Porting for performance...

[firebirdvert305]

Well guys ive been looking into getting a turbo very soon and ive seen alot of people who offer porting. Now my setup is a generally mild setup....i plan on a FP2 cam setup, evo 3 16g, and FMIC...of course with all supporting mods...Well ive read people saying porting of course will help spool-up time on a generally mild setup, but i was also told that porting can hurt top end performance? Is this true? Is there an explination for this? I dont see how so b/c once a turbo hits full boost sooner...say 22psi, its still flowing 22psi no matter what rpm...i dont understand how it will hinder performance...can someone enlighten me or is this a myth?

 

[CanadianTSi]

I'm not sure who told you this, but if anything porting hurts spool up and helps top end.

 

[daren_p]

I think you may be a little confussed as porting will help both spool & top end. Probably what someone was talking about is having the larger wastegate flapper mod. Where they enlarge the wastegate hole & install a bigger flapper to help prevent boost creep. The problem with this is sometimes with the larger size of wg flapper (ie more surface area) the flapper will blow open easier at higher boost. We are usually talking about mid 20's plus for this to happen.

 

[dalatinromeo]

No just like darenp said porting will not hinder topend, but actually it will help it.
Yes, it is a myth,or just misinformation got passed along.

Hopes this helps you. Stay boostin

 

[CanadianTSi]

Some people will argue that having a smaller opening that isn't ported will have a higher velocity therefore spool the turbo faster...but the difference is insignificant IMO.

 

[daren_p]

Some people will argue that having a smaller opening that isn't ported will have a higher velocity therefore spool the turbo faster...but the difference is insignificant IMO.

Well I don't know about my evoIII as I ported it before I installed it but by porting my t25 I gained a couple hundred rpms in spool.

 

[snailed]

it will just hit faster and harder, its hard to explain but you feel more of a pull when you go from 0- 22psi because the tme it takes to get there is shorter and the turbine can flow more air to support bigger power in higher rpm. hope i helped. Its a sweet mod man.

 

[skinnykenny84]

I think what the person meant was if you clip the wheel or not will have an effect on spool and top end. On my last dsm I went with a big 16g and had it clipped. I lost a noticable amount of spool time. On the other hand it pulled super hard up top!

 

[90blacktsiawd]

When i ported my 14b i noticed it spool up alittle quicker. Couldn't tell you exactically how much as i didn't have the car long before i did that. I did however notice that the boost didn't drop off up top like it had before. I also swapped on a ported 2g manifold at the same time so i can't tell you what did what in the end.

 

[BOBS90TURBO]

Rememeber when you start your porting, make sure you port your O2 housing, turbo housing and the bottom of the exhaust manifold(where it mates to the turbo housing inlet). And be sure to spend the money on a nice Tungsten Carbide bit, all the othet types are a waste of money and take forever. Good Luck

 

[90blacktsiawd]

I agree with Bob up here. But don't just port them. Port match them to each other. Get whatever new gaskets you will use and use them as templates. Now the gasket might need to be trimmed to in certian spots.It will help you get the best flow you can out of the setup.

Seeing you'll be doing this on an evo3 and having a bad boost creep problem myself with one. I recommend you follow this guide to how to port the turbo. It also goes alittle into the o2 housing as well.

http://www.dsmtuners.com/forums/showthread.php?t=186525

And here's a FAQ on porting the manifold. It doesn't mention it but do not remove the center divider. That will actually hurt flow instead of help. But polishing it up and smoothing it out is a different story.

http://www.dsmtuners.com/forums/showthread.php?t=213248