Hello all. I just semi blew my s4 turbo 6 port so I am the planning stage for rebuilding and porting my spare s4 na. I will be turboing it also, but I'm quite sure it will last longer this time. I'm going to:

Get a rebuild kit for my original s4 NA.
Take it apart and see how everything looks.
I am for sure no matter how well they look replacing the:
Housings
Apex seals + hard seals
All seals and springs that come in the rebuild kit

I am going to keep the higher compression rotors if they look ok, but if they look at all like there are any issues I am going to find some s4 t2 lower compression rotors.

Anyways, if 6 port irons are basically already stockly ported to their limits, why is it better to port the turbo irons? I'm a little confused. I will most likely be doing a larger street port on 4 port irons but I'm not sure why yet.

Let me know if you have any ideas/tips.

Thanks
~Tweak

 

Since you aren't keeping functional 6-ports, wh don't you just cut out the gap in the middle of the aux/secondary ports... that'd make for a big port.

 

Sorry, I see that is a 6 port and it looks like ... that is a template on making the ports ... bigger ... is that basically a street port on a 6 port? Would it act like a street ported 4 port.

Does any body have any facts on what is going on?


Thanks micaheli. Is this yours?

 

oh jesus.

just frikkin half bridge it.

 

I have no idea whatsoever where you go the idea that nobody ports 6-ports. EVERYBODY ports 6-ports, its the only may to make a noticeable gain in power. You can do fairly substantial porting without even getting to a bridge port.
And yes, a street ported 6-port is the same as a street ported 4-port. Why wouldn't it be? They are just the same as the ports on a 4-port if not smaller, but with the same room to port it out.

 

I would but mine is a daily driver. I can't have 10 mpg in the city.

Well I have been looking at all the information on porting on nopistons.com and such and everyone seems to port 4 port engines. Maybe I am just wrong. So the picture above would be considered a small, large, or wild street port? Since I will be turboing, I should see a huge increase in spool time with exhaust porting correct? Also right now I am running the NA exhaust defusers, I will get rid of those when I rebuild.

 

Yeah. thats mine. What do you mean what is going on?

I'm just trying to make my functional 6-ports work the best they can..... Making them larger and changing their timing a little.. As you can see, the secondaries will open slightly sooner and the secondary AND aux's will close a bit later... Allows more time to get air in and more volume to squeeze the air through.. I haven't cut these shapes yet because I'm still debating if I'm closing the aux too late... the size of the chamber starts getting smaller a ****-hair before the aux port closes.... Probably won't affect my idle since the aux ports will be closed... and I'm hoping the velocity of the air at high RPM's will still be "charging" the intake volume before it shuts.

We'll see... If I were going turbo, I would probably leave the aux the way it was (maybe a little larger toward the corner seal path) and I would cut out the divider between the two ports.. Then feather the split into the runners so that its razor sharp and doesn't cause any wobble in the air flow...

I really know jack **** about intakes and porting, but I'm just trying to use what common sense I was given.... who knows.

 

Half bridges are for ****. Large street port or full bridge port.... no half-assing it.

 

soooo I just did a little mspaint (my photoshop program isnt working right now... I guess adobe wants some more money.. :\ )

Anyways red is stock port and blue is where I am thinking is what I could port out because I am not running any 5/6 ports. From this image, it looks like I would be a pretty big port. Are there any water jackets or anything I will be getting close to porting something this big? Did you use a template to do those lines or did you just free hand it? I need to know where to get some 6 port templates. I will still have make the lines to take out the center peice I guess.



Thanks

~Tweak

 

Yikes

 

?

 

Thats a great port for 11k RPM motors.

 

haha ok well that is basically what he is doing, exept I wont have a middle section at all. His middle section was going to be tiny.. I don't understand why mine would be 11k when his wouldn't. Or would his?



The only difference would be the little blue. Would that really kill the low end and require redline before peak torque?

 

Bigger ports = less power at lower rpms, less fuel economy. That's why the aux ports close at lower rpms. That's also why someone said that huge port would be good for 11k rpm.

Anyway, I hope you do some research before you do this. It would be a shame if you screwed up your motor.

 

Well I'm not doing it till xmas. I just recently blew the side seal so I have just recently started thinking about the rebuild and the port job I want to do.

 

theres not much to port on 6 port engines, and dont go further up on the 6 th port or you will loose power, they close late as it is now

 

So should you port the 6th down? Or port the primary up?

 

^ that is just the outside ported and the middle section gone. So like that?

this is just the middle section gone..... no other porting on the sides.

 

I don't know much about porting 6-ports, but you should really try to get some imput from a real "porter" before cutting the devider... I would personally stay away from that. As far as the picture just posted, you would want to port "out" (to the red line), to get an earlier opening port.

You might have to literally play with an "open" engine in front of you to get a good visual of how the rotor passes over the port as the E-shaft spins.

 

Get a template, and do it yourself, or pay someone. If you want to put the engine together yourself still, id reccomend sending it to someone to have them port it, like ludwig motorsports.

 

So basically I am getting the idea that no one really knows. I guess I will have to do some more research on my own. Thanks.

 

let me see if i can find you a pic of what ludwig did to my friends engine, he has an s5 but it shouldnt be much different.



Car is ablast to ride in compared to other cars, very good top end, until the turbo bleeds boost down.

 

Porting a turbo 6 port is probably rarely done. I would try to talk to Aaroncake about what he did. I know that cutting the bridge and making one large ports makes **** power down low and is a port for an 11k rpm race motor.

Worst case you could always pick up some T2 irons for $60 or so.

 

Compare the 6 port irons to the 4 port irons. The secondary/aux ports on the end plates are MUCH larger then even most 4 port streetports.

The primaries are a bit smaller and have slightly different timing.

Never, ever combine the two ports. The resultant mega-port has almost zero velocity at low RPMs and won't make any power until the engine is spinning 7000+ RPM. If you are making a drag engine then I can see the need for this, but never on the street.

 

Ok so Aaron my friend, other then a bridge port, what would you recommend? I don't want that bad of gas milage and I'm not the biggest fan of brap brap.

On a stock lower compression s4 NA at 4 psi I put down 184.5 whp. From my limited research I have heard people saying a street port can add 10%-20% pretty quickly. I would be exstatic to have 200 whp @ 4 psi still just from a simple port job.

I think I should be able to do well over 200 seeing how

The engine will be fresh with higher compression
I will have a standalone/rtek for better tuning
I might be at 5.5 psi now that I will have a better stock wastegate
putting in the t2 exhaust sleeves to get rid of that stupid na silencer thingy
and then also a little street port.

I have also been thinking of putting the s5 UIM on so I can use the little extra RPM gained from the street port. I thought that alone added 10-15 hp? Maybe that is just on an NA with working 5+6 ports sleeves?

Anyways let me know on your ideas on my ideas.
~Tweak

(I guess forget the whole taking out the middle thing. Would SUCK for drifting to always be at a higher rpm, and my stock turbo wouldn't like it much either.)

Also I am going to post this on the engine building section. I dont think the right people are looking at it over here in the second gen section. If an admin wants to just delete it and move this one, that would would also.