Thoughts on gasket porting? Help with gains?

Warning! This is pretty long but please read carefully and fully and any help you can provide is very much appreciated.

What gains will i see if i port the stock headers before my next tune revision down in this post?

While i'm starting a new thread, i thought id take the time to ask about ways to gain horsepower. Here's my setup. Cobb sf intake (no airbox), gutted stock uppipe, invidia catless dp , GMS exhaust. All of this has been roadtuned to 210 hp over...215 wtq i think? Not sure. And on 91 octane of course. That's the highest i can find at the pump. On tune day, i had intake temps of like 160 and i didn't have the splitter on (i know i was a dumbass), i had a rattle in the engine, and my plugs were completely toast, oh and my clutch was going out as well but replaced with the ACT streetlite and the exedy stage 1 kit.

Before next tune i will have Cobb sf with airbox plus splitter of course, gutted upipe, heatwrapped catless invidia dp, gms exhaust, no rattle in engine hopefully, new stage 1 clutch and 14 lb flywheel, bulletproofed stock tmic, VTA or 50/50 bov, EBCS or MBCS, Ported gaskets (given it isn't all a crock), New z rated all season tires (I'm on worn out winters If that matters). All this running on stock turbo, 18-19psi

Now my two questions are (probably for tuners of the highest calibre):
1. Based on the paragraph above, what gains should i see in this next tune would you say? Give me a range please.

2. What other things can i add to the list to do that will give me noticable gains? My roadtuner says all there is left to give me more power is just raising the turbo psi. True?

Oh and just another real quick question, does the plastic thing on bottom of the car not being there cost me 3-4 mpg? AND will it help in my next tune?

From reading through this it sounds like your tuner is saying to port out the gasket itself? I'm confused.

The collector ports are much larger on the gasket than the stock manifold. If you look at your OEM header, you can see the carbon buildup where the gasket is larger than the port. I've used both OEM and GS exhaust mani gaskets and neither are smaller than the collector port.

Maybe I misunderstand the post, but you should be porting the manifold to match the gasket port size. I did this myself over a weekend with a dremel and flex extension. There are *some* gains (and there are a bunch of posts on it, especially on nasioc), but there will be nowhere near the gains of a full blown aftermarket equal length header.

If you were wanting to stay unequal length for the boxer rumble; porting stock mani vs aftermarket uelh, may as well port your stocker b/c it's free if you do it yourself. Porting stock mani vs aftermarket elh...elh will trump the stock ported mani.

Oh its switched? Yeah he told me port the gaskets but its the collectors and all that. Is there a cat in the stock x-pipe?. And yeah id like to just port these as i dont have money to buy headers. Any gain predictions at stage 2 with just the ported headers running 19 psi?

Yeah, you normally have to port the collectors...gasket matching the collector ports. Hopefully that's what he meant...or I'd be scared. lol No cat in stock x-pipe, can't predict offhand, but it's be worth a little bit. Over on nasioc they have a few posts about it. The only reason I would buy aftermarket headers is to switch back to equal length.

You should not be taking a tool to the ports in the head, leave that to the experts. If you want to open up the gasket go ahead.

I wouldn't be doing it my vendor knows two mechanics that have the tools. Can anyone answer my other q's or is it too jumbled up?

My opinion.
Stop nickle-and-diming and divert the funds into a turbo upgrade.
You can go with a VF52 and keep your stock fueling, but that will neuter the turbo somewhat. But in the end it will still give you better gains than, like I said, "nickle-and-diming" porting here and there to try to squeeze every last drop of the stock VF40/46. Plain and simple LGT means little girly turbo. The stocker is tiny and runs out of steam quick.
Nobody can give you a rough gain estimate on the port because it all depends.
The piping may support x-power but the tuner may only give you y-power due to knock.

What plastic thing are you talking about? are you talking about the skidplate which is literally between the engine and the ground. You do not want to remove it. It is a crucial part of cooling the engine. Remove it and you might see air coming out of your hood scoop instead of going in
The skidplate creates negative pressure and helps air go through the radiator and hood scoop.
You also want to keep the engine cover on, or otherwise devise a way for the scoop so that when you close the hood, it closes the gap between it and the intercooler.
Forcing air to go through the TMIC helps.

Thanks for the reply

Don't get me wrong, you have a solid plan, but I know all too well where it will end for you: you will get used to the bump in power and will want more. I think a VF52 will satisfy.

Hahaha i will always want more. A roadblock for me is this car isnt in the best shape from the last owner and it needs to go in a year or two so i would like to use parts i can switch back out and sell

Do not port the stock exhaust manifolds.

Leave porting to the experts. My heads were done by the machine shop, they did 90% of the porting in the valve pocket and divider area.

They say the underpan helps air flow through the tmic.

ALso not sure who your tuner is, but Shamar AKA Infamous told me he feels 17.5psi is the max you want to go on a VF40 for longevity. I agree with fishbone and max - leave the collectors alone at this level and if you need more power upgrade the turbo. Also read up on a MBC - your car already has a 2 port EBCS and you can upgrade to a 3 port - just avoid the MBC (some run hybrid of both but not just a MBC).

Are you kidding me?

Your car is literally crapping its brains out and you post this? Why don't you focus on one thing at a time? Like getting your car to actually run at all.

http://legacygt.com/forums/showthrea...ed-194302.html

This is for planning ahead and i was curious about porting headers

Waste of time. Get your car running, stopping and steering right before doing anything else to it. Stage 2 tune with a downpipe is the best bang for the buck there is. When it's time for more, consider how much you want to spend on supporting mods before picking a power target and a turbo that can hit that target. Include a decent EL header in that calculation.