porting my 2g mani...

[LRS95TSI]

so i decided to use some of my new tools and port my 2g mani to mate with my new o2 dump from 122performance. after going everywhere to get the necessary bits i started yesterday and took down the collector. then today i started on the runners. here are some rough pix, i will do the smoothing when i have ported the entire mani. please give ne suggestions or feedback as this is my frist time. the collector should be ported out to 7 cm being i am mating it with a ported e316g? how far in should i port the runners? sorry for the long post...

http://gallery.502streetscene.net/uploads/4834/DSC01058.JPG
http://gallery.502streetscene.net/uploads/4834/DSC01062.JPG
http://gallery.502streetscene.net/uploads/4834/DSC01063.JPG


MOD EDIT: Please resize these pictures if you want to post the full versions.

 

[pboglio]

I personally just thin out the flow divider, knife edge and polish it. Never cut it down, bad for flow and hurts spoolup.
Opening up the runners bigger than the exhaust ports also isn't a good idea, causes turbulence. Biggest gains are
in the collector, opening it up some and radiusing the turn into the collector. I'd also try and cutaway some of the wall
that blocks #2 & #3 runners from having a straight shot into the collector itself. Congrats on porting the manifold yourself.

 

[CanadianTSi]

I personally just thin out the flow divider, knife edge and polish it. Never cut it down, bad for flow and hurts spoolup.
Opening up the runners bigger than the exhaust ports also isn't a good idea, causes turbulence. Biggest gains are
in the collector, opening it up some and radiusing the turn into the collector. I'd also try and cutaway some of the wall
that blocks #2 & #3 runners from having a straight shot into the collector itself. Congrats on porting the manifold yourself.

Very good advise, this is exactly what I do. Knife edge the divider and focus on the collector area.

And yes you should go to a full 7cm for the Evo 3.

Also were you using a Carbide bit or a stone? looks like a stone to me, with a carbide bit you can be done in 20 mins tops.

PS might wanna resize those pics.

 

[90CherryTSI]

Yeah those are stone bits, they have to be as my carbide bits did the job in like 15 minutes total. I tried stone and it ate the bits and it was very slow going, like his appears to be. Someone on Ebay sells them, just search for carbide bits. They're like $50 but you get like 15 carbide bits (I somehow got some extra ones in my package free of charge) and those things work like magic.

 

[daren_p]

Yeah those are stone bits, they have to be as my carbide bits did the job in like 15 minutes total. I tried stone and it ate the bits and it was very slow going, like his appears to be. Someone on Ebay sells them, just search for carbide bits. They're like $50 but you get like 15 carbide bits (I somehow got some extra ones in my package free of charge) and those things work like magic.

I think I got mine from the same guy, they work amazing. Have done quite a few jobs with them & I too got a couple extra bits . As for the porting do what has been said enlarge the collector to match a 7cm gasket, don't completely remove the diverter in the collector area as it is designed to direct flow into the turbo. For the runners just port them large enough to match the exhaust ports on the head and go in a far as you can to smooth it all out.

 

[airmail96]

by Knife Edge do you mean like making it as thin as possible? Does anyone have any pictures of this? Doesn't the slowboy one come without the flow divider?

 

[pboglio]

by Knife Edge do you mean like making it as thin as possible? Does anyone have any pictures of this? Doesn't the slowboy one come without the flow divider?

No, you don't need to thin it exactly. Only the very top of the divider should be thinned out. You wanna get rid of that square shape on the top, and sort of streamline it a bit. Just make sure not to take the divider down at all in the process. I got pics somewhere of mine.

 

[airmail96]

No, you don't need to thin it exactly. Only the very top of the divider should be thinned out. You wanna get rid of that square shape on the top, and sort of streamline it a bit. Just make sure not to take the divider down at all in the process. I got pics somewhere of mine.

o ok thank you. Why does slow boy get rid of theres though?

 

[99gst_racer]

o ok thank you. Why does slow boy get rid of theres though?

They don't. SBR ported my 2G manifold for me, and they didn't remove the entire divider. Here's a pic.

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[oldman]

They don't. SBR ported my 2G manifold for me, and they didn't remove the entire divider. Here's a pic.

You paid someone to port your manifold?

 

[airmail96]

o ok i stand corrected , i thought since it wasso low they removed it, thanks for clearing that up

 

[No_Skillz]

You paid someone to port your manifold?

Bruce is starting shit. I should report your post.

Edit: Damn... pwned vvv

 

[oldman]

Bruce is starting shit. I should report your post.

Please stay on topic so I don't have to issue warnings.

 

[99gst_racer]

You paid someone to port your manifold?

I originally sent them my manifold to get a WG flange welded onto it. I then called back a few days later and OK'd them to port it while it was there. It was over a year ago, when I didnt have air tools and porting experience. I've since built a nice collection of air tools and a big compressor, and I ported my head on my 1G and a few different turbine housings.

 

[oldman]

I've since built a nice collection of air tools and a big compressor, and I ported my head on my 1G and a few different turbine housings.

I have ported pretty much everything there is to port but still don't have the balls to port the head, I might try it on my old head and I will hit you up for some advice when I do.

 

[blcknspo0ln]

I got you beat then, bruce. I ported my 2g head (the one currently on the car) to just clear the 2g IM gasket. it wasn't a lot but the ONLY thing I would port is the inlets of the head, but never inside..

 

[daren_p]

They don't. SBR ported my 2G manifold for me, and they didn't remove the entire divider. Here's a pic.

You must be logged in to view this image or video.

Maybe he is refering to their new cast manifold, as it looks like they don't have it cast with much of a divider anymore. I don't have personal experience with their new design as I have their older mani but this is the way it looks from their posted photos.

 

[44pirate]

I sent an email to SBR asking about the divider in their new cast mani. SBR's response was, the divider is not there, you get more flow. I'll see how it works out.

 

[LRS95TSI]

so now im a little confused. i thought that the divider was supposed to be taken away? did u just completely mess up my mani? do i need to take it down nemore? if i make the collector inlet 7 cm should i do anythig else in there. i am using actualy carbide bits. however my compressor runs constantly so my die grinder is not spinning at full potential all the time! damnit! keep suggesting guys i wanna do the best i can for a first timer!

 

[oldman]

so now im a little confused. i thought that the divider was supposed to be taken away? did u just completely mess up my mani? do i need to take it down nemore? if i make the collector inlet 7 cm should i do anythig else in there. i am using actualy carbide bits. however my compressor runs constantly so my die grinder is not spinning at full potential all the time! damnit! keep suggesting guys i wanna do the best i can for a first timer!

Like most have said, knife edge the divider but do not remove it. A cast manifold isn't like a tubular one where runners come into the collector angled towards the turbine housing. Without the dividers to re-direct air, they will most likely end up interferring with each other. That is my opinion.

 

[WatchItExplode]

I once heard a theory that enlarging the runners so they are bigger than the exhaust ports on the head increases power because it prevents exhaust from flowing backwards into the head. Does this not apply on turbocharged engines, or what?

 

[tstkl]

it will create turbulance any way you look at it, and what your refering to is a higher exhaust manifold pressure than intake manifold pressure, which is caused by backpressure from the turbo, this doesnt cause exhaust gases to go back into the combustion chamber, it just makes the stroke where the exhaust gases are pushed out of the chamber by the piston that much harder since there is a lot of pressure in the area where your pushing the exhaust gases, lowering the strokes efficency, and your ve which in turn lowers torque. its not worth it to port the exhaust manifold bigger because this will cause turbulance during all the time when your exhaust manifold pressure isnt larger than your intake manifold pressure, which is under most driving conditions, and most of your rpm range during the driving conditions where it is possible to happen. there are no benifits to porting your exhaust manifold larger than your exhaust ports on your head that can outweigh the negative effects it has performance wise.

 

[pboglio]

Turbo cars run minimal if any cam overlap, N/A cars run a whole lotta overlap. I could see them needing devices to prevent backflow.

Just look at the EVO IX turbo design. Tiny little manifold runners with a flow divider that extends all the way to the turbine wheel.

Its possible SBR got rid of the flow divider so as to make the external wastegate work properly mounted on that 1 runner.

 

[LRS95TSI]

it almost seems as if you shouldn't touch a 2g mani except knife edge the divider from what i'm hearing. after looking on vfaq and MANY posts on here, everyone was doing what i was doing. i ported the runners to match the gasket where it met up with the head. i just find all this hard to believe that what i did was wrong if so many ppl have done it. it's almost like saying if you don't have a ported head an upgraded exhaust manifold is pointless. but if im wrong or missing something please tell me, i feel like i could possibly be struggling with this issue.

 

[pboglio]

Here's a few pics from my "port" job. Just a simple 6cm collector gasket match and a little knife edging and polishing of the flow divider for fun, thats it.