/sound clip of a car with ports similar to this?

Actually... I think keithrulz is far better than this crap:
http://i909.photobucket.com/albums/a...ONROB/mot3.jpg

yuck

UPDATE:
got the build together and running

Want to let everyone know that my exhaust volume (as in sound not flow) DID NOT increase with these ports.. at cruise I'd say it sounds a little quieter actually like the sound fades away more without load!? I'm running 2.5" straight back to a muffler, no cats eventually I want to go 3"


It may be a street port thing or something, but without changing my counterweights of any sort my engine has les vibration and revs much happier/quicker than before. part of the revving quicker is most likely due to my 120 psi on all 6 faces I'm sure as opposed to 75-80

ill have to take a video so everyone can hear. although it won't be a before and after.. for I have no before videos.

Wow, what are the radii on those corners? Looks like a stress concentration was introduced. Be sure to examine and photograph those points next time it's apart.

They're about a 16th to an 8th inch,I left a little more radii on the good housings i used. yea I thought about stress risers but I don't think it will be that big of a issue, we will see whenever I tear her down.