Turbine housing port/polish?

[SHIFT_*grind*]

How much of a difference does it really make? I read a little about it, enough to know that porting/polishing of the turbine housing helps things flow better and bring the boost on sooner, and also help response.

With a decent job, how noticeable would the difference be? Would boost come on much sooner with a small-ish turbo like a journal bearing T28? (specifically, a GTiR T28, one that could use a little help in that department anyway)

[opponheimer]

I doubt you could gain 1hp from porting or "polishing" the cast iron turbine housing of a turbo. Cast iron is strong but brittle.. I wouldnt want to thin out the inner walls anymore. One thing you could port is the WG opening to prevent boost creep. If you want increased flow, get a bigger turbo without the 5-bolt housing.

[steve shadows]

hahahahahhahahahahahahahah

everyone is so broke on here. thats why reading posts is so fun.



just get a larger compressor housing. (like a larger T04B)

[S14DB]

You can prolly increase the VE with a polish. I would not want to port cause you don't know what kind of AR you would end up with.

So, cleaning up(polish) the casting can't hurt. Would stay away from porting.

[steve shadows]

You can prolly increase the VE with a polish. I would not want to port cause you don't know what kind of AR you would end up with.

So, cleaning up(polish) the casting can't hurt. Would stay away from porting.

There is really no conceivable point.

I mean unless he's building a cart car and needs to eek out every single last fraction of hp whats the point?

Get a larger compressor housing with a clean casting (like Garret GT) or stock Garret very smooth inerds. That will increase your spool time very very marginally but peak output will probably be increased on the order of 5%. Depends on setup and size of course.

[spoolint78]

Turbine housing makes a big difference, especially on spool up, and can definitely change the power band of your car, ie make peak power earlier, or later.

From my understanding a bigger a/r is more laggy, hits full boost later, and can make more power in higher rpm. If you go too big, you probably wont even spool the turbo.

The opposite is true for a smaller turbine housing, ie, faster spool, fulll boost earlier, and makes more power earlier, but if too small you can choke the turbo and boost can fall off.

Your best bet is to search around this forum to find out what other people are running and what works best.

[steve shadows]

sorry guys Im a fucktard in this thread.

I thought he said Compressor housing port and polish.

Turbine?

eh I guess.

Still very marginal.

[opponheimer]

I'm sorry, he said turbine did he mean compressor? Does he know the difference? Imho porting polishing either one would be a great waste of time!

[MELLO*SOS]

I don't have any first hand experience... But I've read about both compressor and turbine housing p&p before. Personally I wouldn't spend the money to do it on a stock turbo, because for what it costs you'd probably be better off swapping housings or just upgrading to a larger turbo. For a race setup you'd probably notice quicker spool on an already baller turbo if you p&p both housings... GL


a. Port and polish: Includes heavy porting of exhaust housing, removal of flow obstructions, smoothing of the factory material, and reduction of internal angles to alter flow and evacuation. Entrance to turbo housing (where the exhaust enters the unit) is also heavily ported, removing flow obstructions and smoothing exhaust path. Wastegate pass-through from exhaust housing is also ported, increased slightly in size, and any flow obstructions removed. The most significant improvement with this service is the decreased spool time. Another improvement is the additional torque in the lower RPM band as seen in Lack of low end torque is a common complaint with 2.0L motors.

from http://www.boricua-racing.com/forum/showthread.php?t=692


Porting and polishing the turbine housing has shown to be greatly effective on a variety of turbos including Garrett T25's, Garrett T3's, Mitsubishi TD04 and TD05's, Holset HX35W's (as used on the Dodge Cummins Diesel truck), as well as others.

This option can greatly decrease spool-up time and increase boost potential. It decreases spool-up time by speeding up the exhaust gas velocity through the turbine. It gives top-end boost potential by opening up the biggest restriction in the exhaust system which increases the flow through the turbine.

http://www.gpopshop.com/porting7.jpg
http://www.gpopshop.com/t25port.jpg
http://www.gpopshop.com/porting8.jpg

from http://www.gpopshop.com/portpolish.html


Maybe someone who's actually done this has some useful input.

[steve shadows]

Codyace did something along those lines.

I suppose it would be cost effective if your dead set on using a smaller turbine bottom mount turbo.

[statik]

Codyace did something along those lines.

I suppose it would be cost effective if your dead set on using a smaller turbine bottom mount turbo.

I believe he got the exhaust housing extrude honed along with the stock exhaust manifold. I don't see why it wouldn't help a bit with flow/spool, but extrude honing can be pricey. Doing the stock exhaust manifold is def worth it though.

[SHIFT_*grind*]

just get a larger compressor housing. (like a larger T04B)

Already has an S14 T04B comp housing swap =P

shots from gpopshop

And that's exactly what I read that made me consider this. The reason I asked this question is because I bought the turbo used, and it turns out it needs a rebuild. Sonofabitch. So I'm debating whether or not to rebuild it myself, or send it to gpopshop for a rebuild. So I check out their website in case I decide to send it off. And on their website, they talk all about the port/polish service they offer for ~$120, decreases spool time, brings boost on sooner, etc. And I wanted to know if it's actually worth the ~$120 to get it done along with the rebuild, or if it's a minor improvement and they're making it sound better than it actually is. Looks like it's the latter.

[chuy]

spend YOUR money and let us know

[codyace]

www.extrudehone.com

I swear by this stuff. That, swain, myspace bulletins and JWT haha.

Seriously, my 2871r .64 spools as fast, if not faster than 28RS setups, and has creates big boy torque for a very long time.

As Steve said, this isn't for the faint of heart. I'm set and content with the 400 hp I have, my stock turbo manifold, and that sort. I'm a boost junky, but If I wanted a highway car, it would have 6 cylinders, not 4. (well really 8)


Anywho here are some pictures. This stuff really rocks. I just my stuff all back apart, and it's still nice and smooth inside. I'll hafta get some newer more pictures of it too.
Before:
http://www.e-rak.com/cody/albums/album128/P1010032.sized.jpg

After:
http://www.e-rak.com/cody/albums/album188/P1010169.sized.jpg

http://www.e-rak.com/cody/albums/album188/P1010179.sized.jpg

http://www.e-rak.com/cody/albums/album188/P1010177.sized.jpg

And the manifold

http://www.e-rak.com/cody/albums/album188/ex14.sized.jpg

http://www.e-rak.com/cody/albums/album188/ex5.sized.jpg

http://www.e-rak.com/cody/albums/album188/ex12.sized.jpg


Again, it's a little pricey, but turbine housings are cheap in the grand scheme of things. All in all, it's cheaper to get your manifold and turbine done, than to buy mid range tubular crack afold....and you'll have faster spool and more torque, and no worries :D

[PoorMans180SX]

Nicely done!

Is that white lightning on your exhaust manifold too?

[jspaeth]

Fuck, now I HAVE to try this when I put my new turbo on...

I'm not very hardcore, so I will probably just try to polish the inside of the stock exhaust mani with a dremmel tool or whatever

Also, excuse my ignorance, but does swain-coating the mani act as a heat jacket...how does it compare to good-old heat-wrapping?

[PoorMans180SX]

Good luck reaching very far inside the manifold.

Swain is so much better.

It's a .015" thick true ceramic coating. No corrosion issues like with heat wrap.

[SHIFT_*grind*]

spend YOUR money and let us know

I think, after hearing the responses here, I'm gonna keep my money. I have a paypal account though, if you want to know the results bad enough =P

[SHIFT_*grind*]

Another question:

If I'm getting the turbo rebuilt, how necessary/beneficial would it be to upgrade to a 360* thrust bearing? I searched Tech Talk and found threads where people were shooting for 350+ WHP on a T3/T4, and were being told that a standard 270* bearing wouldn't hold that much without crapping out.

But: This is a GTiR T28 with an S14 T04B comp housing, supposedly only good for ~320WHP at the most. And I'm not trying to exhaust the limits of this turbo, I just want something with a better powerband than my T25 that I can take up to ~300WHP when I can get some fuel/tune upgrades. I'm only going to run like ~10lbs until then. Maybe less.

This shop wants ~$150 for the bearing upgrade :ugh: Basically I'm thinking that a 270* bearing will be fine, since this is just a street car and ~300WHP will be more than enough for me (and if it's not, I'll upgrade again). That's what I think, does anyone know? :)

[HyperTek]

fc RX7 people typically port the wastegate and weld on a bigger washer for the flap.. but thats becuase the OEM flap is sometimes too small for demands.http://www.aaroncake.net/rx-7/s4wastegate.htm


You could shim the actuator to get higher boost, thats a trick too.. but same thing a boost controller does, but i think this way it affects the response.

What are you rocking? if you got like a oem turbo like a t25 or something, i say try doin it.. those are a dime a dozen on the forums so if you dont like the results toss it.

just try to optimizing the exhuast system, porting manifold, 3inch downpiping/exhuast etc

[SHIFT_*grind*]

This is a GTiR T28 with an S14 T04B comp housing

;)

Anyone on the 360* vs. 270* bearing question?

[SHIFT_*grind*]

And actually, scratch that, 360* bearing upgrade is $70, which makes a lot more sense now than 150. Worth it?

[SHIFT_*grind*]

Worth it?

Blah.






thismessageistooSHORT

[SHIFT_*grind*]

Seriously, does anyone know more about whether or not I'll need a 360* thrust bearing for the boost levels that I'll eventually be running? After fuel/tune, 14-15 psi at the most, maybe ~300WHP.

I hate to bump the thread again but I just can't find any more information on this... :(

[PoorMans180SX]

I found this on wikepedia:

"Lower friction means the turbo shaft can be made of lighter materials, reducing so-called turbo lag or boost lag. Some car makers use water cooled turbochargers for added bearing life. This can also account for why many tuners upgrade their standard journal bearing turbos (such as a T25) which use a 270 degree thrust bearing and a brass journal bearing which only has 3 oil passages, to a 360 degree bearing which has a beefier thrust bearing and washer having 6 oil passages to enable better flow, response and cooling efficiency."

Sounds like a good idea to me.

[SHIFT_*grind*]

Update.

I sent the turbo out. The 360* thrust bearing seemed like a good idea by all accounts, so I had it fully rebuilt with that option. It just came back over the weekend, looks absolutely brand new.

The only thing is, the wheels don't spin freely now. I can turn the shaft easily by hand, but as soon as I let go it stops turning. Before it was rebuilt, I could spin it and it would keep going for maybe a turn and a half before it stopped.

I think this could probably be explained by:

1) It's journal bearing,
2) It's basically brand new and everything's tight, might need a few miles on it to break in and loosen everything up,
3) It's not lubricated and hasn't had any oil run through it yet.

But I, of course, am paranoid, so I'm posting to see if this sounds like a problem. :D

Anyone?

[MELLO*SOS]

My journal bearing is the same compared to my stock ball bearing, there is a huge difference in friction. Also being brand new and not "broke in" and having no oil to lubricate it will stiffen it up a little.

I think the 360 bearing was a good idea btw, might as well for as cheap as it is.

Throw up some pictures :)

[SHIFT_*grind*]

I try to get some pics tonight when I get home.

[unicoladron]

3) It's not lubricated and hasn't had any oil run through it yet.


I'm with you on this one. why don't you squirt a little oil into the oil-inlet passage and prime it. this will probably allow it to spin a little more with less effort.

i had something similar happen. water found its way into a t25 i had laying around (left it outside facing up lol). i shot compressed air at the inlet while squeezing some oil into the oil inlet. back to normal.

[SHIFT_*grind*]

Also, while we're on the topic: how should I prime the turbo with oil before initial start-up? I know I remember reading it in a thread a while back but can't remember exactly, or which thread it came from, and I haven't been able to find it again.

Disconnect the CAS and crank for a few seconds?

[chituntang]

My friend, which had a 04 WRX, was going to get a STI turbo and send it to port and polish. He told me that after the port and polish, the turbo would hit full spool about 500 rpm earlier. It is like putting a turbo kit on a Miata. You are stilling max out at about 120mph, but you will hit 120 in a shorter time than stock.

[PoorMans180SX]

Also, while we're on the topic: how should I prime the turbo with oil before initial start-up? I know I remember reading it in a thread a while back but can't remember exactly, or which thread it came from, and I haven't been able to find it again.

Disconnect the CAS and crank for a few seconds?

Yeah, disable the ignition. I take it you have an SR, as you can just pull the coil wire on a KA.

[dynamicck]

disconnect injectors too. seen lotta people crank it too long and flood the motor.

[SHIFT_*grind*]

Thanks, I'll do that. :)

Working on getting some pics up. One other question; my oil drain gasket got lost in the machining/rebuilding process, would I be able to cut a new one out of standard paper-ish gasket material and use that? I'm thinking not, that I'll need a metal one, but it'd be nice if I were wrong.

[sunnys14]

I just used some orange hi temp silicone and it hasnt leaked for 6 months so I guess thats ok.

[godzilla_753]

dam im really interested in this as i have a gtir turbo in need of a rebuild too,
pleaase post some pics up

how much did u pay total, and did u get anything ported?

[SHIFT_*grind*]

No port or polish done, just a basic rebuild with the 360* thrust bearing upgrade. The port/polish probably wouldn't have been worth it. Cost me $300 total, including shipping cost there. www.blaastperformance.com; he's in Canada so the shipping and stuff takes longer and is a little more of a hassle, but it looks great. Prices are good too.

I'll get pictures tonight, seriously this time. :)

[SHIFT_*grind*]

Mostly assembled.

-S14 T28 compressor housing
-360* thrust bearing, no port/polish
-HKS actuator, T25 bracket which was Dremeled to fit (as you can see)
-S14/15 T28 compressor inlet pipe (not pictured), stock T25 outlet pipe (the silicone coupling may have to bend a little, but it should fit fine)

Sorry, my photog skills are exactly 0.
http://smg.photobucket.com/albums/v245/bigjay00213/100_0388.jpg
http://smg.photobucket.com/albums/v245/bigjay00213/100_0391.jpg
http://smg.photobucket.com/albums/v245/bigjay00213/100_0393.jpg
http://smg.photobucket.com/albums/v245/bigjay00213/100_0394.jpg
http://smg.photobucket.com/albums/v245/bigjay00213/100_0395.jpg
http://smg.photobucket.com/albums/v245/bigjay00213/100_0398.jpg

I have some cork/rubber gasket material that I could cut a gasket out of, says it's ideal for oil (i.e. oil pan gaskets, crankcase cover, etc), would there be anything wrong with using that for the turbo oil drain gasket? (I don't like RTV =\ )

[MELLO*SOS]

turbo looks good. don't have any suggestion on the drain gasket.. Either of your options would probably work fine.. Or I'll throw another one out there, you could buy one of those Function7 drain kits. they come with a gasket and a 1/2 npt or AN-10 fitting.. :)

[SHIFT_*grind*]

Eh, I'm gonna go with whatever option will get me on the road tomorrow =D Saturday's the only day I really have to work on it, and it hasn't run in a little more than 2 months. Need to get it going before the gas gets too old.

[codyace]

Use RTV, as originally stated Sunnys14

IMO it's the only substance that actually won't leak (this side of the o ring flanges) at this area. The paper gaskets simply get to brittle from all the heat.

[SHIFT_*grind*]

Will the cork/rubber get brittle the same way the paper gaskets will?

[SHIFT_*grind*]

One last update:

The car runs :) I haven't really boosted yet, just drove around and took it easy. The gas in the car's been in there for ~2 1/2 months so I'll be easy on it for a little while. Runs great though; a little smoke at startup, seemed to go away after a few minutes, no leaks or anything.

Thanks for all the help guys =D