VAP

<center><img src="http://pictureposter.audiworld.com/711/racetb1.jpg"></center><p>Today I'll be doing some sleeve sizing and flow charts for the new 2.8 racing throttle body. This pic is of the "RTB" (left) beside a Stage 3 throttle body (right) just after boring for the new 2mm larger velocity stack internal sleeve. You can tell the larger bore by how much more material is removed from the flange I.D. as well as how the bore has blown thru the wall that divides the primary &amp; secondary venturi.

I now have to machine 10-12 internal velocity stacks of varying lenghs, tapers and diameters to find the "magic" combination. Then I'll flow each one to determine the best combination.

This is also the special and rare B6 291 078 063T throttle body. I just didn't have the heart to use any of the others given the "if we're gonna be a dog, why be a chihuahua" philosophy on this throttle body.

quattro90S6

im saving for one of those see if i can find one though

Mr.D-'97 A4q 12v

Are you sleeving the secondary bore, too?

VAP

will ever become a production item. It'll be like the intake manifold. Far too many hours involved to be a worthwhile venture for me. I'm expecting it to be a 40-50 hour finished piece excluding the preliminary groundwork of flow-testing, sleeve sizing et al.

And much, if not most of it will be hand work rather than machine time. This thing will have between 6-8 ounces of epoxy putty in it by the time it's done just to fill all the holes that shaping &amp; contouring is going to open up between the primary and secondary bores. The entire "flat" section that's there now at the 9 o'clock and 3 o'clock position in the pics will be a gentle taper into the secondary instead of the flat top it is now. And there's a ton of other stuff including new profiled and diffused precision ground butterfly shafts, 37mm primary butterfly (stock is 35mm) grinding and polishing all the screws flush to the shaft. And there's more, LOTS more planned. This one's gonna be an exercise in some seriously clinical obsessive-compulsive behavior.

VAP

Even this throttle body doesn't have sufficient meat to enlarge both. I could've opened up the secondary side but still can't fit it with a velocity stack so I opted to open the primary side as I can benefit more from a 2mm larger bore WITH velocity stack on primary venturi than I can on the secondary venturi sans VS.

Mr.D-'97 A4q 12v

Wow. Can't wait to see how it turns out.

quattro.pilot

so that you still get a modified product but with not nearly the amount of time &amp; work you'll be putting in?

As you say, it flows better than any other TB. So could you give it the same treatment you give the others, in order to capitalize on the natural design of the TB. You don't HAVE-TO go all out (as you have planned)... I'm just lookin for a more affordable solution which you *could* market as an AbnormallyAspirated product. say rS3 TB, heheh?

check yah later

quattro.pilot

or are you still interested in keeping that secret... for now?

check yah later

VAP

This can never be turned into a DIY project.

I am however experimnting with everything before I do the larger butterfly plate and shaft. But even at that it could still easily be a $1k+ throttle body and people arent lined up for Stage 3's at less than half that. Sorry, I'm afraid this one just wouldn't be a prudent strategy for me to incorporate in my repertoire as even at 1/4 finished it would cost double or more the existing Stage 3 due to all the hand work involved.

quattro.pilot

so then had you flow tested the RTB (in stock form) against a S3? If you hadn't, any guesses as to how they would compare? Just curious

check yah later