began porting my TB

[jman050]

I began porting my throttle body today. I only did the one side but tomorrow hopefully I will do the other and polish them both to a nice smooth even finish. The guys on NASIOC all seem to have nice gains from the p&p tb's on their engines so i figured id give it a shot considering I have a extra TB.

A little blurry but you get the idea (http://www.subaru-svx.net/photos/files/jman050/36832.jpg)

needs some finishing touches (http://www.subaru-svx.net/photos/files/jman050/36833.jpg)

[Suby Fan]

SVX throtle bodies can handle some where around 500 hp as is... if i remember correctly... it wont do much of any thing

[jman050]

SVX throtle bodies can handle some where around 500 hp as is... if i remember correctly... it wont do much of any thing

The throttle body is hardly maxxed out but it is easy to see how it is making it more difficult for the engine to breath. I highly doubt stock wrx's max out their throttle bodies and they seem to notice improvement in throttle responce and a noticable hp gain.

Although if anyone has previously done this on an svx and deamed it worthless i would be interested in hearing about it.

[sicksubie]

Can you be more specific? Did you port it all the way up to the butterflies?

[SVXRide]

The throttle body is hardly maxxed out but it is easy to see how it is making it more difficult for the engine to breath. I highly doubt stock wrx's max out their throttle bodies and they seem to notice improvement in throttle responce and a noticable hp gain.

Although if anyone has previously done this on an svx and deamed it worthless i would be interested in hearing about it.

SVXFiles has already done it -- his biggest "finding" was that the throttle plates in his TB didn't open all the way to parallel with the air flow. You might want to PM him about the specifics.
-Bill

[SilverSpear]

He can check the pics in his locker, they are detailed ;)

[longassname]

They aren't supposed to. They open to where the difference in the height of the top and bottom is the same as the thicknes of the shaft on which they rotate.


SVXFiles has already done it -- his biggest "finding" was that the throttle plates in his TB didn't open all the way to parallel with the air flow. You might want to PM him about the specifics.
-Bill

[SVXelerator]

They aren't supposed to. They open to where the difference in the height of the top and bottom is the same as the thicknes of the shaft on which they rotate.

Mr. LAN,
Could you explain the rationale behind your statement? Do you mean that the cross sectional area perpendicular to the flow path is minimized by the TB plates not being parallel to the flow? . Thank you.

[jman050]

Mr. LAN,
Could you explain the rationale behind your statement? Do you mean that the cross sectional area perpendicular to the flow path is minimized by the TB plates not being parallel to the flow? . Thank you.

ex. the shaft that the blades rotate on are lets say 1/2 inch thick. The blade only opens so that either side doesnt stick out beyond that 1/2 inch diameter. Its hard to explain unless you have a TB in your hand:D

[sicksubie]

Maybe a stupid question, but it you bore out your TB when you are completely off the gas pedal and the butterflies are vertical won't there be air passing through which could throw off your AFR at idle?

[jman050]

Maybe a stupid question, but it you bore out your TB when you are completely off the gas pedal and the butterflies are vertical won't there be air passing through which could throw off your AFR at idle?

no because the entire TB isnt being bored out. Only about 3/4 - 1inch or the entrance is being bored out and polished to almost a knife edge.

[Jade Dragon]

not really. it might lean it out at idle, but thats not really a problem