vacum pipes before throttle body.

[jaffaz32]

I am getting ready to fitting a new intake and air scoop.

I just have a couple of questions.

Most intake kits use the excisting pipe that connect the factory air box to the throttle body. the one that looks like a organ, with the ribs.

Has anyone replaced this with a smooth pipe allowing free flowing air? i would imagine the ribs on the pipes disturb the air flow.

That moves onto my second question. The vacum pipes coming off this pipe just before the throtle body, what do these do? and where do they lead? do you need these? have people removed these? if so is there a guide?

I was searching and found a interesting statement which got me thinking

"In order to take full effect of any additional parts, you have to replace the hose that connects to the throttle body."

http://www.nsxprime.com/forums/showpost.php?p=538898&postcount=21

Thanks.

 

[Honcho]

You can use a smooth pipe to connect to the throttle body. There are some intakes for the NSX that do it this way. However, you need two fittings- one for the crankcase ventillation hose that goes to the rear head and one for the check valve that hooks to the throttle.

However, the OEM ribbed bellows works fine and does not affect power. In fact, the general consensus is that the OEM airbox makes the most power and torque for the NSX. Aftermarket kits may sound better, but you will lose some hp and ft/lbs.

The vacuum hoses are critical items. Do not remove them.

 

[ChopsJazz]

Do yourself a favor and return your new intake and spend the money on something that will actually gain you some performance. A search of this forum will tell you that the OEM intake is the most efficient for this (or even other) car(s).

 

[ScienceofSpeed]

The air box coupler that you are referring to is ribbed to allow the engine to torque independently of the air box, which is mounted to the chassis. In our testing, we haven't seen any gain to replacing this. In fact, the best gains we have seen have been with the stock air box with a free-flowing filter, and that coupler joined to the air intake system like this one:
http://scienceofspeed.com/products/exhaust_airflow_products/NSX/Downforce/Air_Intake_Scoop/

The pipes route vacuum signals to the various sensors and emissions components, they clean up the engine bay as opposed to having random vacuum hoses strewn threw the engine bay.

cheers,
-- Chris