Intake/exhaust mani polished?

kinkyllama · Post by **kinkyllama** » Wed Apr 05, 2006 7:36 pm

I'm thinking about getting my intake and exhaust manis polished before I turbo my car. Do you really think it'd be worth it? Im guessing it'd be better on an N/A car as the turbo would just push through any little bumps and stuff.

Let me know your thoughts.

Danny

Audacity Racing · Post by **Audacity Racing** » Wed Apr 05, 2006 7:39 pm

yeah... volumetric efficiency isn't nearly as important with turbo'd cars so i would think it to be more of a waste of money that could be better spent on suspension parts of internals or something.

that's opinion i guess.

kinkyllama · Post by **kinkyllama** » Wed Apr 05, 2006 7:47 pm

Audacityracing wrote:yeah... volumetric efficiency isn't nearly as important with turbo'd cars so i would think it to be more of a waste of money that could be better spent on suspension parts of internals or something.

that's opinion i guess.

How much do you think it'd cost to have done?

My exhaust mani isnt very smooth

Audacity Racing · Post by **Audacity Racing** » Wed Apr 05, 2006 7:48 pm

no idea beacuse that intake manifold is goofy shaped... though i think it wouldn't be much. you could port match it yourself for next to nothing... that's a better option i think

kinkyllama · Post by **kinkyllama** » Wed Apr 05, 2006 7:51 pm

Audacityracing wrote:no idea beacuse that intake manifold is goofy shaped... though i think it wouldn't be much. you could port match it yourself for next to nothing... that's a better option i think

How do I do that?

Audacity Racing · Post by **Audacity Racing** » Wed Apr 05, 2006 8:01 pm

look in the articles of interest post in one of first few posts... there is a fantastic diy there...

all it takes is gaskets, a dremel with a good stone (or other die grinder), and some special dye that won't damage the gaskets/metal (you can get it at auto parts stores)

kinkyllama · Post by **kinkyllama** » Wed Apr 05, 2006 8:14 pm

Audacityracing wrote:look in the articles of interest post in one of first few posts... there is a fantastic diy there...

all it takes is gaskets, a dremel with a good stone (or other die grinder), and some special dye that won't damage the gaskets/metal (you can get it at auto parts stores)

Oh I remember that one. Thanks!

Nubira2.2 · Post by **Nubira2.2** » Wed Apr 05, 2006 8:27 pm

In my opinion:

The roughness in the intake manifold helps in the atomization of the A/F mixture

What you can do is Port Match the mani with the head, I will give you more airflow into the head

With the exhaust mani here the smoothness is important because it gives better flow speed and it will improve turbo lag

There is a treatment that is used to soften the inside of the manifold tubes. U can do the same to yours

If I am not mistaken it is called abrasive flow machining.

ubuyau · Post by **ubuyau** » Wed Apr 05, 2006 9:46 pm

Audacityracing wrote:You could port match it yourself for next to nothing... that's a better option i think

Gasket matching yourself would be a good idea, there is normally a bit of fat in the manifold port. Be careful with the aluminium intake manifold though, a dremel will eat into that material VERY quickly - so be gentle

Id consider gasket matching the throttle body to the intake manifold too...

Getting it polished would make a tiny bit of difference in a boosted application. Since the air pressurised it'll easily push past any casting imperfections, the benefit would be in increasing the displacement of the maifolds so you can get more air into the engine.

On the exhaust side dont go tooo big on the manifold ports, you'll want to make sure you still maintain the best velocity for exhaust gas to spin you turbo quickly and reduce lag.

So in summary - gasket match things yourself with a dremel and spend the polishing money on other areas...

--Tim

woo · Post by **woo** » Fri Apr 07, 2006 6:42 am

to port the intake manifold you have to get someone to cut it up, port it then weld it back together