what would be some good mods to expand my s4 na power band? im in the process of porting my tb and im just finished porting my upper intake manifold? and does anyone know how much power or gain the the powerband i get with these mods?

 

you are losing power. the intake manifold was designed precisely to free up the powerband, and because you messed with it, it is going to be off.

the best thing you can do, is go full exhaust, and get a piggy back or a stand elone engine management system.

those are the BEST ways to make power without cracking open the block. once you crack open the block, well... the sky is the limit, when it comes to porting.

 

damm so i lost power the hmmm yea i kinda noticed something different good thing i used an extra one i had laying around

 

Get a full exhaust and lightweight flywheel. Upgrade suspension if you haven't already.

 

I don't see how porting the TB would hurt, but yeah, leave the intake runners alone. Making the air entrance transition at the TB shouldn't hurt. Just don't mess with the intake runners.

 

If by "sky's the limit" you mean "200-225rwhp", then yes, you're right.

 

You can just get this:

http://kalecoauto.com/index.php?main...products_id=30

It allows full range adjustment, it should get you what you are looking for.

 

do your aux ports even work?

 

turbo

 

Agreed.

 

^Thats fricken' hilarious

Porting your throttle body and intake mani will theoretically give you more top end power.
Any sort of porting generally sacrifices low-RPM power for greater peak power at High-RPM.
You probably wont notice much of a difference from what you've already done. As it may have been stated before, as long as your secondary TB plates are still there then your idle won't be effected either.

Just don't go any further with porting if you're looking for BROAD range power.

 

still, i would not have messed with the intake manifold at all. 180 to 190 wheel hp is obtainable if you go with a proper exhaust ( you will need about 20 revisions of the exhaust to get it right), and fiddle with the tune.

 

Major: Cat, mufflers, properly functioning auxiliary ports (or home-made air pump activation if not, see www.aaroncake.net). Tune it. That's about all you can do without porting the engine or going turbo. For the engine block a street port is best for gaining power without losing much low end.

Minor: A lighter flywheel would help whenever you down-shift, but not much otherwise. So if what you're after is good initial response after down-shifting that may help. I dunno how much. Going too light has drawbacks. If you mean you want to drive it in the low rpms 100% of the time and still have power, it'll only cause carbon buildup and there is virtually no reliability advantage to doing this. A cone intake surrounded by a cold air box adds a couple HP, while without the cold air box you lose a couple HP compared to stock which already sucks in cold air.