soundengineer

iTrader: (16)

Differences?? better of staying with stock P&P or go with 80mm
Its not a money issue....
just want to know If I will get more hp out of an 80 mm or stock ported
got a chance to get one cheap....

Fred99LS1

I'm not sure if a 80 MM TB would give more HP or not, but mine put down the numbers in the sig with a ported stock TB. I'm sure someone in here probably knows better, Fred

TRAGIC

I would definately say use the stock throttle body and port it!

Here's my story, yesterday I went to the track to test out my car right after I got the ported throttle body. The car loved it. My best ET before the ported TB was 13.59 @ 102mph. With the ported TB and TB bypass the car dropped down to 13.15 @ 105!!!! ....and that was on street tires.

Consider porting yours, it helped me out alot. A real noticable difference on the bottom end. But if you don't have sticky tires... you might need them after you port yours, I know I do because I had some traction issues on the 13.15 pass with my street tires.

1320_PERFORMANCE

What kindah ported TB's you guys got? Tragic, nice et's w/ the tb

Mark

Drew98TA

I've got a Janzter ported TB. The quality is exceptional and had no issues at all with it. Mine is also power-coated black and it looks badass

Fred99LS1

Stock TB, which has been ported.

soundengineer

iTrader: (16)

I need more people who have done both...
I have stock Ported and Polished right now....
I Just have a chance to get an 80mm for my stcok P&P... swap with a buddy deal......

demonspeed

iTrader: (7)

I'm going with a Jantzer myself...

just my .02.

BlueSS

i have the 80mm BBk on my 99 SS and i felt a good gain i ported and polished the TB on my ex 2000 chevy 5.3 and din't feel the same gain al though i did feel sum... 80 mm IMO good luck

PREDATOR-Z

Actually it is not that the stock ported TB is better, it is the fact that the intake has a 75mm mouth therefore negating some of the gained effect at the 80 mm TB.
The one thing I thought about is that putting a 80 mm should in theory increase the air pressure in the stock manifold (going from big to smaller) but maybe I'm wrong.

I'm satisfied with mine and it definitly is an improvement over the stock one. Not to mention so many poeple ask me if I have a blower (The 80 mm sound like a Hoover)

Larry

iTrader: (4)

How would an 80mm throttle body improve flow with only the stock 66.2 mm equivalent diameter mass air body?

I've read posts saying the factory mass air is big enough to support 500 hp. If this is true then the factory throttle body is larger than a factory mass air body eliminting it as a restriction.

PREDATOR-Z

Most poeple that mod TB do also mod MAF or get ported ends with the stock one.

Jason 98 TA

iTrader: (4)

We are finishing up our bigger blade ported stock housing throttle bodies that should be ready in about another week! Pricing will be $179 with the larger blade!

CamaroCain

iTrader: (1)

i am currently running a stock size ported TB from Bauer------->
my MAF only has the screened removed, i do not plan to touch the MAF, of course i have an A4

raceguy333

I'm in fluid mechanics right now. decreasing diameter increases velocity (mass flow rate) but decreases pressure. increasing diameter increases pressure.

There was a post about this in the lounge (i think it was this board) dealing with "ram air" and how the shape of the openings do not increase pressure at all (velocity yes, pressure no).

just thought i'd throw that in.

PREDATOR-Z

Ok, assuming this is true (increased velocity) wouldn't that have a beneficial effect on the way the charge refils the chambers and perhaps increase the combustion rate?? and/or perhaps increase the inlet charge size itself? Therefore giving you more power!

raceguy333

I would assume that the increased velocity is the reason people see gains from aftermarket intake systems as opposed to increased pressure. Most of them make a smoother path (decreasing obstructions and restrictions) which should increase velocity also.

Either way, more air = more power from what I've read.

PREDATOR-Z

Don't forget more fuel

Old SStroker

Think of the TB just as a door that lets air into a big hallway (plenum). The air gets into the plenum, which "stores" it for a short time before a cylinder opens it's door (valve) off the hallway and asks for air. The velocity that makes a difference in cylinder filling is the velocity along the intake runner and intake port, leaving the hallway/plenum, not the velocity into the plenum.

A larger or ported stock-diameter TB removes the restrictions from in front of the door (75 mm plenum on stock intake), guides the air in and makes sure the door is fully open and the doorknobs don't stick out into the flow.

Yes, as the air slows down as it enters the large volume plenum, the pressure rises a little, but it's still below atmospheric pressure, or the air would flow back out thru the "door".

Sorry if this analogy is too basic. No offense intended to anyone.

raceguy333

good point... forgot about that