I pretty much just opened it up enough that it is flush with the sleeve. But is still looks pretty small compared to some that i have seen. Is it important to keep the top side at an upward angle? I've seen some ports were the bottom side is sloped pretty far down should i do more of that too? I want to go bigger if i can to help spool my turbo. I still need to clean up the edges a little to. Any suggestion or criticisms would be great.



http://www.pbase.com/image/30541480.jpg

http://www.pbase.com/image/30541483.jpg



Thanks

~Luke

What kinda housings are thoose? I've never seen one with 3 air holes like that.

Ports look good to me. Dont forget to bevel them. You can go bigger, but like everything, there are trade offs.

whats the car for? those are not really ported just "cleaned up" if anythng https://www.nopistons.com/forums/pub...DIR#>/wink.png



the 3rd hoel is the threaded hole where the stud for teh exhaust goes

To me it seems if i go any larger i will be cutting into the sleeve. They are FD housings and i'm trying to go pretty large, trying to spool up a 1.32 divided housing turbo with a divided manifold so the more the better. Like on your Kahren you bottom edge slopes down alot, but others i have seen dont slope down so much.

Luke, take a ruler and draw a line across the bottom and top of both ports with them stacked side by side. Use that as a guide line to keep the matched up. Keep the top the way it is but you can bring to lower edge down some. This will help it spool slighlty faster as the exhaust gasses will be going out sooner.

i like to go large on the exahust, this was ported for a 60-1 to4s 1.00 exahust

the one in my avatar is doesnt go down so much, they both go up by about 2mm from stock

one more

and last one

actually one more https://www.nopistons.com/forums/pub...IR#>/smile.png

I understand porting the exhaust so the gasses leave earlier so it spools the turbo faster, but doing this will make a little less power right. I see it this way, the exhaust gasses (power) are leaving quicker so it can power the turbo faster in tern this “power” leave the rotor earlier and will not turn the rotor as much. There is now more power to the turbo and less rotating the rotor. I’m sure in the long run you want the turbo to spool faster so in the end you will make more power so yes porting helps in the long run but before the turbo kicks in at the lower rpm rand doesn’t this make you have less power. I’m learning https://www.nopistons.com/forums/pub...IR#>/smile.png

the biggest amount of power transfer to the eccentric shaft from the rotor occurs at teh first 1/3 of the power stroke, so dont worry about portign too much down because of that, but you dont want to have it open too early as the low will suffer. basicly any porting you do will hurt low end.

i try to keep the low end as best as i can to that of what comes from factory





the green line is stock s4 motor with stock turbo, 3 inch exahust and big IC

at 9 psi

the red line is a ported motor with a 60-1 t04s at 7 psi untill 4k , but that is good enouf to compare low end we are looking at under 4k rpm anyway.



the blue line is the same ported car but with boost going up.



this is the same exahust port that you see in my sig, which is slightly smaller then the pictures that u see above.

wow thats great info. It really helps me understand how it effects the car with thos charts. Im kinda mad though about the green line. I plan on 3in all the way back with 10psi and a big V-mount IC. I wa shooting for 250 at the wheels and the one you show has 239hp.

well that was at 9 psi so i am sure u can get 250 with 10 psi , given same mods https://www.nopistons.com/forums/pub...IR#>/smile.png timign was also retarded from stock on that just to keep it on teh safe side.

Where you using stock injectors and stock ecu? I will be using the rtec 1.5 and I feel that will allow me boost safely to 10psi. I will also be using my friends wideband to make sure I don’t run to lean. I know this will be pushing the stock fuel injectors, but I do have an fd fuel pump which should help me a little.

u cant do that with stock stuff, you will start to lean out in the midrange, and the afc cant correct that, not sure what you have.



at the time there were secondary 950 cc incjtors, afc, fcd stock ecu 9 psi

racign beat turbo back.



we had the car at 220 at the wheels before the big IC and it started to lean out in the midrange so with the intercooler the 950cc went in.

How much was your timeing off. mine will be retarded 2 deg. at 10psi

i think at the time it was retarded by 2 degrees.