Throttle Body Questions...

[rakarb]

Has anyone tried, or have any of you heard of or seen any mods to the stock throttle body?
IE, 80mm bore / polished / bead blasted inside / spiral grooving in the bore, anything?
I am asking because I have been asked to fab an aluminum model for a Contour SVT in a larger bore. If I were to x-fer the dimensions of a stock TB onto a CAD drawing, (hint here mholhut wink ) I think a larger bore is
feasible.
Discuss amongst yourselves....

<small>[ April 15, 2002, 11:53 PM: Message edited by: rakarb ]</small>

 

[rockfordsho]

hi im linda richman and welcome to coffee talk.

 

[mholhut]

Yeah, yeah, yeah... I was just cleaning up my spare TB today in preparation for shipping it out to ya. I was looking at the inside of the TB and decided to grind down the lip that's in there while I still have it. More polishing can still be done to it, but it was the best I could do with such crude instruments.

There was an old thread on the V8SHO list a while ago that had to do with the flow characteristics of the V8 intake. To sum it up, the MAF and TB in stock form will flow more air than the motor could ever use, so there's probalby little use in punching it out, if that could be done. The ID on the TB is already 75mm so I'm not sure it could be bored out that much. If you could, you'd have to find a larger throttle plate as well.

Just let me clean all the shavings out of it tomarrow and I'll see if I can't get it to the post office on Wednesday along with the intake gaskets.

 

[rakarb]

That's not the way I meant you to take the hint Mr. Holhut.
I was trying to get at maybe you being a ****** again, so sorry for the mistake.

Brad

 

[SHODWN]

The Throttle body is 2.56 inches or 65mm, Mike must be set to SAE still Sorry just had to..

The idea of faster flow mixing the fuel is moot on these cars as that happens in the cylinder where velocities and quantity of air is limited by the size of the valves ands the fuel is effectively atomized by the FI. The intake track leading into the surge is not a very restrictive one with a 3" setup. If you were to go to a smaller diameter tubing you would increase the velocity only in the smaller tube. As the air hit the larger TB and 90 behind it would actually slow down some what. Then it would enter the surge tank and slow down more. The surge tank acts as a storage/buffer area for the incoming air, smoothing out the transition and pulsating of the individual runners.