Stock Standard TB: 308CFM
Stock 'Special TB': 338CFM
S1 Standard TB: 342CFM (discontinued)
S2 Standard TB: 378CFM (discontinued)
S3 Standard TB: 415CFM (discontinued)
XTB Standard TB: 615CFM $325
XTB 'S' TB: 707CFM $355
RTB 'S' TB: 675CFM (not available)
RXTB Standard TB: 755CFM (not available)
RSXTB: 'S' TB: 800+CFM (not available)

Prices include shipping and new TB/IM gasket on all models. Refundable core charge deposit of $200 on all "exchange unit" throttle bodies. Prices do reflect a $10 increase on all units due to consumable grinding/honing media used to hand-finish the throttle body bore inlets and gaskets for all units.

Orders will start to be taken for these and all other pieces sometime this weekend. First come/first served on TB's and plan on one week for any TB conversions. I do have all my exchange unit TB's converted to S1, S2 and XTB specs in anticipation of any rush and the S1/S2's can be quickly upgraded to the next higher spec if necessary.

"XTB Standard TB: 615CFM $310
XTB 'Special TB': 707CFM $310"

same price, yet a 92 cfm difference in flow rate - why would anyone choose not to be 'special'?

or is special just short for "only available to mr. d"? ;)

thanks for the clarification and i look forward to placing my order for an xtb and s3 hose kit this weekend!

and that will cost you an additional $100. Same work, but just a tougher part to find and you must supply it :)

<center><img src="http://pictureposter.audiworld.com/711/racetb2.jpg"></center><p>
The "special" throttle body's are special because they came from Audi with a 2mm larger primary bore. We "think" they came from 97/98 Cabriolets and A6's (400-500lb heavier car) but we're not positive as the numbers stamped on the TB's are different than the part numbers found at the dealer or in ETKA.

So far the ONLY thing thats certain is that these numbers qualify as "special" because they have been measured. And it's not only possible but probable that there are other 'special' ones with entirely different numbers as this list is in no way comprehensive or complete.

B6 291 078 063 T
B7 091 078 063 T

And just because someone has a TB with numbers that are close, or only one digit off or match the last 3, first 3, middle 3 is no guarantee they have anything more than a standard throttle body. The only way to know for sure is to measure.

If you look very closely at the pic above you can see the difference in the "web" thickness that separates the primary bore from the secondary bore. The one on the left is the 'special TB' while the one on right is standard. Also remember that the bore on the special TB is an equal amount lager on the right side, opposite the web separator but you can't see it as there's no way to compare it to anything in this picture.

cool, thanks for clarifying the situation for the this audi tb noob =s

I remember when you were working on the RTB you had said there was some hesitation due to the increased flow, how has the increased flow of the XTB affected said hesitation, and will this increased flow cause a lean condition without the use of something to adjust mixture? Just doing some more learnin, and dont want to be creating a lean running timebomb...Thanks

<ul><li><a href="http://forums.audiworld.com/12v/msgs/20141.phtml">http://forums.audiworld.com/12v/msgs/20141.phtml</a</li></ul>

<ul><li><a href="http://forums.audiworld.com/12v/msgs/20207.phtml">S1/S2-to-XTB upgrade prices</a></li></ul>