Port a T25

[IslandTSI]

Im going to be porting my o2 housing this winter as well as a few other small maintenance things. I was thinking that i pretty much have to pull the turbo anyways to get the o2 housing off so would I see any benefit if I pulled the turbine housing off the turbo and ported the hell out of it? I cant see it hurting anything and even if it helps with my boost creep its worth it.

Has anyone done this before, and seen any results?

 

[silvah_gsx]

On a t-25, I wouldn't bother with porting. If that turbo creeps its probably some other problem, but that turbo is too small for porting to really matter. Go ahead and port the O2 housing though, as it will work better with whatever turbo you get next.

 

[blcknspo0ln]

Agreed. Not worth it to port that rinky-dink turbo. If you must, however, focus ONLY on the inlet of the turbine housing. DO NOT port your outlet. Both inlet and outlet are casted in a conical shape to provide optimum flow and if you just port the hell out of it and not keep that shape, you will be hurting things more than helping. One good thing to do is remove the "step" that is causing a 90* turn to your wastegate flapper. Again, I stress, do not port your oulet as you will most likely make it worse, rather than improve flow.

 

[IslandTSI]

Well thats about all I would be looking to do is try to help out with boost creep. Odds are I will end up picking up a 14b or 16g varient over the winter anyways.

 

[CanadianTSi]

People always say it isn't worth it but if it's only gonna cost you some time then why not?

My friend recently purchased a 2G and he hogged out the manifold turbo and o2 housing. That along with a Intake and UICP netted him 14.0 at 98mph...On the stock exhaust. So if you ask me I say yes its worth it.

 

[nanokpsi]

I am willing to bet you are getting a bost spike, not creep. I don't see how anyone could get boost creep with a t25.

 

[IslandTSI]

Well I have the turbine housing off the turbo now and the more I look at it the more material I can see to take off. Im going to do it and see what if any gains I can get from it. By the looks of it at the very least I can open up the wastegate passage significantly. Hopefully let me control my boost a little better. Also it seems like there is a lot of room to open up the top of the turbine housing.

 

[paul s]

People always say it isn't worth it but if it's only gonna cost you some time then why not?

My friend recently purchased a 2G and he hogged out the manifold turbo and o2 housing. That along with a Intake and UICP netted him 14.0 at 98mph...On the stock exhaust. So if you ask me I say yes its worth it.

I'm the friend, as stated I have ported and gasket mached every hole on that car. Match the turbo inlet to the 7cm gasked along with the manifold, clean up the runners on the manifold, clean up the casting from the turbo outlet. Open up the O2 housing to match the evo gasket. I get 16psi at 2300rpm and 27lb/min(dsmlink). The top end will always drop off with that small t25 but you gain a lot of torque. I'm still on stock pump(rewired) and exhaust and the injectors are at 87% while trapping 98mph.

 

[PieEyedPiper]

I'm also considering porting the exhaust inlet of my t25 because It is horribley matched with the EVO III GT manifold (7cm) I replaced my cracked up 2g manifold with.

 

[IslandTSI]

That I would reccomend for sure. The 7cm outlet and the small inlet on a t25 would be working hell on the airflow. Turbulence is a killer

 

[IslandTSI]

Another question. How many carbide burrs would you usually go through portin an exhaust mani, turbo and o2 housing?

Should 2 be enough?

 

[MrBoxx]

I used one carbide burr to port my O2 housing and 14b turbine housing and the burr cut like it was brand new till the end.

 

[Nonrml4]

Another question. How many carbide burrs would you usually go through portin an exhaust mani, turbo and o2 housing?

Should 2 be enough?

Depends where you go. I went to a local supply shop for professional shops, one $13 carbide bit, still cuts like new. I would bet that its probably going to last longer than some of my other tools.

 

[IslandTSI]

Cool that sounds good, I just picked up 2 of them for $12 so hopefully they last. I'll just keep em well cooled and lubed up.

I'll most likely be posting up pictures in the future for some pointers as well as a review of the difference all the porting made

 

[daren_p]

Some people say its not worth it on the T25 but porting is basically free & you will notice a difference. Back when I had the T25 I ported it when I ported my O2 housing & with the 2 items done I noticed several hundred rpms quicker spool & probably help the top end as well. I did the turbine outlet as well but didn't actually "port" it out, just did enough to take away all the rough casting marks, not sure if I even used carbide bits or just sanding & flapper wheels to give it a nice smooth finish without altering its shape, which like mentioned is a bad thing.

If you get a good quality carbide bit they will last a long time. I bought a set of about 8 on Ebay for around $50 and have ported 3 complete turbo's, 3 exhaust mani's a couple O2 housings as well as a bunch of odd automotive & home jobs & mine still work like new.

 

[IslandTSI]

Well I had to pull the turbo and manifold to fix a broken manifold stud, so while I have it all off I might as well port it. No point in opening up the exhaust manifold to 7cm if I dont match the turbo inlet.

If all I see is better boost control and less creep in the middle rpm's I'll be happy. And when ever I decide to put a bigger turbo on everything will already be ported.